From 79218fd0b38bb05e8dcb80a49342836274046432 Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Mon, 17 Oct 2022 16:00:45 -0700 Subject: iommu/amd: Drop unnecessary checks in amd_iommu_attach_device() The same checks are done in amd_iommu_probe_device(). If any of them fails there, then the device won't get a group, so there's no way for it to even reach amd_iommu_attach_device anymore. Link: https://lore.kernel.org/r/c054654a81f2b675c73108fe4bf10e45335a721a.1666042872.git.nicolinc@nvidia.com Suggested-by: Robin Murphy Cc: Joerg Roedel Cc: Suravee Suthikulpanit Reviewed-by: Vasant Hegde Reviewed-by: Jason Gunthorpe Signed-off-by: Nicolin Chen Signed-off-by: Jason Gunthorpe --- drivers/iommu/amd/iommu.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index d3b39d0416fa..45299eb7e8e3 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -2155,21 +2155,13 @@ static void amd_iommu_detach_device(struct iommu_domain *dom, static int amd_iommu_attach_device(struct iommu_domain *dom, struct device *dev) { + struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev); struct protection_domain *domain = to_pdomain(dom); - struct iommu_dev_data *dev_data; - struct amd_iommu *iommu; + struct amd_iommu *iommu = rlookup_amd_iommu(dev); int ret; - if (!check_device(dev)) - return -EINVAL; - - dev_data = dev_iommu_priv_get(dev); dev_data->defer_attach = false; - iommu = rlookup_amd_iommu(dev); - if (!iommu) - return -EINVAL; - if (dev_data->domain) detach_device(dev); -- cgit v1.2.3 From 00208852d351ca6e4a8b9ff0c5376fa3a8ed8eaa Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Mon, 17 Oct 2022 16:01:22 -0700 Subject: iommu: Add return value rules to attach_dev op and APIs Cases like VFIO wish to attach a device to an existing domain that was not allocated specifically from the device. This raises a condition where the IOMMU driver can fail the domain attach because the domain and device are incompatible with each other. This is a soft failure that can be resolved by using a different domain. Provide a dedicated errno EINVAL from the IOMMU driver during attach that the reason why the attach failed is because of domain incompatibility. VFIO can use this to know that the attach is a soft failure and it should continue searching. Otherwise, the attach will be a hard failure and VFIO will return the code to userspace. Update kdocs to add rules of return value to the attach_dev op and APIs. Link: https://lore.kernel.org/r/bd56d93c18621104a0fa1b0de31e9b760b81b769.1666042872.git.nicolinc@nvidia.com Suggested-by: Jason Gunthorpe Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Signed-off-by: Nicolin Chen Reviewed-by: Lu Baolu Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommu.c | 24 ++++++++++++++++++++++++ include/linux/iommu.h | 12 ++++++++++++ 2 files changed, 36 insertions(+) (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 65a3b3d886dc..972731f0b328 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -1949,6 +1949,18 @@ static int __iommu_attach_device(struct iommu_domain *domain, return ret; } +/** + * iommu_attach_device - Attach an IOMMU domain to a device + * @domain: IOMMU domain to attach + * @dev: Device that will be attached + * + * Returns 0 on success and error code on failure + * + * Note that EINVAL can be treated as a soft failure, indicating + * that certain configuration of the domain is incompatible with + * the device. In this case attaching a different domain to the + * device may succeed. + */ int iommu_attach_device(struct iommu_domain *domain, struct device *dev) { struct iommu_group *group; @@ -2075,6 +2087,18 @@ static int __iommu_attach_group(struct iommu_domain *domain, return ret; } +/** + * iommu_attach_group - Attach an IOMMU domain to an IOMMU group + * @domain: IOMMU domain to attach + * @group: IOMMU group that will be attached + * + * Returns 0 on success and error code on failure + * + * Note that EINVAL can be treated as a soft failure, indicating + * that certain configuration of the domain is incompatible with + * the group. In this case attaching a different domain to the + * group may succeed. + */ int iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group) { int ret; diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 3c9da1f8979e..857898d102b3 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -266,6 +266,18 @@ struct iommu_ops { /** * struct iommu_domain_ops - domain specific operations * @attach_dev: attach an iommu domain to a device + * Return: + * * 0 - success + * * EINVAL - can indicate that device and domain are incompatible due to + * some previous configuration of the domain, in which case the + * driver shouldn't log an error, since it is legitimate for a + * caller to test reuse of existing domains. Otherwise, it may + * still represent some other fundamental problem + * * ENOMEM - out of memory + * * ENOSPC - non-ENOMEM type of resource allocation failures + * * EBUSY - device is attached to a domain and cannot be changed + * * ENODEV - device specific errors, not able to be attached + * * - treated as ENODEV by the caller. Use is discouraged * @detach_dev: detach an iommu domain from a device * @map: map a physically contiguous memory region to an iommu domain * @map_pages: map a physically contiguous set of pages of the same size to -- cgit v1.2.3 From bd7ebb7719356d750b1b4d671535922bae43fb3b Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Mon, 17 Oct 2022 16:02:13 -0700 Subject: iommu: Regulate EINVAL in ->attach_dev callback functions Following the new rules in include/linux/iommu.h kdocs, EINVAL now can be used to indicate that domain and device are incompatible by a caller that treats it as a soft failure and tries attaching to another domain. On the other hand, there are ->attach_dev callback functions returning it for obvious device-specific errors. They will result in some inefficiency in the caller handling routine. Update these places to corresponding errnos following the new rules. Link: https://lore.kernel.org/r/5924c03bea637f05feb2a20d624bae086b555ec5.1666042872.git.nicolinc@nvidia.com Reviewed-by: Jean-Philippe Brucker Reviewed-by: Lu Baolu Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Signed-off-by: Nicolin Chen Signed-off-by: Jason Gunthorpe --- drivers/iommu/fsl_pamu.c | 2 +- drivers/iommu/fsl_pamu_domain.c | 4 ++-- drivers/iommu/intel/pasid.c | 6 ++++-- drivers/iommu/mtk_iommu.c | 2 +- drivers/iommu/omap-iommu.c | 4 ++-- drivers/iommu/virtio-iommu.c | 2 +- 6 files changed, 11 insertions(+), 9 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/fsl_pamu.c b/drivers/iommu/fsl_pamu.c index 0d03f837a5d4..2eb3211c8167 100644 --- a/drivers/iommu/fsl_pamu.c +++ b/drivers/iommu/fsl_pamu.c @@ -211,7 +211,7 @@ int pamu_config_ppaace(int liodn, u32 omi, u32 stashid, int prot) ppaace->op_encode.index_ot.omi = omi; } else if (~omi != 0) { pr_debug("bad operation mapping index: %d\n", omi); - return -EINVAL; + return -ENODEV; } /* configure stash id */ diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c index fa20f4b03e12..4408ac3c49b6 100644 --- a/drivers/iommu/fsl_pamu_domain.c +++ b/drivers/iommu/fsl_pamu_domain.c @@ -258,7 +258,7 @@ static int fsl_pamu_attach_device(struct iommu_domain *domain, liodn = of_get_property(dev->of_node, "fsl,liodn", &len); if (!liodn) { pr_debug("missing fsl,liodn property at %pOF\n", dev->of_node); - return -EINVAL; + return -ENODEV; } spin_lock_irqsave(&dma_domain->domain_lock, flags); @@ -267,7 +267,7 @@ static int fsl_pamu_attach_device(struct iommu_domain *domain, if (liodn[i] >= PAACE_NUMBER_ENTRIES) { pr_debug("Invalid liodn %d, attach device failed for %pOF\n", liodn[i], dev->of_node); - ret = -EINVAL; + ret = -ENODEV; break; } diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c index c30ddac40ee5..95d73f19ab61 100644 --- a/drivers/iommu/intel/pasid.c +++ b/drivers/iommu/intel/pasid.c @@ -101,8 +101,10 @@ int intel_pasid_alloc_table(struct device *dev) might_sleep(); info = dev_iommu_priv_get(dev); - if (WARN_ON(!info || !dev_is_pci(dev) || info->pasid_table)) - return -EINVAL; + if (WARN_ON(!info || !dev_is_pci(dev))) + return -ENODEV; + if (WARN_ON(info->pasid_table)) + return -EEXIST; pasid_table = kzalloc(sizeof(*pasid_table), GFP_KERNEL); if (!pasid_table) diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index 2ab2ecfe01f8..eda441d0c6b6 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -609,7 +609,7 @@ static int mtk_iommu_domain_finalise(struct mtk_iommu_domain *dom, dom->iop = alloc_io_pgtable_ops(ARM_V7S, &dom->cfg, data); if (!dom->iop) { dev_err(data->dev, "Failed to alloc io pgtable\n"); - return -EINVAL; + return -ENOMEM; } /* Update our support page sizes bitmap */ diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c index 07ee2600113c..3f153f9e0ac5 100644 --- a/drivers/iommu/omap-iommu.c +++ b/drivers/iommu/omap-iommu.c @@ -1414,7 +1414,7 @@ static int omap_iommu_attach_init(struct device *dev, odomain->num_iommus = omap_iommu_count(dev); if (!odomain->num_iommus) - return -EINVAL; + return -ENODEV; odomain->iommus = kcalloc(odomain->num_iommus, sizeof(*iommu), GFP_ATOMIC); @@ -1464,7 +1464,7 @@ omap_iommu_attach_dev(struct iommu_domain *domain, struct device *dev) if (!arch_data || !arch_data->iommu_dev) { dev_err(dev, "device doesn't have an associated iommu\n"); - return -EINVAL; + return -ENODEV; } spin_lock(&omap_domain->lock); diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c index 8b1b5c270e50..0b64e7f64e68 100644 --- a/drivers/iommu/virtio-iommu.c +++ b/drivers/iommu/virtio-iommu.c @@ -670,7 +670,7 @@ static int viommu_domain_finalise(struct viommu_endpoint *vdev, dev_err(vdev->dev, "granule 0x%lx larger than system page size 0x%lx\n", viommu_page_size, PAGE_SIZE); - return -EINVAL; + return -ENODEV; } ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain, -- cgit v1.2.3 From f4a14773579302e5f0c4bf80b03f0db7ce67f2ce Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Mon, 17 Oct 2022 16:02:21 -0700 Subject: iommu: Use EINVAL for incompatible device/domain in ->attach_dev Following the new rules in include/linux/iommu.h kdocs, update all drivers ->attach_dev callback functions to return EINVAL in the failure paths that are related to domain incompatibility. Also, drop adjacent error prints to prevent a kernel log spam. Link: https://lore.kernel.org/r/f52a07f7320da94afe575c9631340d0019a203a7.1666042873.git.nicolinc@nvidia.com Reviewed-by: Jean-Philippe Brucker Reviewed-by: Lu Baolu Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Signed-off-by: Nicolin Chen Signed-off-by: Jason Gunthorpe --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 11 +---------- drivers/iommu/arm/arm-smmu/arm-smmu.c | 3 --- drivers/iommu/arm/arm-smmu/qcom_iommu.c | 7 +------ drivers/iommu/intel/iommu.c | 10 +++------- drivers/iommu/ipmmu-vmsa.c | 2 -- drivers/iommu/omap-iommu.c | 2 +- drivers/iommu/sprd-iommu.c | 4 +--- drivers/iommu/tegra-gart.c | 2 +- drivers/iommu/virtio-iommu.c | 3 +-- 9 files changed, 9 insertions(+), 35 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index 6d5df91c5c46..8b0a1e476d44 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -2430,23 +2430,14 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) goto out_unlock; } } else if (smmu_domain->smmu != smmu) { - dev_err(dev, - "cannot attach to SMMU %s (upstream of %s)\n", - dev_name(smmu_domain->smmu->dev), - dev_name(smmu->dev)); - ret = -ENXIO; + ret = -EINVAL; goto out_unlock; } else if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1 && master->ssid_bits != smmu_domain->s1_cfg.s1cdmax) { - dev_err(dev, - "cannot attach to incompatible domain (%u SSID bits != %u)\n", - smmu_domain->s1_cfg.s1cdmax, master->ssid_bits); ret = -EINVAL; goto out_unlock; } else if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1 && smmu_domain->stall_enabled != master->stall_enabled) { - dev_err(dev, "cannot attach to stall-%s domain\n", - smmu_domain->stall_enabled ? "enabled" : "disabled"); ret = -EINVAL; goto out_unlock; } diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c index 30dab1418e3f..719fbca1fe52 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c @@ -1150,9 +1150,6 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) * different SMMUs. */ if (smmu_domain->smmu != smmu) { - dev_err(dev, - "cannot attach to SMMU %s whilst already attached to domain on SMMU %s\n", - dev_name(smmu_domain->smmu->dev), dev_name(smmu->dev)); ret = -EINVAL; goto rpm_put; } diff --git a/drivers/iommu/arm/arm-smmu/qcom_iommu.c b/drivers/iommu/arm/arm-smmu/qcom_iommu.c index 3869c3ecda8c..bfd7b51eb5db 100644 --- a/drivers/iommu/arm/arm-smmu/qcom_iommu.c +++ b/drivers/iommu/arm/arm-smmu/qcom_iommu.c @@ -381,13 +381,8 @@ static int qcom_iommu_attach_dev(struct iommu_domain *domain, struct device *dev * Sanity check the domain. We don't support domains across * different IOMMUs. */ - if (qcom_domain->iommu != qcom_iommu) { - dev_err(dev, "cannot attach to IOMMU %s while already " - "attached to domain on IOMMU %s\n", - dev_name(qcom_domain->iommu->dev), - dev_name(qcom_iommu->dev)); + if (qcom_domain->iommu != qcom_iommu) return -EINVAL; - } return 0; } diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 48cdcd0a5cf3..6f1a59206d2e 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4194,19 +4194,15 @@ static int prepare_domain_attach_device(struct iommu_domain *domain, return -ENODEV; if (dmar_domain->force_snooping && !ecap_sc_support(iommu->ecap)) - return -EOPNOTSUPP; + return -EINVAL; /* check if this iommu agaw is sufficient for max mapped address */ addr_width = agaw_to_width(iommu->agaw); if (addr_width > cap_mgaw(iommu->cap)) addr_width = cap_mgaw(iommu->cap); - if (dmar_domain->max_addr > (1LL << addr_width)) { - dev_err(dev, "%s: iommu width (%d) is not " - "sufficient for the mapped address (%llx)\n", - __func__, addr_width, dmar_domain->max_addr); - return -EFAULT; - } + if (dmar_domain->max_addr > (1LL << addr_width)) + return -EINVAL; dmar_domain->gaw = addr_width; /* diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c index 3b30c0752274..22230cc15dcd 100644 --- a/drivers/iommu/ipmmu-vmsa.c +++ b/drivers/iommu/ipmmu-vmsa.c @@ -628,8 +628,6 @@ static int ipmmu_attach_device(struct iommu_domain *io_domain, * Something is wrong, we can't attach two devices using * different IOMMUs to the same domain. */ - dev_err(dev, "Can't attach IPMMU %s to domain on IPMMU %s\n", - dev_name(mmu->dev), dev_name(domain->mmu->dev)); ret = -EINVAL; } else dev_info(dev, "Reusing IPMMU context %u\n", domain->context_id); diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c index 3f153f9e0ac5..2fd7702c6709 100644 --- a/drivers/iommu/omap-iommu.c +++ b/drivers/iommu/omap-iommu.c @@ -1472,7 +1472,7 @@ omap_iommu_attach_dev(struct iommu_domain *domain, struct device *dev) /* only a single client device can be attached to a domain */ if (omap_domain->dev) { dev_err(dev, "iommu domain is already attached\n"); - ret = -EBUSY; + ret = -EINVAL; goto out; } diff --git a/drivers/iommu/sprd-iommu.c b/drivers/iommu/sprd-iommu.c index fadd2c907222..e02793375598 100644 --- a/drivers/iommu/sprd-iommu.c +++ b/drivers/iommu/sprd-iommu.c @@ -237,10 +237,8 @@ static int sprd_iommu_attach_device(struct iommu_domain *domain, struct sprd_iommu_domain *dom = to_sprd_domain(domain); size_t pgt_size = sprd_iommu_pgt_size(domain); - if (dom->sdev) { - pr_err("There's already a device attached to this domain.\n"); + if (dom->sdev) return -EINVAL; - } dom->pgt_va = dma_alloc_coherent(sdev->dev, pgt_size, &dom->pgt_pa, GFP_KERNEL); if (!dom->pgt_va) diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c index e5ca3cf1a949..ed53279d1106 100644 --- a/drivers/iommu/tegra-gart.c +++ b/drivers/iommu/tegra-gart.c @@ -112,7 +112,7 @@ static int gart_iommu_attach_dev(struct iommu_domain *domain, spin_lock(&gart->dom_lock); if (gart->active_domain && gart->active_domain != domain) { - ret = -EBUSY; + ret = -EINVAL; } else if (dev_iommu_priv_get(dev) != domain) { dev_iommu_priv_set(dev, domain); gart->active_domain = domain; diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c index 0b64e7f64e68..8226b4da4350 100644 --- a/drivers/iommu/virtio-iommu.c +++ b/drivers/iommu/virtio-iommu.c @@ -734,8 +734,7 @@ static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev) */ ret = viommu_domain_finalise(vdev, domain); } else if (vdomain->viommu != vdev->viommu) { - dev_err(dev, "cannot attach to foreign vIOMMU\n"); - ret = -EXDEV; + ret = -EINVAL; } mutex_unlock(&vdomain->mutex); -- cgit v1.2.3 From 04cee82e04d2aff3d177ef0021ecdff228daf7b8 Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Mon, 17 Oct 2022 16:02:36 -0700 Subject: iommu: Propagate return value in ->attach_dev callback functions The mtk_iommu and virtio drivers have places in the ->attach_dev callback functions that return hardcode errnos instead of the returned values, but callers of these ->attach_dv callback functions may care. Propagate them directly without the extra conversions. Link: https://lore.kernel.org/r/ca8c5a447b87002334f83325f28823008b4ce420.1666042873.git.nicolinc@nvidia.com Reviewed-by: Kevin Tian Reviewed-by: Jean-Philippe Brucker Reviewed-by: Jason Gunthorpe Reviewed-by: Yong Wu Signed-off-by: Nicolin Chen Signed-off-by: Jason Gunthorpe --- drivers/iommu/mtk_iommu.c | 2 +- drivers/iommu/virtio-iommu.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index eda441d0c6b6..b383c8327f9c 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -668,7 +668,7 @@ static int mtk_iommu_attach_device(struct iommu_domain *domain, ret = mtk_iommu_domain_finalise(dom, frstdata, region_id); if (ret) { mutex_unlock(&dom->mutex); - return -ENODEV; + return ret; } dom->bank = &data->bank[bankid]; } diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c index 8226b4da4350..5b8fe9bfa9a5 100644 --- a/drivers/iommu/virtio-iommu.c +++ b/drivers/iommu/virtio-iommu.c @@ -697,7 +697,7 @@ static int viommu_domain_finalise(struct viommu_endpoint *vdev, if (ret) { ida_free(&viommu->domain_ids, vdomain->id); vdomain->viommu = NULL; - return -EOPNOTSUPP; + return ret; } } -- cgit v1.2.3 From 1adf3cc20d693569ebee90fd91fa34b0570fcd6f Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 31 Oct 2022 08:59:05 +0800 Subject: iommu: Add max_pasids field in struct iommu_device Use this field to keep the number of supported PASIDs that an IOMMU hardware is able to support. This is a generic attribute of an IOMMU and lifting it into the per-IOMMU device structure makes it possible to allocate a PASID for device without calls into the IOMMU drivers. Any iommu driver that supports PASID related features should set this field before enabling them on the devices. In the Intel IOMMU driver, intel_iommu_sm is moved to CONFIG_INTEL_IOMMU enclave so that the pasid_supported() helper could be used in dmar.c without compilation errors. Signed-off-by: Lu Baolu Reviewed-by: Jean-Philippe Brucker Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Reviewed-by: Yi Liu Tested-by: Zhangfei Gao Tested-by: Tony Zhu Link: https://lore.kernel.org/r/20221031005917.45690-2-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 1 + drivers/iommu/intel/dmar.c | 7 +++++++ drivers/iommu/intel/iommu.h | 4 ++-- include/linux/iommu.h | 2 ++ 4 files changed, 12 insertions(+), 2 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index 6d5df91c5c46..21cb13da122c 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -3543,6 +3543,7 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu) /* SID/SSID sizes */ smmu->ssid_bits = FIELD_GET(IDR1_SSIDSIZE, reg); smmu->sid_bits = FIELD_GET(IDR1_SIDSIZE, reg); + smmu->iommu.max_pasids = 1UL << smmu->ssid_bits; /* * If the SMMU supports fewer bits than would fill a single L2 stream diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c index 5a8f780e7ffd..3528058d253e 100644 --- a/drivers/iommu/intel/dmar.c +++ b/drivers/iommu/intel/dmar.c @@ -1104,6 +1104,13 @@ static int alloc_iommu(struct dmar_drhd_unit *drhd) raw_spin_lock_init(&iommu->register_lock); + /* + * A value of N in PSS field of eCap register indicates hardware + * supports PASID field of N+1 bits. + */ + if (pasid_supported(iommu)) + iommu->iommu.max_pasids = 2UL << ecap_pss(iommu->ecap); + /* * This is only for hotplug; at boot time intel_iommu_enabled won't * be set yet. When intel_iommu_init() runs, it registers the units diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h index 92023dff9513..cce0598f4109 100644 --- a/drivers/iommu/intel/iommu.h +++ b/drivers/iommu/intel/iommu.h @@ -480,8 +480,6 @@ enum { #define VTD_FLAG_IRQ_REMAP_PRE_ENABLED (1 << 1) #define VTD_FLAG_SVM_CAPABLE (1 << 2) -extern int intel_iommu_sm; - #define sm_supported(iommu) (intel_iommu_sm && ecap_smts((iommu)->ecap)) #define pasid_supported(iommu) (sm_supported(iommu) && \ ecap_pasid((iommu)->ecap)) @@ -795,6 +793,7 @@ struct context_entry *iommu_context_addr(struct intel_iommu *iommu, u8 bus, extern const struct iommu_ops intel_iommu_ops; #ifdef CONFIG_INTEL_IOMMU +extern int intel_iommu_sm; extern int iommu_calculate_agaw(struct intel_iommu *iommu); extern int iommu_calculate_max_sagaw(struct intel_iommu *iommu); extern int dmar_disabled; @@ -810,6 +809,7 @@ static inline int iommu_calculate_max_sagaw(struct intel_iommu *iommu) } #define dmar_disabled (1) #define intel_iommu_enabled (0) +#define intel_iommu_sm (0) #endif static inline const char *decode_prq_descriptor(char *str, size_t size, diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 3c9da1f8979e..e3af4f46e6e0 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -322,12 +322,14 @@ struct iommu_domain_ops { * @list: Used by the iommu-core to keep a list of registered iommus * @ops: iommu-ops for talking to this iommu * @dev: struct device for sysfs handling + * @max_pasids: number of supported PASIDs */ struct iommu_device { struct list_head list; const struct iommu_ops *ops; struct fwnode_handle *fwnode; struct device *dev; + u32 max_pasids; }; /** -- cgit v1.2.3 From 22d2c7afb3697a68c7fc05c935ef662dee06dc60 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 31 Oct 2022 08:59:06 +0800 Subject: iommu: Add max_pasids field in struct dev_iommu Use this field to save the number of PASIDs that a device is able to consume. It is a generic attribute of a device and lifting it into the per-device dev_iommu struct could help to avoid the boilerplate code in various IOMMU drivers. Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Reviewed-by: Yi Liu Tested-by: Zhangfei Gao Tested-by: Tony Zhu Link: https://lore.kernel.org/r/20221031005917.45690-3-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/iommu.c | 20 ++++++++++++++++++++ include/linux/iommu.h | 2 ++ 2 files changed, 22 insertions(+) (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 65a3b3d886dc..297ac79bc21c 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include #include @@ -278,6 +279,24 @@ static void dev_iommu_free(struct device *dev) kfree(param); } +static u32 dev_iommu_get_max_pasids(struct device *dev) +{ + u32 max_pasids = 0, bits = 0; + int ret; + + if (dev_is_pci(dev)) { + ret = pci_max_pasids(to_pci_dev(dev)); + if (ret > 0) + max_pasids = ret; + } else { + ret = device_property_read_u32(dev, "pasid-num-bits", &bits); + if (!ret) + max_pasids = 1UL << bits; + } + + return min_t(u32, max_pasids, dev->iommu->iommu_dev->max_pasids); +} + static int __iommu_probe_device(struct device *dev, struct list_head *group_list) { const struct iommu_ops *ops = dev->bus->iommu_ops; @@ -303,6 +322,7 @@ static int __iommu_probe_device(struct device *dev, struct list_head *group_list } dev->iommu->iommu_dev = iommu_dev; + dev->iommu->max_pasids = dev_iommu_get_max_pasids(dev); group = iommu_group_get_for_dev(dev); if (IS_ERR(group)) { diff --git a/include/linux/iommu.h b/include/linux/iommu.h index e3af4f46e6e0..ac3f6c6dcc6d 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -368,6 +368,7 @@ struct iommu_fault_param { * @fwspec: IOMMU fwspec data * @iommu_dev: IOMMU device this device is linked to * @priv: IOMMU Driver private data + * @max_pasids: number of PASIDs this device can consume * * TODO: migrate other per device data pointers under iommu_dev_data, e.g. * struct iommu_group *iommu_group; @@ -379,6 +380,7 @@ struct dev_iommu { struct iommu_fwspec *fwspec; struct iommu_device *iommu_dev; void *priv; + u32 max_pasids; }; int iommu_device_register(struct iommu_device *iommu, -- cgit v1.2.3 From 942fd5435dccb273f90176b046ae6bbba60cfbd8 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 31 Oct 2022 08:59:07 +0800 Subject: iommu: Remove SVM_FLAG_SUPERVISOR_MODE support The current kernel DMA with PASID support is based on the SVA with a flag SVM_FLAG_SUPERVISOR_MODE. The IOMMU driver binds the kernel memory address space to a PASID of the device. The device driver programs the device with kernel virtual address (KVA) for DMA access. There have been security and functional issues with this approach: - The lack of IOTLB synchronization upon kernel page table updates. (vmalloc, module/BPF loading, CONFIG_DEBUG_PAGEALLOC etc.) - Other than slight more protection, using kernel virtual address (KVA) has little advantage over physical address. There are also no use cases yet where DMA engines need kernel virtual addresses for in-kernel DMA. This removes SVM_FLAG_SUPERVISOR_MODE support from the IOMMU interface. The device drivers are suggested to handle kernel DMA with PASID through the kernel DMA APIs. The drvdata parameter in iommu_sva_bind_device() and all callbacks is not needed anymore. Cleanup them as well. Link: https://lore.kernel.org/linux-iommu/20210511194726.GP1002214@nvidia.com/ Signed-off-by: Jacob Pan Signed-off-by: Lu Baolu Reviewed-by: Jason Gunthorpe Reviewed-by: Jean-Philippe Brucker Reviewed-by: Kevin Tian Reviewed-by: Fenghua Yu Tested-by: Zhangfei Gao Tested-by: Tony Zhu Link: https://lore.kernel.org/r/20221031005917.45690-4-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/dma/idxd/cdev.c | 3 +- drivers/dma/idxd/init.c | 25 +---------- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 3 +- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 5 +-- drivers/iommu/intel/iommu.h | 3 +- drivers/iommu/intel/svm.c | 55 ++++++------------------- drivers/iommu/iommu.c | 5 +-- drivers/misc/uacce/uacce.c | 2 +- include/linux/intel-svm.h | 13 ------ include/linux/iommu.h | 8 ++-- 10 files changed, 25 insertions(+), 97 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c index c2808fd081d6..66720001ba1c 100644 --- a/drivers/dma/idxd/cdev.c +++ b/drivers/dma/idxd/cdev.c @@ -6,7 +6,6 @@ #include #include #include -#include #include #include #include @@ -100,7 +99,7 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp) filp->private_data = ctx; if (device_user_pasid_enabled(idxd)) { - sva = iommu_sva_bind_device(dev, current->mm, NULL); + sva = iommu_sva_bind_device(dev, current->mm); if (IS_ERR(sva)) { rc = PTR_ERR(sva); dev_err(dev, "pasid allocation failed: %d\n", rc); diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c index 2b18d512cbfc..2c0fcfdc75c7 100644 --- a/drivers/dma/idxd/init.c +++ b/drivers/dma/idxd/init.c @@ -14,7 +14,6 @@ #include #include #include -#include #include #include #include @@ -502,29 +501,7 @@ static struct idxd_device *idxd_alloc(struct pci_dev *pdev, struct idxd_driver_d static int idxd_enable_system_pasid(struct idxd_device *idxd) { - int flags; - unsigned int pasid; - struct iommu_sva *sva; - - flags = SVM_FLAG_SUPERVISOR_MODE; - - sva = iommu_sva_bind_device(&idxd->pdev->dev, NULL, &flags); - if (IS_ERR(sva)) { - dev_warn(&idxd->pdev->dev, - "iommu sva bind failed: %ld\n", PTR_ERR(sva)); - return PTR_ERR(sva); - } - - pasid = iommu_sva_get_pasid(sva); - if (pasid == IOMMU_PASID_INVALID) { - iommu_sva_unbind_device(sva); - return -ENODEV; - } - - idxd->sva = sva; - idxd->pasid = pasid; - dev_dbg(&idxd->pdev->dev, "system pasid: %u\n", pasid); - return 0; + return -EOPNOTSUPP; } static void idxd_disable_system_pasid(struct idxd_device *idxd) diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c index 5968a568aae2..8fcf0df4bd0e 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c @@ -367,8 +367,7 @@ err_free_bond: return ERR_PTR(ret); } -struct iommu_sva * -arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm, void *drvdata) +struct iommu_sva *arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm) { struct iommu_sva *handle; struct iommu_domain *domain = iommu_get_domain_for_dev(dev); diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h index cd48590ada30..d2ba86470c42 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h @@ -754,8 +754,7 @@ bool arm_smmu_master_sva_enabled(struct arm_smmu_master *master); int arm_smmu_master_enable_sva(struct arm_smmu_master *master); int arm_smmu_master_disable_sva(struct arm_smmu_master *master); bool arm_smmu_master_iopf_supported(struct arm_smmu_master *master); -struct iommu_sva *arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm, - void *drvdata); +struct iommu_sva *arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm); void arm_smmu_sva_unbind(struct iommu_sva *handle); u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle); void arm_smmu_sva_notifier_synchronize(void); @@ -791,7 +790,7 @@ static inline bool arm_smmu_master_iopf_supported(struct arm_smmu_master *master } static inline struct iommu_sva * -arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm, void *drvdata) +arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm) { return ERR_PTR(-ENODEV); } diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h index cce0598f4109..33e5bcaf2a6c 100644 --- a/drivers/iommu/intel/iommu.h +++ b/drivers/iommu/intel/iommu.h @@ -748,8 +748,7 @@ struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn); extern void intel_svm_check(struct intel_iommu *iommu); extern int intel_svm_enable_prq(struct intel_iommu *iommu); extern int intel_svm_finish_prq(struct intel_iommu *iommu); -struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct *mm, - void *drvdata); +struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct *mm); void intel_svm_unbind(struct iommu_sva *handle); u32 intel_svm_get_pasid(struct iommu_sva *handle); int intel_svm_page_response(struct device *dev, struct iommu_fault_event *evt, diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index 7d08eb034f2d..94bc47b68c93 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -296,8 +296,7 @@ out: return 0; } -static int intel_svm_alloc_pasid(struct device *dev, struct mm_struct *mm, - unsigned int flags) +static int intel_svm_alloc_pasid(struct device *dev, struct mm_struct *mm) { ioasid_t max_pasid = dev_is_pci(dev) ? pci_max_pasids(to_pci_dev(dev)) : intel_pasid_max_id; @@ -307,8 +306,7 @@ static int intel_svm_alloc_pasid(struct device *dev, struct mm_struct *mm, static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu, struct device *dev, - struct mm_struct *mm, - unsigned int flags) + struct mm_struct *mm) { struct device_domain_info *info = dev_iommu_priv_get(dev); struct intel_svm_dev *sdev; @@ -324,22 +322,18 @@ static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu, svm->pasid = mm->pasid; svm->mm = mm; - svm->flags = flags; INIT_LIST_HEAD_RCU(&svm->devs); - if (!(flags & SVM_FLAG_SUPERVISOR_MODE)) { - svm->notifier.ops = &intel_mmuops; - ret = mmu_notifier_register(&svm->notifier, mm); - if (ret) { - kfree(svm); - return ERR_PTR(ret); - } + svm->notifier.ops = &intel_mmuops; + ret = mmu_notifier_register(&svm->notifier, mm); + if (ret) { + kfree(svm); + return ERR_PTR(ret); } ret = pasid_private_add(svm->pasid, svm); if (ret) { - if (svm->notifier.ops) - mmu_notifier_unregister(&svm->notifier, mm); + mmu_notifier_unregister(&svm->notifier, mm); kfree(svm); return ERR_PTR(ret); } @@ -374,9 +368,7 @@ static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu, } /* Setup the pasid table: */ - sflags = (flags & SVM_FLAG_SUPERVISOR_MODE) ? - PASID_FLAG_SUPERVISOR_MODE : 0; - sflags |= cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0; + sflags = cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0; ret = intel_pasid_setup_first_level(iommu, dev, mm->pgd, mm->pasid, FLPT_DEFAULT_DID, sflags); if (ret) @@ -390,8 +382,7 @@ free_sdev: kfree(sdev); free_svm: if (list_empty(&svm->devs)) { - if (svm->notifier.ops) - mmu_notifier_unregister(&svm->notifier, mm); + mmu_notifier_unregister(&svm->notifier, mm); pasid_private_remove(mm->pasid); kfree(svm); } @@ -780,40 +771,20 @@ prq_advance: return IRQ_RETVAL(handled); } -struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct *mm, void *drvdata) +struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct *mm) { struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL); - unsigned int flags = 0; struct iommu_sva *sva; int ret; - if (drvdata) - flags = *(unsigned int *)drvdata; - - if (flags & SVM_FLAG_SUPERVISOR_MODE) { - if (!ecap_srs(iommu->ecap)) { - dev_err(dev, "%s: Supervisor PASID not supported\n", - iommu->name); - return ERR_PTR(-EOPNOTSUPP); - } - - if (mm) { - dev_err(dev, "%s: Supervisor PASID with user provided mm\n", - iommu->name); - return ERR_PTR(-EINVAL); - } - - mm = &init_mm; - } - mutex_lock(&pasid_mutex); - ret = intel_svm_alloc_pasid(dev, mm, flags); + ret = intel_svm_alloc_pasid(dev, mm); if (ret) { mutex_unlock(&pasid_mutex); return ERR_PTR(ret); } - sva = intel_svm_bind_mm(iommu, dev, mm, flags); + sva = intel_svm_bind_mm(iommu, dev, mm); mutex_unlock(&pasid_mutex); return sva; diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 297ac79bc21c..a94ec648c88b 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2750,7 +2750,6 @@ EXPORT_SYMBOL_GPL(iommu_dev_disable_feature); * iommu_sva_bind_device() - Bind a process address space to a device * @dev: the device * @mm: the mm to bind, caller must hold a reference to it - * @drvdata: opaque data pointer to pass to bind callback * * Create a bond between device and address space, allowing the device to access * the mm using the returned PASID. If a bond already exists between @device and @@ -2763,7 +2762,7 @@ EXPORT_SYMBOL_GPL(iommu_dev_disable_feature); * On error, returns an ERR_PTR value. */ struct iommu_sva * -iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata) +iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) { struct iommu_group *group; struct iommu_sva *handle = ERR_PTR(-EINVAL); @@ -2788,7 +2787,7 @@ iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata) if (iommu_group_device_count(group) != 1) goto out_unlock; - handle = ops->sva_bind(dev, mm, drvdata); + handle = ops->sva_bind(dev, mm); out_unlock: mutex_unlock(&group->mutex); diff --git a/drivers/misc/uacce/uacce.c b/drivers/misc/uacce/uacce.c index b70a013139c7..905eff1f840e 100644 --- a/drivers/misc/uacce/uacce.c +++ b/drivers/misc/uacce/uacce.c @@ -108,7 +108,7 @@ static int uacce_bind_queue(struct uacce_device *uacce, struct uacce_queue *q) if (!(uacce->flags & UACCE_DEV_SVA)) return 0; - handle = iommu_sva_bind_device(uacce->parent, current->mm, NULL); + handle = iommu_sva_bind_device(uacce->parent, current->mm); if (IS_ERR(handle)) return PTR_ERR(handle); diff --git a/include/linux/intel-svm.h b/include/linux/intel-svm.h index 207ef06ba3e1..f9a0d44f6fdb 100644 --- a/include/linux/intel-svm.h +++ b/include/linux/intel-svm.h @@ -13,17 +13,4 @@ #define PRQ_RING_MASK ((0x1000 << PRQ_ORDER) - 0x20) #define PRQ_DEPTH ((0x1000 << PRQ_ORDER) >> 5) -/* - * The SVM_FLAG_SUPERVISOR_MODE flag requests a PASID which can be used only - * for access to kernel addresses. No IOTLB flushes are automatically done - * for kernel mappings; it is valid only for access to the kernel's static - * 1:1 mapping of physical memory — not to vmalloc or even module mappings. - * A future API addition may permit the use of such ranges, by means of an - * explicit IOTLB flush call (akin to the DMA API's unmap method). - * - * It is unlikely that we will ever hook into flush_tlb_kernel_range() to - * do such IOTLB flushes automatically. - */ -#define SVM_FLAG_SUPERVISOR_MODE BIT(0) - #endif /* __INTEL_SVM_H__ */ diff --git a/include/linux/iommu.h b/include/linux/iommu.h index ac3f6c6dcc6d..72bb0531aa76 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -247,8 +247,7 @@ struct iommu_ops { int (*dev_enable_feat)(struct device *dev, enum iommu_dev_features f); int (*dev_disable_feat)(struct device *dev, enum iommu_dev_features f); - struct iommu_sva *(*sva_bind)(struct device *dev, struct mm_struct *mm, - void *drvdata); + struct iommu_sva *(*sva_bind)(struct device *dev, struct mm_struct *mm); void (*sva_unbind)(struct iommu_sva *handle); u32 (*sva_get_pasid)(struct iommu_sva *handle); @@ -668,8 +667,7 @@ int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features f); int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features f); struct iommu_sva *iommu_sva_bind_device(struct device *dev, - struct mm_struct *mm, - void *drvdata); + struct mm_struct *mm); void iommu_sva_unbind_device(struct iommu_sva *handle); u32 iommu_sva_get_pasid(struct iommu_sva *handle); @@ -1000,7 +998,7 @@ iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat) } static inline struct iommu_sva * -iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata) +iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) { return NULL; } -- cgit v1.2.3 From 16603704559c7a68718059c4f75287886c01b20f Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 31 Oct 2022 08:59:09 +0800 Subject: iommu: Add attach/detach_dev_pasid iommu interfaces Attaching an IOMMU domain to a PASID of a device is a generic operation for modern IOMMU drivers which support PASID-granular DMA address translation. Currently visible usage scenarios include (but not limited): - SVA (Shared Virtual Address) - kernel DMA with PASID - hardware-assist mediated device This adds the set_dev_pasid domain ops for setting the domain onto a PASID of a device and remove_dev_pasid iommu ops for removing any setup on a PASID of device. This also adds interfaces for device drivers to attach/detach/retrieve a domain for a PASID of a device. If multiple devices share a single group, it's fine as long the fabric always routes every TLP marked with a PASID to the host bridge and only the host bridge. For example, ACS achieves this universally and has been checked when pci_enable_pasid() is called. As we can't reliably tell the source apart in a group, all the devices in a group have to be considered as the same source, and mapped to the same PASID table. The DMA ownership is about the whole device (more precisely, iommu group), including the RID and PASIDs. When the ownership is converted, the pasid array must be empty. This also adds necessary checks in the DMA ownership interfaces. Signed-off-by: Lu Baolu Reviewed-by: Jean-Philippe Brucker Reviewed-by: Kevin Tian Reviewed-by: Yi Liu Reviewed-by: Jason Gunthorpe Tested-by: Zhangfei Gao Tested-by: Tony Zhu Link: https://lore.kernel.org/r/20221031005917.45690-6-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/iommu.c | 141 ++++++++++++++++++++++++++++++++++++++++++++++++-- include/linux/iommu.h | 32 ++++++++++++ 2 files changed, 169 insertions(+), 4 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index a94ec648c88b..bf22992beb98 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -43,6 +43,7 @@ struct iommu_group { struct kobject kobj; struct kobject *devices_kobj; struct list_head devices; + struct xarray pasid_array; struct mutex mutex; void *iommu_data; void (*iommu_data_release)(void *iommu_data); @@ -723,6 +724,7 @@ struct iommu_group *iommu_group_alloc(void) mutex_init(&group->mutex); INIT_LIST_HEAD(&group->devices); INIT_LIST_HEAD(&group->entry); + xa_init(&group->pasid_array); ret = ida_alloc(&iommu_group_ida, GFP_KERNEL); if (ret < 0) { @@ -3106,7 +3108,8 @@ int iommu_device_use_default_domain(struct device *dev) mutex_lock(&group->mutex); if (group->owner_cnt) { - if (group->owner || !iommu_is_default_domain(group)) { + if (group->owner || !iommu_is_default_domain(group) || + !xa_empty(&group->pasid_array)) { ret = -EBUSY; goto unlock_out; } @@ -3137,7 +3140,7 @@ void iommu_device_unuse_default_domain(struct device *dev) return; mutex_lock(&group->mutex); - if (!WARN_ON(!group->owner_cnt)) + if (!WARN_ON(!group->owner_cnt || !xa_empty(&group->pasid_array))) group->owner_cnt--; mutex_unlock(&group->mutex); @@ -3185,7 +3188,8 @@ int iommu_group_claim_dma_owner(struct iommu_group *group, void *owner) ret = -EPERM; goto unlock_out; } else { - if (group->domain && group->domain != group->default_domain) { + if ((group->domain && group->domain != group->default_domain) || + !xa_empty(&group->pasid_array)) { ret = -EBUSY; goto unlock_out; } @@ -3219,7 +3223,8 @@ void iommu_group_release_dma_owner(struct iommu_group *group) int ret; mutex_lock(&group->mutex); - if (WARN_ON(!group->owner_cnt || !group->owner)) + if (WARN_ON(!group->owner_cnt || !group->owner || + !xa_empty(&group->pasid_array))) goto unlock_out; group->owner_cnt = 0; @@ -3250,3 +3255,131 @@ bool iommu_group_dma_owner_claimed(struct iommu_group *group) return user; } EXPORT_SYMBOL_GPL(iommu_group_dma_owner_claimed); + +static int __iommu_set_group_pasid(struct iommu_domain *domain, + struct iommu_group *group, ioasid_t pasid) +{ + struct group_device *device; + int ret = 0; + + list_for_each_entry(device, &group->devices, list) { + ret = domain->ops->set_dev_pasid(domain, device->dev, pasid); + if (ret) + break; + } + + return ret; +} + +static void __iommu_remove_group_pasid(struct iommu_group *group, + ioasid_t pasid) +{ + struct group_device *device; + const struct iommu_ops *ops; + + list_for_each_entry(device, &group->devices, list) { + ops = dev_iommu_ops(device->dev); + ops->remove_dev_pasid(device->dev, pasid); + } +} + +/* + * iommu_attach_device_pasid() - Attach a domain to pasid of device + * @domain: the iommu domain. + * @dev: the attached device. + * @pasid: the pasid of the device. + * + * Return: 0 on success, or an error. + */ +int iommu_attach_device_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t pasid) +{ + struct iommu_group *group; + void *curr; + int ret; + + if (!domain->ops->set_dev_pasid) + return -EOPNOTSUPP; + + group = iommu_group_get(dev); + if (!group) + return -ENODEV; + + mutex_lock(&group->mutex); + curr = xa_cmpxchg(&group->pasid_array, pasid, NULL, domain, GFP_KERNEL); + if (curr) { + ret = xa_err(curr) ? : -EBUSY; + goto out_unlock; + } + + ret = __iommu_set_group_pasid(domain, group, pasid); + if (ret) { + __iommu_remove_group_pasid(group, pasid); + xa_erase(&group->pasid_array, pasid); + } +out_unlock: + mutex_unlock(&group->mutex); + iommu_group_put(group); + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_attach_device_pasid); + +/* + * iommu_detach_device_pasid() - Detach the domain from pasid of device + * @domain: the iommu domain. + * @dev: the attached device. + * @pasid: the pasid of the device. + * + * The @domain must have been attached to @pasid of the @dev with + * iommu_attach_device_pasid(). + */ +void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev, + ioasid_t pasid) +{ + struct iommu_group *group = iommu_group_get(dev); + + mutex_lock(&group->mutex); + __iommu_remove_group_pasid(group, pasid); + WARN_ON(xa_erase(&group->pasid_array, pasid) != domain); + mutex_unlock(&group->mutex); + + iommu_group_put(group); +} +EXPORT_SYMBOL_GPL(iommu_detach_device_pasid); + +/* + * iommu_get_domain_for_dev_pasid() - Retrieve domain for @pasid of @dev + * @dev: the queried device + * @pasid: the pasid of the device + * @type: matched domain type, 0 for any match + * + * This is a variant of iommu_get_domain_for_dev(). It returns the existing + * domain attached to pasid of a device. Callers must hold a lock around this + * function, and both iommu_attach/detach_dev_pasid() whenever a domain of + * type is being manipulated. This API does not internally resolve races with + * attach/detach. + * + * Return: attached domain on success, NULL otherwise. + */ +struct iommu_domain *iommu_get_domain_for_dev_pasid(struct device *dev, + ioasid_t pasid, + unsigned int type) +{ + struct iommu_domain *domain; + struct iommu_group *group; + + group = iommu_group_get(dev); + if (!group) + return NULL; + + xa_lock(&group->pasid_array); + domain = xa_load(&group->pasid_array, pasid); + if (type && domain && domain->type != type) + domain = ERR_PTR(-EBUSY); + xa_unlock(&group->pasid_array); + iommu_group_put(group); + + return domain; +} +EXPORT_SYMBOL_GPL(iommu_get_domain_for_dev_pasid); diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 72bb0531aa76..5d2b78ac5416 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -223,6 +223,9 @@ struct iommu_iotlb_gather { * - IOMMU_DOMAIN_DMA: must use a dma domain * - 0: use the default setting * @default_domain_ops: the default ops for domains + * @remove_dev_pasid: Remove any translation configurations of a specific + * pasid, so that any DMA transactions with this pasid + * will be blocked by the hardware. * @pgsize_bitmap: bitmap of all possible supported page sizes * @owner: Driver module providing these ops */ @@ -256,6 +259,7 @@ struct iommu_ops { struct iommu_page_response *msg); int (*def_domain_type)(struct device *dev); + void (*remove_dev_pasid)(struct device *dev, ioasid_t pasid); const struct iommu_domain_ops *default_domain_ops; unsigned long pgsize_bitmap; @@ -266,6 +270,7 @@ struct iommu_ops { * struct iommu_domain_ops - domain specific operations * @attach_dev: attach an iommu domain to a device * @detach_dev: detach an iommu domain from a device + * @set_dev_pasid: set an iommu domain to a pasid of device * @map: map a physically contiguous memory region to an iommu domain * @map_pages: map a physically contiguous set of pages of the same size to * an iommu domain. @@ -286,6 +291,8 @@ struct iommu_ops { struct iommu_domain_ops { int (*attach_dev)(struct iommu_domain *domain, struct device *dev); void (*detach_dev)(struct iommu_domain *domain, struct device *dev); + int (*set_dev_pasid)(struct iommu_domain *domain, struct device *dev, + ioasid_t pasid); int (*map)(struct iommu_domain *domain, unsigned long iova, phys_addr_t paddr, size_t size, int prot, gfp_t gfp); @@ -678,6 +685,13 @@ int iommu_group_claim_dma_owner(struct iommu_group *group, void *owner); void iommu_group_release_dma_owner(struct iommu_group *group); bool iommu_group_dma_owner_claimed(struct iommu_group *group); +int iommu_attach_device_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t pasid); +void iommu_detach_device_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t pasid); +struct iommu_domain * +iommu_get_domain_for_dev_pasid(struct device *dev, ioasid_t pasid, + unsigned int type); #else /* CONFIG_IOMMU_API */ struct iommu_ops {}; @@ -1040,6 +1054,24 @@ static inline bool iommu_group_dma_owner_claimed(struct iommu_group *group) { return false; } + +static inline int iommu_attach_device_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t pasid) +{ + return -ENODEV; +} + +static inline void iommu_detach_device_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t pasid) +{ +} + +static inline struct iommu_domain * +iommu_get_domain_for_dev_pasid(struct device *dev, ioasid_t pasid, + unsigned int type) +{ + return NULL; +} #endif /* CONFIG_IOMMU_API */ /** -- cgit v1.2.3 From 136467962e49931dbc6240aea8197fab7e407ba4 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 31 Oct 2022 08:59:10 +0800 Subject: iommu: Add IOMMU SVA domain support The SVA iommu_domain represents a hardware pagetable that the IOMMU hardware could use for SVA translation. This adds some infrastructures to support SVA domain in the iommu core. It includes: - Extend the iommu_domain to support a new IOMMU_DOMAIN_SVA domain type. The IOMMU drivers that support allocation of the SVA domain should provide its own SVA domain specific iommu_domain_ops. - Add a helper to allocate an SVA domain. The iommu_domain_free() is still used to free an SVA domain. The report_iommu_fault() should be replaced by the new iommu_report_device_fault(). Leave the existing fault handler with the existing users and the newly added SVA members excludes it. Suggested-by: Jean-Philippe Brucker Suggested-by: Jason Gunthorpe Signed-off-by: Lu Baolu Reviewed-by: Jean-Philippe Brucker Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Reviewed-by: Yi Liu Tested-by: Zhangfei Gao Tested-by: Tony Zhu Link: https://lore.kernel.org/r/20221031005917.45690-7-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/iommu.c | 20 ++++++++++++++++++++ include/linux/iommu.h | 25 +++++++++++++++++++++++-- 2 files changed, 43 insertions(+), 2 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index bf22992beb98..6a1cd2018e30 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -29,6 +29,7 @@ #include #include #include +#include #include "dma-iommu.h" @@ -1934,6 +1935,8 @@ EXPORT_SYMBOL_GPL(iommu_domain_alloc); void iommu_domain_free(struct iommu_domain *domain) { + if (domain->type == IOMMU_DOMAIN_SVA) + mmdrop(domain->mm); iommu_put_dma_cookie(domain); domain->ops->free(domain); } @@ -3383,3 +3386,20 @@ struct iommu_domain *iommu_get_domain_for_dev_pasid(struct device *dev, return domain; } EXPORT_SYMBOL_GPL(iommu_get_domain_for_dev_pasid); + +struct iommu_domain *iommu_sva_domain_alloc(struct device *dev, + struct mm_struct *mm) +{ + const struct iommu_ops *ops = dev_iommu_ops(dev); + struct iommu_domain *domain; + + domain = ops->domain_alloc(IOMMU_DOMAIN_SVA); + if (!domain) + return NULL; + + domain->type = IOMMU_DOMAIN_SVA; + mmgrab(mm); + domain->mm = mm; + + return domain; +} diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 5d2b78ac5416..776baa375967 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -64,6 +64,8 @@ struct iommu_domain_geometry { #define __IOMMU_DOMAIN_PT (1U << 2) /* Domain is identity mapped */ #define __IOMMU_DOMAIN_DMA_FQ (1U << 3) /* DMA-API uses flush queue */ +#define __IOMMU_DOMAIN_SVA (1U << 4) /* Shared process address space */ + /* * This are the possible domain-types * @@ -77,6 +79,8 @@ struct iommu_domain_geometry { * certain optimizations for these domains * IOMMU_DOMAIN_DMA_FQ - As above, but definitely using batched TLB * invalidation. + * IOMMU_DOMAIN_SVA - DMA addresses are shared process addresses + * represented by mm_struct's. */ #define IOMMU_DOMAIN_BLOCKED (0U) #define IOMMU_DOMAIN_IDENTITY (__IOMMU_DOMAIN_PT) @@ -86,15 +90,24 @@ struct iommu_domain_geometry { #define IOMMU_DOMAIN_DMA_FQ (__IOMMU_DOMAIN_PAGING | \ __IOMMU_DOMAIN_DMA_API | \ __IOMMU_DOMAIN_DMA_FQ) +#define IOMMU_DOMAIN_SVA (__IOMMU_DOMAIN_SVA) struct iommu_domain { unsigned type; const struct iommu_domain_ops *ops; unsigned long pgsize_bitmap; /* Bitmap of page sizes in use */ - iommu_fault_handler_t handler; - void *handler_token; struct iommu_domain_geometry geometry; struct iommu_dma_cookie *iova_cookie; + union { + struct { + iommu_fault_handler_t handler; + void *handler_token; + }; + struct { /* IOMMU_DOMAIN_SVA */ + struct mm_struct *mm; + int users; + }; + }; }; static inline bool iommu_is_dma_domain(struct iommu_domain *domain) @@ -685,6 +698,8 @@ int iommu_group_claim_dma_owner(struct iommu_group *group, void *owner); void iommu_group_release_dma_owner(struct iommu_group *group); bool iommu_group_dma_owner_claimed(struct iommu_group *group); +struct iommu_domain *iommu_sva_domain_alloc(struct device *dev, + struct mm_struct *mm); int iommu_attach_device_pasid(struct iommu_domain *domain, struct device *dev, ioasid_t pasid); void iommu_detach_device_pasid(struct iommu_domain *domain, @@ -1055,6 +1070,12 @@ static inline bool iommu_group_dma_owner_claimed(struct iommu_group *group) return false; } +static inline struct iommu_domain * +iommu_sva_domain_alloc(struct device *dev, struct mm_struct *mm) +{ + return NULL; +} + static inline int iommu_attach_device_pasid(struct iommu_domain *domain, struct device *dev, ioasid_t pasid) { -- cgit v1.2.3 From eaca8889a1ef50783bcaad143668b735d136fe46 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 31 Oct 2022 08:59:11 +0800 Subject: iommu/vt-d: Add SVA domain support Add support for SVA domain allocation and provide an SVA-specific iommu_domain_ops. This implementation is based on the existing SVA code. Possible cleanup and refactoring are left for incremental changes later. The VT-d driver will also need to support setting a DMA domain to a PASID of device. Current SVA implementation uses different data structures to track the domain and device PASID relationship. That's the reason why we need to check the domain type in remove_dev_pasid callback. Eventually we'll consolidate the data structures and remove the need of domain type check. Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Reviewed-by: Yi Liu Tested-by: Tony Zhu Link: https://lore.kernel.org/r/20221031005917.45690-8-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/intel/iommu.c | 25 ++++++++++++++++++++++++ drivers/iommu/intel/iommu.h | 10 ++++++++++ drivers/iommu/intel/svm.c | 47 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 82 insertions(+) (limited to 'drivers/iommu') diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 48cdcd0a5cf3..7b67e431dd36 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4169,6 +4169,8 @@ static struct iommu_domain *intel_iommu_domain_alloc(unsigned type) return domain; case IOMMU_DOMAIN_IDENTITY: return &si_domain->domain; + case IOMMU_DOMAIN_SVA: + return intel_svm_domain_alloc(); default: return NULL; } @@ -4712,6 +4714,28 @@ static void intel_iommu_iotlb_sync_map(struct iommu_domain *domain, __mapping_notify_one(info->iommu, dmar_domain, pfn, pages); } +static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid) +{ + struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL); + struct iommu_domain *domain; + + /* Domain type specific cleanup: */ + domain = iommu_get_domain_for_dev_pasid(dev, pasid, 0); + if (domain) { + switch (domain->type) { + case IOMMU_DOMAIN_SVA: + intel_svm_remove_dev_pasid(dev, pasid); + break; + default: + /* should never reach here */ + WARN_ON(1); + break; + } + } + + intel_pasid_tear_down_entry(iommu, dev, pasid, false); +} + const struct iommu_ops intel_iommu_ops = { .capable = intel_iommu_capable, .domain_alloc = intel_iommu_domain_alloc, @@ -4724,6 +4748,7 @@ const struct iommu_ops intel_iommu_ops = { .dev_disable_feat = intel_iommu_dev_disable_feat, .is_attach_deferred = intel_iommu_is_attach_deferred, .def_domain_type = device_def_domain_type, + .remove_dev_pasid = intel_iommu_remove_dev_pasid, .pgsize_bitmap = SZ_4K, #ifdef CONFIG_INTEL_IOMMU_SVM .sva_bind = intel_svm_bind, diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h index 33e5bcaf2a6c..252fa344f88a 100644 --- a/drivers/iommu/intel/iommu.h +++ b/drivers/iommu/intel/iommu.h @@ -753,6 +753,8 @@ void intel_svm_unbind(struct iommu_sva *handle); u32 intel_svm_get_pasid(struct iommu_sva *handle); int intel_svm_page_response(struct device *dev, struct iommu_fault_event *evt, struct iommu_page_response *msg); +struct iommu_domain *intel_svm_domain_alloc(void); +void intel_svm_remove_dev_pasid(struct device *dev, ioasid_t pasid); struct intel_svm_dev { struct list_head list; @@ -777,6 +779,14 @@ struct intel_svm { }; #else static inline void intel_svm_check(struct intel_iommu *iommu) {} +static inline struct iommu_domain *intel_svm_domain_alloc(void) +{ + return NULL; +} + +static inline void intel_svm_remove_dev_pasid(struct device *dev, ioasid_t pasid) +{ +} #endif #ifdef CONFIG_INTEL_IOMMU_DEBUGFS diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index 94bc47b68c93..86c8ea0d9635 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -882,3 +882,50 @@ int intel_svm_page_response(struct device *dev, out: return ret; } + +void intel_svm_remove_dev_pasid(struct device *dev, ioasid_t pasid) +{ + mutex_lock(&pasid_mutex); + intel_svm_unbind_mm(dev, pasid); + mutex_unlock(&pasid_mutex); +} + +static int intel_svm_set_dev_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t pasid) +{ + struct device_domain_info *info = dev_iommu_priv_get(dev); + struct intel_iommu *iommu = info->iommu; + struct mm_struct *mm = domain->mm; + struct iommu_sva *sva; + int ret = 0; + + mutex_lock(&pasid_mutex); + sva = intel_svm_bind_mm(iommu, dev, mm); + if (IS_ERR(sva)) + ret = PTR_ERR(sva); + mutex_unlock(&pasid_mutex); + + return ret; +} + +static void intel_svm_domain_free(struct iommu_domain *domain) +{ + kfree(to_dmar_domain(domain)); +} + +static const struct iommu_domain_ops intel_svm_domain_ops = { + .set_dev_pasid = intel_svm_set_dev_pasid, + .free = intel_svm_domain_free +}; + +struct iommu_domain *intel_svm_domain_alloc(void) +{ + struct dmar_domain *domain; + + domain = kzalloc(sizeof(*domain), GFP_KERNEL); + if (!domain) + return NULL; + domain->domain.ops = &intel_svm_domain_ops; + + return &domain->domain; +} -- cgit v1.2.3 From 386fa64fd52baadb849ed60c78b024fd1618278e Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 31 Oct 2022 08:59:12 +0800 Subject: arm-smmu-v3/sva: Add SVA domain support Add support for SVA domain allocation and provide an SVA-specific iommu_domain_ops. This implementation is based on the existing SVA code. Possible cleanup and refactoring are left for incremental changes later. Signed-off-by: Lu Baolu Reviewed-by: Jean-Philippe Brucker Reviewed-by: Jason Gunthorpe Tested-by: Zhangfei Gao Link: https://lore.kernel.org/r/20221031005917.45690-9-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 61 +++++++++++++++++++++++++ drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 15 ++++++ drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 14 ++++++ 3 files changed, 90 insertions(+) (limited to 'drivers/iommu') diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c index 8fcf0df4bd0e..2d188d12419e 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c @@ -549,3 +549,64 @@ void arm_smmu_sva_notifier_synchronize(void) */ mmu_notifier_synchronize(); } + +void arm_smmu_sva_remove_dev_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t id) +{ + struct mm_struct *mm = domain->mm; + struct arm_smmu_bond *bond = NULL, *t; + struct arm_smmu_master *master = dev_iommu_priv_get(dev); + + mutex_lock(&sva_lock); + list_for_each_entry(t, &master->bonds, list) { + if (t->mm == mm) { + bond = t; + break; + } + } + + if (!WARN_ON(!bond) && refcount_dec_and_test(&bond->refs)) { + list_del(&bond->list); + arm_smmu_mmu_notifier_put(bond->smmu_mn); + kfree(bond); + } + mutex_unlock(&sva_lock); +} + +static int arm_smmu_sva_set_dev_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t id) +{ + int ret = 0; + struct iommu_sva *handle; + struct mm_struct *mm = domain->mm; + + mutex_lock(&sva_lock); + handle = __arm_smmu_sva_bind(dev, mm); + if (IS_ERR(handle)) + ret = PTR_ERR(handle); + mutex_unlock(&sva_lock); + + return ret; +} + +static void arm_smmu_sva_domain_free(struct iommu_domain *domain) +{ + kfree(domain); +} + +static const struct iommu_domain_ops arm_smmu_sva_domain_ops = { + .set_dev_pasid = arm_smmu_sva_set_dev_pasid, + .free = arm_smmu_sva_domain_free +}; + +struct iommu_domain *arm_smmu_sva_domain_alloc(void) +{ + struct iommu_domain *domain; + + domain = kzalloc(sizeof(*domain), GFP_KERNEL); + if (!domain) + return NULL; + domain->ops = &arm_smmu_sva_domain_ops; + + return domain; +} diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index 21cb13da122c..eed2eb8effa3 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -2009,6 +2009,9 @@ static struct iommu_domain *arm_smmu_domain_alloc(unsigned type) { struct arm_smmu_domain *smmu_domain; + if (type == IOMMU_DOMAIN_SVA) + return arm_smmu_sva_domain_alloc(); + if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA && type != IOMMU_DOMAIN_DMA_FQ && @@ -2838,6 +2841,17 @@ static int arm_smmu_def_domain_type(struct device *dev) return 0; } +static void arm_smmu_remove_dev_pasid(struct device *dev, ioasid_t pasid) +{ + struct iommu_domain *domain; + + domain = iommu_get_domain_for_dev_pasid(dev, pasid, IOMMU_DOMAIN_SVA); + if (WARN_ON(IS_ERR(domain)) || !domain) + return; + + arm_smmu_sva_remove_dev_pasid(domain, dev, pasid); +} + static struct iommu_ops arm_smmu_ops = { .capable = arm_smmu_capable, .domain_alloc = arm_smmu_domain_alloc, @@ -2846,6 +2860,7 @@ static struct iommu_ops arm_smmu_ops = { .device_group = arm_smmu_device_group, .of_xlate = arm_smmu_of_xlate, .get_resv_regions = arm_smmu_get_resv_regions, + .remove_dev_pasid = arm_smmu_remove_dev_pasid, .dev_enable_feat = arm_smmu_dev_enable_feature, .dev_disable_feat = arm_smmu_dev_disable_feature, .sva_bind = arm_smmu_sva_bind, diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h index d2ba86470c42..5aa853e98d38 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h @@ -758,6 +758,9 @@ struct iommu_sva *arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm); void arm_smmu_sva_unbind(struct iommu_sva *handle); u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle); void arm_smmu_sva_notifier_synchronize(void); +struct iommu_domain *arm_smmu_sva_domain_alloc(void); +void arm_smmu_sva_remove_dev_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t id); #else /* CONFIG_ARM_SMMU_V3_SVA */ static inline bool arm_smmu_sva_supported(struct arm_smmu_device *smmu) { @@ -803,5 +806,16 @@ static inline u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle) } static inline void arm_smmu_sva_notifier_synchronize(void) {} + +static inline struct iommu_domain *arm_smmu_sva_domain_alloc(void) +{ + return NULL; +} + +static inline void arm_smmu_sva_remove_dev_pasid(struct iommu_domain *domain, + struct device *dev, + ioasid_t id) +{ +} #endif /* CONFIG_ARM_SMMU_V3_SVA */ #endif /* _ARM_SMMU_V3_H */ -- cgit v1.2.3 From be51b1d6bbff48c7d1943a8ff1e5a55777807f6e Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 31 Oct 2022 08:59:13 +0800 Subject: iommu/sva: Refactoring iommu_sva_bind/unbind_device() The existing iommu SVA interfaces are implemented by calling the SVA specific iommu ops provided by the IOMMU drivers. There's no need for any SVA specific ops in iommu_ops vector anymore as we can achieve this through the generic attach/detach_dev_pasid domain ops. This refactors the IOMMU SVA interfaces implementation by using the iommu_attach/detach_device_pasid interfaces and align them with the concept of the SVA iommu domain. Put the new SVA code in the SVA related file in order to make it self-contained. Signed-off-by: Lu Baolu Reviewed-by: Jean-Philippe Brucker Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Tested-by: Zhangfei Gao Tested-by: Tony Zhu Link: https://lore.kernel.org/r/20221031005917.45690-10-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/iommu-sva-lib.c | 111 ++++++++++++++++++++++++++++++++++++++++++ drivers/iommu/iommu.c | 91 ---------------------------------- include/linux/iommu.h | 43 ++++++++-------- 3 files changed, 134 insertions(+), 111 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c index 106506143896..e425573a1787 100644 --- a/drivers/iommu/iommu-sva-lib.c +++ b/drivers/iommu/iommu-sva-lib.c @@ -4,6 +4,7 @@ */ #include #include +#include #include "iommu-sva-lib.h" @@ -69,3 +70,113 @@ struct mm_struct *iommu_sva_find(ioasid_t pasid) return ioasid_find(&iommu_sva_pasid, pasid, __mmget_not_zero); } EXPORT_SYMBOL_GPL(iommu_sva_find); + +/** + * iommu_sva_bind_device() - Bind a process address space to a device + * @dev: the device + * @mm: the mm to bind, caller must hold a reference to mm_users + * + * Create a bond between device and address space, allowing the device to + * access the mm using the PASID returned by iommu_sva_get_pasid(). If a + * bond already exists between @device and @mm, an additional internal + * reference is taken. Caller must call iommu_sva_unbind_device() + * to release each reference. + * + * iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) must be called first, to + * initialize the required SVA features. + * + * On error, returns an ERR_PTR value. + */ +struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) +{ + struct iommu_domain *domain; + struct iommu_sva *handle; + ioasid_t max_pasids; + int ret; + + max_pasids = dev->iommu->max_pasids; + if (!max_pasids) + return ERR_PTR(-EOPNOTSUPP); + + /* Allocate mm->pasid if necessary. */ + ret = iommu_sva_alloc_pasid(mm, 1, max_pasids - 1); + if (ret) + return ERR_PTR(ret); + + handle = kzalloc(sizeof(*handle), GFP_KERNEL); + if (!handle) + return ERR_PTR(-ENOMEM); + + mutex_lock(&iommu_sva_lock); + /* Search for an existing domain. */ + domain = iommu_get_domain_for_dev_pasid(dev, mm->pasid, + IOMMU_DOMAIN_SVA); + if (IS_ERR(domain)) { + ret = PTR_ERR(domain); + goto out_unlock; + } + + if (domain) { + domain->users++; + goto out; + } + + /* Allocate a new domain and set it on device pasid. */ + domain = iommu_sva_domain_alloc(dev, mm); + if (!domain) { + ret = -ENOMEM; + goto out_unlock; + } + + ret = iommu_attach_device_pasid(domain, dev, mm->pasid); + if (ret) + goto out_free_domain; + domain->users = 1; +out: + mutex_unlock(&iommu_sva_lock); + handle->dev = dev; + handle->domain = domain; + + return handle; + +out_free_domain: + iommu_domain_free(domain); +out_unlock: + mutex_unlock(&iommu_sva_lock); + kfree(handle); + + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(iommu_sva_bind_device); + +/** + * iommu_sva_unbind_device() - Remove a bond created with iommu_sva_bind_device + * @handle: the handle returned by iommu_sva_bind_device() + * + * Put reference to a bond between device and address space. The device should + * not be issuing any more transaction for this PASID. All outstanding page + * requests for this PASID must have been flushed to the IOMMU. + */ +void iommu_sva_unbind_device(struct iommu_sva *handle) +{ + struct iommu_domain *domain = handle->domain; + ioasid_t pasid = domain->mm->pasid; + struct device *dev = handle->dev; + + mutex_lock(&iommu_sva_lock); + if (--domain->users == 0) { + iommu_detach_device_pasid(domain, dev, pasid); + iommu_domain_free(domain); + } + mutex_unlock(&iommu_sva_lock); + kfree(handle); +} +EXPORT_SYMBOL_GPL(iommu_sva_unbind_device); + +u32 iommu_sva_get_pasid(struct iommu_sva *handle) +{ + struct iommu_domain *domain = handle->domain; + + return domain->mm->pasid; +} +EXPORT_SYMBOL_GPL(iommu_sva_get_pasid); diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 6a1cd2018e30..c9da0a1bb3b8 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2751,97 +2751,6 @@ int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat) } EXPORT_SYMBOL_GPL(iommu_dev_disable_feature); -/** - * iommu_sva_bind_device() - Bind a process address space to a device - * @dev: the device - * @mm: the mm to bind, caller must hold a reference to it - * - * Create a bond between device and address space, allowing the device to access - * the mm using the returned PASID. If a bond already exists between @device and - * @mm, it is returned and an additional reference is taken. Caller must call - * iommu_sva_unbind_device() to release each reference. - * - * iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) must be called first, to - * initialize the required SVA features. - * - * On error, returns an ERR_PTR value. - */ -struct iommu_sva * -iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) -{ - struct iommu_group *group; - struct iommu_sva *handle = ERR_PTR(-EINVAL); - const struct iommu_ops *ops = dev_iommu_ops(dev); - - if (!ops->sva_bind) - return ERR_PTR(-ENODEV); - - group = iommu_group_get(dev); - if (!group) - return ERR_PTR(-ENODEV); - - /* Ensure device count and domain don't change while we're binding */ - mutex_lock(&group->mutex); - - /* - * To keep things simple, SVA currently doesn't support IOMMU groups - * with more than one device. Existing SVA-capable systems are not - * affected by the problems that required IOMMU groups (lack of ACS - * isolation, device ID aliasing and other hardware issues). - */ - if (iommu_group_device_count(group) != 1) - goto out_unlock; - - handle = ops->sva_bind(dev, mm); - -out_unlock: - mutex_unlock(&group->mutex); - iommu_group_put(group); - - return handle; -} -EXPORT_SYMBOL_GPL(iommu_sva_bind_device); - -/** - * iommu_sva_unbind_device() - Remove a bond created with iommu_sva_bind_device - * @handle: the handle returned by iommu_sva_bind_device() - * - * Put reference to a bond between device and address space. The device should - * not be issuing any more transaction for this PASID. All outstanding page - * requests for this PASID must have been flushed to the IOMMU. - */ -void iommu_sva_unbind_device(struct iommu_sva *handle) -{ - struct iommu_group *group; - struct device *dev = handle->dev; - const struct iommu_ops *ops = dev_iommu_ops(dev); - - if (!ops->sva_unbind) - return; - - group = iommu_group_get(dev); - if (!group) - return; - - mutex_lock(&group->mutex); - ops->sva_unbind(handle); - mutex_unlock(&group->mutex); - - iommu_group_put(group); -} -EXPORT_SYMBOL_GPL(iommu_sva_unbind_device); - -u32 iommu_sva_get_pasid(struct iommu_sva *handle) -{ - const struct iommu_ops *ops = dev_iommu_ops(handle->dev); - - if (!ops->sva_get_pasid) - return IOMMU_PASID_INVALID; - - return ops->sva_get_pasid(handle); -} -EXPORT_SYMBOL_GPL(iommu_sva_get_pasid); - /* * Changes the default domain of an iommu group that has *only* one device * diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 776baa375967..bee5659d07eb 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -645,6 +645,7 @@ struct iommu_fwspec { */ struct iommu_sva { struct device *dev; + struct iommu_domain *domain; }; int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode, @@ -686,11 +687,6 @@ void iommu_release_device(struct device *dev); int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features f); int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features f); -struct iommu_sva *iommu_sva_bind_device(struct device *dev, - struct mm_struct *mm); -void iommu_sva_unbind_device(struct iommu_sva *handle); -u32 iommu_sva_get_pasid(struct iommu_sva *handle); - int iommu_device_use_default_domain(struct device *dev); void iommu_device_unuse_default_domain(struct device *dev); @@ -1026,21 +1022,6 @@ iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat) return -ENODEV; } -static inline struct iommu_sva * -iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) -{ - return NULL; -} - -static inline void iommu_sva_unbind_device(struct iommu_sva *handle) -{ -} - -static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle) -{ - return IOMMU_PASID_INVALID; -} - static inline struct iommu_fwspec *dev_iommu_fwspec_get(struct device *dev) { return NULL; @@ -1154,4 +1135,26 @@ static inline void iommu_dma_compose_msi_msg(struct msi_desc *desc, struct msi_m #endif /* CONFIG_IOMMU_DMA */ +#ifdef CONFIG_IOMMU_SVA +struct iommu_sva *iommu_sva_bind_device(struct device *dev, + struct mm_struct *mm); +void iommu_sva_unbind_device(struct iommu_sva *handle); +u32 iommu_sva_get_pasid(struct iommu_sva *handle); +#else +static inline struct iommu_sva * +iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) +{ + return NULL; +} + +static inline void iommu_sva_unbind_device(struct iommu_sva *handle) +{ +} + +static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle) +{ + return IOMMU_PASID_INVALID; +} +#endif /* CONFIG_IOMMU_SVA */ + #endif /* __LINUX_IOMMU_H */ -- cgit v1.2.3 From 1c263576f4735e063e234fa5f43fd3046d36b5b3 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 31 Oct 2022 08:59:14 +0800 Subject: iommu: Remove SVA related callbacks from iommu ops These ops'es have been deprecated. There's no need for them anymore. Remove them to avoid dead code. Signed-off-by: Lu Baolu Reviewed-by: Jean-Philippe Brucker Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Reviewed-by: Yi Liu Tested-by: Zhangfei Gao Tested-by: Tony Zhu Link: https://lore.kernel.org/r/20221031005917.45690-11-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 40 -------------------- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 3 -- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 16 -------- drivers/iommu/intel/iommu.c | 3 -- drivers/iommu/intel/iommu.h | 3 -- drivers/iommu/intel/svm.c | 49 ------------------------- include/linux/iommu.h | 7 ---- 7 files changed, 121 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c index 2d188d12419e..9541afbba73c 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c @@ -344,11 +344,6 @@ __arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm) if (!bond) return ERR_PTR(-ENOMEM); - /* Allocate a PASID for this mm if necessary */ - ret = iommu_sva_alloc_pasid(mm, 1, (1U << master->ssid_bits) - 1); - if (ret) - goto err_free_bond; - bond->mm = mm; bond->sva.dev = dev; refcount_set(&bond->refs, 1); @@ -367,41 +362,6 @@ err_free_bond: return ERR_PTR(ret); } -struct iommu_sva *arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm) -{ - struct iommu_sva *handle; - struct iommu_domain *domain = iommu_get_domain_for_dev(dev); - struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain); - - if (smmu_domain->stage != ARM_SMMU_DOMAIN_S1) - return ERR_PTR(-EINVAL); - - mutex_lock(&sva_lock); - handle = __arm_smmu_sva_bind(dev, mm); - mutex_unlock(&sva_lock); - return handle; -} - -void arm_smmu_sva_unbind(struct iommu_sva *handle) -{ - struct arm_smmu_bond *bond = sva_to_bond(handle); - - mutex_lock(&sva_lock); - if (refcount_dec_and_test(&bond->refs)) { - list_del(&bond->list); - arm_smmu_mmu_notifier_put(bond->smmu_mn); - kfree(bond); - } - mutex_unlock(&sva_lock); -} - -u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle) -{ - struct arm_smmu_bond *bond = sva_to_bond(handle); - - return bond->mm->pasid; -} - bool arm_smmu_sva_supported(struct arm_smmu_device *smmu) { unsigned long reg, fld; diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index eed2eb8effa3..891e87ea54db 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -2863,9 +2863,6 @@ static struct iommu_ops arm_smmu_ops = { .remove_dev_pasid = arm_smmu_remove_dev_pasid, .dev_enable_feat = arm_smmu_dev_enable_feature, .dev_disable_feat = arm_smmu_dev_disable_feature, - .sva_bind = arm_smmu_sva_bind, - .sva_unbind = arm_smmu_sva_unbind, - .sva_get_pasid = arm_smmu_sva_get_pasid, .page_response = arm_smmu_page_response, .def_domain_type = arm_smmu_def_domain_type, .pgsize_bitmap = -1UL, /* Restricted during device attach */ diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h index 5aa853e98d38..8d772ea8a583 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h @@ -754,9 +754,6 @@ bool arm_smmu_master_sva_enabled(struct arm_smmu_master *master); int arm_smmu_master_enable_sva(struct arm_smmu_master *master); int arm_smmu_master_disable_sva(struct arm_smmu_master *master); bool arm_smmu_master_iopf_supported(struct arm_smmu_master *master); -struct iommu_sva *arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm); -void arm_smmu_sva_unbind(struct iommu_sva *handle); -u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle); void arm_smmu_sva_notifier_synchronize(void); struct iommu_domain *arm_smmu_sva_domain_alloc(void); void arm_smmu_sva_remove_dev_pasid(struct iommu_domain *domain, @@ -792,19 +789,6 @@ static inline bool arm_smmu_master_iopf_supported(struct arm_smmu_master *master return false; } -static inline struct iommu_sva * -arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm) -{ - return ERR_PTR(-ENODEV); -} - -static inline void arm_smmu_sva_unbind(struct iommu_sva *handle) {} - -static inline u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle) -{ - return IOMMU_PASID_INVALID; -} - static inline void arm_smmu_sva_notifier_synchronize(void) {} static inline struct iommu_domain *arm_smmu_sva_domain_alloc(void) diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 7b67e431dd36..5a41b10593b7 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4751,9 +4751,6 @@ const struct iommu_ops intel_iommu_ops = { .remove_dev_pasid = intel_iommu_remove_dev_pasid, .pgsize_bitmap = SZ_4K, #ifdef CONFIG_INTEL_IOMMU_SVM - .sva_bind = intel_svm_bind, - .sva_unbind = intel_svm_unbind, - .sva_get_pasid = intel_svm_get_pasid, .page_response = intel_svm_page_response, #endif .default_domain_ops = &(const struct iommu_domain_ops) { diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h index 252fa344f88a..251a609fdce3 100644 --- a/drivers/iommu/intel/iommu.h +++ b/drivers/iommu/intel/iommu.h @@ -748,9 +748,6 @@ struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn); extern void intel_svm_check(struct intel_iommu *iommu); extern int intel_svm_enable_prq(struct intel_iommu *iommu); extern int intel_svm_finish_prq(struct intel_iommu *iommu); -struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct *mm); -void intel_svm_unbind(struct iommu_sva *handle); -u32 intel_svm_get_pasid(struct iommu_sva *handle); int intel_svm_page_response(struct device *dev, struct iommu_fault_event *evt, struct iommu_page_response *msg); struct iommu_domain *intel_svm_domain_alloc(void); diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index 86c8ea0d9635..fceae9387018 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -296,14 +296,6 @@ out: return 0; } -static int intel_svm_alloc_pasid(struct device *dev, struct mm_struct *mm) -{ - ioasid_t max_pasid = dev_is_pci(dev) ? - pci_max_pasids(to_pci_dev(dev)) : intel_pasid_max_id; - - return iommu_sva_alloc_pasid(mm, PASID_MIN, max_pasid - 1); -} - static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu, struct device *dev, struct mm_struct *mm) @@ -771,47 +763,6 @@ prq_advance: return IRQ_RETVAL(handled); } -struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct *mm) -{ - struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL); - struct iommu_sva *sva; - int ret; - - mutex_lock(&pasid_mutex); - ret = intel_svm_alloc_pasid(dev, mm); - if (ret) { - mutex_unlock(&pasid_mutex); - return ERR_PTR(ret); - } - - sva = intel_svm_bind_mm(iommu, dev, mm); - mutex_unlock(&pasid_mutex); - - return sva; -} - -void intel_svm_unbind(struct iommu_sva *sva) -{ - struct intel_svm_dev *sdev = to_intel_svm_dev(sva); - - mutex_lock(&pasid_mutex); - intel_svm_unbind_mm(sdev->dev, sdev->pasid); - mutex_unlock(&pasid_mutex); -} - -u32 intel_svm_get_pasid(struct iommu_sva *sva) -{ - struct intel_svm_dev *sdev; - u32 pasid; - - mutex_lock(&pasid_mutex); - sdev = to_intel_svm_dev(sva); - pasid = sdev->pasid; - mutex_unlock(&pasid_mutex); - - return pasid; -} - int intel_svm_page_response(struct device *dev, struct iommu_fault_event *evt, struct iommu_page_response *msg) diff --git a/include/linux/iommu.h b/include/linux/iommu.h index bee5659d07eb..c337ef1c97bc 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -227,9 +227,6 @@ struct iommu_iotlb_gather { * driver init to device driver init (default no) * @dev_enable/disable_feat: per device entries to enable/disable * iommu specific features. - * @sva_bind: Bind process address space to device - * @sva_unbind: Unbind process address space from device - * @sva_get_pasid: Get PASID associated to a SVA handle * @page_response: handle page request response * @def_domain_type: device default domain type, return value: * - IOMMU_DOMAIN_IDENTITY: must use an identity domain @@ -263,10 +260,6 @@ struct iommu_ops { int (*dev_enable_feat)(struct device *dev, enum iommu_dev_features f); int (*dev_disable_feat)(struct device *dev, enum iommu_dev_features f); - struct iommu_sva *(*sva_bind)(struct device *dev, struct mm_struct *mm); - void (*sva_unbind)(struct iommu_sva *handle); - u32 (*sva_get_pasid)(struct iommu_sva *handle); - int (*page_response)(struct device *dev, struct iommu_fault_event *evt, struct iommu_page_response *msg); -- cgit v1.2.3 From 8cc93159f91960b4812ea48887e9e7501babc95a Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 31 Oct 2022 08:59:15 +0800 Subject: iommu: Prepare IOMMU domain for IOPF This adds some mechanisms around the iommu_domain so that the I/O page fault handling framework could route a page fault to the domain and call the fault handler from it. Add pointers to the page fault handler and its private data in struct iommu_domain. The fault handler will be called with the private data as a parameter once a page fault is routed to the domain. Any kernel component which owns an iommu domain could install handler and its private parameter so that the page fault could be further routed and handled. This also prepares the SVA implementation to be the first consumer of the per-domain page fault handling model. The I/O page fault handler for SVA is copied to the SVA file with mmget_not_zero() added before mmap_read_lock(). Suggested-by: Jean-Philippe Brucker Signed-off-by: Lu Baolu Reviewed-by: Jean-Philippe Brucker Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Tested-by: Zhangfei Gao Tested-by: Tony Zhu Link: https://lore.kernel.org/r/20221031005917.45690-12-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/io-pgfault.c | 7 ++++++ drivers/iommu/iommu-sva-lib.c | 58 +++++++++++++++++++++++++++++++++++++++++++ drivers/iommu/iommu-sva-lib.h | 8 ++++++ drivers/iommu/iommu.c | 4 +++ include/linux/iommu.h | 3 +++ 5 files changed, 80 insertions(+) (limited to 'drivers/iommu') diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c index 1df8c1dcae77..aee9e033012f 100644 --- a/drivers/iommu/io-pgfault.c +++ b/drivers/iommu/io-pgfault.c @@ -181,6 +181,13 @@ static void iopf_handle_group(struct work_struct *work) * request completes, outstanding faults will have been dealt with by the time * the PASID is freed. * + * Any valid page fault will be eventually routed to an iommu domain and the + * page fault handler installed there will get called. The users of this + * handling framework should guarantee that the iommu domain could only be + * freed after the device has stopped generating page faults (or the iommu + * hardware has been set to block the page faults) and the pending page faults + * have been flushed. + * * Return: 0 on success and <0 on error. */ int iommu_queue_iopf(struct iommu_fault *fault, void *cookie) diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c index e425573a1787..089fd61ff453 100644 --- a/drivers/iommu/iommu-sva-lib.c +++ b/drivers/iommu/iommu-sva-lib.c @@ -180,3 +180,61 @@ u32 iommu_sva_get_pasid(struct iommu_sva *handle) return domain->mm->pasid; } EXPORT_SYMBOL_GPL(iommu_sva_get_pasid); + +/* + * I/O page fault handler for SVA + */ +enum iommu_page_response_code +iommu_sva_handle_iopf(struct iommu_fault *fault, void *data) +{ + vm_fault_t ret; + struct vm_area_struct *vma; + struct mm_struct *mm = data; + unsigned int access_flags = 0; + unsigned int fault_flags = FAULT_FLAG_REMOTE; + struct iommu_fault_page_request *prm = &fault->prm; + enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID; + + if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID)) + return status; + + if (!mmget_not_zero(mm)) + return status; + + mmap_read_lock(mm); + + vma = find_extend_vma(mm, prm->addr); + if (!vma) + /* Unmapped area */ + goto out_put_mm; + + if (prm->perm & IOMMU_FAULT_PERM_READ) + access_flags |= VM_READ; + + if (prm->perm & IOMMU_FAULT_PERM_WRITE) { + access_flags |= VM_WRITE; + fault_flags |= FAULT_FLAG_WRITE; + } + + if (prm->perm & IOMMU_FAULT_PERM_EXEC) { + access_flags |= VM_EXEC; + fault_flags |= FAULT_FLAG_INSTRUCTION; + } + + if (!(prm->perm & IOMMU_FAULT_PERM_PRIV)) + fault_flags |= FAULT_FLAG_USER; + + if (access_flags & ~vma->vm_flags) + /* Access fault */ + goto out_put_mm; + + ret = handle_mm_fault(vma, prm->addr, fault_flags, NULL); + status = ret & VM_FAULT_ERROR ? IOMMU_PAGE_RESP_INVALID : + IOMMU_PAGE_RESP_SUCCESS; + +out_put_mm: + mmap_read_unlock(mm); + mmput(mm); + + return status; +} diff --git a/drivers/iommu/iommu-sva-lib.h b/drivers/iommu/iommu-sva-lib.h index 8909ea1094e3..1b3ace4b5863 100644 --- a/drivers/iommu/iommu-sva-lib.h +++ b/drivers/iommu/iommu-sva-lib.h @@ -26,6 +26,8 @@ int iopf_queue_flush_dev(struct device *dev); struct iopf_queue *iopf_queue_alloc(const char *name); void iopf_queue_free(struct iopf_queue *queue); int iopf_queue_discard_partial(struct iopf_queue *queue); +enum iommu_page_response_code +iommu_sva_handle_iopf(struct iommu_fault *fault, void *data); #else /* CONFIG_IOMMU_SVA */ static inline int iommu_queue_iopf(struct iommu_fault *fault, void *cookie) @@ -63,5 +65,11 @@ static inline int iopf_queue_discard_partial(struct iopf_queue *queue) { return -ENODEV; } + +static inline enum iommu_page_response_code +iommu_sva_handle_iopf(struct iommu_fault *fault, void *data) +{ + return IOMMU_PAGE_RESP_INVALID; +} #endif /* CONFIG_IOMMU_SVA */ #endif /* _IOMMU_SVA_LIB_H */ diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index c9da0a1bb3b8..9e0fb18e1b34 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -33,6 +33,8 @@ #include "dma-iommu.h" +#include "iommu-sva-lib.h" + static struct kset *iommu_group_kset; static DEFINE_IDA(iommu_group_ida); @@ -3309,6 +3311,8 @@ struct iommu_domain *iommu_sva_domain_alloc(struct device *dev, domain->type = IOMMU_DOMAIN_SVA; mmgrab(mm); domain->mm = mm; + domain->iopf_handler = iommu_sva_handle_iopf; + domain->fault_data = mm; return domain; } diff --git a/include/linux/iommu.h b/include/linux/iommu.h index c337ef1c97bc..7d2648058e43 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -98,6 +98,9 @@ struct iommu_domain { unsigned long pgsize_bitmap; /* Bitmap of page sizes in use */ struct iommu_domain_geometry geometry; struct iommu_dma_cookie *iova_cookie; + enum iommu_page_response_code (*iopf_handler)(struct iommu_fault *fault, + void *data); + void *fault_data; union { struct { iommu_fault_handler_t handler; -- cgit v1.2.3 From 4bb4211e48fbfb392bb07168b75b1a92832b62f5 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 31 Oct 2022 08:59:16 +0800 Subject: iommu: Per-domain I/O page fault handling Tweak the I/O page fault handling framework to route the page faults to the domain and call the page fault handler retrieved from the domain. This makes the I/O page fault handling framework possible to serve more usage scenarios as long as they have an IOMMU domain and install a page fault handler in it. Some unused functions are also removed to avoid dead code. The iommu_get_domain_for_dev_pasid() which retrieves attached domain for a {device, PASID} pair is used. It will be used by the page fault handling framework which knows {device, PASID} reported from the iommu driver. We have a guarantee that the SVA domain doesn't go away during IOPF handling, because unbind() won't free the domain until all the pending page requests have been flushed from the pipeline. The drivers either call iopf_queue_flush_dev() explicitly, or in stall case, the device driver is required to flush all DMAs including stalled transactions before calling unbind(). This also renames iopf_handle_group() to iopf_handler() to avoid confusing. Signed-off-by: Lu Baolu Reviewed-by: Jean-Philippe Brucker Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Tested-by: Zhangfei Gao Tested-by: Tony Zhu Link: https://lore.kernel.org/r/20221031005917.45690-13-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/io-pgfault.c | 68 ++++++---------------------------------------- 1 file changed, 9 insertions(+), 59 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c index aee9e033012f..d046d89cec55 100644 --- a/drivers/iommu/io-pgfault.c +++ b/drivers/iommu/io-pgfault.c @@ -69,69 +69,18 @@ static int iopf_complete_group(struct device *dev, struct iopf_fault *iopf, return iommu_page_response(dev, &resp); } -static enum iommu_page_response_code -iopf_handle_single(struct iopf_fault *iopf) -{ - vm_fault_t ret; - struct mm_struct *mm; - struct vm_area_struct *vma; - unsigned int access_flags = 0; - unsigned int fault_flags = FAULT_FLAG_REMOTE; - struct iommu_fault_page_request *prm = &iopf->fault.prm; - enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID; - - if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID)) - return status; - - mm = iommu_sva_find(prm->pasid); - if (IS_ERR_OR_NULL(mm)) - return status; - - mmap_read_lock(mm); - - vma = find_extend_vma(mm, prm->addr); - if (!vma) - /* Unmapped area */ - goto out_put_mm; - - if (prm->perm & IOMMU_FAULT_PERM_READ) - access_flags |= VM_READ; - - if (prm->perm & IOMMU_FAULT_PERM_WRITE) { - access_flags |= VM_WRITE; - fault_flags |= FAULT_FLAG_WRITE; - } - - if (prm->perm & IOMMU_FAULT_PERM_EXEC) { - access_flags |= VM_EXEC; - fault_flags |= FAULT_FLAG_INSTRUCTION; - } - - if (!(prm->perm & IOMMU_FAULT_PERM_PRIV)) - fault_flags |= FAULT_FLAG_USER; - - if (access_flags & ~vma->vm_flags) - /* Access fault */ - goto out_put_mm; - - ret = handle_mm_fault(vma, prm->addr, fault_flags, NULL); - status = ret & VM_FAULT_ERROR ? IOMMU_PAGE_RESP_INVALID : - IOMMU_PAGE_RESP_SUCCESS; - -out_put_mm: - mmap_read_unlock(mm); - mmput(mm); - - return status; -} - -static void iopf_handle_group(struct work_struct *work) +static void iopf_handler(struct work_struct *work) { struct iopf_group *group; + struct iommu_domain *domain; struct iopf_fault *iopf, *next; enum iommu_page_response_code status = IOMMU_PAGE_RESP_SUCCESS; group = container_of(work, struct iopf_group, work); + domain = iommu_get_domain_for_dev_pasid(group->dev, + group->last_fault.fault.prm.pasid, 0); + if (!domain || !domain->iopf_handler) + status = IOMMU_PAGE_RESP_INVALID; list_for_each_entry_safe(iopf, next, &group->faults, list) { /* @@ -139,7 +88,8 @@ static void iopf_handle_group(struct work_struct *work) * faults in the group if there is an error. */ if (status == IOMMU_PAGE_RESP_SUCCESS) - status = iopf_handle_single(iopf); + status = domain->iopf_handler(&iopf->fault, + domain->fault_data); if (!(iopf->fault.prm.flags & IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE)) @@ -242,7 +192,7 @@ int iommu_queue_iopf(struct iommu_fault *fault, void *cookie) group->last_fault.fault = *fault; INIT_LIST_HEAD(&group->faults); list_add(&group->last_fault.list, &group->faults); - INIT_WORK(&group->work, iopf_handle_group); + INIT_WORK(&group->work, iopf_handler); /* See if we have partial faults for this group */ list_for_each_entry_safe(iopf, next, &iopf_param->partial, list) { -- cgit v1.2.3 From 757636ed2607a3269cd2764e3e4a0480384c6c26 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 31 Oct 2022 08:59:17 +0800 Subject: iommu: Rename iommu-sva-lib.{c,h} Rename iommu-sva-lib.c[h] to iommu-sva.c[h] as it contains all code for SVA implementation in iommu core. Signed-off-by: Lu Baolu Reviewed-by: Jean-Philippe Brucker Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Tested-by: Zhangfei Gao Tested-by: Tony Zhu Link: https://lore.kernel.org/r/20221031005917.45690-14-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/Makefile | 2 +- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 2 +- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 +- drivers/iommu/intel/iommu.c | 2 +- drivers/iommu/intel/svm.c | 2 +- drivers/iommu/io-pgfault.c | 2 +- drivers/iommu/iommu-sva-lib.c | 240 ------------------------ drivers/iommu/iommu-sva-lib.h | 75 -------- drivers/iommu/iommu-sva.c | 240 ++++++++++++++++++++++++ drivers/iommu/iommu-sva.h | 75 ++++++++ drivers/iommu/iommu.c | 2 +- 11 files changed, 322 insertions(+), 322 deletions(-) delete mode 100644 drivers/iommu/iommu-sva-lib.c delete mode 100644 drivers/iommu/iommu-sva-lib.h create mode 100644 drivers/iommu/iommu-sva.c create mode 100644 drivers/iommu/iommu-sva.h (limited to 'drivers/iommu') diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile index cc9f381013c3..7fbf6a337662 100644 --- a/drivers/iommu/Makefile +++ b/drivers/iommu/Makefile @@ -28,6 +28,6 @@ obj-$(CONFIG_FSL_PAMU) += fsl_pamu.o fsl_pamu_domain.o obj-$(CONFIG_S390_IOMMU) += s390-iommu.o obj-$(CONFIG_HYPERV_IOMMU) += hyperv-iommu.o obj-$(CONFIG_VIRTIO_IOMMU) += virtio-iommu.o -obj-$(CONFIG_IOMMU_SVA) += iommu-sva-lib.o io-pgfault.o +obj-$(CONFIG_IOMMU_SVA) += iommu-sva.o io-pgfault.o obj-$(CONFIG_SPRD_IOMMU) += sprd-iommu.o obj-$(CONFIG_APPLE_DART) += apple-dart.o diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c index 9541afbba73c..a5a63b1c947e 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c @@ -10,7 +10,7 @@ #include #include "arm-smmu-v3.h" -#include "../../iommu-sva-lib.h" +#include "../../iommu-sva.h" #include "../../io-pgtable-arm.h" struct arm_smmu_mmu_notifier { diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index 891e87ea54db..94a2e53368af 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -29,7 +29,7 @@ #include "arm-smmu-v3.h" #include "../../dma-iommu.h" -#include "../../iommu-sva-lib.h" +#include "../../iommu-sva.h" static bool disable_bypass = true; module_param(disable_bypass, bool, 0444); diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 5a41b10593b7..a934a46bb9e6 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -27,7 +27,7 @@ #include "iommu.h" #include "../dma-iommu.h" #include "../irq_remapping.h" -#include "../iommu-sva-lib.h" +#include "../iommu-sva.h" #include "pasid.h" #include "cap_audit.h" diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index fceae9387018..f32de15da61a 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -24,7 +24,7 @@ #include "iommu.h" #include "pasid.h" #include "perf.h" -#include "../iommu-sva-lib.h" +#include "../iommu-sva.h" #include "trace.h" static irqreturn_t prq_event_thread(int irq, void *d); diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c index d046d89cec55..e5b8b9110c13 100644 --- a/drivers/iommu/io-pgfault.c +++ b/drivers/iommu/io-pgfault.c @@ -11,7 +11,7 @@ #include #include -#include "iommu-sva-lib.h" +#include "iommu-sva.h" /** * struct iopf_queue - IO Page Fault queue diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c deleted file mode 100644 index 089fd61ff453..000000000000 --- a/drivers/iommu/iommu-sva-lib.c +++ /dev/null @@ -1,240 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * Helpers for IOMMU drivers implementing SVA - */ -#include -#include -#include - -#include "iommu-sva-lib.h" - -static DEFINE_MUTEX(iommu_sva_lock); -static DECLARE_IOASID_SET(iommu_sva_pasid); - -/** - * iommu_sva_alloc_pasid - Allocate a PASID for the mm - * @mm: the mm - * @min: minimum PASID value (inclusive) - * @max: maximum PASID value (inclusive) - * - * Try to allocate a PASID for this mm, or take a reference to the existing one - * provided it fits within the [@min, @max] range. On success the PASID is - * available in mm->pasid and will be available for the lifetime of the mm. - * - * Returns 0 on success and < 0 on error. - */ -int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max) -{ - int ret = 0; - ioasid_t pasid; - - if (min == INVALID_IOASID || max == INVALID_IOASID || - min == 0 || max < min) - return -EINVAL; - - mutex_lock(&iommu_sva_lock); - /* Is a PASID already associated with this mm? */ - if (pasid_valid(mm->pasid)) { - if (mm->pasid < min || mm->pasid >= max) - ret = -EOVERFLOW; - goto out; - } - - pasid = ioasid_alloc(&iommu_sva_pasid, min, max, mm); - if (!pasid_valid(pasid)) - ret = -ENOMEM; - else - mm_pasid_set(mm, pasid); -out: - mutex_unlock(&iommu_sva_lock); - return ret; -} -EXPORT_SYMBOL_GPL(iommu_sva_alloc_pasid); - -/* ioasid_find getter() requires a void * argument */ -static bool __mmget_not_zero(void *mm) -{ - return mmget_not_zero(mm); -} - -/** - * iommu_sva_find() - Find mm associated to the given PASID - * @pasid: Process Address Space ID assigned to the mm - * - * On success a reference to the mm is taken, and must be released with mmput(). - * - * Returns the mm corresponding to this PASID, or an error if not found. - */ -struct mm_struct *iommu_sva_find(ioasid_t pasid) -{ - return ioasid_find(&iommu_sva_pasid, pasid, __mmget_not_zero); -} -EXPORT_SYMBOL_GPL(iommu_sva_find); - -/** - * iommu_sva_bind_device() - Bind a process address space to a device - * @dev: the device - * @mm: the mm to bind, caller must hold a reference to mm_users - * - * Create a bond between device and address space, allowing the device to - * access the mm using the PASID returned by iommu_sva_get_pasid(). If a - * bond already exists between @device and @mm, an additional internal - * reference is taken. Caller must call iommu_sva_unbind_device() - * to release each reference. - * - * iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) must be called first, to - * initialize the required SVA features. - * - * On error, returns an ERR_PTR value. - */ -struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) -{ - struct iommu_domain *domain; - struct iommu_sva *handle; - ioasid_t max_pasids; - int ret; - - max_pasids = dev->iommu->max_pasids; - if (!max_pasids) - return ERR_PTR(-EOPNOTSUPP); - - /* Allocate mm->pasid if necessary. */ - ret = iommu_sva_alloc_pasid(mm, 1, max_pasids - 1); - if (ret) - return ERR_PTR(ret); - - handle = kzalloc(sizeof(*handle), GFP_KERNEL); - if (!handle) - return ERR_PTR(-ENOMEM); - - mutex_lock(&iommu_sva_lock); - /* Search for an existing domain. */ - domain = iommu_get_domain_for_dev_pasid(dev, mm->pasid, - IOMMU_DOMAIN_SVA); - if (IS_ERR(domain)) { - ret = PTR_ERR(domain); - goto out_unlock; - } - - if (domain) { - domain->users++; - goto out; - } - - /* Allocate a new domain and set it on device pasid. */ - domain = iommu_sva_domain_alloc(dev, mm); - if (!domain) { - ret = -ENOMEM; - goto out_unlock; - } - - ret = iommu_attach_device_pasid(domain, dev, mm->pasid); - if (ret) - goto out_free_domain; - domain->users = 1; -out: - mutex_unlock(&iommu_sva_lock); - handle->dev = dev; - handle->domain = domain; - - return handle; - -out_free_domain: - iommu_domain_free(domain); -out_unlock: - mutex_unlock(&iommu_sva_lock); - kfree(handle); - - return ERR_PTR(ret); -} -EXPORT_SYMBOL_GPL(iommu_sva_bind_device); - -/** - * iommu_sva_unbind_device() - Remove a bond created with iommu_sva_bind_device - * @handle: the handle returned by iommu_sva_bind_device() - * - * Put reference to a bond between device and address space. The device should - * not be issuing any more transaction for this PASID. All outstanding page - * requests for this PASID must have been flushed to the IOMMU. - */ -void iommu_sva_unbind_device(struct iommu_sva *handle) -{ - struct iommu_domain *domain = handle->domain; - ioasid_t pasid = domain->mm->pasid; - struct device *dev = handle->dev; - - mutex_lock(&iommu_sva_lock); - if (--domain->users == 0) { - iommu_detach_device_pasid(domain, dev, pasid); - iommu_domain_free(domain); - } - mutex_unlock(&iommu_sva_lock); - kfree(handle); -} -EXPORT_SYMBOL_GPL(iommu_sva_unbind_device); - -u32 iommu_sva_get_pasid(struct iommu_sva *handle) -{ - struct iommu_domain *domain = handle->domain; - - return domain->mm->pasid; -} -EXPORT_SYMBOL_GPL(iommu_sva_get_pasid); - -/* - * I/O page fault handler for SVA - */ -enum iommu_page_response_code -iommu_sva_handle_iopf(struct iommu_fault *fault, void *data) -{ - vm_fault_t ret; - struct vm_area_struct *vma; - struct mm_struct *mm = data; - unsigned int access_flags = 0; - unsigned int fault_flags = FAULT_FLAG_REMOTE; - struct iommu_fault_page_request *prm = &fault->prm; - enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID; - - if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID)) - return status; - - if (!mmget_not_zero(mm)) - return status; - - mmap_read_lock(mm); - - vma = find_extend_vma(mm, prm->addr); - if (!vma) - /* Unmapped area */ - goto out_put_mm; - - if (prm->perm & IOMMU_FAULT_PERM_READ) - access_flags |= VM_READ; - - if (prm->perm & IOMMU_FAULT_PERM_WRITE) { - access_flags |= VM_WRITE; - fault_flags |= FAULT_FLAG_WRITE; - } - - if (prm->perm & IOMMU_FAULT_PERM_EXEC) { - access_flags |= VM_EXEC; - fault_flags |= FAULT_FLAG_INSTRUCTION; - } - - if (!(prm->perm & IOMMU_FAULT_PERM_PRIV)) - fault_flags |= FAULT_FLAG_USER; - - if (access_flags & ~vma->vm_flags) - /* Access fault */ - goto out_put_mm; - - ret = handle_mm_fault(vma, prm->addr, fault_flags, NULL); - status = ret & VM_FAULT_ERROR ? IOMMU_PAGE_RESP_INVALID : - IOMMU_PAGE_RESP_SUCCESS; - -out_put_mm: - mmap_read_unlock(mm); - mmput(mm); - - return status; -} diff --git a/drivers/iommu/iommu-sva-lib.h b/drivers/iommu/iommu-sva-lib.h deleted file mode 100644 index 1b3ace4b5863..000000000000 --- a/drivers/iommu/iommu-sva-lib.h +++ /dev/null @@ -1,75 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * SVA library for IOMMU drivers - */ -#ifndef _IOMMU_SVA_LIB_H -#define _IOMMU_SVA_LIB_H - -#include -#include - -int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max); -struct mm_struct *iommu_sva_find(ioasid_t pasid); - -/* I/O Page fault */ -struct device; -struct iommu_fault; -struct iopf_queue; - -#ifdef CONFIG_IOMMU_SVA -int iommu_queue_iopf(struct iommu_fault *fault, void *cookie); - -int iopf_queue_add_device(struct iopf_queue *queue, struct device *dev); -int iopf_queue_remove_device(struct iopf_queue *queue, - struct device *dev); -int iopf_queue_flush_dev(struct device *dev); -struct iopf_queue *iopf_queue_alloc(const char *name); -void iopf_queue_free(struct iopf_queue *queue); -int iopf_queue_discard_partial(struct iopf_queue *queue); -enum iommu_page_response_code -iommu_sva_handle_iopf(struct iommu_fault *fault, void *data); - -#else /* CONFIG_IOMMU_SVA */ -static inline int iommu_queue_iopf(struct iommu_fault *fault, void *cookie) -{ - return -ENODEV; -} - -static inline int iopf_queue_add_device(struct iopf_queue *queue, - struct device *dev) -{ - return -ENODEV; -} - -static inline int iopf_queue_remove_device(struct iopf_queue *queue, - struct device *dev) -{ - return -ENODEV; -} - -static inline int iopf_queue_flush_dev(struct device *dev) -{ - return -ENODEV; -} - -static inline struct iopf_queue *iopf_queue_alloc(const char *name) -{ - return NULL; -} - -static inline void iopf_queue_free(struct iopf_queue *queue) -{ -} - -static inline int iopf_queue_discard_partial(struct iopf_queue *queue) -{ - return -ENODEV; -} - -static inline enum iommu_page_response_code -iommu_sva_handle_iopf(struct iommu_fault *fault, void *data) -{ - return IOMMU_PAGE_RESP_INVALID; -} -#endif /* CONFIG_IOMMU_SVA */ -#endif /* _IOMMU_SVA_LIB_H */ diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c new file mode 100644 index 000000000000..24bf9b2b58aa --- /dev/null +++ b/drivers/iommu/iommu-sva.c @@ -0,0 +1,240 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Helpers for IOMMU drivers implementing SVA + */ +#include +#include +#include + +#include "iommu-sva.h" + +static DEFINE_MUTEX(iommu_sva_lock); +static DECLARE_IOASID_SET(iommu_sva_pasid); + +/** + * iommu_sva_alloc_pasid - Allocate a PASID for the mm + * @mm: the mm + * @min: minimum PASID value (inclusive) + * @max: maximum PASID value (inclusive) + * + * Try to allocate a PASID for this mm, or take a reference to the existing one + * provided it fits within the [@min, @max] range. On success the PASID is + * available in mm->pasid and will be available for the lifetime of the mm. + * + * Returns 0 on success and < 0 on error. + */ +int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max) +{ + int ret = 0; + ioasid_t pasid; + + if (min == INVALID_IOASID || max == INVALID_IOASID || + min == 0 || max < min) + return -EINVAL; + + mutex_lock(&iommu_sva_lock); + /* Is a PASID already associated with this mm? */ + if (pasid_valid(mm->pasid)) { + if (mm->pasid < min || mm->pasid >= max) + ret = -EOVERFLOW; + goto out; + } + + pasid = ioasid_alloc(&iommu_sva_pasid, min, max, mm); + if (!pasid_valid(pasid)) + ret = -ENOMEM; + else + mm_pasid_set(mm, pasid); +out: + mutex_unlock(&iommu_sva_lock); + return ret; +} +EXPORT_SYMBOL_GPL(iommu_sva_alloc_pasid); + +/* ioasid_find getter() requires a void * argument */ +static bool __mmget_not_zero(void *mm) +{ + return mmget_not_zero(mm); +} + +/** + * iommu_sva_find() - Find mm associated to the given PASID + * @pasid: Process Address Space ID assigned to the mm + * + * On success a reference to the mm is taken, and must be released with mmput(). + * + * Returns the mm corresponding to this PASID, or an error if not found. + */ +struct mm_struct *iommu_sva_find(ioasid_t pasid) +{ + return ioasid_find(&iommu_sva_pasid, pasid, __mmget_not_zero); +} +EXPORT_SYMBOL_GPL(iommu_sva_find); + +/** + * iommu_sva_bind_device() - Bind a process address space to a device + * @dev: the device + * @mm: the mm to bind, caller must hold a reference to mm_users + * + * Create a bond between device and address space, allowing the device to + * access the mm using the PASID returned by iommu_sva_get_pasid(). If a + * bond already exists between @device and @mm, an additional internal + * reference is taken. Caller must call iommu_sva_unbind_device() + * to release each reference. + * + * iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) must be called first, to + * initialize the required SVA features. + * + * On error, returns an ERR_PTR value. + */ +struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) +{ + struct iommu_domain *domain; + struct iommu_sva *handle; + ioasid_t max_pasids; + int ret; + + max_pasids = dev->iommu->max_pasids; + if (!max_pasids) + return ERR_PTR(-EOPNOTSUPP); + + /* Allocate mm->pasid if necessary. */ + ret = iommu_sva_alloc_pasid(mm, 1, max_pasids - 1); + if (ret) + return ERR_PTR(ret); + + handle = kzalloc(sizeof(*handle), GFP_KERNEL); + if (!handle) + return ERR_PTR(-ENOMEM); + + mutex_lock(&iommu_sva_lock); + /* Search for an existing domain. */ + domain = iommu_get_domain_for_dev_pasid(dev, mm->pasid, + IOMMU_DOMAIN_SVA); + if (IS_ERR(domain)) { + ret = PTR_ERR(domain); + goto out_unlock; + } + + if (domain) { + domain->users++; + goto out; + } + + /* Allocate a new domain and set it on device pasid. */ + domain = iommu_sva_domain_alloc(dev, mm); + if (!domain) { + ret = -ENOMEM; + goto out_unlock; + } + + ret = iommu_attach_device_pasid(domain, dev, mm->pasid); + if (ret) + goto out_free_domain; + domain->users = 1; +out: + mutex_unlock(&iommu_sva_lock); + handle->dev = dev; + handle->domain = domain; + + return handle; + +out_free_domain: + iommu_domain_free(domain); +out_unlock: + mutex_unlock(&iommu_sva_lock); + kfree(handle); + + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(iommu_sva_bind_device); + +/** + * iommu_sva_unbind_device() - Remove a bond created with iommu_sva_bind_device + * @handle: the handle returned by iommu_sva_bind_device() + * + * Put reference to a bond between device and address space. The device should + * not be issuing any more transaction for this PASID. All outstanding page + * requests for this PASID must have been flushed to the IOMMU. + */ +void iommu_sva_unbind_device(struct iommu_sva *handle) +{ + struct iommu_domain *domain = handle->domain; + ioasid_t pasid = domain->mm->pasid; + struct device *dev = handle->dev; + + mutex_lock(&iommu_sva_lock); + if (--domain->users == 0) { + iommu_detach_device_pasid(domain, dev, pasid); + iommu_domain_free(domain); + } + mutex_unlock(&iommu_sva_lock); + kfree(handle); +} +EXPORT_SYMBOL_GPL(iommu_sva_unbind_device); + +u32 iommu_sva_get_pasid(struct iommu_sva *handle) +{ + struct iommu_domain *domain = handle->domain; + + return domain->mm->pasid; +} +EXPORT_SYMBOL_GPL(iommu_sva_get_pasid); + +/* + * I/O page fault handler for SVA + */ +enum iommu_page_response_code +iommu_sva_handle_iopf(struct iommu_fault *fault, void *data) +{ + vm_fault_t ret; + struct vm_area_struct *vma; + struct mm_struct *mm = data; + unsigned int access_flags = 0; + unsigned int fault_flags = FAULT_FLAG_REMOTE; + struct iommu_fault_page_request *prm = &fault->prm; + enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID; + + if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID)) + return status; + + if (!mmget_not_zero(mm)) + return status; + + mmap_read_lock(mm); + + vma = find_extend_vma(mm, prm->addr); + if (!vma) + /* Unmapped area */ + goto out_put_mm; + + if (prm->perm & IOMMU_FAULT_PERM_READ) + access_flags |= VM_READ; + + if (prm->perm & IOMMU_FAULT_PERM_WRITE) { + access_flags |= VM_WRITE; + fault_flags |= FAULT_FLAG_WRITE; + } + + if (prm->perm & IOMMU_FAULT_PERM_EXEC) { + access_flags |= VM_EXEC; + fault_flags |= FAULT_FLAG_INSTRUCTION; + } + + if (!(prm->perm & IOMMU_FAULT_PERM_PRIV)) + fault_flags |= FAULT_FLAG_USER; + + if (access_flags & ~vma->vm_flags) + /* Access fault */ + goto out_put_mm; + + ret = handle_mm_fault(vma, prm->addr, fault_flags, NULL); + status = ret & VM_FAULT_ERROR ? IOMMU_PAGE_RESP_INVALID : + IOMMU_PAGE_RESP_SUCCESS; + +out_put_mm: + mmap_read_unlock(mm); + mmput(mm); + + return status; +} diff --git a/drivers/iommu/iommu-sva.h b/drivers/iommu/iommu-sva.h new file mode 100644 index 000000000000..7215a761b962 --- /dev/null +++ b/drivers/iommu/iommu-sva.h @@ -0,0 +1,75 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * SVA library for IOMMU drivers + */ +#ifndef _IOMMU_SVA_H +#define _IOMMU_SVA_H + +#include +#include + +int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max); +struct mm_struct *iommu_sva_find(ioasid_t pasid); + +/* I/O Page fault */ +struct device; +struct iommu_fault; +struct iopf_queue; + +#ifdef CONFIG_IOMMU_SVA +int iommu_queue_iopf(struct iommu_fault *fault, void *cookie); + +int iopf_queue_add_device(struct iopf_queue *queue, struct device *dev); +int iopf_queue_remove_device(struct iopf_queue *queue, + struct device *dev); +int iopf_queue_flush_dev(struct device *dev); +struct iopf_queue *iopf_queue_alloc(const char *name); +void iopf_queue_free(struct iopf_queue *queue); +int iopf_queue_discard_partial(struct iopf_queue *queue); +enum iommu_page_response_code +iommu_sva_handle_iopf(struct iommu_fault *fault, void *data); + +#else /* CONFIG_IOMMU_SVA */ +static inline int iommu_queue_iopf(struct iommu_fault *fault, void *cookie) +{ + return -ENODEV; +} + +static inline int iopf_queue_add_device(struct iopf_queue *queue, + struct device *dev) +{ + return -ENODEV; +} + +static inline int iopf_queue_remove_device(struct iopf_queue *queue, + struct device *dev) +{ + return -ENODEV; +} + +static inline int iopf_queue_flush_dev(struct device *dev) +{ + return -ENODEV; +} + +static inline struct iopf_queue *iopf_queue_alloc(const char *name) +{ + return NULL; +} + +static inline void iopf_queue_free(struct iopf_queue *queue) +{ +} + +static inline int iopf_queue_discard_partial(struct iopf_queue *queue) +{ + return -ENODEV; +} + +static inline enum iommu_page_response_code +iommu_sva_handle_iopf(struct iommu_fault *fault, void *data) +{ + return IOMMU_PAGE_RESP_INVALID; +} +#endif /* CONFIG_IOMMU_SVA */ +#endif /* _IOMMU_SVA_H */ diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 9e0fb18e1b34..c50f68b2b656 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -33,7 +33,7 @@ #include "dma-iommu.h" -#include "iommu-sva-lib.h" +#include "iommu-sva.h" static struct kset *iommu_group_kset; static DEFINE_IDA(iommu_group_ida); -- cgit v1.2.3 From 4989764d8ed3d3d1024e4e831ff2affc40ee01d6 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 29 Nov 2022 16:29:24 -0400 Subject: iommu: Add IOMMU_CAP_ENFORCE_CACHE_COHERENCY This queries if a domain linked to a device should expect to support enforce_cache_coherency() so iommufd can negotiate the rules for when a domain should be shared or not. For iommufd a device that declares IOMMU_CAP_ENFORCE_CACHE_COHERENCY will not be attached to a domain that does not support it. Link: https://lore.kernel.org/r/1-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Reviewed-by: Lu Baolu Reviewed-by: Kevin Tian Tested-by: Nicolin Chen Tested-by: Yi Liu Tested-by: Lixiao Yang Tested-by: Matthew Rosato Tested-by: Yu He Signed-off-by: Jason Gunthorpe --- drivers/iommu/amd/iommu.c | 2 ++ drivers/iommu/intel/iommu.c | 16 +++++++++++----- include/linux/iommu.h | 5 +++++ 3 files changed, 18 insertions(+), 5 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index 45299eb7e8e3..240c535e317c 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -2278,6 +2278,8 @@ static bool amd_iommu_capable(struct device *dev, enum iommu_cap cap) return false; case IOMMU_CAP_PRE_BOOT_PROTECTION: return amdr_ivrs_remap_support; + case IOMMU_CAP_ENFORCE_CACHE_COHERENCY: + return true; default: break; } diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index f298e51d5aa6..157c97274110 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4450,14 +4450,20 @@ static bool intel_iommu_enforce_cache_coherency(struct iommu_domain *domain) static bool intel_iommu_capable(struct device *dev, enum iommu_cap cap) { - if (cap == IOMMU_CAP_CACHE_COHERENCY) + struct device_domain_info *info = dev_iommu_priv_get(dev); + + switch (cap) { + case IOMMU_CAP_CACHE_COHERENCY: return true; - if (cap == IOMMU_CAP_INTR_REMAP) + case IOMMU_CAP_INTR_REMAP: return irq_remapping_enabled == 1; - if (cap == IOMMU_CAP_PRE_BOOT_PROTECTION) + case IOMMU_CAP_PRE_BOOT_PROTECTION: return dmar_platform_optin(); - - return false; + case IOMMU_CAP_ENFORCE_CACHE_COHERENCY: + return ecap_sc_support(info->iommu->ecap); + default: + return false; + } } static struct iommu_device *intel_iommu_probe_device(struct device *dev) diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 68d7d304cdb7..a09fd32d8cc2 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -124,6 +124,11 @@ enum iommu_cap { IOMMU_CAP_NOEXEC, /* IOMMU_NOEXEC flag */ IOMMU_CAP_PRE_BOOT_PROTECTION, /* Firmware says it used the IOMMU for DMA protection and we should too */ + /* + * Per-device flag indicating if enforce_cache_coherency() will work on + * this device. + */ + IOMMU_CAP_ENFORCE_CACHE_COHERENCY, }; /* These are the possible reserved region types */ -- cgit v1.2.3 From 89395ccedbc153fecbc29342fbb94a6dfadf24cd Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Tue, 29 Nov 2022 16:29:25 -0400 Subject: iommu: Add device-centric DMA ownership interfaces These complement the group interfaces used by VFIO and are for use by iommufd. The main difference is that multiple devices in the same group can all share the ownership by passing the same ownership pointer. Move the common code into shared functions. Link: https://lore.kernel.org/r/2-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Tested-by: Nicolin Chen Tested-by: Yi Liu Tested-by: Lixiao Yang Tested-by: Matthew Rosato Reviewed-by: Kevin Tian Reviewed-by: Eric Auger Signed-off-by: Lu Baolu Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommu.c | 121 +++++++++++++++++++++++++++++++++++++++----------- include/linux/iommu.h | 12 +++++ 2 files changed, 107 insertions(+), 26 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 6ca377f4fbf9..d69ebba81beb 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -3108,41 +3108,49 @@ static int __iommu_group_alloc_blocking_domain(struct iommu_group *group) return 0; } +static int __iommu_take_dma_ownership(struct iommu_group *group, void *owner) +{ + int ret; + + if ((group->domain && group->domain != group->default_domain) || + !xa_empty(&group->pasid_array)) + return -EBUSY; + + ret = __iommu_group_alloc_blocking_domain(group); + if (ret) + return ret; + ret = __iommu_group_set_domain(group, group->blocking_domain); + if (ret) + return ret; + + group->owner = owner; + group->owner_cnt++; + return 0; +} + /** * iommu_group_claim_dma_owner() - Set DMA ownership of a group * @group: The group. * @owner: Caller specified pointer. Used for exclusive ownership. * - * This is to support backward compatibility for vfio which manages - * the dma ownership in iommu_group level. New invocations on this - * interface should be prohibited. + * This is to support backward compatibility for vfio which manages the dma + * ownership in iommu_group level. New invocations on this interface should be + * prohibited. Only a single owner may exist for a group. */ int iommu_group_claim_dma_owner(struct iommu_group *group, void *owner) { int ret = 0; + if (WARN_ON(!owner)) + return -EINVAL; + mutex_lock(&group->mutex); if (group->owner_cnt) { ret = -EPERM; goto unlock_out; - } else { - if ((group->domain && group->domain != group->default_domain) || - !xa_empty(&group->pasid_array)) { - ret = -EBUSY; - goto unlock_out; - } - - ret = __iommu_group_alloc_blocking_domain(group); - if (ret) - goto unlock_out; - - ret = __iommu_group_set_domain(group, group->blocking_domain); - if (ret) - goto unlock_out; - group->owner = owner; } - group->owner_cnt++; + ret = __iommu_take_dma_ownership(group, owner); unlock_out: mutex_unlock(&group->mutex); @@ -3151,30 +3159,91 @@ unlock_out: EXPORT_SYMBOL_GPL(iommu_group_claim_dma_owner); /** - * iommu_group_release_dma_owner() - Release DMA ownership of a group - * @group: The group. + * iommu_device_claim_dma_owner() - Set DMA ownership of a device + * @dev: The device. + * @owner: Caller specified pointer. Used for exclusive ownership. * - * Release the DMA ownership claimed by iommu_group_claim_dma_owner(). + * Claim the DMA ownership of a device. Multiple devices in the same group may + * concurrently claim ownership if they present the same owner value. Returns 0 + * on success and error code on failure */ -void iommu_group_release_dma_owner(struct iommu_group *group) +int iommu_device_claim_dma_owner(struct device *dev, void *owner) { - int ret; + struct iommu_group *group = iommu_group_get(dev); + int ret = 0; + + if (!group) + return -ENODEV; + if (WARN_ON(!owner)) + return -EINVAL; mutex_lock(&group->mutex); + if (group->owner_cnt) { + if (group->owner != owner) { + ret = -EPERM; + goto unlock_out; + } + group->owner_cnt++; + goto unlock_out; + } + + ret = __iommu_take_dma_ownership(group, owner); +unlock_out: + mutex_unlock(&group->mutex); + iommu_group_put(group); + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_device_claim_dma_owner); + +static void __iommu_release_dma_ownership(struct iommu_group *group) +{ + int ret; + if (WARN_ON(!group->owner_cnt || !group->owner || !xa_empty(&group->pasid_array))) - goto unlock_out; + return; group->owner_cnt = 0; group->owner = NULL; ret = __iommu_group_set_domain(group, group->default_domain); WARN(ret, "iommu driver failed to attach the default domain"); +} -unlock_out: +/** + * iommu_group_release_dma_owner() - Release DMA ownership of a group + * @dev: The device + * + * Release the DMA ownership claimed by iommu_group_claim_dma_owner(). + */ +void iommu_group_release_dma_owner(struct iommu_group *group) +{ + mutex_lock(&group->mutex); + __iommu_release_dma_ownership(group); mutex_unlock(&group->mutex); } EXPORT_SYMBOL_GPL(iommu_group_release_dma_owner); +/** + * iommu_device_release_dma_owner() - Release DMA ownership of a device + * @group: The device. + * + * Release the DMA ownership claimed by iommu_device_claim_dma_owner(). + */ +void iommu_device_release_dma_owner(struct device *dev) +{ + struct iommu_group *group = iommu_group_get(dev); + + mutex_lock(&group->mutex); + if (group->owner_cnt > 1) + group->owner_cnt--; + else + __iommu_release_dma_ownership(group); + mutex_unlock(&group->mutex); + iommu_group_put(group); +} +EXPORT_SYMBOL_GPL(iommu_device_release_dma_owner); + /** * iommu_group_dma_owner_claimed() - Query group dma ownership status * @group: The group. diff --git a/include/linux/iommu.h b/include/linux/iommu.h index a09fd32d8cc2..1690c334e516 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -707,6 +707,9 @@ int iommu_group_claim_dma_owner(struct iommu_group *group, void *owner); void iommu_group_release_dma_owner(struct iommu_group *group); bool iommu_group_dma_owner_claimed(struct iommu_group *group); +int iommu_device_claim_dma_owner(struct device *dev, void *owner); +void iommu_device_release_dma_owner(struct device *dev); + struct iommu_domain *iommu_sva_domain_alloc(struct device *dev, struct mm_struct *mm); int iommu_attach_device_pasid(struct iommu_domain *domain, @@ -1064,6 +1067,15 @@ static inline bool iommu_group_dma_owner_claimed(struct iommu_group *group) return false; } +static inline void iommu_device_release_dma_owner(struct device *dev) +{ +} + +static inline int iommu_device_claim_dma_owner(struct device *dev, void *owner) +{ + return -ENODEV; +} + static inline struct iommu_domain * iommu_sva_domain_alloc(struct device *dev, struct mm_struct *mm) { -- cgit v1.2.3 From 2ff4bed7fee72ba1abfcff5f11ae8f8e570353f2 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 29 Nov 2022 16:29:29 -0400 Subject: iommufd: File descriptor, context, kconfig and makefiles This is the basic infrastructure of a new miscdevice to hold the iommufd IOCTL API. It provides: - A miscdevice to create file descriptors to run the IOCTL interface over - A table based ioctl dispatch and centralized extendable pre-validation step - An xarray mapping userspace ID's to kernel objects. The design has multiple inter-related objects held within in a single IOMMUFD fd - A simple usage count to build a graph of object relations and protect against hostile userspace racing ioctls The only IOCTL provided in this patch is the generic 'destroy any object by handle' operation. Link: https://lore.kernel.org/r/6-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Reviewed-by: Lu Baolu Reviewed-by: Kevin Tian Reviewed-by: Eric Auger Tested-by: Nicolin Chen Tested-by: Yi Liu Tested-by: Lixiao Yang Tested-by: Matthew Rosato Signed-off-by: Yi Liu Signed-off-by: Jason Gunthorpe --- Documentation/userspace-api/ioctl/ioctl-number.rst | 1 + MAINTAINERS | 12 + drivers/iommu/Kconfig | 1 + drivers/iommu/Makefile | 2 +- drivers/iommu/iommufd/Kconfig | 12 + drivers/iommu/iommufd/Makefile | 5 + drivers/iommu/iommufd/iommufd_private.h | 109 +++++++ drivers/iommu/iommufd/main.c | 344 +++++++++++++++++++++ include/linux/iommufd.h | 31 ++ include/uapi/linux/iommufd.h | 55 ++++ 10 files changed, 571 insertions(+), 1 deletion(-) create mode 100644 drivers/iommu/iommufd/Kconfig create mode 100644 drivers/iommu/iommufd/Makefile create mode 100644 drivers/iommu/iommufd/iommufd_private.h create mode 100644 drivers/iommu/iommufd/main.c create mode 100644 include/linux/iommufd.h create mode 100644 include/uapi/linux/iommufd.h (limited to 'drivers/iommu') diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst index 5f81e2a24a5c..eb045fc495a4 100644 --- a/Documentation/userspace-api/ioctl/ioctl-number.rst +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst @@ -105,6 +105,7 @@ Code Seq# Include File Comments '8' all SNP8023 advanced NIC card ';' 64-7F linux/vfio.h +';' 80-FF linux/iommufd.h '=' 00-3f uapi/linux/ptp_clock.h '@' 00-0F linux/radeonfb.h conflict! '@' 00-0F drivers/video/aty/aty128fb.c conflict! diff --git a/MAINTAINERS b/MAINTAINERS index 379945f82a64..c0a93779731d 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10717,6 +10717,18 @@ F: drivers/iommu/dma-iommu.h F: drivers/iommu/iova.c F: include/linux/iova.h +IOMMUFD +M: Jason Gunthorpe +M: Kevin Tian +L: iommu@lists.linux.dev +S: Maintained +T: git git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd.git +F: Documentation/userspace-api/iommufd.rst +F: drivers/iommu/iommufd/ +F: include/linux/iommufd.h +F: include/uapi/linux/iommufd.h +F: tools/testing/selftests/iommu/ + IOMMU SUBSYSTEM M: Joerg Roedel M: Will Deacon diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index dc5f7a156ff5..319966cde5cf 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -188,6 +188,7 @@ config MSM_IOMMU source "drivers/iommu/amd/Kconfig" source "drivers/iommu/intel/Kconfig" +source "drivers/iommu/iommufd/Kconfig" config IRQ_REMAP bool "Support for Interrupt Remapping" diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile index 7fbf6a337662..f461d0651385 100644 --- a/drivers/iommu/Makefile +++ b/drivers/iommu/Makefile @@ -1,5 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 -obj-y += amd/ intel/ arm/ +obj-y += amd/ intel/ arm/ iommufd/ obj-$(CONFIG_IOMMU_API) += iommu.o obj-$(CONFIG_IOMMU_API) += iommu-traces.o obj-$(CONFIG_IOMMU_API) += iommu-sysfs.o diff --git a/drivers/iommu/iommufd/Kconfig b/drivers/iommu/iommufd/Kconfig new file mode 100644 index 000000000000..164812084a67 --- /dev/null +++ b/drivers/iommu/iommufd/Kconfig @@ -0,0 +1,12 @@ +# SPDX-License-Identifier: GPL-2.0-only +config IOMMUFD + tristate "IOMMU Userspace API" + select INTERVAL_TREE + select INTERVAL_TREE_SPAN_ITER + select IOMMU_API + default n + help + Provides /dev/iommu, the user API to control the IOMMU subsystem as + it relates to managing IO page tables that point at user space memory. + + If you don't know what to do here, say N. diff --git a/drivers/iommu/iommufd/Makefile b/drivers/iommu/iommufd/Makefile new file mode 100644 index 000000000000..a07a8cffe937 --- /dev/null +++ b/drivers/iommu/iommufd/Makefile @@ -0,0 +1,5 @@ +# SPDX-License-Identifier: GPL-2.0-only +iommufd-y := \ + main.o + +obj-$(CONFIG_IOMMUFD) += iommufd.o diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h new file mode 100644 index 000000000000..bb720bc11317 --- /dev/null +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -0,0 +1,109 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES + */ +#ifndef __IOMMUFD_PRIVATE_H +#define __IOMMUFD_PRIVATE_H + +#include +#include +#include +#include + +struct iommufd_ctx { + struct file *file; + struct xarray objects; +}; + +struct iommufd_ucmd { + struct iommufd_ctx *ictx; + void __user *ubuffer; + u32 user_size; + void *cmd; +}; + +/* Copy the response in ucmd->cmd back to userspace. */ +static inline int iommufd_ucmd_respond(struct iommufd_ucmd *ucmd, + size_t cmd_len) +{ + if (copy_to_user(ucmd->ubuffer, ucmd->cmd, + min_t(size_t, ucmd->user_size, cmd_len))) + return -EFAULT; + return 0; +} + +enum iommufd_object_type { + IOMMUFD_OBJ_NONE, + IOMMUFD_OBJ_ANY = IOMMUFD_OBJ_NONE, +}; + +/* Base struct for all objects with a userspace ID handle. */ +struct iommufd_object { + struct rw_semaphore destroy_rwsem; + refcount_t users; + enum iommufd_object_type type; + unsigned int id; +}; + +static inline bool iommufd_lock_obj(struct iommufd_object *obj) +{ + if (!down_read_trylock(&obj->destroy_rwsem)) + return false; + if (!refcount_inc_not_zero(&obj->users)) { + up_read(&obj->destroy_rwsem); + return false; + } + return true; +} + +struct iommufd_object *iommufd_get_object(struct iommufd_ctx *ictx, u32 id, + enum iommufd_object_type type); +static inline void iommufd_put_object(struct iommufd_object *obj) +{ + refcount_dec(&obj->users); + up_read(&obj->destroy_rwsem); +} + +/** + * iommufd_ref_to_users() - Switch from destroy_rwsem to users refcount + * protection + * @obj - Object to release + * + * Objects have two refcount protections (destroy_rwsem and the refcount_t + * users). Holding either of these will prevent the object from being destroyed. + * + * Depending on the use case, one protection or the other is appropriate. In + * most cases references are being protected by the destroy_rwsem. This allows + * orderly destruction of the object because iommufd_object_destroy_user() will + * wait for it to become unlocked. However, as a rwsem, it cannot be held across + * a system call return. So cases that have longer term needs must switch + * to the weaker users refcount_t. + * + * With users protection iommufd_object_destroy_user() will return false, + * refusing to destroy the object, causing -EBUSY to userspace. + */ +static inline void iommufd_ref_to_users(struct iommufd_object *obj) +{ + up_read(&obj->destroy_rwsem); + /* iommufd_lock_obj() obtains users as well */ +} +void iommufd_object_abort(struct iommufd_ctx *ictx, struct iommufd_object *obj); +void iommufd_object_abort_and_destroy(struct iommufd_ctx *ictx, + struct iommufd_object *obj); +void iommufd_object_finalize(struct iommufd_ctx *ictx, + struct iommufd_object *obj); +bool iommufd_object_destroy_user(struct iommufd_ctx *ictx, + struct iommufd_object *obj); +struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx, + size_t size, + enum iommufd_object_type type); + +#define iommufd_object_alloc(ictx, ptr, type) \ + container_of(_iommufd_object_alloc( \ + ictx, \ + sizeof(*(ptr)) + BUILD_BUG_ON_ZERO( \ + offsetof(typeof(*(ptr)), \ + obj) != 0), \ + type), \ + typeof(*(ptr)), obj) + +#endif diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c new file mode 100644 index 000000000000..dfbc68b97506 --- /dev/null +++ b/drivers/iommu/iommufd/main.c @@ -0,0 +1,344 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (C) 2021 Intel Corporation + * Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES + * + * iommufd provides control over the IOMMU HW objects created by IOMMU kernel + * drivers. IOMMU HW objects revolve around IO page tables that map incoming DMA + * addresses (IOVA) to CPU addresses. + */ +#define pr_fmt(fmt) "iommufd: " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "iommufd_private.h" + +struct iommufd_object_ops { + void (*destroy)(struct iommufd_object *obj); +}; +static const struct iommufd_object_ops iommufd_object_ops[]; + +struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx, + size_t size, + enum iommufd_object_type type) +{ + struct iommufd_object *obj; + int rc; + + obj = kzalloc(size, GFP_KERNEL_ACCOUNT); + if (!obj) + return ERR_PTR(-ENOMEM); + obj->type = type; + init_rwsem(&obj->destroy_rwsem); + refcount_set(&obj->users, 1); + + /* + * Reserve an ID in the xarray but do not publish the pointer yet since + * the caller hasn't initialized it yet. Once the pointer is published + * in the xarray and visible to other threads we can't reliably destroy + * it anymore, so the caller must complete all errorable operations + * before calling iommufd_object_finalize(). + */ + rc = xa_alloc(&ictx->objects, &obj->id, XA_ZERO_ENTRY, + xa_limit_32b, GFP_KERNEL_ACCOUNT); + if (rc) + goto out_free; + return obj; +out_free: + kfree(obj); + return ERR_PTR(rc); +} + +/* + * Allow concurrent access to the object. + * + * Once another thread can see the object pointer it can prevent object + * destruction. Expect for special kernel-only objects there is no in-kernel way + * to reliably destroy a single object. Thus all APIs that are creating objects + * must use iommufd_object_abort() to handle their errors and only call + * iommufd_object_finalize() once object creation cannot fail. + */ +void iommufd_object_finalize(struct iommufd_ctx *ictx, + struct iommufd_object *obj) +{ + void *old; + + old = xa_store(&ictx->objects, obj->id, obj, GFP_KERNEL); + /* obj->id was returned from xa_alloc() so the xa_store() cannot fail */ + WARN_ON(old); +} + +/* Undo _iommufd_object_alloc() if iommufd_object_finalize() was not called */ +void iommufd_object_abort(struct iommufd_ctx *ictx, struct iommufd_object *obj) +{ + void *old; + + old = xa_erase(&ictx->objects, obj->id); + WARN_ON(old); + kfree(obj); +} + +/* + * Abort an object that has been fully initialized and needs destroy, but has + * not been finalized. + */ +void iommufd_object_abort_and_destroy(struct iommufd_ctx *ictx, + struct iommufd_object *obj) +{ + iommufd_object_ops[obj->type].destroy(obj); + iommufd_object_abort(ictx, obj); +} + +struct iommufd_object *iommufd_get_object(struct iommufd_ctx *ictx, u32 id, + enum iommufd_object_type type) +{ + struct iommufd_object *obj; + + xa_lock(&ictx->objects); + obj = xa_load(&ictx->objects, id); + if (!obj || (type != IOMMUFD_OBJ_ANY && obj->type != type) || + !iommufd_lock_obj(obj)) + obj = ERR_PTR(-ENOENT); + xa_unlock(&ictx->objects); + return obj; +} + +/* + * The caller holds a users refcount and wants to destroy the object. Returns + * true if the object was destroyed. In all cases the caller no longer has a + * reference on obj. + */ +bool iommufd_object_destroy_user(struct iommufd_ctx *ictx, + struct iommufd_object *obj) +{ + /* + * The purpose of the destroy_rwsem is to ensure deterministic + * destruction of objects used by external drivers and destroyed by this + * function. Any temporary increment of the refcount must hold the read + * side of this, such as during ioctl execution. + */ + down_write(&obj->destroy_rwsem); + xa_lock(&ictx->objects); + refcount_dec(&obj->users); + if (!refcount_dec_if_one(&obj->users)) { + xa_unlock(&ictx->objects); + up_write(&obj->destroy_rwsem); + return false; + } + __xa_erase(&ictx->objects, obj->id); + xa_unlock(&ictx->objects); + up_write(&obj->destroy_rwsem); + + iommufd_object_ops[obj->type].destroy(obj); + kfree(obj); + return true; +} + +static int iommufd_destroy(struct iommufd_ucmd *ucmd) +{ + struct iommu_destroy *cmd = ucmd->cmd; + struct iommufd_object *obj; + + obj = iommufd_get_object(ucmd->ictx, cmd->id, IOMMUFD_OBJ_ANY); + if (IS_ERR(obj)) + return PTR_ERR(obj); + iommufd_ref_to_users(obj); + /* See iommufd_ref_to_users() */ + if (!iommufd_object_destroy_user(ucmd->ictx, obj)) + return -EBUSY; + return 0; +} + +static int iommufd_fops_open(struct inode *inode, struct file *filp) +{ + struct iommufd_ctx *ictx; + + ictx = kzalloc(sizeof(*ictx), GFP_KERNEL_ACCOUNT); + if (!ictx) + return -ENOMEM; + + xa_init_flags(&ictx->objects, XA_FLAGS_ALLOC1 | XA_FLAGS_ACCOUNT); + ictx->file = filp; + filp->private_data = ictx; + return 0; +} + +static int iommufd_fops_release(struct inode *inode, struct file *filp) +{ + struct iommufd_ctx *ictx = filp->private_data; + struct iommufd_object *obj; + + /* + * The objects in the xarray form a graph of "users" counts, and we have + * to destroy them in a depth first manner. Leaf objects will reduce the + * users count of interior objects when they are destroyed. + * + * Repeatedly destroying all the "1 users" leaf objects will progress + * until the entire list is destroyed. If this can't progress then there + * is some bug related to object refcounting. + */ + while (!xa_empty(&ictx->objects)) { + unsigned int destroyed = 0; + unsigned long index; + + xa_for_each(&ictx->objects, index, obj) { + if (!refcount_dec_if_one(&obj->users)) + continue; + destroyed++; + xa_erase(&ictx->objects, index); + iommufd_object_ops[obj->type].destroy(obj); + kfree(obj); + } + /* Bug related to users refcount */ + if (WARN_ON(!destroyed)) + break; + } + kfree(ictx); + return 0; +} + +union ucmd_buffer { + struct iommu_destroy destroy; +}; + +struct iommufd_ioctl_op { + unsigned int size; + unsigned int min_size; + unsigned int ioctl_num; + int (*execute)(struct iommufd_ucmd *ucmd); +}; + +#define IOCTL_OP(_ioctl, _fn, _struct, _last) \ + [_IOC_NR(_ioctl) - IOMMUFD_CMD_BASE] = { \ + .size = sizeof(_struct) + \ + BUILD_BUG_ON_ZERO(sizeof(union ucmd_buffer) < \ + sizeof(_struct)), \ + .min_size = offsetofend(_struct, _last), \ + .ioctl_num = _ioctl, \ + .execute = _fn, \ + } +static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = { + IOCTL_OP(IOMMU_DESTROY, iommufd_destroy, struct iommu_destroy, id), +}; + +static long iommufd_fops_ioctl(struct file *filp, unsigned int cmd, + unsigned long arg) +{ + const struct iommufd_ioctl_op *op; + struct iommufd_ucmd ucmd = {}; + union ucmd_buffer buf; + unsigned int nr; + int ret; + + ucmd.ictx = filp->private_data; + ucmd.ubuffer = (void __user *)arg; + ret = get_user(ucmd.user_size, (u32 __user *)ucmd.ubuffer); + if (ret) + return ret; + + nr = _IOC_NR(cmd); + if (nr < IOMMUFD_CMD_BASE || + (nr - IOMMUFD_CMD_BASE) >= ARRAY_SIZE(iommufd_ioctl_ops)) + return -ENOIOCTLCMD; + op = &iommufd_ioctl_ops[nr - IOMMUFD_CMD_BASE]; + if (op->ioctl_num != cmd) + return -ENOIOCTLCMD; + if (ucmd.user_size < op->min_size) + return -EINVAL; + + ucmd.cmd = &buf; + ret = copy_struct_from_user(ucmd.cmd, op->size, ucmd.ubuffer, + ucmd.user_size); + if (ret) + return ret; + ret = op->execute(&ucmd); + return ret; +} + +static const struct file_operations iommufd_fops = { + .owner = THIS_MODULE, + .open = iommufd_fops_open, + .release = iommufd_fops_release, + .unlocked_ioctl = iommufd_fops_ioctl, +}; + +/** + * iommufd_ctx_get - Get a context reference + * @ictx: Context to get + * + * The caller must already hold a valid reference to ictx. + */ +void iommufd_ctx_get(struct iommufd_ctx *ictx) +{ + get_file(ictx->file); +} +EXPORT_SYMBOL_NS_GPL(iommufd_ctx_get, IOMMUFD); + +/** + * iommufd_ctx_from_file - Acquires a reference to the iommufd context + * @file: File to obtain the reference from + * + * Returns a pointer to the iommufd_ctx, otherwise ERR_PTR. The struct file + * remains owned by the caller and the caller must still do fput. On success + * the caller is responsible to call iommufd_ctx_put(). + */ +struct iommufd_ctx *iommufd_ctx_from_file(struct file *file) +{ + struct iommufd_ctx *ictx; + + if (file->f_op != &iommufd_fops) + return ERR_PTR(-EBADFD); + ictx = file->private_data; + iommufd_ctx_get(ictx); + return ictx; +} +EXPORT_SYMBOL_NS_GPL(iommufd_ctx_from_file, IOMMUFD); + +/** + * iommufd_ctx_put - Put back a reference + * @ictx: Context to put back + */ +void iommufd_ctx_put(struct iommufd_ctx *ictx) +{ + fput(ictx->file); +} +EXPORT_SYMBOL_NS_GPL(iommufd_ctx_put, IOMMUFD); + +static const struct iommufd_object_ops iommufd_object_ops[] = { +}; + +static struct miscdevice iommu_misc_dev = { + .minor = MISC_DYNAMIC_MINOR, + .name = "iommu", + .fops = &iommufd_fops, + .nodename = "iommu", + .mode = 0660, +}; + +static int __init iommufd_init(void) +{ + int ret; + + ret = misc_register(&iommu_misc_dev); + if (ret) + return ret; + return 0; +} + +static void __exit iommufd_exit(void) +{ + misc_deregister(&iommu_misc_dev); +} + +module_init(iommufd_init); +module_exit(iommufd_exit); + +MODULE_DESCRIPTION("I/O Address Space Management for passthrough devices"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h new file mode 100644 index 000000000000..d1817472c273 --- /dev/null +++ b/include/linux/iommufd.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2021 Intel Corporation + * Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES + */ +#ifndef __LINUX_IOMMUFD_H +#define __LINUX_IOMMUFD_H + +#include +#include +#include + +struct iommufd_ctx; +struct file; + +void iommufd_ctx_get(struct iommufd_ctx *ictx); + +#if IS_ENABLED(CONFIG_IOMMUFD) +struct iommufd_ctx *iommufd_ctx_from_file(struct file *file); +void iommufd_ctx_put(struct iommufd_ctx *ictx); +#else /* !CONFIG_IOMMUFD */ +static inline struct iommufd_ctx *iommufd_ctx_from_file(struct file *file) +{ + return ERR_PTR(-EOPNOTSUPP); +} + +static inline void iommufd_ctx_put(struct iommufd_ctx *ictx) +{ +} +#endif /* CONFIG_IOMMUFD */ +#endif diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h new file mode 100644 index 000000000000..37de92f0534b --- /dev/null +++ b/include/uapi/linux/iommufd.h @@ -0,0 +1,55 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES. + */ +#ifndef _UAPI_IOMMUFD_H +#define _UAPI_IOMMUFD_H + +#include +#include + +#define IOMMUFD_TYPE (';') + +/** + * DOC: General ioctl format + * + * The ioctl interface follows a general format to allow for extensibility. Each + * ioctl is passed in a structure pointer as the argument providing the size of + * the structure in the first u32. The kernel checks that any structure space + * beyond what it understands is 0. This allows userspace to use the backward + * compatible portion while consistently using the newer, larger, structures. + * + * ioctls use a standard meaning for common errnos: + * + * - ENOTTY: The IOCTL number itself is not supported at all + * - E2BIG: The IOCTL number is supported, but the provided structure has + * non-zero in a part the kernel does not understand. + * - EOPNOTSUPP: The IOCTL number is supported, and the structure is + * understood, however a known field has a value the kernel does not + * understand or support. + * - EINVAL: Everything about the IOCTL was understood, but a field is not + * correct. + * - ENOENT: An ID or IOVA provided does not exist. + * - ENOMEM: Out of memory. + * - EOVERFLOW: Mathematics overflowed. + * + * As well as additional errnos, within specific ioctls. + */ +enum { + IOMMUFD_CMD_BASE = 0x80, + IOMMUFD_CMD_DESTROY = IOMMUFD_CMD_BASE, +}; + +/** + * struct iommu_destroy - ioctl(IOMMU_DESTROY) + * @size: sizeof(struct iommu_destroy) + * @id: iommufd object ID to destroy. Can by any destroyable object type. + * + * Destroy any object held within iommufd. + */ +struct iommu_destroy { + __u32 size; + __u32 id; +}; +#define IOMMU_DESTROY _IO(IOMMUFD_TYPE, IOMMUFD_CMD_DESTROY) + +#endif -- cgit v1.2.3 From f394576eb11dbcd3a740fa41e577b97f0720d26e Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 29 Nov 2022 16:29:31 -0400 Subject: iommufd: PFN handling for iopt_pages The top of the data structure provides an IO Address Space (IOAS) that is similar to a VFIO container. The IOAS allows map/unmap of memory into ranges of IOVA called iopt_areas. Multiple IOMMU domains (IO page tables) and in-kernel accesses (like VFIO mdevs) can be attached to the IOAS to access the PFNs that those IOVA areas cover. The IO Address Space (IOAS) datastructure is composed of: - struct io_pagetable holding the IOVA map - struct iopt_areas representing populated portions of IOVA - struct iopt_pages representing the storage of PFNs - struct iommu_domain representing each IO page table in the system IOMMU - struct iopt_pages_access representing in-kernel accesses of PFNs (ie VFIO mdevs) - struct xarray pinned_pfns holding a list of pages pinned by in-kernel accesses This patch introduces the lowest part of the datastructure - the movement of PFNs in a tiered storage scheme: 1) iopt_pages::pinned_pfns xarray 2) Multiple iommu_domains 3) The origin of the PFNs, i.e. the userspace pointer PFN have to be copied between all combinations of tiers, depending on the configuration. The interface is an iterator called a 'pfn_reader' which determines which tier each PFN is stored and loads it into a list of PFNs held in a struct pfn_batch. Each step of the iterator will fill up the pfn_batch, then the caller can use the pfn_batch to send the PFNs to the required destination. Repeating this loop will read all the PFNs in an IOVA range. The pfn_reader and pfn_batch also keep track of the pinned page accounting. While PFNs are always stored and accessed as full PAGE_SIZE units the iommu_domain tier can store with a sub-page offset/length to support IOMMUs with a smaller IOPTE size than PAGE_SIZE. Link: https://lore.kernel.org/r/8-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Reviewed-by: Kevin Tian Tested-by: Nicolin Chen Tested-by: Yi Liu Tested-by: Lixiao Yang Tested-by: Matthew Rosato Signed-off-by: Jason Gunthorpe --- .clang-format | 1 + drivers/iommu/iommufd/Makefile | 3 +- drivers/iommu/iommufd/double_span.h | 53 ++ drivers/iommu/iommufd/io_pagetable.h | 109 ++++ drivers/iommu/iommufd/iommufd_private.h | 24 + drivers/iommu/iommufd/pages.c | 1066 +++++++++++++++++++++++++++++++ include/linux/iommufd.h | 7 + 7 files changed, 1262 insertions(+), 1 deletion(-) create mode 100644 drivers/iommu/iommufd/double_span.h create mode 100644 drivers/iommu/iommufd/io_pagetable.h create mode 100644 drivers/iommu/iommufd/pages.c (limited to 'drivers/iommu') diff --git a/.clang-format b/.clang-format index 96d07786dcfb..501241f89776 100644 --- a/.clang-format +++ b/.clang-format @@ -440,6 +440,7 @@ ForEachMacros: - 'inet_lhash2_for_each_icsk' - 'inet_lhash2_for_each_icsk_continue' - 'inet_lhash2_for_each_icsk_rcu' + - 'interval_tree_for_each_double_span' - 'interval_tree_for_each_span' - 'intlist__for_each_entry' - 'intlist__for_each_entry_safe' diff --git a/drivers/iommu/iommufd/Makefile b/drivers/iommu/iommufd/Makefile index a07a8cffe937..05a0e91e30af 100644 --- a/drivers/iommu/iommufd/Makefile +++ b/drivers/iommu/iommufd/Makefile @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0-only iommufd-y := \ - main.o + main.o \ + pages.o obj-$(CONFIG_IOMMUFD) += iommufd.o diff --git a/drivers/iommu/iommufd/double_span.h b/drivers/iommu/iommufd/double_span.h new file mode 100644 index 000000000000..b37aab7488c0 --- /dev/null +++ b/drivers/iommu/iommufd/double_span.h @@ -0,0 +1,53 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (c) 2022, NVIDIA CORPORATION & AFFILIATES. + */ +#ifndef __IOMMUFD_DOUBLE_SPAN_H +#define __IOMMUFD_DOUBLE_SPAN_H + +#include + +/* + * This is a variation of the general interval_tree_span_iter that computes the + * spans over the union of two different interval trees. Used ranges are broken + * up and reported based on the tree that provides the interval. The first span + * always takes priority. Like interval_tree_span_iter it is greedy and the same + * value of is_used will not repeat on two iteration cycles. + */ +struct interval_tree_double_span_iter { + struct rb_root_cached *itrees[2]; + struct interval_tree_span_iter spans[2]; + union { + unsigned long start_hole; + unsigned long start_used; + }; + union { + unsigned long last_hole; + unsigned long last_used; + }; + /* 0 = hole, 1 = used span[0], 2 = used span[1], -1 done iteration */ + int is_used; +}; + +void interval_tree_double_span_iter_update( + struct interval_tree_double_span_iter *iter); +void interval_tree_double_span_iter_first( + struct interval_tree_double_span_iter *iter, + struct rb_root_cached *itree1, struct rb_root_cached *itree2, + unsigned long first_index, unsigned long last_index); +void interval_tree_double_span_iter_next( + struct interval_tree_double_span_iter *iter); + +static inline bool +interval_tree_double_span_iter_done(struct interval_tree_double_span_iter *state) +{ + return state->is_used == -1; +} + +#define interval_tree_for_each_double_span(span, itree1, itree2, first_index, \ + last_index) \ + for (interval_tree_double_span_iter_first(span, itree1, itree2, \ + first_index, last_index); \ + !interval_tree_double_span_iter_done(span); \ + interval_tree_double_span_iter_next(span)) + +#endif diff --git a/drivers/iommu/iommufd/io_pagetable.h b/drivers/iommu/iommufd/io_pagetable.h new file mode 100644 index 000000000000..b74bf01ffc52 --- /dev/null +++ b/drivers/iommu/iommufd/io_pagetable.h @@ -0,0 +1,109 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES. + * + */ +#ifndef __IO_PAGETABLE_H +#define __IO_PAGETABLE_H + +#include +#include +#include +#include + +#include "iommufd_private.h" + +struct iommu_domain; + +/* + * Each io_pagetable is composed of intervals of areas which cover regions of + * the iova that are backed by something. iova not covered by areas is not + * populated in the page table. Each area is fully populated with pages. + * + * iovas are in byte units, but must be iopt->iova_alignment aligned. + * + * pages can be NULL, this means some other thread is still working on setting + * up or tearing down the area. When observed under the write side of the + * domain_rwsem a NULL pages must mean the area is still being setup and no + * domains are filled. + * + * storage_domain points at an arbitrary iommu_domain that is holding the PFNs + * for this area. It is locked by the pages->mutex. This simplifies the locking + * as the pages code can rely on the storage_domain without having to get the + * iopt->domains_rwsem. + * + * The io_pagetable::iova_rwsem protects node + * The iopt_pages::mutex protects pages_node + * iopt and immu_prot are immutable + * The pages::mutex protects num_accesses + */ +struct iopt_area { + struct interval_tree_node node; + struct interval_tree_node pages_node; + struct io_pagetable *iopt; + struct iopt_pages *pages; + struct iommu_domain *storage_domain; + /* How many bytes into the first page the area starts */ + unsigned int page_offset; + /* IOMMU_READ, IOMMU_WRITE, etc */ + int iommu_prot; + unsigned int num_accesses; +}; + +static inline unsigned long iopt_area_index(struct iopt_area *area) +{ + return area->pages_node.start; +} + +static inline unsigned long iopt_area_last_index(struct iopt_area *area) +{ + return area->pages_node.last; +} + +static inline unsigned long iopt_area_iova(struct iopt_area *area) +{ + return area->node.start; +} + +static inline unsigned long iopt_area_last_iova(struct iopt_area *area) +{ + return area->node.last; +} + +enum { + IOPT_PAGES_ACCOUNT_NONE = 0, + IOPT_PAGES_ACCOUNT_USER = 1, + IOPT_PAGES_ACCOUNT_MM = 2, +}; + +/* + * This holds a pinned page list for multiple areas of IO address space. The + * pages always originate from a linear chunk of userspace VA. Multiple + * io_pagetable's, through their iopt_area's, can share a single iopt_pages + * which avoids multi-pinning and double accounting of page consumption. + * + * indexes in this structure are measured in PAGE_SIZE units, are 0 based from + * the start of the uptr and extend to npages. pages are pinned dynamically + * according to the intervals in the access_itree and domains_itree, npinned + * records the current number of pages pinned. + */ +struct iopt_pages { + struct kref kref; + struct mutex mutex; + size_t npages; + size_t npinned; + size_t last_npinned; + struct task_struct *source_task; + struct mm_struct *source_mm; + struct user_struct *source_user; + void __user *uptr; + bool writable:1; + u8 account_mode; + + struct xarray pinned_pfns; + /* Of iopt_pages_access::node */ + struct rb_root_cached access_itree; + /* Of iopt_area::pages_node */ + struct rb_root_cached domains_itree; +}; + +#endif diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index bb720bc11317..169a30ff3bf0 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -14,6 +14,30 @@ struct iommufd_ctx { struct xarray objects; }; +/* + * The IOVA to PFN map. The map automatically copies the PFNs into multiple + * domains and permits sharing of PFNs between io_pagetable instances. This + * supports both a design where IOAS's are 1:1 with a domain (eg because the + * domain is HW customized), or where the IOAS is 1:N with multiple generic + * domains. The io_pagetable holds an interval tree of iopt_areas which point + * to shared iopt_pages which hold the pfns mapped to the page table. + * + * The locking order is domains_rwsem -> iova_rwsem -> pages::mutex + */ +struct io_pagetable { + struct rw_semaphore domains_rwsem; + struct xarray domains; + unsigned int next_domain_id; + + struct rw_semaphore iova_rwsem; + struct rb_root_cached area_itree; + /* IOVA that cannot become reserved, struct iopt_allowed */ + struct rb_root_cached allowed_itree; + /* IOVA that cannot be allocated, struct iopt_reserved */ + struct rb_root_cached reserved_itree; + u8 disable_large_pages; +}; + struct iommufd_ucmd { struct iommufd_ctx *ictx; void __user *ubuffer; diff --git a/drivers/iommu/iommufd/pages.c b/drivers/iommu/iommufd/pages.c new file mode 100644 index 000000000000..ebca78e743c6 --- /dev/null +++ b/drivers/iommu/iommufd/pages.c @@ -0,0 +1,1066 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES. + * + * The iopt_pages is the center of the storage and motion of PFNs. Each + * iopt_pages represents a logical linear array of full PFNs. The array is 0 + * based and has npages in it. Accessors use 'index' to refer to the entry in + * this logical array, regardless of its storage location. + * + * PFNs are stored in a tiered scheme: + * 1) iopt_pages::pinned_pfns xarray + * 2) An iommu_domain + * 3) The origin of the PFNs, i.e. the userspace pointer + * + * PFN have to be copied between all combinations of tiers, depending on the + * configuration. + * + * When a PFN is taken out of the userspace pointer it is pinned exactly once. + * The storage locations of the PFN's index are tracked in the two interval + * trees. If no interval includes the index then it is not pinned. + * + * If access_itree includes the PFN's index then an in-kernel access has + * requested the page. The PFN is stored in the xarray so other requestors can + * continue to find it. + * + * If the domains_itree includes the PFN's index then an iommu_domain is storing + * the PFN and it can be read back using iommu_iova_to_phys(). To avoid + * duplicating storage the xarray is not used if only iommu_domains are using + * the PFN's index. + * + * As a general principle this is designed so that destroy never fails. This + * means removing an iommu_domain or releasing a in-kernel access will not fail + * due to insufficient memory. In practice this means some cases have to hold + * PFNs in the xarray even though they are also being stored in an iommu_domain. + * + * While the iopt_pages can use an iommu_domain as storage, it does not have an + * IOVA itself. Instead the iopt_area represents a range of IOVA and uses the + * iopt_pages as the PFN provider. Multiple iopt_areas can share the iopt_pages + * and reference their own slice of the PFN array, with sub page granularity. + * + * In this file the term 'last' indicates an inclusive and closed interval, eg + * [0,0] refers to a single PFN. 'end' means an open range, eg [0,0) refers to + * no PFNs. + * + * Be cautious of overflow. An IOVA can go all the way up to U64_MAX, so + * last_iova + 1 can overflow. An iopt_pages index will always be much less than + * ULONG_MAX so last_index + 1 cannot overflow. + */ +#include +#include +#include +#include +#include +#include +#include + +#include "io_pagetable.h" +#include "double_span.h" + +#define TEMP_MEMORY_LIMIT 65536 +#define BATCH_BACKUP_SIZE 32 + +/* + * More memory makes pin_user_pages() and the batching more efficient, but as + * this is only a performance optimization don't try too hard to get it. A 64k + * allocation can hold about 26M of 4k pages and 13G of 2M pages in an + * pfn_batch. Various destroy paths cannot fail and provide a small amount of + * stack memory as a backup contingency. If backup_len is given this cannot + * fail. + */ +static void *temp_kmalloc(size_t *size, void *backup, size_t backup_len) +{ + void *res; + + if (WARN_ON(*size == 0)) + return NULL; + + if (*size < backup_len) + return backup; + *size = min_t(size_t, *size, TEMP_MEMORY_LIMIT); + res = kmalloc(*size, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY); + if (res) + return res; + *size = PAGE_SIZE; + if (backup_len) { + res = kmalloc(*size, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY); + if (res) + return res; + *size = backup_len; + return backup; + } + return kmalloc(*size, GFP_KERNEL); +} + +void interval_tree_double_span_iter_update( + struct interval_tree_double_span_iter *iter) +{ + unsigned long last_hole = ULONG_MAX; + unsigned int i; + + for (i = 0; i != ARRAY_SIZE(iter->spans); i++) { + if (interval_tree_span_iter_done(&iter->spans[i])) { + iter->is_used = -1; + return; + } + + if (iter->spans[i].is_hole) { + last_hole = min(last_hole, iter->spans[i].last_hole); + continue; + } + + iter->is_used = i + 1; + iter->start_used = iter->spans[i].start_used; + iter->last_used = min(iter->spans[i].last_used, last_hole); + return; + } + + iter->is_used = 0; + iter->start_hole = iter->spans[0].start_hole; + iter->last_hole = + min(iter->spans[0].last_hole, iter->spans[1].last_hole); +} + +void interval_tree_double_span_iter_first( + struct interval_tree_double_span_iter *iter, + struct rb_root_cached *itree1, struct rb_root_cached *itree2, + unsigned long first_index, unsigned long last_index) +{ + unsigned int i; + + iter->itrees[0] = itree1; + iter->itrees[1] = itree2; + for (i = 0; i != ARRAY_SIZE(iter->spans); i++) + interval_tree_span_iter_first(&iter->spans[i], iter->itrees[i], + first_index, last_index); + interval_tree_double_span_iter_update(iter); +} + +void interval_tree_double_span_iter_next( + struct interval_tree_double_span_iter *iter) +{ + unsigned int i; + + if (iter->is_used == -1 || + iter->last_hole == iter->spans[0].last_index) { + iter->is_used = -1; + return; + } + + for (i = 0; i != ARRAY_SIZE(iter->spans); i++) + interval_tree_span_iter_advance( + &iter->spans[i], iter->itrees[i], iter->last_hole + 1); + interval_tree_double_span_iter_update(iter); +} + +static void iopt_pages_add_npinned(struct iopt_pages *pages, size_t npages) +{ + pages->npinned += npages; +} + +static void iopt_pages_sub_npinned(struct iopt_pages *pages, size_t npages) +{ + pages->npinned -= npages; +} + +static void iopt_pages_err_unpin(struct iopt_pages *pages, + unsigned long start_index, + unsigned long last_index, + struct page **page_list) +{ + unsigned long npages = last_index - start_index + 1; + + unpin_user_pages(page_list, npages); + iopt_pages_sub_npinned(pages, npages); +} + +/* + * index is the number of PAGE_SIZE units from the start of the area's + * iopt_pages. If the iova is sub page-size then the area has an iova that + * covers a portion of the first and last pages in the range. + */ +static unsigned long iopt_area_index_to_iova(struct iopt_area *area, + unsigned long index) +{ + index -= iopt_area_index(area); + if (index == 0) + return iopt_area_iova(area); + return iopt_area_iova(area) - area->page_offset + index * PAGE_SIZE; +} + +static unsigned long iopt_area_index_to_iova_last(struct iopt_area *area, + unsigned long index) +{ + if (index == iopt_area_last_index(area)) + return iopt_area_last_iova(area); + return iopt_area_iova(area) - area->page_offset + + (index - iopt_area_index(area) + 1) * PAGE_SIZE - 1; +} + +static void iommu_unmap_nofail(struct iommu_domain *domain, unsigned long iova, + size_t size) +{ + size_t ret; + + ret = iommu_unmap(domain, iova, size); + /* + * It is a logic error in this code or a driver bug if the IOMMU unmaps + * something other than exactly as requested. This implies that the + * iommu driver may not fail unmap for reasons beyond bad agruments. + * Particularly, the iommu driver may not do a memory allocation on the + * unmap path. + */ + WARN_ON(ret != size); +} + +static struct iopt_area *iopt_pages_find_domain_area(struct iopt_pages *pages, + unsigned long index) +{ + struct interval_tree_node *node; + + node = interval_tree_iter_first(&pages->domains_itree, index, index); + if (!node) + return NULL; + return container_of(node, struct iopt_area, pages_node); +} + +/* + * A simple datastructure to hold a vector of PFNs, optimized for contiguous + * PFNs. This is used as a temporary holding memory for shuttling pfns from one + * place to another. Generally everything is made more efficient if operations + * work on the largest possible grouping of pfns. eg fewer lock/unlock cycles, + * better cache locality, etc + */ +struct pfn_batch { + unsigned long *pfns; + u32 *npfns; + unsigned int array_size; + unsigned int end; + unsigned int total_pfns; +}; + +static void batch_clear(struct pfn_batch *batch) +{ + batch->total_pfns = 0; + batch->end = 0; + batch->pfns[0] = 0; + batch->npfns[0] = 0; +} + +/* + * Carry means we carry a portion of the final hugepage over to the front of the + * batch + */ +static void batch_clear_carry(struct pfn_batch *batch, unsigned int keep_pfns) +{ + if (!keep_pfns) + return batch_clear(batch); + + batch->total_pfns = keep_pfns; + batch->npfns[0] = keep_pfns; + batch->pfns[0] = batch->pfns[batch->end - 1] + + (batch->npfns[batch->end - 1] - keep_pfns); + batch->end = 0; +} + +static void batch_skip_carry(struct pfn_batch *batch, unsigned int skip_pfns) +{ + if (!batch->total_pfns) + return; + skip_pfns = min(batch->total_pfns, skip_pfns); + batch->pfns[0] += skip_pfns; + batch->npfns[0] -= skip_pfns; + batch->total_pfns -= skip_pfns; +} + +static int __batch_init(struct pfn_batch *batch, size_t max_pages, void *backup, + size_t backup_len) +{ + const size_t elmsz = sizeof(*batch->pfns) + sizeof(*batch->npfns); + size_t size = max_pages * elmsz; + + batch->pfns = temp_kmalloc(&size, backup, backup_len); + if (!batch->pfns) + return -ENOMEM; + batch->array_size = size / elmsz; + batch->npfns = (u32 *)(batch->pfns + batch->array_size); + batch_clear(batch); + return 0; +} + +static int batch_init(struct pfn_batch *batch, size_t max_pages) +{ + return __batch_init(batch, max_pages, NULL, 0); +} + +static void batch_init_backup(struct pfn_batch *batch, size_t max_pages, + void *backup, size_t backup_len) +{ + __batch_init(batch, max_pages, backup, backup_len); +} + +static void batch_destroy(struct pfn_batch *batch, void *backup) +{ + if (batch->pfns != backup) + kfree(batch->pfns); +} + +/* true if the pfn could be added, false otherwise */ +static bool batch_add_pfn(struct pfn_batch *batch, unsigned long pfn) +{ + const unsigned int MAX_NPFNS = type_max(typeof(*batch->npfns)); + + if (batch->end && + pfn == batch->pfns[batch->end - 1] + batch->npfns[batch->end - 1] && + batch->npfns[batch->end - 1] != MAX_NPFNS) { + batch->npfns[batch->end - 1]++; + batch->total_pfns++; + return true; + } + if (batch->end == batch->array_size) + return false; + batch->total_pfns++; + batch->pfns[batch->end] = pfn; + batch->npfns[batch->end] = 1; + batch->end++; + return true; +} + +/* + * Fill the batch with pfns from the domain. When the batch is full, or it + * reaches last_index, the function will return. The caller should use + * batch->total_pfns to determine the starting point for the next iteration. + */ +static void batch_from_domain(struct pfn_batch *batch, + struct iommu_domain *domain, + struct iopt_area *area, unsigned long start_index, + unsigned long last_index) +{ + unsigned int page_offset = 0; + unsigned long iova; + phys_addr_t phys; + + iova = iopt_area_index_to_iova(area, start_index); + if (start_index == iopt_area_index(area)) + page_offset = area->page_offset; + while (start_index <= last_index) { + /* + * This is pretty slow, it would be nice to get the page size + * back from the driver, or have the driver directly fill the + * batch. + */ + phys = iommu_iova_to_phys(domain, iova) - page_offset; + if (!batch_add_pfn(batch, PHYS_PFN(phys))) + return; + iova += PAGE_SIZE - page_offset; + page_offset = 0; + start_index++; + } +} + +static struct page **raw_pages_from_domain(struct iommu_domain *domain, + struct iopt_area *area, + unsigned long start_index, + unsigned long last_index, + struct page **out_pages) +{ + unsigned int page_offset = 0; + unsigned long iova; + phys_addr_t phys; + + iova = iopt_area_index_to_iova(area, start_index); + if (start_index == iopt_area_index(area)) + page_offset = area->page_offset; + while (start_index <= last_index) { + phys = iommu_iova_to_phys(domain, iova) - page_offset; + *(out_pages++) = pfn_to_page(PHYS_PFN(phys)); + iova += PAGE_SIZE - page_offset; + page_offset = 0; + start_index++; + } + return out_pages; +} + +/* Continues reading a domain until we reach a discontiguity in the pfns. */ +static void batch_from_domain_continue(struct pfn_batch *batch, + struct iommu_domain *domain, + struct iopt_area *area, + unsigned long start_index, + unsigned long last_index) +{ + unsigned int array_size = batch->array_size; + + batch->array_size = batch->end; + batch_from_domain(batch, domain, area, start_index, last_index); + batch->array_size = array_size; +} + +/* + * This is part of the VFIO compatibility support for VFIO_TYPE1_IOMMU. That + * mode permits splitting a mapped area up, and then one of the splits is + * unmapped. Doing this normally would cause us to violate our invariant of + * pairing map/unmap. Thus, to support old VFIO compatibility disable support + * for batching consecutive PFNs. All PFNs mapped into the iommu are done in + * PAGE_SIZE units, not larger or smaller. + */ +static int batch_iommu_map_small(struct iommu_domain *domain, + unsigned long iova, phys_addr_t paddr, + size_t size, int prot) +{ + unsigned long start_iova = iova; + int rc; + + while (size) { + rc = iommu_map(domain, iova, paddr, PAGE_SIZE, prot); + if (rc) + goto err_unmap; + iova += PAGE_SIZE; + paddr += PAGE_SIZE; + size -= PAGE_SIZE; + } + return 0; + +err_unmap: + if (start_iova != iova) + iommu_unmap_nofail(domain, start_iova, iova - start_iova); + return rc; +} + +static int batch_to_domain(struct pfn_batch *batch, struct iommu_domain *domain, + struct iopt_area *area, unsigned long start_index) +{ + bool disable_large_pages = area->iopt->disable_large_pages; + unsigned long last_iova = iopt_area_last_iova(area); + unsigned int page_offset = 0; + unsigned long start_iova; + unsigned long next_iova; + unsigned int cur = 0; + unsigned long iova; + int rc; + + /* The first index might be a partial page */ + if (start_index == iopt_area_index(area)) + page_offset = area->page_offset; + next_iova = iova = start_iova = + iopt_area_index_to_iova(area, start_index); + while (cur < batch->end) { + next_iova = min(last_iova + 1, + next_iova + batch->npfns[cur] * PAGE_SIZE - + page_offset); + if (disable_large_pages) + rc = batch_iommu_map_small( + domain, iova, + PFN_PHYS(batch->pfns[cur]) + page_offset, + next_iova - iova, area->iommu_prot); + else + rc = iommu_map(domain, iova, + PFN_PHYS(batch->pfns[cur]) + page_offset, + next_iova - iova, area->iommu_prot); + if (rc) + goto err_unmap; + iova = next_iova; + page_offset = 0; + cur++; + } + return 0; +err_unmap: + if (start_iova != iova) + iommu_unmap_nofail(domain, start_iova, iova - start_iova); + return rc; +} + +static void batch_from_xarray(struct pfn_batch *batch, struct xarray *xa, + unsigned long start_index, + unsigned long last_index) +{ + XA_STATE(xas, xa, start_index); + void *entry; + + rcu_read_lock(); + while (true) { + entry = xas_next(&xas); + if (xas_retry(&xas, entry)) + continue; + WARN_ON(!xa_is_value(entry)); + if (!batch_add_pfn(batch, xa_to_value(entry)) || + start_index == last_index) + break; + start_index++; + } + rcu_read_unlock(); +} + +static void batch_from_xarray_clear(struct pfn_batch *batch, struct xarray *xa, + unsigned long start_index, + unsigned long last_index) +{ + XA_STATE(xas, xa, start_index); + void *entry; + + xas_lock(&xas); + while (true) { + entry = xas_next(&xas); + if (xas_retry(&xas, entry)) + continue; + WARN_ON(!xa_is_value(entry)); + if (!batch_add_pfn(batch, xa_to_value(entry))) + break; + xas_store(&xas, NULL); + if (start_index == last_index) + break; + start_index++; + } + xas_unlock(&xas); +} + +static void clear_xarray(struct xarray *xa, unsigned long start_index, + unsigned long last_index) +{ + XA_STATE(xas, xa, start_index); + void *entry; + + xas_lock(&xas); + xas_for_each(&xas, entry, last_index) + xas_store(&xas, NULL); + xas_unlock(&xas); +} + +static int pages_to_xarray(struct xarray *xa, unsigned long start_index, + unsigned long last_index, struct page **pages) +{ + struct page **end_pages = pages + (last_index - start_index) + 1; + XA_STATE(xas, xa, start_index); + + do { + void *old; + + xas_lock(&xas); + while (pages != end_pages) { + old = xas_store(&xas, xa_mk_value(page_to_pfn(*pages))); + if (xas_error(&xas)) + break; + WARN_ON(old); + pages++; + xas_next(&xas); + } + xas_unlock(&xas); + } while (xas_nomem(&xas, GFP_KERNEL)); + + if (xas_error(&xas)) { + if (xas.xa_index != start_index) + clear_xarray(xa, start_index, xas.xa_index - 1); + return xas_error(&xas); + } + return 0; +} + +static void batch_from_pages(struct pfn_batch *batch, struct page **pages, + size_t npages) +{ + struct page **end = pages + npages; + + for (; pages != end; pages++) + if (!batch_add_pfn(batch, page_to_pfn(*pages))) + break; +} + +static void batch_unpin(struct pfn_batch *batch, struct iopt_pages *pages, + unsigned int first_page_off, size_t npages) +{ + unsigned int cur = 0; + + while (first_page_off) { + if (batch->npfns[cur] > first_page_off) + break; + first_page_off -= batch->npfns[cur]; + cur++; + } + + while (npages) { + size_t to_unpin = min_t(size_t, npages, + batch->npfns[cur] - first_page_off); + + unpin_user_page_range_dirty_lock( + pfn_to_page(batch->pfns[cur] + first_page_off), + to_unpin, pages->writable); + iopt_pages_sub_npinned(pages, to_unpin); + cur++; + first_page_off = 0; + npages -= to_unpin; + } +} + +static void copy_data_page(struct page *page, void *data, unsigned long offset, + size_t length, unsigned int flags) +{ + void *mem; + + mem = kmap_local_page(page); + if (flags & IOMMUFD_ACCESS_RW_WRITE) { + memcpy(mem + offset, data, length); + set_page_dirty_lock(page); + } else { + memcpy(data, mem + offset, length); + } + kunmap_local(mem); +} + +static unsigned long batch_rw(struct pfn_batch *batch, void *data, + unsigned long offset, unsigned long length, + unsigned int flags) +{ + unsigned long copied = 0; + unsigned int npage = 0; + unsigned int cur = 0; + + while (cur < batch->end) { + unsigned long bytes = min(length, PAGE_SIZE - offset); + + copy_data_page(pfn_to_page(batch->pfns[cur] + npage), data, + offset, bytes, flags); + offset = 0; + length -= bytes; + data += bytes; + copied += bytes; + npage++; + if (npage == batch->npfns[cur]) { + npage = 0; + cur++; + } + if (!length) + break; + } + return copied; +} + +/* pfn_reader_user is just the pin_user_pages() path */ +struct pfn_reader_user { + struct page **upages; + size_t upages_len; + unsigned long upages_start; + unsigned long upages_end; + unsigned int gup_flags; + /* + * 1 means mmget() and mmap_read_lock(), 0 means only mmget(), -1 is + * neither + */ + int locked; +}; + +static void pfn_reader_user_init(struct pfn_reader_user *user, + struct iopt_pages *pages) +{ + user->upages = NULL; + user->upages_start = 0; + user->upages_end = 0; + user->locked = -1; + + if (pages->writable) { + user->gup_flags = FOLL_LONGTERM | FOLL_WRITE; + } else { + /* Still need to break COWs on read */ + user->gup_flags = FOLL_LONGTERM | FOLL_FORCE | FOLL_WRITE; + } +} + +static void pfn_reader_user_destroy(struct pfn_reader_user *user, + struct iopt_pages *pages) +{ + if (user->locked != -1) { + if (user->locked) + mmap_read_unlock(pages->source_mm); + if (pages->source_mm != current->mm) + mmput(pages->source_mm); + user->locked = 0; + } + + kfree(user->upages); + user->upages = NULL; +} + +static int pfn_reader_user_pin(struct pfn_reader_user *user, + struct iopt_pages *pages, + unsigned long start_index, + unsigned long last_index) +{ + bool remote_mm = pages->source_mm != current->mm; + unsigned long npages; + uintptr_t uptr; + long rc; + + if (!user->upages) { + /* All undone in pfn_reader_destroy() */ + user->upages_len = + (last_index - start_index + 1) * sizeof(*user->upages); + user->upages = temp_kmalloc(&user->upages_len, NULL, 0); + if (!user->upages) + return -ENOMEM; + } + + if (user->locked == -1) { + /* + * The majority of usages will run the map task within the mm + * providing the pages, so we can optimize into + * get_user_pages_fast() + */ + if (remote_mm) { + if (!mmget_not_zero(pages->source_mm)) + return -EFAULT; + } + user->locked = 0; + } + + npages = min_t(unsigned long, last_index - start_index + 1, + user->upages_len / sizeof(*user->upages)); + + uptr = (uintptr_t)(pages->uptr + start_index * PAGE_SIZE); + if (!remote_mm) + rc = pin_user_pages_fast(uptr, npages, user->gup_flags, + user->upages); + else { + if (!user->locked) { + mmap_read_lock(pages->source_mm); + user->locked = 1; + } + /* + * FIXME: last NULL can be &pfns->locked once the GUP patch + * is merged. + */ + rc = pin_user_pages_remote(pages->source_mm, uptr, npages, + user->gup_flags, user->upages, NULL, + NULL); + } + if (rc <= 0) { + if (WARN_ON(!rc)) + return -EFAULT; + return rc; + } + iopt_pages_add_npinned(pages, rc); + user->upages_start = start_index; + user->upages_end = start_index + rc; + return 0; +} + +/* This is the "modern" and faster accounting method used by io_uring */ +static int incr_user_locked_vm(struct iopt_pages *pages, unsigned long npages) +{ + unsigned long lock_limit; + unsigned long cur_pages; + unsigned long new_pages; + + lock_limit = task_rlimit(pages->source_task, RLIMIT_MEMLOCK) >> + PAGE_SHIFT; + npages = pages->npinned - pages->last_npinned; + do { + cur_pages = atomic_long_read(&pages->source_user->locked_vm); + new_pages = cur_pages + npages; + if (new_pages > lock_limit) + return -ENOMEM; + } while (atomic_long_cmpxchg(&pages->source_user->locked_vm, cur_pages, + new_pages) != cur_pages); + return 0; +} + +static void decr_user_locked_vm(struct iopt_pages *pages, unsigned long npages) +{ + if (WARN_ON(atomic_long_read(&pages->source_user->locked_vm) < npages)) + return; + atomic_long_sub(npages, &pages->source_user->locked_vm); +} + +/* This is the accounting method used for compatibility with VFIO */ +static int update_mm_locked_vm(struct iopt_pages *pages, unsigned long npages, + bool inc, struct pfn_reader_user *user) +{ + bool do_put = false; + int rc; + + if (user && user->locked) { + mmap_read_unlock(pages->source_mm); + user->locked = 0; + /* If we had the lock then we also have a get */ + } else if ((!user || !user->upages) && + pages->source_mm != current->mm) { + if (!mmget_not_zero(pages->source_mm)) + return -EINVAL; + do_put = true; + } + + mmap_write_lock(pages->source_mm); + rc = __account_locked_vm(pages->source_mm, npages, inc, + pages->source_task, false); + mmap_write_unlock(pages->source_mm); + + if (do_put) + mmput(pages->source_mm); + return rc; +} + +static int do_update_pinned(struct iopt_pages *pages, unsigned long npages, + bool inc, struct pfn_reader_user *user) +{ + int rc = 0; + + switch (pages->account_mode) { + case IOPT_PAGES_ACCOUNT_NONE: + break; + case IOPT_PAGES_ACCOUNT_USER: + if (inc) + rc = incr_user_locked_vm(pages, npages); + else + decr_user_locked_vm(pages, npages); + break; + case IOPT_PAGES_ACCOUNT_MM: + rc = update_mm_locked_vm(pages, npages, inc, user); + break; + } + if (rc) + return rc; + + pages->last_npinned = pages->npinned; + if (inc) + atomic64_add(npages, &pages->source_mm->pinned_vm); + else + atomic64_sub(npages, &pages->source_mm->pinned_vm); + return 0; +} + +static void update_unpinned(struct iopt_pages *pages) +{ + if (WARN_ON(pages->npinned > pages->last_npinned)) + return; + if (pages->npinned == pages->last_npinned) + return; + do_update_pinned(pages, pages->last_npinned - pages->npinned, false, + NULL); +} + +/* + * Changes in the number of pages pinned is done after the pages have been read + * and processed. If the user lacked the limit then the error unwind will unpin + * everything that was just pinned. This is because it is expensive to calculate + * how many pages we have already pinned within a range to generate an accurate + * prediction in advance of doing the work to actually pin them. + */ +static int pfn_reader_user_update_pinned(struct pfn_reader_user *user, + struct iopt_pages *pages) +{ + unsigned long npages; + bool inc; + + lockdep_assert_held(&pages->mutex); + + if (pages->npinned == pages->last_npinned) + return 0; + + if (pages->npinned < pages->last_npinned) { + npages = pages->last_npinned - pages->npinned; + inc = false; + } else { + npages = pages->npinned - pages->last_npinned; + inc = true; + } + return do_update_pinned(pages, npages, inc, user); +} + +/* + * PFNs are stored in three places, in order of preference: + * - The iopt_pages xarray. This is only populated if there is a + * iopt_pages_access + * - The iommu_domain under an area + * - The original PFN source, ie pages->source_mm + * + * This iterator reads the pfns optimizing to load according to the + * above order. + */ +struct pfn_reader { + struct iopt_pages *pages; + struct interval_tree_double_span_iter span; + struct pfn_batch batch; + unsigned long batch_start_index; + unsigned long batch_end_index; + unsigned long last_index; + + struct pfn_reader_user user; +}; + +static int pfn_reader_update_pinned(struct pfn_reader *pfns) +{ + return pfn_reader_user_update_pinned(&pfns->user, pfns->pages); +} + +/* + * The batch can contain a mixture of pages that are still in use and pages that + * need to be unpinned. Unpin only pages that are not held anywhere else. + */ +static void pfn_reader_unpin(struct pfn_reader *pfns) +{ + unsigned long last = pfns->batch_end_index - 1; + unsigned long start = pfns->batch_start_index; + struct interval_tree_double_span_iter span; + struct iopt_pages *pages = pfns->pages; + + lockdep_assert_held(&pages->mutex); + + interval_tree_for_each_double_span(&span, &pages->access_itree, + &pages->domains_itree, start, last) { + if (span.is_used) + continue; + + batch_unpin(&pfns->batch, pages, span.start_hole - start, + span.last_hole - span.start_hole + 1); + } +} + +/* Process a single span to load it from the proper storage */ +static int pfn_reader_fill_span(struct pfn_reader *pfns) +{ + struct interval_tree_double_span_iter *span = &pfns->span; + unsigned long start_index = pfns->batch_end_index; + struct iopt_area *area; + int rc; + + if (span->is_used == 1) { + batch_from_xarray(&pfns->batch, &pfns->pages->pinned_pfns, + start_index, span->last_used); + return 0; + } + + if (span->is_used == 2) { + /* + * Pull as many pages from the first domain we find in the + * target span. If it is too small then we will be called again + * and we'll find another area. + */ + area = iopt_pages_find_domain_area(pfns->pages, start_index); + if (WARN_ON(!area)) + return -EINVAL; + + /* The storage_domain cannot change without the pages mutex */ + batch_from_domain( + &pfns->batch, area->storage_domain, area, start_index, + min(iopt_area_last_index(area), span->last_used)); + return 0; + } + + if (start_index >= pfns->user.upages_end) { + rc = pfn_reader_user_pin(&pfns->user, pfns->pages, start_index, + span->last_hole); + if (rc) + return rc; + } + + batch_from_pages(&pfns->batch, + pfns->user.upages + + (start_index - pfns->user.upages_start), + pfns->user.upages_end - start_index); + return 0; +} + +static bool pfn_reader_done(struct pfn_reader *pfns) +{ + return pfns->batch_start_index == pfns->last_index + 1; +} + +static int pfn_reader_next(struct pfn_reader *pfns) +{ + int rc; + + batch_clear(&pfns->batch); + pfns->batch_start_index = pfns->batch_end_index; + + while (pfns->batch_end_index != pfns->last_index + 1) { + unsigned int npfns = pfns->batch.total_pfns; + + rc = pfn_reader_fill_span(pfns); + if (rc) + return rc; + + if (WARN_ON(!pfns->batch.total_pfns)) + return -EINVAL; + + pfns->batch_end_index = + pfns->batch_start_index + pfns->batch.total_pfns; + if (pfns->batch_end_index == pfns->span.last_used + 1) + interval_tree_double_span_iter_next(&pfns->span); + + /* Batch is full */ + if (npfns == pfns->batch.total_pfns) + return 0; + } + return 0; +} + +static int pfn_reader_init(struct pfn_reader *pfns, struct iopt_pages *pages, + unsigned long start_index, unsigned long last_index) +{ + int rc; + + lockdep_assert_held(&pages->mutex); + + pfns->pages = pages; + pfns->batch_start_index = start_index; + pfns->batch_end_index = start_index; + pfns->last_index = last_index; + pfn_reader_user_init(&pfns->user, pages); + rc = batch_init(&pfns->batch, last_index - start_index + 1); + if (rc) + return rc; + interval_tree_double_span_iter_first(&pfns->span, &pages->access_itree, + &pages->domains_itree, start_index, + last_index); + return 0; +} + +/* + * There are many assertions regarding the state of pages->npinned vs + * pages->last_pinned, for instance something like unmapping a domain must only + * decrement the npinned, and pfn_reader_destroy() must be called only after all + * the pins are updated. This is fine for success flows, but error flows + * sometimes need to release the pins held inside the pfn_reader before going on + * to complete unmapping and releasing pins held in domains. + */ +static void pfn_reader_release_pins(struct pfn_reader *pfns) +{ + struct iopt_pages *pages = pfns->pages; + + if (pfns->user.upages_end > pfns->batch_end_index) { + size_t npages = pfns->user.upages_end - pfns->batch_end_index; + + /* Any pages not transferred to the batch are just unpinned */ + unpin_user_pages(pfns->user.upages + (pfns->batch_end_index - + pfns->user.upages_start), + npages); + iopt_pages_sub_npinned(pages, npages); + pfns->user.upages_end = pfns->batch_end_index; + } + if (pfns->batch_start_index != pfns->batch_end_index) { + pfn_reader_unpin(pfns); + pfns->batch_start_index = pfns->batch_end_index; + } +} + +static void pfn_reader_destroy(struct pfn_reader *pfns) +{ + struct iopt_pages *pages = pfns->pages; + + pfn_reader_release_pins(pfns); + pfn_reader_user_destroy(&pfns->user, pfns->pages); + batch_destroy(&pfns->batch, NULL); + WARN_ON(pages->last_npinned != pages->npinned); +} + +static int pfn_reader_first(struct pfn_reader *pfns, struct iopt_pages *pages, + unsigned long start_index, unsigned long last_index) +{ + int rc; + + rc = pfn_reader_init(pfns, pages, start_index, last_index); + if (rc) + return rc; + rc = pfn_reader_next(pfns); + if (rc) { + pfn_reader_destroy(pfns); + return rc; + } + return 0; +} diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h index d1817472c273..26e09d539737 100644 --- a/include/linux/iommufd.h +++ b/include/linux/iommufd.h @@ -13,6 +13,13 @@ struct iommufd_ctx; struct file; +enum { + IOMMUFD_ACCESS_RW_READ = 0, + IOMMUFD_ACCESS_RW_WRITE = 1 << 0, + /* Set if the caller is in a kthread then rw will use kthread_use_mm() */ + IOMMUFD_ACCESS_RW_KTHREAD = 1 << 1, +}; + void iommufd_ctx_get(struct iommufd_ctx *ictx); #if IS_ENABLED(CONFIG_IOMMUFD) -- cgit v1.2.3 From 8d160cd4d5066f864ec0f2c981470e55ac03ac27 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 29 Nov 2022 16:29:32 -0400 Subject: iommufd: Algorithms for PFN storage The iopt_pages which represents a logical linear list of full PFNs held in different storage tiers. Each area points to a slice of exactly one iopt_pages, and each iopt_pages can have multiple areas and accesses. The three storage tiers are managed to meet these objectives: - If no iommu_domain or in-kerenel access exists then minimal memory should be consumed by iomufd - If a page has been pinned then an iopt_pages will not pin it again - If an in-kernel access exists then the xarray must provide the backing storage to avoid allocations on domain removals - Otherwise any iommu_domain will be used for storage In a common configuration with only an iommu_domain the iopt_pages does not allocate significant memory itself. The external interface for pages has several logical operations: iopt_area_fill_domain() will load the PFNs from storage into a single domain. This is used when attaching a new domain to an existing IOAS. iopt_area_fill_domains() will load the PFNs from storage into multiple domains. This is used when creating a new IOVA map in an existing IOAS iopt_pages_add_access() creates an iopt_pages_access that tracks an in-kernel access of PFNs. This is some external driver that might be accessing the IOVA using the CPU, or programming PFNs with the DMA API. ie a VFIO mdev. iopt_pages_rw_access() directly perform a memcpy on the PFNs, without the overhead of iopt_pages_add_access() iopt_pages_fill_xarray() will load PFNs into the xarray and return a 'struct page *' array. It is used by iopt_pages_access's to extract PFNs for in-kernel use. iopt_pages_fill_from_xarray() is a fast path when it is known the xarray is already filled. As an iopt_pages can be referred to in slices by many areas and accesses it uses interval trees to keep track of which storage tiers currently hold the PFNs. On a page-by-page basis any request for a PFN will be satisfied from one of the storage tiers and the PFN copied to target domain/array. Unfill actions are similar, on a page by page basis domains are unmapped, xarray entries freed or struct pages fully put back. Significant complexity is required to fully optimize all of these data motions. The implementation calculates the largest consecutive range of same-storage indexes and operates in blocks. The accumulation of PFNs always generates the largest contiguous PFN range possible to optimize and this gathering can cross storage tier boundaries. For cases like 'fill domains' care is taken to avoid duplicated work and PFNs are read once and pushed into all domains. The map/unmap interaction with the iommu_domain always works in contiguous PFN blocks. The implementation does not require or benefit from any split/merge optimization in the iommu_domain driver. This design suggests several possible improvements in the IOMMU API that would greatly help performance, particularly a way for the driver to map and read the pfns lists instead of working with one driver call per page to read, and one driver call per contiguous range to store. Link: https://lore.kernel.org/r/9-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Reviewed-by: Kevin Tian Tested-by: Nicolin Chen Tested-by: Yi Liu Tested-by: Lixiao Yang Tested-by: Matthew Rosato Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/io_pagetable.h | 74 +++ drivers/iommu/iommufd/pages.c | 843 +++++++++++++++++++++++++++++++++++ 2 files changed, 917 insertions(+) (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommufd/io_pagetable.h b/drivers/iommu/iommufd/io_pagetable.h index b74bf01ffc52..a2b724175057 100644 --- a/drivers/iommu/iommufd/io_pagetable.h +++ b/drivers/iommu/iommufd/io_pagetable.h @@ -49,6 +49,15 @@ struct iopt_area { unsigned int num_accesses; }; +int iopt_area_fill_domains(struct iopt_area *area, struct iopt_pages *pages); +void iopt_area_unfill_domains(struct iopt_area *area, struct iopt_pages *pages); + +int iopt_area_fill_domain(struct iopt_area *area, struct iommu_domain *domain); +void iopt_area_unfill_domain(struct iopt_area *area, struct iopt_pages *pages, + struct iommu_domain *domain); +void iopt_area_unmap_domain(struct iopt_area *area, + struct iommu_domain *domain); + static inline unsigned long iopt_area_index(struct iopt_area *area) { return area->pages_node.start; @@ -69,6 +78,39 @@ static inline unsigned long iopt_area_last_iova(struct iopt_area *area) return area->node.last; } +static inline size_t iopt_area_length(struct iopt_area *area) +{ + return (area->node.last - area->node.start) + 1; +} + +#define __make_iopt_iter(name) \ + static inline struct iopt_##name *iopt_##name##_iter_first( \ + struct io_pagetable *iopt, unsigned long start, \ + unsigned long last) \ + { \ + struct interval_tree_node *node; \ + \ + lockdep_assert_held(&iopt->iova_rwsem); \ + node = interval_tree_iter_first(&iopt->name##_itree, start, \ + last); \ + if (!node) \ + return NULL; \ + return container_of(node, struct iopt_##name, node); \ + } \ + static inline struct iopt_##name *iopt_##name##_iter_next( \ + struct iopt_##name *last_node, unsigned long start, \ + unsigned long last) \ + { \ + struct interval_tree_node *node; \ + \ + node = interval_tree_iter_next(&last_node->node, start, last); \ + if (!node) \ + return NULL; \ + return container_of(node, struct iopt_##name, node); \ + } + +__make_iopt_iter(area) + enum { IOPT_PAGES_ACCOUNT_NONE = 0, IOPT_PAGES_ACCOUNT_USER = 1, @@ -106,4 +148,36 @@ struct iopt_pages { struct rb_root_cached domains_itree; }; +struct iopt_pages *iopt_alloc_pages(void __user *uptr, unsigned long length, + bool writable); +void iopt_release_pages(struct kref *kref); +static inline void iopt_put_pages(struct iopt_pages *pages) +{ + kref_put(&pages->kref, iopt_release_pages); +} + +void iopt_pages_fill_from_xarray(struct iopt_pages *pages, unsigned long start, + unsigned long last, struct page **out_pages); +int iopt_pages_fill_xarray(struct iopt_pages *pages, unsigned long start, + unsigned long last, struct page **out_pages); +void iopt_pages_unfill_xarray(struct iopt_pages *pages, unsigned long start, + unsigned long last); + +int iopt_area_add_access(struct iopt_area *area, unsigned long start, + unsigned long last, struct page **out_pages, + unsigned int flags); +void iopt_area_remove_access(struct iopt_area *area, unsigned long start, + unsigned long last); +int iopt_pages_rw_access(struct iopt_pages *pages, unsigned long start_byte, + void *data, unsigned long length, unsigned int flags); + +/* + * Each interval represents an active iopt_access_pages(), it acts as an + * interval lock that keeps the PFNs pinned and stored in the xarray. + */ +struct iopt_pages_access { + struct interval_tree_node node; + unsigned int users; +}; + #endif diff --git a/drivers/iommu/iommufd/pages.c b/drivers/iommu/iommufd/pages.c index ebca78e743c6..bafeee9d73e8 100644 --- a/drivers/iommu/iommufd/pages.c +++ b/drivers/iommu/iommufd/pages.c @@ -212,6 +212,18 @@ static void iommu_unmap_nofail(struct iommu_domain *domain, unsigned long iova, WARN_ON(ret != size); } +static void iopt_area_unmap_domain_range(struct iopt_area *area, + struct iommu_domain *domain, + unsigned long start_index, + unsigned long last_index) +{ + unsigned long start_iova = iopt_area_index_to_iova(area, start_index); + + iommu_unmap_nofail(domain, start_iova, + iopt_area_index_to_iova_last(area, last_index) - + start_iova + 1); +} + static struct iopt_area *iopt_pages_find_domain_area(struct iopt_pages *pages, unsigned long index) { @@ -1064,3 +1076,834 @@ static int pfn_reader_first(struct pfn_reader *pfns, struct iopt_pages *pages, } return 0; } + +struct iopt_pages *iopt_alloc_pages(void __user *uptr, unsigned long length, + bool writable) +{ + struct iopt_pages *pages; + + /* + * The iommu API uses size_t as the length, and protect the DIV_ROUND_UP + * below from overflow + */ + if (length > SIZE_MAX - PAGE_SIZE || length == 0) + return ERR_PTR(-EINVAL); + + pages = kzalloc(sizeof(*pages), GFP_KERNEL_ACCOUNT); + if (!pages) + return ERR_PTR(-ENOMEM); + + kref_init(&pages->kref); + xa_init_flags(&pages->pinned_pfns, XA_FLAGS_ACCOUNT); + mutex_init(&pages->mutex); + pages->source_mm = current->mm; + mmgrab(pages->source_mm); + pages->uptr = (void __user *)ALIGN_DOWN((uintptr_t)uptr, PAGE_SIZE); + pages->npages = DIV_ROUND_UP(length + (uptr - pages->uptr), PAGE_SIZE); + pages->access_itree = RB_ROOT_CACHED; + pages->domains_itree = RB_ROOT_CACHED; + pages->writable = writable; + if (capable(CAP_IPC_LOCK)) + pages->account_mode = IOPT_PAGES_ACCOUNT_NONE; + else + pages->account_mode = IOPT_PAGES_ACCOUNT_USER; + pages->source_task = current->group_leader; + get_task_struct(current->group_leader); + pages->source_user = get_uid(current_user()); + return pages; +} + +void iopt_release_pages(struct kref *kref) +{ + struct iopt_pages *pages = container_of(kref, struct iopt_pages, kref); + + WARN_ON(!RB_EMPTY_ROOT(&pages->access_itree.rb_root)); + WARN_ON(!RB_EMPTY_ROOT(&pages->domains_itree.rb_root)); + WARN_ON(pages->npinned); + WARN_ON(!xa_empty(&pages->pinned_pfns)); + mmdrop(pages->source_mm); + mutex_destroy(&pages->mutex); + put_task_struct(pages->source_task); + free_uid(pages->source_user); + kfree(pages); +} + +static void +iopt_area_unpin_domain(struct pfn_batch *batch, struct iopt_area *area, + struct iopt_pages *pages, struct iommu_domain *domain, + unsigned long start_index, unsigned long last_index, + unsigned long *unmapped_end_index, + unsigned long real_last_index) +{ + while (start_index <= last_index) { + unsigned long batch_last_index; + + if (*unmapped_end_index <= last_index) { + unsigned long start = + max(start_index, *unmapped_end_index); + + batch_from_domain(batch, domain, area, start, + last_index); + batch_last_index = start + batch->total_pfns - 1; + } else { + batch_last_index = last_index; + } + + /* + * unmaps must always 'cut' at a place where the pfns are not + * contiguous to pair with the maps that always install + * contiguous pages. Thus, if we have to stop unpinning in the + * middle of the domains we need to keep reading pfns until we + * find a cut point to do the unmap. The pfns we read are + * carried over and either skipped or integrated into the next + * batch. + */ + if (batch_last_index == last_index && + last_index != real_last_index) + batch_from_domain_continue(batch, domain, area, + last_index + 1, + real_last_index); + + if (*unmapped_end_index <= batch_last_index) { + iopt_area_unmap_domain_range( + area, domain, *unmapped_end_index, + start_index + batch->total_pfns - 1); + *unmapped_end_index = start_index + batch->total_pfns; + } + + /* unpin must follow unmap */ + batch_unpin(batch, pages, 0, + batch_last_index - start_index + 1); + start_index = batch_last_index + 1; + + batch_clear_carry(batch, + *unmapped_end_index - batch_last_index - 1); + } +} + +static void __iopt_area_unfill_domain(struct iopt_area *area, + struct iopt_pages *pages, + struct iommu_domain *domain, + unsigned long last_index) +{ + struct interval_tree_double_span_iter span; + unsigned long start_index = iopt_area_index(area); + unsigned long unmapped_end_index = start_index; + u64 backup[BATCH_BACKUP_SIZE]; + struct pfn_batch batch; + + lockdep_assert_held(&pages->mutex); + + /* + * For security we must not unpin something that is still DMA mapped, + * so this must unmap any IOVA before we go ahead and unpin the pages. + * This creates a complexity where we need to skip over unpinning pages + * held in the xarray, but continue to unmap from the domain. + * + * The domain unmap cannot stop in the middle of a contiguous range of + * PFNs. To solve this problem the unpinning step will read ahead to the + * end of any contiguous span, unmap that whole span, and then only + * unpin the leading part that does not have any accesses. The residual + * PFNs that were unmapped but not unpinned are called a "carry" in the + * batch as they are moved to the front of the PFN list and continue on + * to the next iteration(s). + */ + batch_init_backup(&batch, last_index + 1, backup, sizeof(backup)); + interval_tree_for_each_double_span(&span, &pages->domains_itree, + &pages->access_itree, start_index, + last_index) { + if (span.is_used) { + batch_skip_carry(&batch, + span.last_used - span.start_used + 1); + continue; + } + iopt_area_unpin_domain(&batch, area, pages, domain, + span.start_hole, span.last_hole, + &unmapped_end_index, last_index); + } + /* + * If the range ends in a access then we do the residual unmap without + * any unpins. + */ + if (unmapped_end_index != last_index + 1) + iopt_area_unmap_domain_range(area, domain, unmapped_end_index, + last_index); + WARN_ON(batch.total_pfns); + batch_destroy(&batch, backup); + update_unpinned(pages); +} + +static void iopt_area_unfill_partial_domain(struct iopt_area *area, + struct iopt_pages *pages, + struct iommu_domain *domain, + unsigned long end_index) +{ + if (end_index != iopt_area_index(area)) + __iopt_area_unfill_domain(area, pages, domain, end_index - 1); +} + +/** + * iopt_area_unmap_domain() - Unmap without unpinning PFNs in a domain + * @area: The IOVA range to unmap + * @domain: The domain to unmap + * + * The caller must know that unpinning is not required, usually because there + * are other domains in the iopt. + */ +void iopt_area_unmap_domain(struct iopt_area *area, struct iommu_domain *domain) +{ + iommu_unmap_nofail(domain, iopt_area_iova(area), + iopt_area_length(area)); +} + +/** + * iopt_area_unfill_domain() - Unmap and unpin PFNs in a domain + * @area: IOVA area to use + * @pages: page supplier for the area (area->pages is NULL) + * @domain: Domain to unmap from + * + * The domain should be removed from the domains_itree before calling. The + * domain will always be unmapped, but the PFNs may not be unpinned if there are + * still accesses. + */ +void iopt_area_unfill_domain(struct iopt_area *area, struct iopt_pages *pages, + struct iommu_domain *domain) +{ + __iopt_area_unfill_domain(area, pages, domain, + iopt_area_last_index(area)); +} + +/** + * iopt_area_fill_domain() - Map PFNs from the area into a domain + * @area: IOVA area to use + * @domain: Domain to load PFNs into + * + * Read the pfns from the area's underlying iopt_pages and map them into the + * given domain. Called when attaching a new domain to an io_pagetable. + */ +int iopt_area_fill_domain(struct iopt_area *area, struct iommu_domain *domain) +{ + unsigned long done_end_index; + struct pfn_reader pfns; + int rc; + + lockdep_assert_held(&area->pages->mutex); + + rc = pfn_reader_first(&pfns, area->pages, iopt_area_index(area), + iopt_area_last_index(area)); + if (rc) + return rc; + + while (!pfn_reader_done(&pfns)) { + done_end_index = pfns.batch_start_index; + rc = batch_to_domain(&pfns.batch, domain, area, + pfns.batch_start_index); + if (rc) + goto out_unmap; + done_end_index = pfns.batch_end_index; + + rc = pfn_reader_next(&pfns); + if (rc) + goto out_unmap; + } + + rc = pfn_reader_update_pinned(&pfns); + if (rc) + goto out_unmap; + goto out_destroy; + +out_unmap: + pfn_reader_release_pins(&pfns); + iopt_area_unfill_partial_domain(area, area->pages, domain, + done_end_index); +out_destroy: + pfn_reader_destroy(&pfns); + return rc; +} + +/** + * iopt_area_fill_domains() - Install PFNs into the area's domains + * @area: The area to act on + * @pages: The pages associated with the area (area->pages is NULL) + * + * Called during area creation. The area is freshly created and not inserted in + * the domains_itree yet. PFNs are read and loaded into every domain held in the + * area's io_pagetable and the area is installed in the domains_itree. + * + * On failure all domains are left unchanged. + */ +int iopt_area_fill_domains(struct iopt_area *area, struct iopt_pages *pages) +{ + unsigned long done_first_end_index; + unsigned long done_all_end_index; + struct iommu_domain *domain; + unsigned long unmap_index; + struct pfn_reader pfns; + unsigned long index; + int rc; + + lockdep_assert_held(&area->iopt->domains_rwsem); + + if (xa_empty(&area->iopt->domains)) + return 0; + + mutex_lock(&pages->mutex); + rc = pfn_reader_first(&pfns, pages, iopt_area_index(area), + iopt_area_last_index(area)); + if (rc) + goto out_unlock; + + while (!pfn_reader_done(&pfns)) { + done_first_end_index = pfns.batch_end_index; + done_all_end_index = pfns.batch_start_index; + xa_for_each(&area->iopt->domains, index, domain) { + rc = batch_to_domain(&pfns.batch, domain, area, + pfns.batch_start_index); + if (rc) + goto out_unmap; + } + done_all_end_index = done_first_end_index; + + rc = pfn_reader_next(&pfns); + if (rc) + goto out_unmap; + } + rc = pfn_reader_update_pinned(&pfns); + if (rc) + goto out_unmap; + + area->storage_domain = xa_load(&area->iopt->domains, 0); + interval_tree_insert(&area->pages_node, &pages->domains_itree); + goto out_destroy; + +out_unmap: + pfn_reader_release_pins(&pfns); + xa_for_each(&area->iopt->domains, unmap_index, domain) { + unsigned long end_index; + + if (unmap_index < index) + end_index = done_first_end_index; + else + end_index = done_all_end_index; + + /* + * The area is not yet part of the domains_itree so we have to + * manage the unpinning specially. The last domain does the + * unpin, every other domain is just unmapped. + */ + if (unmap_index != area->iopt->next_domain_id - 1) { + if (end_index != iopt_area_index(area)) + iopt_area_unmap_domain_range( + area, domain, iopt_area_index(area), + end_index - 1); + } else { + iopt_area_unfill_partial_domain(area, pages, domain, + end_index); + } + } +out_destroy: + pfn_reader_destroy(&pfns); +out_unlock: + mutex_unlock(&pages->mutex); + return rc; +} + +/** + * iopt_area_unfill_domains() - unmap PFNs from the area's domains + * @area: The area to act on + * @pages: The pages associated with the area (area->pages is NULL) + * + * Called during area destruction. This unmaps the iova's covered by all the + * area's domains and releases the PFNs. + */ +void iopt_area_unfill_domains(struct iopt_area *area, struct iopt_pages *pages) +{ + struct io_pagetable *iopt = area->iopt; + struct iommu_domain *domain; + unsigned long index; + + lockdep_assert_held(&iopt->domains_rwsem); + + mutex_lock(&pages->mutex); + if (!area->storage_domain) + goto out_unlock; + + xa_for_each(&iopt->domains, index, domain) + if (domain != area->storage_domain) + iopt_area_unmap_domain_range( + area, domain, iopt_area_index(area), + iopt_area_last_index(area)); + + interval_tree_remove(&area->pages_node, &pages->domains_itree); + iopt_area_unfill_domain(area, pages, area->storage_domain); + area->storage_domain = NULL; +out_unlock: + mutex_unlock(&pages->mutex); +} + +static void iopt_pages_unpin_xarray(struct pfn_batch *batch, + struct iopt_pages *pages, + unsigned long start_index, + unsigned long end_index) +{ + while (start_index <= end_index) { + batch_from_xarray_clear(batch, &pages->pinned_pfns, start_index, + end_index); + batch_unpin(batch, pages, 0, batch->total_pfns); + start_index += batch->total_pfns; + batch_clear(batch); + } +} + +/** + * iopt_pages_unfill_xarray() - Update the xarry after removing an access + * @pages: The pages to act on + * @start_index: Starting PFN index + * @last_index: Last PFN index + * + * Called when an iopt_pages_access is removed, removes pages from the itree. + * The access should already be removed from the access_itree. + */ +void iopt_pages_unfill_xarray(struct iopt_pages *pages, + unsigned long start_index, + unsigned long last_index) +{ + struct interval_tree_double_span_iter span; + u64 backup[BATCH_BACKUP_SIZE]; + struct pfn_batch batch; + bool batch_inited = false; + + lockdep_assert_held(&pages->mutex); + + interval_tree_for_each_double_span(&span, &pages->access_itree, + &pages->domains_itree, start_index, + last_index) { + if (!span.is_used) { + if (!batch_inited) { + batch_init_backup(&batch, + last_index - start_index + 1, + backup, sizeof(backup)); + batch_inited = true; + } + iopt_pages_unpin_xarray(&batch, pages, span.start_hole, + span.last_hole); + } else if (span.is_used == 2) { + /* Covered by a domain */ + clear_xarray(&pages->pinned_pfns, span.start_used, + span.last_used); + } + /* Otherwise covered by an existing access */ + } + if (batch_inited) + batch_destroy(&batch, backup); + update_unpinned(pages); +} + +/** + * iopt_pages_fill_from_xarray() - Fast path for reading PFNs + * @pages: The pages to act on + * @start_index: The first page index in the range + * @last_index: The last page index in the range + * @out_pages: The output array to return the pages + * + * This can be called if the caller is holding a refcount on an + * iopt_pages_access that is known to have already been filled. It quickly reads + * the pages directly from the xarray. + * + * This is part of the SW iommu interface to read pages for in-kernel use. + */ +void iopt_pages_fill_from_xarray(struct iopt_pages *pages, + unsigned long start_index, + unsigned long last_index, + struct page **out_pages) +{ + XA_STATE(xas, &pages->pinned_pfns, start_index); + void *entry; + + rcu_read_lock(); + while (start_index <= last_index) { + entry = xas_next(&xas); + if (xas_retry(&xas, entry)) + continue; + WARN_ON(!xa_is_value(entry)); + *(out_pages++) = pfn_to_page(xa_to_value(entry)); + start_index++; + } + rcu_read_unlock(); +} + +static int iopt_pages_fill_from_domain(struct iopt_pages *pages, + unsigned long start_index, + unsigned long last_index, + struct page **out_pages) +{ + while (start_index != last_index + 1) { + unsigned long domain_last; + struct iopt_area *area; + + area = iopt_pages_find_domain_area(pages, start_index); + if (WARN_ON(!area)) + return -EINVAL; + + domain_last = min(iopt_area_last_index(area), last_index); + out_pages = raw_pages_from_domain(area->storage_domain, area, + start_index, domain_last, + out_pages); + start_index = domain_last + 1; + } + return 0; +} + +static int iopt_pages_fill_from_mm(struct iopt_pages *pages, + struct pfn_reader_user *user, + unsigned long start_index, + unsigned long last_index, + struct page **out_pages) +{ + unsigned long cur_index = start_index; + int rc; + + while (cur_index != last_index + 1) { + user->upages = out_pages + (cur_index - start_index); + rc = pfn_reader_user_pin(user, pages, cur_index, last_index); + if (rc) + goto out_unpin; + cur_index = user->upages_end; + } + return 0; + +out_unpin: + if (start_index != cur_index) + iopt_pages_err_unpin(pages, start_index, cur_index - 1, + out_pages); + return rc; +} + +/** + * iopt_pages_fill_xarray() - Read PFNs + * @pages: The pages to act on + * @start_index: The first page index in the range + * @last_index: The last page index in the range + * @out_pages: The output array to return the pages, may be NULL + * + * This populates the xarray and returns the pages in out_pages. As the slow + * path this is able to copy pages from other storage tiers into the xarray. + * + * On failure the xarray is left unchanged. + * + * This is part of the SW iommu interface to read pages for in-kernel use. + */ +int iopt_pages_fill_xarray(struct iopt_pages *pages, unsigned long start_index, + unsigned long last_index, struct page **out_pages) +{ + struct interval_tree_double_span_iter span; + unsigned long xa_end = start_index; + struct pfn_reader_user user; + int rc; + + lockdep_assert_held(&pages->mutex); + + pfn_reader_user_init(&user, pages); + user.upages_len = (last_index - start_index + 1) * sizeof(*out_pages); + interval_tree_for_each_double_span(&span, &pages->access_itree, + &pages->domains_itree, start_index, + last_index) { + struct page **cur_pages; + + if (span.is_used == 1) { + cur_pages = out_pages + (span.start_used - start_index); + iopt_pages_fill_from_xarray(pages, span.start_used, + span.last_used, cur_pages); + continue; + } + + if (span.is_used == 2) { + cur_pages = out_pages + (span.start_used - start_index); + iopt_pages_fill_from_domain(pages, span.start_used, + span.last_used, cur_pages); + rc = pages_to_xarray(&pages->pinned_pfns, + span.start_used, span.last_used, + cur_pages); + if (rc) + goto out_clean_xa; + xa_end = span.last_used + 1; + continue; + } + + /* hole */ + cur_pages = out_pages + (span.start_hole - start_index); + rc = iopt_pages_fill_from_mm(pages, &user, span.start_hole, + span.last_hole, cur_pages); + if (rc) + goto out_clean_xa; + rc = pages_to_xarray(&pages->pinned_pfns, span.start_hole, + span.last_hole, cur_pages); + if (rc) { + iopt_pages_err_unpin(pages, span.start_hole, + span.last_hole, cur_pages); + goto out_clean_xa; + } + xa_end = span.last_hole + 1; + } + rc = pfn_reader_user_update_pinned(&user, pages); + if (rc) + goto out_clean_xa; + user.upages = NULL; + pfn_reader_user_destroy(&user, pages); + return 0; + +out_clean_xa: + if (start_index != xa_end) + iopt_pages_unfill_xarray(pages, start_index, xa_end - 1); + user.upages = NULL; + pfn_reader_user_destroy(&user, pages); + return rc; +} + +/* + * This uses the pfn_reader instead of taking a shortcut by using the mm. It can + * do every scenario and is fully consistent with what an iommu_domain would + * see. + */ +static int iopt_pages_rw_slow(struct iopt_pages *pages, + unsigned long start_index, + unsigned long last_index, unsigned long offset, + void *data, unsigned long length, + unsigned int flags) +{ + struct pfn_reader pfns; + int rc; + + mutex_lock(&pages->mutex); + + rc = pfn_reader_first(&pfns, pages, start_index, last_index); + if (rc) + goto out_unlock; + + while (!pfn_reader_done(&pfns)) { + unsigned long done; + + done = batch_rw(&pfns.batch, data, offset, length, flags); + data += done; + length -= done; + offset = 0; + pfn_reader_unpin(&pfns); + + rc = pfn_reader_next(&pfns); + if (rc) + goto out_destroy; + } + if (WARN_ON(length != 0)) + rc = -EINVAL; +out_destroy: + pfn_reader_destroy(&pfns); +out_unlock: + mutex_unlock(&pages->mutex); + return rc; +} + +/* + * A medium speed path that still allows DMA inconsistencies, but doesn't do any + * memory allocations or interval tree searches. + */ +static int iopt_pages_rw_page(struct iopt_pages *pages, unsigned long index, + unsigned long offset, void *data, + unsigned long length, unsigned int flags) +{ + struct page *page = NULL; + int rc; + + if (!mmget_not_zero(pages->source_mm)) + return iopt_pages_rw_slow(pages, index, index, offset, data, + length, flags); + + mmap_read_lock(pages->source_mm); + rc = pin_user_pages_remote( + pages->source_mm, (uintptr_t)(pages->uptr + index * PAGE_SIZE), + 1, (flags & IOMMUFD_ACCESS_RW_WRITE) ? FOLL_WRITE : 0, &page, + NULL, NULL); + mmap_read_unlock(pages->source_mm); + if (rc != 1) { + if (WARN_ON(rc >= 0)) + rc = -EINVAL; + goto out_mmput; + } + copy_data_page(page, data, offset, length, flags); + unpin_user_page(page); + rc = 0; + +out_mmput: + mmput(pages->source_mm); + return rc; +} + +/** + * iopt_pages_rw_access - Copy to/from a linear slice of the pages + * @pages: pages to act on + * @start_byte: First byte of pages to copy to/from + * @data: Kernel buffer to get/put the data + * @length: Number of bytes to copy + * @flags: IOMMUFD_ACCESS_RW_* flags + * + * This will find each page in the range, kmap it and then memcpy to/from + * the given kernel buffer. + */ +int iopt_pages_rw_access(struct iopt_pages *pages, unsigned long start_byte, + void *data, unsigned long length, unsigned int flags) +{ + unsigned long start_index = start_byte / PAGE_SIZE; + unsigned long last_index = (start_byte + length - 1) / PAGE_SIZE; + bool change_mm = current->mm != pages->source_mm; + int rc = 0; + + if ((flags & IOMMUFD_ACCESS_RW_WRITE) && !pages->writable) + return -EPERM; + + if (!(flags & IOMMUFD_ACCESS_RW_KTHREAD) && change_mm) { + if (start_index == last_index) + return iopt_pages_rw_page(pages, start_index, + start_byte % PAGE_SIZE, data, + length, flags); + return iopt_pages_rw_slow(pages, start_index, last_index, + start_byte % PAGE_SIZE, data, length, + flags); + } + + /* + * Try to copy using copy_to_user(). We do this as a fast path and + * ignore any pinning inconsistencies, unlike a real DMA path. + */ + if (change_mm) { + if (!mmget_not_zero(pages->source_mm)) + return iopt_pages_rw_slow(pages, start_index, + last_index, + start_byte % PAGE_SIZE, data, + length, flags); + kthread_use_mm(pages->source_mm); + } + + if (flags & IOMMUFD_ACCESS_RW_WRITE) { + if (copy_to_user(pages->uptr + start_byte, data, length)) + rc = -EFAULT; + } else { + if (copy_from_user(data, pages->uptr + start_byte, length)) + rc = -EFAULT; + } + + if (change_mm) { + kthread_unuse_mm(pages->source_mm); + mmput(pages->source_mm); + } + + return rc; +} + +static struct iopt_pages_access * +iopt_pages_get_exact_access(struct iopt_pages *pages, unsigned long index, + unsigned long last) +{ + struct interval_tree_node *node; + + lockdep_assert_held(&pages->mutex); + + /* There can be overlapping ranges in this interval tree */ + for (node = interval_tree_iter_first(&pages->access_itree, index, last); + node; node = interval_tree_iter_next(node, index, last)) + if (node->start == index && node->last == last) + return container_of(node, struct iopt_pages_access, + node); + return NULL; +} + +/** + * iopt_area_add_access() - Record an in-knerel access for PFNs + * @area: The source of PFNs + * @start_index: First page index + * @last_index: Inclusive last page index + * @out_pages: Output list of struct page's representing the PFNs + * @flags: IOMMUFD_ACCESS_RW_* flags + * + * Record that an in-kernel access will be accessing the pages, ensure they are + * pinned, and return the PFNs as a simple list of 'struct page *'. + * + * This should be undone through a matching call to iopt_area_remove_access() + */ +int iopt_area_add_access(struct iopt_area *area, unsigned long start_index, + unsigned long last_index, struct page **out_pages, + unsigned int flags) +{ + struct iopt_pages *pages = area->pages; + struct iopt_pages_access *access; + int rc; + + if ((flags & IOMMUFD_ACCESS_RW_WRITE) && !pages->writable) + return -EPERM; + + mutex_lock(&pages->mutex); + access = iopt_pages_get_exact_access(pages, start_index, last_index); + if (access) { + area->num_accesses++; + access->users++; + iopt_pages_fill_from_xarray(pages, start_index, last_index, + out_pages); + mutex_unlock(&pages->mutex); + return 0; + } + + access = kzalloc(sizeof(*access), GFP_KERNEL_ACCOUNT); + if (!access) { + rc = -ENOMEM; + goto err_unlock; + } + + rc = iopt_pages_fill_xarray(pages, start_index, last_index, out_pages); + if (rc) + goto err_free; + + access->node.start = start_index; + access->node.last = last_index; + access->users = 1; + area->num_accesses++; + interval_tree_insert(&access->node, &pages->access_itree); + mutex_unlock(&pages->mutex); + return 0; + +err_free: + kfree(access); +err_unlock: + mutex_unlock(&pages->mutex); + return rc; +} + +/** + * iopt_area_remove_access() - Release an in-kernel access for PFNs + * @area: The source of PFNs + * @start_index: First page index + * @last_index: Inclusive last page index + * + * Undo iopt_area_add_access() and unpin the pages if necessary. The caller + * must stop using the PFNs before calling this. + */ +void iopt_area_remove_access(struct iopt_area *area, unsigned long start_index, + unsigned long last_index) +{ + struct iopt_pages *pages = area->pages; + struct iopt_pages_access *access; + + mutex_lock(&pages->mutex); + access = iopt_pages_get_exact_access(pages, start_index, last_index); + if (WARN_ON(!access)) + goto out_unlock; + + WARN_ON(area->num_accesses == 0 || access->users == 0); + area->num_accesses--; + access->users--; + if (access->users) + goto out_unlock; + + interval_tree_remove(&access->node, &pages->access_itree); + iopt_pages_unfill_xarray(pages, start_index, last_index); + kfree(access); +out_unlock: + mutex_unlock(&pages->mutex); +} -- cgit v1.2.3 From 51fe6141f0f64ae0bbc096a41a07572273e8c0ef Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 29 Nov 2022 16:29:33 -0400 Subject: iommufd: Data structure to provide IOVA to PFN mapping This is the remainder of the IOAS data structure. Provide an object called an io_pagetable that is composed of iopt_areas pointing at iopt_pages, along with a list of iommu_domains that mirror the IOVA to PFN map. At the top this is a simple interval tree of iopt_areas indicating the map of IOVA to iopt_pages. An xarray keeps track of a list of domains. Based on the attached domains there is a minimum alignment for areas (which may be smaller than PAGE_SIZE), an interval tree of reserved IOVA that can't be mapped and an IOVA of allowed IOVA that can always be mappable. The concept of an 'access' refers to something like a VFIO mdev that is accessing the IOVA and using a 'struct page *' for CPU based access. Externally an API is provided that matches the requirements of the IOCTL interface for map/unmap and domain attachment. The API provides a 'copy' primitive to establish a new IOVA map in a different IOAS from an existing mapping by re-using the iopt_pages. This is the basic mechanism to provide single pinning. This is designed to support a pre-registration flow where userspace would setup an dummy IOAS with no domains, map in memory and then establish an access to pin all PFNs into the xarray. Copy can then be used to create new IOVA mappings in a different IOAS, with iommu_domains attached. Upon copy the PFNs will be read out of the xarray and mapped into the iommu_domains, avoiding any pin_user_pages() overheads. Link: https://lore.kernel.org/r/10-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Tested-by: Nicolin Chen Tested-by: Yi Liu Tested-by: Lixiao Yang Tested-by: Matthew Rosato Reviewed-by: Kevin Tian Signed-off-by: Yi Liu Signed-off-by: Nicolin Chen Signed-off-by: Jason Gunthorpe --- .clang-format | 1 + drivers/iommu/iommufd/Makefile | 1 + drivers/iommu/iommufd/io_pagetable.c | 1186 +++++++++++++++++++++++++++++++ drivers/iommu/iommufd/io_pagetable.h | 55 ++ drivers/iommu/iommufd/iommufd_private.h | 52 ++ 5 files changed, 1295 insertions(+) create mode 100644 drivers/iommu/iommufd/io_pagetable.c (limited to 'drivers/iommu') diff --git a/.clang-format b/.clang-format index 501241f89776..78aba4a10b1b 100644 --- a/.clang-format +++ b/.clang-format @@ -444,6 +444,7 @@ ForEachMacros: - 'interval_tree_for_each_span' - 'intlist__for_each_entry' - 'intlist__for_each_entry_safe' + - 'iopt_for_each_contig_area' - 'kcore_copy__for_each_phdr' - 'key_for_each' - 'key_for_each_safe' diff --git a/drivers/iommu/iommufd/Makefile b/drivers/iommu/iommufd/Makefile index 05a0e91e30af..b66a8c47ff55 100644 --- a/drivers/iommu/iommufd/Makefile +++ b/drivers/iommu/iommufd/Makefile @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0-only iommufd-y := \ + io_pagetable.o \ main.o \ pages.o diff --git a/drivers/iommu/iommufd/io_pagetable.c b/drivers/iommu/iommufd/io_pagetable.c new file mode 100644 index 000000000000..756d347948f0 --- /dev/null +++ b/drivers/iommu/iommufd/io_pagetable.c @@ -0,0 +1,1186 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES. + * + * The io_pagetable is the top of datastructure that maps IOVA's to PFNs. The + * PFNs can be placed into an iommu_domain, or returned to the caller as a page + * list for access by an in-kernel user. + * + * The datastructure uses the iopt_pages to optimize the storage of the PFNs + * between the domains and xarray. + */ +#include +#include +#include +#include +#include +#include +#include + +#include "io_pagetable.h" +#include "double_span.h" + +struct iopt_pages_list { + struct iopt_pages *pages; + struct iopt_area *area; + struct list_head next; + unsigned long start_byte; + unsigned long length; +}; + +struct iopt_area *iopt_area_contig_init(struct iopt_area_contig_iter *iter, + struct io_pagetable *iopt, + unsigned long iova, + unsigned long last_iova) +{ + lockdep_assert_held(&iopt->iova_rwsem); + + iter->cur_iova = iova; + iter->last_iova = last_iova; + iter->area = iopt_area_iter_first(iopt, iova, iova); + if (!iter->area) + return NULL; + if (!iter->area->pages) { + iter->area = NULL; + return NULL; + } + return iter->area; +} + +struct iopt_area *iopt_area_contig_next(struct iopt_area_contig_iter *iter) +{ + unsigned long last_iova; + + if (!iter->area) + return NULL; + last_iova = iopt_area_last_iova(iter->area); + if (iter->last_iova <= last_iova) + return NULL; + + iter->cur_iova = last_iova + 1; + iter->area = iopt_area_iter_next(iter->area, iter->cur_iova, + iter->last_iova); + if (!iter->area) + return NULL; + if (iter->cur_iova != iopt_area_iova(iter->area) || + !iter->area->pages) { + iter->area = NULL; + return NULL; + } + return iter->area; +} + +static bool __alloc_iova_check_hole(struct interval_tree_double_span_iter *span, + unsigned long length, + unsigned long iova_alignment, + unsigned long page_offset) +{ + if (span->is_used || span->last_hole - span->start_hole < length - 1) + return false; + + span->start_hole = ALIGN(span->start_hole, iova_alignment) | + page_offset; + if (span->start_hole > span->last_hole || + span->last_hole - span->start_hole < length - 1) + return false; + return true; +} + +static bool __alloc_iova_check_used(struct interval_tree_span_iter *span, + unsigned long length, + unsigned long iova_alignment, + unsigned long page_offset) +{ + if (span->is_hole || span->last_used - span->start_used < length - 1) + return false; + + span->start_used = ALIGN(span->start_used, iova_alignment) | + page_offset; + if (span->start_used > span->last_used || + span->last_used - span->start_used < length - 1) + return false; + return true; +} + +/* + * Automatically find a block of IOVA that is not being used and not reserved. + * Does not return a 0 IOVA even if it is valid. + */ +static int iopt_alloc_iova(struct io_pagetable *iopt, unsigned long *iova, + unsigned long uptr, unsigned long length) +{ + unsigned long page_offset = uptr % PAGE_SIZE; + struct interval_tree_double_span_iter used_span; + struct interval_tree_span_iter allowed_span; + unsigned long iova_alignment; + + lockdep_assert_held(&iopt->iova_rwsem); + + /* Protect roundup_pow-of_two() from overflow */ + if (length == 0 || length >= ULONG_MAX / 2) + return -EOVERFLOW; + + /* + * Keep alignment present in the uptr when building the IOVA, this + * increases the chance we can map a THP. + */ + if (!uptr) + iova_alignment = roundup_pow_of_two(length); + else + iova_alignment = min_t(unsigned long, + roundup_pow_of_two(length), + 1UL << __ffs64(uptr)); + + if (iova_alignment < iopt->iova_alignment) + return -EINVAL; + + interval_tree_for_each_span(&allowed_span, &iopt->allowed_itree, + PAGE_SIZE, ULONG_MAX - PAGE_SIZE) { + if (RB_EMPTY_ROOT(&iopt->allowed_itree.rb_root)) { + allowed_span.start_used = PAGE_SIZE; + allowed_span.last_used = ULONG_MAX - PAGE_SIZE; + allowed_span.is_hole = false; + } + + if (!__alloc_iova_check_used(&allowed_span, length, + iova_alignment, page_offset)) + continue; + + interval_tree_for_each_double_span( + &used_span, &iopt->reserved_itree, &iopt->area_itree, + allowed_span.start_used, allowed_span.last_used) { + if (!__alloc_iova_check_hole(&used_span, length, + iova_alignment, + page_offset)) + continue; + + *iova = used_span.start_hole; + return 0; + } + } + return -ENOSPC; +} + +static int iopt_check_iova(struct io_pagetable *iopt, unsigned long iova, + unsigned long length) +{ + unsigned long last; + + lockdep_assert_held(&iopt->iova_rwsem); + + if ((iova & (iopt->iova_alignment - 1))) + return -EINVAL; + + if (check_add_overflow(iova, length - 1, &last)) + return -EOVERFLOW; + + /* No reserved IOVA intersects the range */ + if (iopt_reserved_iter_first(iopt, iova, last)) + return -EINVAL; + + /* Check that there is not already a mapping in the range */ + if (iopt_area_iter_first(iopt, iova, last)) + return -EEXIST; + return 0; +} + +/* + * The area takes a slice of the pages from start_bytes to start_byte + length + */ +static int iopt_insert_area(struct io_pagetable *iopt, struct iopt_area *area, + struct iopt_pages *pages, unsigned long iova, + unsigned long start_byte, unsigned long length, + int iommu_prot) +{ + lockdep_assert_held_write(&iopt->iova_rwsem); + + if ((iommu_prot & IOMMU_WRITE) && !pages->writable) + return -EPERM; + + area->iommu_prot = iommu_prot; + area->page_offset = start_byte % PAGE_SIZE; + if (area->page_offset & (iopt->iova_alignment - 1)) + return -EINVAL; + + area->node.start = iova; + if (check_add_overflow(iova, length - 1, &area->node.last)) + return -EOVERFLOW; + + area->pages_node.start = start_byte / PAGE_SIZE; + if (check_add_overflow(start_byte, length - 1, &area->pages_node.last)) + return -EOVERFLOW; + area->pages_node.last = area->pages_node.last / PAGE_SIZE; + if (WARN_ON(area->pages_node.last >= pages->npages)) + return -EOVERFLOW; + + /* + * The area is inserted with a NULL pages indicating it is not fully + * initialized yet. + */ + area->iopt = iopt; + interval_tree_insert(&area->node, &iopt->area_itree); + return 0; +} + +static int iopt_alloc_area_pages(struct io_pagetable *iopt, + struct list_head *pages_list, + unsigned long length, unsigned long *dst_iova, + int iommu_prot, unsigned int flags) +{ + struct iopt_pages_list *elm; + unsigned long iova; + int rc = 0; + + list_for_each_entry(elm, pages_list, next) { + elm->area = kzalloc(sizeof(*elm->area), GFP_KERNEL_ACCOUNT); + if (!elm->area) + return -ENOMEM; + } + + down_write(&iopt->iova_rwsem); + if ((length & (iopt->iova_alignment - 1)) || !length) { + rc = -EINVAL; + goto out_unlock; + } + + if (flags & IOPT_ALLOC_IOVA) { + /* Use the first entry to guess the ideal IOVA alignment */ + elm = list_first_entry(pages_list, struct iopt_pages_list, + next); + rc = iopt_alloc_iova( + iopt, dst_iova, + (uintptr_t)elm->pages->uptr + elm->start_byte, length); + if (rc) + goto out_unlock; + } else { + rc = iopt_check_iova(iopt, *dst_iova, length); + if (rc) + goto out_unlock; + } + + /* + * Areas are created with a NULL pages so that the IOVA space is + * reserved and we can unlock the iova_rwsem. + */ + iova = *dst_iova; + list_for_each_entry(elm, pages_list, next) { + rc = iopt_insert_area(iopt, elm->area, elm->pages, iova, + elm->start_byte, elm->length, iommu_prot); + if (rc) + goto out_unlock; + iova += elm->length; + } + +out_unlock: + up_write(&iopt->iova_rwsem); + return rc; +} + +static void iopt_abort_area(struct iopt_area *area) +{ + if (area->iopt) { + down_write(&area->iopt->iova_rwsem); + interval_tree_remove(&area->node, &area->iopt->area_itree); + up_write(&area->iopt->iova_rwsem); + } + kfree(area); +} + +void iopt_free_pages_list(struct list_head *pages_list) +{ + struct iopt_pages_list *elm; + + while ((elm = list_first_entry_or_null(pages_list, + struct iopt_pages_list, next))) { + if (elm->area) + iopt_abort_area(elm->area); + if (elm->pages) + iopt_put_pages(elm->pages); + list_del(&elm->next); + kfree(elm); + } +} + +static int iopt_fill_domains_pages(struct list_head *pages_list) +{ + struct iopt_pages_list *undo_elm; + struct iopt_pages_list *elm; + int rc; + + list_for_each_entry(elm, pages_list, next) { + rc = iopt_area_fill_domains(elm->area, elm->pages); + if (rc) + goto err_undo; + } + return 0; + +err_undo: + list_for_each_entry(undo_elm, pages_list, next) { + if (undo_elm == elm) + break; + iopt_area_unfill_domains(undo_elm->area, undo_elm->pages); + } + return rc; +} + +int iopt_map_pages(struct io_pagetable *iopt, struct list_head *pages_list, + unsigned long length, unsigned long *dst_iova, + int iommu_prot, unsigned int flags) +{ + struct iopt_pages_list *elm; + int rc; + + rc = iopt_alloc_area_pages(iopt, pages_list, length, dst_iova, + iommu_prot, flags); + if (rc) + return rc; + + down_read(&iopt->domains_rwsem); + rc = iopt_fill_domains_pages(pages_list); + if (rc) + goto out_unlock_domains; + + down_write(&iopt->iova_rwsem); + list_for_each_entry(elm, pages_list, next) { + /* + * area->pages must be set inside the domains_rwsem to ensure + * any newly added domains will get filled. Moves the reference + * in from the list. + */ + elm->area->pages = elm->pages; + elm->pages = NULL; + elm->area = NULL; + } + up_write(&iopt->iova_rwsem); +out_unlock_domains: + up_read(&iopt->domains_rwsem); + return rc; +} + +/** + * iopt_map_user_pages() - Map a user VA to an iova in the io page table + * @ictx: iommufd_ctx the iopt is part of + * @iopt: io_pagetable to act on + * @iova: If IOPT_ALLOC_IOVA is set this is unused on input and contains + * the chosen iova on output. Otherwise is the iova to map to on input + * @uptr: User VA to map + * @length: Number of bytes to map + * @iommu_prot: Combination of IOMMU_READ/WRITE/etc bits for the mapping + * @flags: IOPT_ALLOC_IOVA or zero + * + * iova, uptr, and length must be aligned to iova_alignment. For domain backed + * page tables this will pin the pages and load them into the domain at iova. + * For non-domain page tables this will only setup a lazy reference and the + * caller must use iopt_access_pages() to touch them. + * + * iopt_unmap_iova() must be called to undo this before the io_pagetable can be + * destroyed. + */ +int iopt_map_user_pages(struct iommufd_ctx *ictx, struct io_pagetable *iopt, + unsigned long *iova, void __user *uptr, + unsigned long length, int iommu_prot, + unsigned int flags) +{ + struct iopt_pages_list elm = {}; + LIST_HEAD(pages_list); + int rc; + + elm.pages = iopt_alloc_pages(uptr, length, iommu_prot & IOMMU_WRITE); + if (IS_ERR(elm.pages)) + return PTR_ERR(elm.pages); + if (ictx->account_mode == IOPT_PAGES_ACCOUNT_MM && + elm.pages->account_mode == IOPT_PAGES_ACCOUNT_USER) + elm.pages->account_mode = IOPT_PAGES_ACCOUNT_MM; + elm.start_byte = uptr - elm.pages->uptr; + elm.length = length; + list_add(&elm.next, &pages_list); + + rc = iopt_map_pages(iopt, &pages_list, length, iova, iommu_prot, flags); + if (rc) { + if (elm.area) + iopt_abort_area(elm.area); + if (elm.pages) + iopt_put_pages(elm.pages); + return rc; + } + return 0; +} + +int iopt_get_pages(struct io_pagetable *iopt, unsigned long iova, + unsigned long length, struct list_head *pages_list) +{ + struct iopt_area_contig_iter iter; + unsigned long last_iova; + struct iopt_area *area; + int rc; + + if (!length) + return -EINVAL; + if (check_add_overflow(iova, length - 1, &last_iova)) + return -EOVERFLOW; + + down_read(&iopt->iova_rwsem); + iopt_for_each_contig_area(&iter, area, iopt, iova, last_iova) { + struct iopt_pages_list *elm; + unsigned long last = min(last_iova, iopt_area_last_iova(area)); + + elm = kzalloc(sizeof(*elm), GFP_KERNEL_ACCOUNT); + if (!elm) { + rc = -ENOMEM; + goto err_free; + } + elm->start_byte = iopt_area_start_byte(area, iter.cur_iova); + elm->pages = area->pages; + elm->length = (last - iter.cur_iova) + 1; + kref_get(&elm->pages->kref); + list_add_tail(&elm->next, pages_list); + } + if (!iopt_area_contig_done(&iter)) { + rc = -ENOENT; + goto err_free; + } + up_read(&iopt->iova_rwsem); + return 0; +err_free: + up_read(&iopt->iova_rwsem); + iopt_free_pages_list(pages_list); + return rc; +} + +static int iopt_unmap_iova_range(struct io_pagetable *iopt, unsigned long start, + unsigned long last, unsigned long *unmapped) +{ + struct iopt_area *area; + unsigned long unmapped_bytes = 0; + int rc = -ENOENT; + + /* + * The domains_rwsem must be held in read mode any time any area->pages + * is NULL. This prevents domain attach/detatch from running + * concurrently with cleaning up the area. + */ + down_read(&iopt->domains_rwsem); + down_write(&iopt->iova_rwsem); + while ((area = iopt_area_iter_first(iopt, start, last))) { + unsigned long area_last = iopt_area_last_iova(area); + unsigned long area_first = iopt_area_iova(area); + struct iopt_pages *pages; + + /* Userspace should not race map/unmap's of the same area */ + if (!area->pages) { + rc = -EBUSY; + goto out_unlock_iova; + } + + if (area_first < start || area_last > last) { + rc = -ENOENT; + goto out_unlock_iova; + } + + /* + * num_accesses writers must hold the iova_rwsem too, so we can + * safely read it under the write side of the iovam_rwsem + * without the pages->mutex. + */ + if (area->num_accesses) { + start = area_first; + area->prevent_access = true; + up_write(&iopt->iova_rwsem); + up_read(&iopt->domains_rwsem); + /* Later patch calls back to drivers to unmap */ + return -EBUSY; + } + + pages = area->pages; + area->pages = NULL; + up_write(&iopt->iova_rwsem); + + iopt_area_unfill_domains(area, pages); + iopt_abort_area(area); + iopt_put_pages(pages); + + unmapped_bytes += area_last - area_first + 1; + + down_write(&iopt->iova_rwsem); + } + if (unmapped_bytes) + rc = 0; + +out_unlock_iova: + up_write(&iopt->iova_rwsem); + up_read(&iopt->domains_rwsem); + if (unmapped) + *unmapped = unmapped_bytes; + return rc; +} + +/** + * iopt_unmap_iova() - Remove a range of iova + * @iopt: io_pagetable to act on + * @iova: Starting iova to unmap + * @length: Number of bytes to unmap + * @unmapped: Return number of bytes unmapped + * + * The requested range must be a superset of existing ranges. + * Splitting/truncating IOVA mappings is not allowed. + */ +int iopt_unmap_iova(struct io_pagetable *iopt, unsigned long iova, + unsigned long length, unsigned long *unmapped) +{ + unsigned long iova_last; + + if (!length) + return -EINVAL; + + if (check_add_overflow(iova, length - 1, &iova_last)) + return -EOVERFLOW; + + return iopt_unmap_iova_range(iopt, iova, iova_last, unmapped); +} + +int iopt_unmap_all(struct io_pagetable *iopt, unsigned long *unmapped) +{ + int rc; + + rc = iopt_unmap_iova_range(iopt, 0, ULONG_MAX, unmapped); + /* If the IOVAs are empty then unmap all succeeds */ + if (rc == -ENOENT) + return 0; + return rc; +} + +/* The caller must always free all the nodes in the allowed_iova rb_root. */ +int iopt_set_allow_iova(struct io_pagetable *iopt, + struct rb_root_cached *allowed_iova) +{ + struct iopt_allowed *allowed; + + down_write(&iopt->iova_rwsem); + swap(*allowed_iova, iopt->allowed_itree); + + for (allowed = iopt_allowed_iter_first(iopt, 0, ULONG_MAX); allowed; + allowed = iopt_allowed_iter_next(allowed, 0, ULONG_MAX)) { + if (iopt_reserved_iter_first(iopt, allowed->node.start, + allowed->node.last)) { + swap(*allowed_iova, iopt->allowed_itree); + up_write(&iopt->iova_rwsem); + return -EADDRINUSE; + } + } + up_write(&iopt->iova_rwsem); + return 0; +} + +int iopt_reserve_iova(struct io_pagetable *iopt, unsigned long start, + unsigned long last, void *owner) +{ + struct iopt_reserved *reserved; + + lockdep_assert_held_write(&iopt->iova_rwsem); + + if (iopt_area_iter_first(iopt, start, last) || + iopt_allowed_iter_first(iopt, start, last)) + return -EADDRINUSE; + + reserved = kzalloc(sizeof(*reserved), GFP_KERNEL_ACCOUNT); + if (!reserved) + return -ENOMEM; + reserved->node.start = start; + reserved->node.last = last; + reserved->owner = owner; + interval_tree_insert(&reserved->node, &iopt->reserved_itree); + return 0; +} + +static void __iopt_remove_reserved_iova(struct io_pagetable *iopt, void *owner) +{ + struct iopt_reserved *reserved, *next; + + lockdep_assert_held_write(&iopt->iova_rwsem); + + for (reserved = iopt_reserved_iter_first(iopt, 0, ULONG_MAX); reserved; + reserved = next) { + next = iopt_reserved_iter_next(reserved, 0, ULONG_MAX); + + if (reserved->owner == owner) { + interval_tree_remove(&reserved->node, + &iopt->reserved_itree); + kfree(reserved); + } + } +} + +void iopt_remove_reserved_iova(struct io_pagetable *iopt, void *owner) +{ + down_write(&iopt->iova_rwsem); + __iopt_remove_reserved_iova(iopt, owner); + up_write(&iopt->iova_rwsem); +} + +void iopt_init_table(struct io_pagetable *iopt) +{ + init_rwsem(&iopt->iova_rwsem); + init_rwsem(&iopt->domains_rwsem); + iopt->area_itree = RB_ROOT_CACHED; + iopt->allowed_itree = RB_ROOT_CACHED; + iopt->reserved_itree = RB_ROOT_CACHED; + xa_init_flags(&iopt->domains, XA_FLAGS_ACCOUNT); + xa_init_flags(&iopt->access_list, XA_FLAGS_ALLOC); + + /* + * iopt's start as SW tables that can use the entire size_t IOVA space + * due to the use of size_t in the APIs. They have no alignment + * restriction. + */ + iopt->iova_alignment = 1; +} + +void iopt_destroy_table(struct io_pagetable *iopt) +{ + struct interval_tree_node *node; + + while ((node = interval_tree_iter_first(&iopt->allowed_itree, 0, + ULONG_MAX))) { + interval_tree_remove(node, &iopt->allowed_itree); + kfree(container_of(node, struct iopt_allowed, node)); + } + + WARN_ON(!RB_EMPTY_ROOT(&iopt->reserved_itree.rb_root)); + WARN_ON(!xa_empty(&iopt->domains)); + WARN_ON(!xa_empty(&iopt->access_list)); + WARN_ON(!RB_EMPTY_ROOT(&iopt->area_itree.rb_root)); +} + +/** + * iopt_unfill_domain() - Unfill a domain with PFNs + * @iopt: io_pagetable to act on + * @domain: domain to unfill + * + * This is used when removing a domain from the iopt. Every area in the iopt + * will be unmapped from the domain. The domain must already be removed from the + * domains xarray. + */ +static void iopt_unfill_domain(struct io_pagetable *iopt, + struct iommu_domain *domain) +{ + struct iopt_area *area; + + lockdep_assert_held(&iopt->iova_rwsem); + lockdep_assert_held_write(&iopt->domains_rwsem); + + /* + * Some other domain is holding all the pfns still, rapidly unmap this + * domain. + */ + if (iopt->next_domain_id != 0) { + /* Pick an arbitrary remaining domain to act as storage */ + struct iommu_domain *storage_domain = + xa_load(&iopt->domains, 0); + + for (area = iopt_area_iter_first(iopt, 0, ULONG_MAX); area; + area = iopt_area_iter_next(area, 0, ULONG_MAX)) { + struct iopt_pages *pages = area->pages; + + if (!pages) + continue; + + mutex_lock(&pages->mutex); + if (area->storage_domain == domain) + area->storage_domain = storage_domain; + mutex_unlock(&pages->mutex); + + iopt_area_unmap_domain(area, domain); + } + return; + } + + for (area = iopt_area_iter_first(iopt, 0, ULONG_MAX); area; + area = iopt_area_iter_next(area, 0, ULONG_MAX)) { + struct iopt_pages *pages = area->pages; + + if (!pages) + continue; + + mutex_lock(&pages->mutex); + interval_tree_remove(&area->pages_node, &pages->domains_itree); + WARN_ON(area->storage_domain != domain); + area->storage_domain = NULL; + iopt_area_unfill_domain(area, pages, domain); + mutex_unlock(&pages->mutex); + } +} + +/** + * iopt_fill_domain() - Fill a domain with PFNs + * @iopt: io_pagetable to act on + * @domain: domain to fill + * + * Fill the domain with PFNs from every area in the iopt. On failure the domain + * is left unchanged. + */ +static int iopt_fill_domain(struct io_pagetable *iopt, + struct iommu_domain *domain) +{ + struct iopt_area *end_area; + struct iopt_area *area; + int rc; + + lockdep_assert_held(&iopt->iova_rwsem); + lockdep_assert_held_write(&iopt->domains_rwsem); + + for (area = iopt_area_iter_first(iopt, 0, ULONG_MAX); area; + area = iopt_area_iter_next(area, 0, ULONG_MAX)) { + struct iopt_pages *pages = area->pages; + + if (!pages) + continue; + + mutex_lock(&pages->mutex); + rc = iopt_area_fill_domain(area, domain); + if (rc) { + mutex_unlock(&pages->mutex); + goto out_unfill; + } + if (!area->storage_domain) { + WARN_ON(iopt->next_domain_id != 0); + area->storage_domain = domain; + interval_tree_insert(&area->pages_node, + &pages->domains_itree); + } + mutex_unlock(&pages->mutex); + } + return 0; + +out_unfill: + end_area = area; + for (area = iopt_area_iter_first(iopt, 0, ULONG_MAX); area; + area = iopt_area_iter_next(area, 0, ULONG_MAX)) { + struct iopt_pages *pages = area->pages; + + if (area == end_area) + break; + if (!pages) + continue; + mutex_lock(&pages->mutex); + if (iopt->next_domain_id == 0) { + interval_tree_remove(&area->pages_node, + &pages->domains_itree); + area->storage_domain = NULL; + } + iopt_area_unfill_domain(area, pages, domain); + mutex_unlock(&pages->mutex); + } + return rc; +} + +/* All existing area's conform to an increased page size */ +static int iopt_check_iova_alignment(struct io_pagetable *iopt, + unsigned long new_iova_alignment) +{ + unsigned long align_mask = new_iova_alignment - 1; + struct iopt_area *area; + + lockdep_assert_held(&iopt->iova_rwsem); + lockdep_assert_held(&iopt->domains_rwsem); + + for (area = iopt_area_iter_first(iopt, 0, ULONG_MAX); area; + area = iopt_area_iter_next(area, 0, ULONG_MAX)) + if ((iopt_area_iova(area) & align_mask) || + (iopt_area_length(area) & align_mask) || + (area->page_offset & align_mask)) + return -EADDRINUSE; + return 0; +} + +int iopt_table_add_domain(struct io_pagetable *iopt, + struct iommu_domain *domain) +{ + const struct iommu_domain_geometry *geometry = &domain->geometry; + struct iommu_domain *iter_domain; + unsigned int new_iova_alignment; + unsigned long index; + int rc; + + down_write(&iopt->domains_rwsem); + down_write(&iopt->iova_rwsem); + + xa_for_each(&iopt->domains, index, iter_domain) { + if (WARN_ON(iter_domain == domain)) { + rc = -EEXIST; + goto out_unlock; + } + } + + /* + * The io page size drives the iova_alignment. Internally the iopt_pages + * works in PAGE_SIZE units and we adjust when mapping sub-PAGE_SIZE + * objects into the iommu_domain. + * + * A iommu_domain must always be able to accept PAGE_SIZE to be + * compatible as we can't guarantee higher contiguity. + */ + new_iova_alignment = max_t(unsigned long, + 1UL << __ffs(domain->pgsize_bitmap), + iopt->iova_alignment); + if (new_iova_alignment > PAGE_SIZE) { + rc = -EINVAL; + goto out_unlock; + } + if (new_iova_alignment != iopt->iova_alignment) { + rc = iopt_check_iova_alignment(iopt, new_iova_alignment); + if (rc) + goto out_unlock; + } + + /* No area exists that is outside the allowed domain aperture */ + if (geometry->aperture_start != 0) { + rc = iopt_reserve_iova(iopt, 0, geometry->aperture_start - 1, + domain); + if (rc) + goto out_reserved; + } + if (geometry->aperture_end != ULONG_MAX) { + rc = iopt_reserve_iova(iopt, geometry->aperture_end + 1, + ULONG_MAX, domain); + if (rc) + goto out_reserved; + } + + rc = xa_reserve(&iopt->domains, iopt->next_domain_id, GFP_KERNEL); + if (rc) + goto out_reserved; + + rc = iopt_fill_domain(iopt, domain); + if (rc) + goto out_release; + + iopt->iova_alignment = new_iova_alignment; + xa_store(&iopt->domains, iopt->next_domain_id, domain, GFP_KERNEL); + iopt->next_domain_id++; + up_write(&iopt->iova_rwsem); + up_write(&iopt->domains_rwsem); + return 0; +out_release: + xa_release(&iopt->domains, iopt->next_domain_id); +out_reserved: + __iopt_remove_reserved_iova(iopt, domain); +out_unlock: + up_write(&iopt->iova_rwsem); + up_write(&iopt->domains_rwsem); + return rc; +} + +static int iopt_calculate_iova_alignment(struct io_pagetable *iopt) +{ + unsigned long new_iova_alignment; + struct iommufd_access *access; + struct iommu_domain *domain; + unsigned long index; + + lockdep_assert_held_write(&iopt->iova_rwsem); + lockdep_assert_held(&iopt->domains_rwsem); + + /* See batch_iommu_map_small() */ + if (iopt->disable_large_pages) + new_iova_alignment = PAGE_SIZE; + else + new_iova_alignment = 1; + + xa_for_each(&iopt->domains, index, domain) + new_iova_alignment = max_t(unsigned long, + 1UL << __ffs(domain->pgsize_bitmap), + new_iova_alignment); + xa_for_each(&iopt->access_list, index, access) + new_iova_alignment = max_t(unsigned long, + access->iova_alignment, + new_iova_alignment); + + if (new_iova_alignment > iopt->iova_alignment) { + int rc; + + rc = iopt_check_iova_alignment(iopt, new_iova_alignment); + if (rc) + return rc; + } + iopt->iova_alignment = new_iova_alignment; + return 0; +} + +void iopt_table_remove_domain(struct io_pagetable *iopt, + struct iommu_domain *domain) +{ + struct iommu_domain *iter_domain = NULL; + unsigned long index; + + down_write(&iopt->domains_rwsem); + down_write(&iopt->iova_rwsem); + + xa_for_each(&iopt->domains, index, iter_domain) + if (iter_domain == domain) + break; + if (WARN_ON(iter_domain != domain) || index >= iopt->next_domain_id) + goto out_unlock; + + /* + * Compress the xarray to keep it linear by swapping the entry to erase + * with the tail entry and shrinking the tail. + */ + iopt->next_domain_id--; + iter_domain = xa_erase(&iopt->domains, iopt->next_domain_id); + if (index != iopt->next_domain_id) + xa_store(&iopt->domains, index, iter_domain, GFP_KERNEL); + + iopt_unfill_domain(iopt, domain); + __iopt_remove_reserved_iova(iopt, domain); + + WARN_ON(iopt_calculate_iova_alignment(iopt)); +out_unlock: + up_write(&iopt->iova_rwsem); + up_write(&iopt->domains_rwsem); +} + +/** + * iopt_area_split - Split an area into two parts at iova + * @area: The area to split + * @iova: Becomes the last of a new area + * + * This splits an area into two. It is part of the VFIO compatibility to allow + * poking a hole in the mapping. The two areas continue to point at the same + * iopt_pages, just with different starting bytes. + */ +static int iopt_area_split(struct iopt_area *area, unsigned long iova) +{ + unsigned long alignment = area->iopt->iova_alignment; + unsigned long last_iova = iopt_area_last_iova(area); + unsigned long start_iova = iopt_area_iova(area); + unsigned long new_start = iova + 1; + struct io_pagetable *iopt = area->iopt; + struct iopt_pages *pages = area->pages; + struct iopt_area *lhs; + struct iopt_area *rhs; + int rc; + + lockdep_assert_held_write(&iopt->iova_rwsem); + + if (iova == start_iova || iova == last_iova) + return 0; + + if (!pages || area->prevent_access) + return -EBUSY; + + if (new_start & (alignment - 1) || + iopt_area_start_byte(area, new_start) & (alignment - 1)) + return -EINVAL; + + lhs = kzalloc(sizeof(*area), GFP_KERNEL_ACCOUNT); + if (!lhs) + return -ENOMEM; + + rhs = kzalloc(sizeof(*area), GFP_KERNEL_ACCOUNT); + if (!rhs) { + rc = -ENOMEM; + goto err_free_lhs; + } + + mutex_lock(&pages->mutex); + /* + * Splitting is not permitted if an access exists, we don't track enough + * information to split existing accesses. + */ + if (area->num_accesses) { + rc = -EINVAL; + goto err_unlock; + } + + /* + * Splitting is not permitted if a domain could have been mapped with + * huge pages. + */ + if (area->storage_domain && !iopt->disable_large_pages) { + rc = -EINVAL; + goto err_unlock; + } + + interval_tree_remove(&area->node, &iopt->area_itree); + rc = iopt_insert_area(iopt, lhs, area->pages, start_iova, + iopt_area_start_byte(area, start_iova), + (new_start - 1) - start_iova + 1, + area->iommu_prot); + if (WARN_ON(rc)) + goto err_insert; + + rc = iopt_insert_area(iopt, rhs, area->pages, new_start, + iopt_area_start_byte(area, new_start), + last_iova - new_start + 1, area->iommu_prot); + if (WARN_ON(rc)) + goto err_remove_lhs; + + lhs->storage_domain = area->storage_domain; + lhs->pages = area->pages; + rhs->storage_domain = area->storage_domain; + rhs->pages = area->pages; + kref_get(&rhs->pages->kref); + kfree(area); + mutex_unlock(&pages->mutex); + + /* + * No change to domains or accesses because the pages hasn't been + * changed + */ + return 0; + +err_remove_lhs: + interval_tree_remove(&lhs->node, &iopt->area_itree); +err_insert: + interval_tree_insert(&area->node, &iopt->area_itree); +err_unlock: + mutex_unlock(&pages->mutex); + kfree(rhs); +err_free_lhs: + kfree(lhs); + return rc; +} + +int iopt_cut_iova(struct io_pagetable *iopt, unsigned long *iovas, + size_t num_iovas) +{ + int rc = 0; + int i; + + down_write(&iopt->iova_rwsem); + for (i = 0; i < num_iovas; i++) { + struct iopt_area *area; + + area = iopt_area_iter_first(iopt, iovas[i], iovas[i]); + if (!area) + continue; + rc = iopt_area_split(area, iovas[i]); + if (rc) + break; + } + up_write(&iopt->iova_rwsem); + return rc; +} + +void iopt_enable_large_pages(struct io_pagetable *iopt) +{ + int rc; + + down_write(&iopt->domains_rwsem); + down_write(&iopt->iova_rwsem); + WRITE_ONCE(iopt->disable_large_pages, false); + rc = iopt_calculate_iova_alignment(iopt); + WARN_ON(rc); + up_write(&iopt->iova_rwsem); + up_write(&iopt->domains_rwsem); +} + +int iopt_disable_large_pages(struct io_pagetable *iopt) +{ + int rc = 0; + + down_write(&iopt->domains_rwsem); + down_write(&iopt->iova_rwsem); + if (iopt->disable_large_pages) + goto out_unlock; + + /* Won't do it if domains already have pages mapped in them */ + if (!xa_empty(&iopt->domains) && + !RB_EMPTY_ROOT(&iopt->area_itree.rb_root)) { + rc = -EINVAL; + goto out_unlock; + } + + WRITE_ONCE(iopt->disable_large_pages, true); + rc = iopt_calculate_iova_alignment(iopt); + if (rc) + WRITE_ONCE(iopt->disable_large_pages, false); +out_unlock: + up_write(&iopt->iova_rwsem); + up_write(&iopt->domains_rwsem); + return rc; +} + +int iopt_add_access(struct io_pagetable *iopt, struct iommufd_access *access) +{ + int rc; + + down_write(&iopt->domains_rwsem); + down_write(&iopt->iova_rwsem); + rc = xa_alloc(&iopt->access_list, &access->iopt_access_list_id, access, + xa_limit_16b, GFP_KERNEL_ACCOUNT); + if (rc) + goto out_unlock; + + rc = iopt_calculate_iova_alignment(iopt); + if (rc) { + xa_erase(&iopt->access_list, access->iopt_access_list_id); + goto out_unlock; + } + +out_unlock: + up_write(&iopt->iova_rwsem); + up_write(&iopt->domains_rwsem); + return rc; +} + +void iopt_remove_access(struct io_pagetable *iopt, + struct iommufd_access *access) +{ + down_write(&iopt->domains_rwsem); + down_write(&iopt->iova_rwsem); + WARN_ON(xa_erase(&iopt->access_list, access->iopt_access_list_id) != + access); + WARN_ON(iopt_calculate_iova_alignment(iopt)); + up_write(&iopt->iova_rwsem); + up_write(&iopt->domains_rwsem); +} + +/* Narrow the valid_iova_itree to include reserved ranges from a group. */ +int iopt_table_enforce_group_resv_regions(struct io_pagetable *iopt, + struct device *device, + struct iommu_group *group, + phys_addr_t *sw_msi_start) +{ + struct iommu_resv_region *resv; + struct iommu_resv_region *tmp; + LIST_HEAD(group_resv_regions); + int rc; + + down_write(&iopt->iova_rwsem); + rc = iommu_get_group_resv_regions(group, &group_resv_regions); + if (rc) + goto out_unlock; + + list_for_each_entry(resv, &group_resv_regions, list) { + if (resv->type == IOMMU_RESV_DIRECT_RELAXABLE) + continue; + + /* + * The presence of any 'real' MSI regions should take precedence + * over the software-managed one if the IOMMU driver happens to + * advertise both types. + */ + if (sw_msi_start && resv->type == IOMMU_RESV_MSI) { + *sw_msi_start = 0; + sw_msi_start = NULL; + } + if (sw_msi_start && resv->type == IOMMU_RESV_SW_MSI) + *sw_msi_start = resv->start; + + rc = iopt_reserve_iova(iopt, resv->start, + resv->length - 1 + resv->start, device); + if (rc) + goto out_reserved; + } + rc = 0; + goto out_free_resv; + +out_reserved: + __iopt_remove_reserved_iova(iopt, device); +out_free_resv: + list_for_each_entry_safe(resv, tmp, &group_resv_regions, list) + kfree(resv); +out_unlock: + up_write(&iopt->iova_rwsem); + return rc; +} diff --git a/drivers/iommu/iommufd/io_pagetable.h b/drivers/iommu/iommufd/io_pagetable.h index a2b724175057..2ee6942c3ef4 100644 --- a/drivers/iommu/iommufd/io_pagetable.h +++ b/drivers/iommu/iommufd/io_pagetable.h @@ -46,9 +46,19 @@ struct iopt_area { unsigned int page_offset; /* IOMMU_READ, IOMMU_WRITE, etc */ int iommu_prot; + bool prevent_access : 1; unsigned int num_accesses; }; +struct iopt_allowed { + struct interval_tree_node node; +}; + +struct iopt_reserved { + struct interval_tree_node node; + void *owner; +}; + int iopt_area_fill_domains(struct iopt_area *area, struct iopt_pages *pages); void iopt_area_unfill_domains(struct iopt_area *area, struct iopt_pages *pages); @@ -83,6 +93,24 @@ static inline size_t iopt_area_length(struct iopt_area *area) return (area->node.last - area->node.start) + 1; } +/* + * Number of bytes from the start of the iopt_pages that the iova begins. + * iopt_area_start_byte() / PAGE_SIZE encodes the starting page index + * iopt_area_start_byte() % PAGE_SIZE encodes the offset within that page + */ +static inline unsigned long iopt_area_start_byte(struct iopt_area *area, + unsigned long iova) +{ + return (iova - iopt_area_iova(area)) + area->page_offset + + iopt_area_index(area) * PAGE_SIZE; +} + +static inline unsigned long iopt_area_iova_to_index(struct iopt_area *area, + unsigned long iova) +{ + return iopt_area_start_byte(area, iova) / PAGE_SIZE; +} + #define __make_iopt_iter(name) \ static inline struct iopt_##name *iopt_##name##_iter_first( \ struct io_pagetable *iopt, unsigned long start, \ @@ -110,6 +138,33 @@ static inline size_t iopt_area_length(struct iopt_area *area) } __make_iopt_iter(area) +__make_iopt_iter(allowed) +__make_iopt_iter(reserved) + +struct iopt_area_contig_iter { + unsigned long cur_iova; + unsigned long last_iova; + struct iopt_area *area; +}; +struct iopt_area *iopt_area_contig_init(struct iopt_area_contig_iter *iter, + struct io_pagetable *iopt, + unsigned long iova, + unsigned long last_iova); +struct iopt_area *iopt_area_contig_next(struct iopt_area_contig_iter *iter); + +static inline bool iopt_area_contig_done(struct iopt_area_contig_iter *iter) +{ + return iter->area && iter->last_iova <= iopt_area_last_iova(iter->area); +} + +/* + * Iterate over a contiguous list of areas that span the iova,last_iova range. + * The caller must check iopt_area_contig_done() after the loop to see if + * contiguous areas existed. + */ +#define iopt_for_each_contig_area(iter, area, iopt, iova, last_iova) \ + for (area = iopt_area_contig_init(iter, iopt, iova, last_iova); area; \ + area = iopt_area_contig_next(iter)) enum { IOPT_PAGES_ACCOUNT_NONE = 0, diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 169a30ff3bf0..f7ab6c6edafd 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -9,9 +9,14 @@ #include #include +struct iommu_domain; +struct iommu_group; + struct iommufd_ctx { struct file *file; struct xarray objects; + + u8 account_mode; }; /* @@ -27,6 +32,7 @@ struct iommufd_ctx { struct io_pagetable { struct rw_semaphore domains_rwsem; struct xarray domains; + struct xarray access_list; unsigned int next_domain_id; struct rw_semaphore iova_rwsem; @@ -36,7 +42,45 @@ struct io_pagetable { /* IOVA that cannot be allocated, struct iopt_reserved */ struct rb_root_cached reserved_itree; u8 disable_large_pages; + unsigned long iova_alignment; +}; + +void iopt_init_table(struct io_pagetable *iopt); +void iopt_destroy_table(struct io_pagetable *iopt); +int iopt_get_pages(struct io_pagetable *iopt, unsigned long iova, + unsigned long length, struct list_head *pages_list); +void iopt_free_pages_list(struct list_head *pages_list); +enum { + IOPT_ALLOC_IOVA = 1 << 0, }; +int iopt_map_user_pages(struct iommufd_ctx *ictx, struct io_pagetable *iopt, + unsigned long *iova, void __user *uptr, + unsigned long length, int iommu_prot, + unsigned int flags); +int iopt_map_pages(struct io_pagetable *iopt, struct list_head *pages_list, + unsigned long length, unsigned long *dst_iova, + int iommu_prot, unsigned int flags); +int iopt_unmap_iova(struct io_pagetable *iopt, unsigned long iova, + unsigned long length, unsigned long *unmapped); +int iopt_unmap_all(struct io_pagetable *iopt, unsigned long *unmapped); + +int iopt_table_add_domain(struct io_pagetable *iopt, + struct iommu_domain *domain); +void iopt_table_remove_domain(struct io_pagetable *iopt, + struct iommu_domain *domain); +int iopt_table_enforce_group_resv_regions(struct io_pagetable *iopt, + struct device *device, + struct iommu_group *group, + phys_addr_t *sw_msi_start); +int iopt_set_allow_iova(struct io_pagetable *iopt, + struct rb_root_cached *allowed_iova); +int iopt_reserve_iova(struct io_pagetable *iopt, unsigned long start, + unsigned long last, void *owner); +void iopt_remove_reserved_iova(struct io_pagetable *iopt, void *owner); +int iopt_cut_iova(struct io_pagetable *iopt, unsigned long *iovas, + size_t num_iovas); +void iopt_enable_large_pages(struct io_pagetable *iopt); +int iopt_disable_large_pages(struct io_pagetable *iopt); struct iommufd_ucmd { struct iommufd_ctx *ictx; @@ -130,4 +174,12 @@ struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx, type), \ typeof(*(ptr)), obj) +struct iommufd_access { + unsigned long iova_alignment; + u32 iopt_access_list_id; +}; + +int iopt_add_access(struct io_pagetable *iopt, struct iommufd_access *access); +void iopt_remove_access(struct io_pagetable *iopt, + struct iommufd_access *access); #endif -- cgit v1.2.3 From aad37e71d5c4dc1d3c25734f0bcd51c324f94b5e Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 29 Nov 2022 16:29:34 -0400 Subject: iommufd: IOCTLs for the io_pagetable Connect the IOAS to its IOCTL interface. This exposes most of the functionality in the io_pagetable to userspace. This is intended to be the core of the generic interface that IOMMUFD will provide. Every IOMMU driver should be able to implement an iommu_domain that is compatible with this generic mechanism. It is also designed to be easy to use for simple non virtual machine monitor users, like DPDK: - Universal simple support for all IOMMUs (no PPC special path) - An IOVA allocator that considers the aperture and the allowed/reserved ranges - io_pagetable allows any number of iommu_domains to be connected to the IOAS - Automatic allocation and re-use of iommu_domains Along with room in the design to add non-generic features to cater to specific HW functionality. Link: https://lore.kernel.org/r/11-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Tested-by: Nicolin Chen Tested-by: Yi Liu Tested-by: Lixiao Yang Tested-by: Matthew Rosato Reviewed-by: Kevin Tian Reviewed-by: Eric Auger Signed-off-by: Nicolin Chen Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/Makefile | 1 + drivers/iommu/iommufd/ioas.c | 392 ++++++++++++++++++++++++++++++++ drivers/iommu/iommufd/iommufd_private.h | 33 +++ drivers/iommu/iommufd/main.c | 48 ++++ include/uapi/linux/iommufd.h | 258 ++++++++++++++++++++- 5 files changed, 731 insertions(+), 1 deletion(-) create mode 100644 drivers/iommu/iommufd/ioas.c (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommufd/Makefile b/drivers/iommu/iommufd/Makefile index b66a8c47ff55..2b4f36f1b72f 100644 --- a/drivers/iommu/iommufd/Makefile +++ b/drivers/iommu/iommufd/Makefile @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0-only iommufd-y := \ io_pagetable.o \ + ioas.o \ main.o \ pages.o diff --git a/drivers/iommu/iommufd/ioas.c b/drivers/iommu/iommufd/ioas.c new file mode 100644 index 000000000000..6ff97dafc891 --- /dev/null +++ b/drivers/iommu/iommufd/ioas.c @@ -0,0 +1,392 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES + */ +#include +#include +#include +#include + +#include "io_pagetable.h" + +void iommufd_ioas_destroy(struct iommufd_object *obj) +{ + struct iommufd_ioas *ioas = container_of(obj, struct iommufd_ioas, obj); + int rc; + + rc = iopt_unmap_all(&ioas->iopt, NULL); + WARN_ON(rc && rc != -ENOENT); + iopt_destroy_table(&ioas->iopt); +} + +struct iommufd_ioas *iommufd_ioas_alloc(struct iommufd_ctx *ictx) +{ + struct iommufd_ioas *ioas; + + ioas = iommufd_object_alloc(ictx, ioas, IOMMUFD_OBJ_IOAS); + if (IS_ERR(ioas)) + return ioas; + + iopt_init_table(&ioas->iopt); + return ioas; +} + +int iommufd_ioas_alloc_ioctl(struct iommufd_ucmd *ucmd) +{ + struct iommu_ioas_alloc *cmd = ucmd->cmd; + struct iommufd_ioas *ioas; + int rc; + + if (cmd->flags) + return -EOPNOTSUPP; + + ioas = iommufd_ioas_alloc(ucmd->ictx); + if (IS_ERR(ioas)) + return PTR_ERR(ioas); + + cmd->out_ioas_id = ioas->obj.id; + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); + if (rc) + goto out_table; + iommufd_object_finalize(ucmd->ictx, &ioas->obj); + return 0; + +out_table: + iommufd_object_abort_and_destroy(ucmd->ictx, &ioas->obj); + return rc; +} + +int iommufd_ioas_iova_ranges(struct iommufd_ucmd *ucmd) +{ + struct iommu_iova_range __user *ranges; + struct iommu_ioas_iova_ranges *cmd = ucmd->cmd; + struct iommufd_ioas *ioas; + struct interval_tree_span_iter span; + u32 max_iovas; + int rc; + + if (cmd->__reserved) + return -EOPNOTSUPP; + + ioas = iommufd_get_ioas(ucmd, cmd->ioas_id); + if (IS_ERR(ioas)) + return PTR_ERR(ioas); + + down_read(&ioas->iopt.iova_rwsem); + max_iovas = cmd->num_iovas; + ranges = u64_to_user_ptr(cmd->allowed_iovas); + cmd->num_iovas = 0; + cmd->out_iova_alignment = ioas->iopt.iova_alignment; + interval_tree_for_each_span(&span, &ioas->iopt.reserved_itree, 0, + ULONG_MAX) { + if (!span.is_hole) + continue; + if (cmd->num_iovas < max_iovas) { + struct iommu_iova_range elm = { + .start = span.start_hole, + .last = span.last_hole, + }; + + if (copy_to_user(&ranges[cmd->num_iovas], &elm, + sizeof(elm))) { + rc = -EFAULT; + goto out_put; + } + } + cmd->num_iovas++; + } + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); + if (rc) + goto out_put; + if (cmd->num_iovas > max_iovas) + rc = -EMSGSIZE; +out_put: + up_read(&ioas->iopt.iova_rwsem); + iommufd_put_object(&ioas->obj); + return rc; +} + +static int iommufd_ioas_load_iovas(struct rb_root_cached *itree, + struct iommu_iova_range __user *ranges, + u32 num) +{ + u32 i; + + for (i = 0; i != num; i++) { + struct iommu_iova_range range; + struct iopt_allowed *allowed; + + if (copy_from_user(&range, ranges + i, sizeof(range))) + return -EFAULT; + + if (range.start >= range.last) + return -EINVAL; + + if (interval_tree_iter_first(itree, range.start, range.last)) + return -EINVAL; + + allowed = kzalloc(sizeof(*allowed), GFP_KERNEL_ACCOUNT); + if (!allowed) + return -ENOMEM; + allowed->node.start = range.start; + allowed->node.last = range.last; + + interval_tree_insert(&allowed->node, itree); + } + return 0; +} + +int iommufd_ioas_allow_iovas(struct iommufd_ucmd *ucmd) +{ + struct iommu_ioas_allow_iovas *cmd = ucmd->cmd; + struct rb_root_cached allowed_iova = RB_ROOT_CACHED; + struct interval_tree_node *node; + struct iommufd_ioas *ioas; + struct io_pagetable *iopt; + int rc = 0; + + if (cmd->__reserved) + return -EOPNOTSUPP; + + ioas = iommufd_get_ioas(ucmd, cmd->ioas_id); + if (IS_ERR(ioas)) + return PTR_ERR(ioas); + iopt = &ioas->iopt; + + rc = iommufd_ioas_load_iovas(&allowed_iova, + u64_to_user_ptr(cmd->allowed_iovas), + cmd->num_iovas); + if (rc) + goto out_free; + + /* + * We want the allowed tree update to be atomic, so we have to keep the + * original nodes around, and keep track of the new nodes as we allocate + * memory for them. The simplest solution is to have a new/old tree and + * then swap new for old. On success we free the old tree, on failure we + * free the new tree. + */ + rc = iopt_set_allow_iova(iopt, &allowed_iova); +out_free: + while ((node = interval_tree_iter_first(&allowed_iova, 0, ULONG_MAX))) { + interval_tree_remove(node, &allowed_iova); + kfree(container_of(node, struct iopt_allowed, node)); + } + iommufd_put_object(&ioas->obj); + return rc; +} + +static int conv_iommu_prot(u32 map_flags) +{ + /* + * We provide no manual cache coherency ioctls to userspace and most + * architectures make the CPU ops for cache flushing privileged. + * Therefore we require the underlying IOMMU to support CPU coherent + * operation. Support for IOMMU_CACHE is enforced by the + * IOMMU_CAP_CACHE_COHERENCY test during bind. + */ + int iommu_prot = IOMMU_CACHE; + + if (map_flags & IOMMU_IOAS_MAP_WRITEABLE) + iommu_prot |= IOMMU_WRITE; + if (map_flags & IOMMU_IOAS_MAP_READABLE) + iommu_prot |= IOMMU_READ; + return iommu_prot; +} + +int iommufd_ioas_map(struct iommufd_ucmd *ucmd) +{ + struct iommu_ioas_map *cmd = ucmd->cmd; + unsigned long iova = cmd->iova; + struct iommufd_ioas *ioas; + unsigned int flags = 0; + int rc; + + if ((cmd->flags & + ~(IOMMU_IOAS_MAP_FIXED_IOVA | IOMMU_IOAS_MAP_WRITEABLE | + IOMMU_IOAS_MAP_READABLE)) || + cmd->__reserved) + return -EOPNOTSUPP; + if (cmd->iova >= ULONG_MAX || cmd->length >= ULONG_MAX) + return -EOVERFLOW; + + ioas = iommufd_get_ioas(ucmd, cmd->ioas_id); + if (IS_ERR(ioas)) + return PTR_ERR(ioas); + + if (!(cmd->flags & IOMMU_IOAS_MAP_FIXED_IOVA)) + flags = IOPT_ALLOC_IOVA; + rc = iopt_map_user_pages(ucmd->ictx, &ioas->iopt, &iova, + u64_to_user_ptr(cmd->user_va), cmd->length, + conv_iommu_prot(cmd->flags), flags); + if (rc) + goto out_put; + + cmd->iova = iova; + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); +out_put: + iommufd_put_object(&ioas->obj); + return rc; +} + +int iommufd_ioas_copy(struct iommufd_ucmd *ucmd) +{ + struct iommu_ioas_copy *cmd = ucmd->cmd; + struct iommufd_ioas *src_ioas; + struct iommufd_ioas *dst_ioas; + unsigned int flags = 0; + LIST_HEAD(pages_list); + unsigned long iova; + int rc; + + if ((cmd->flags & + ~(IOMMU_IOAS_MAP_FIXED_IOVA | IOMMU_IOAS_MAP_WRITEABLE | + IOMMU_IOAS_MAP_READABLE))) + return -EOPNOTSUPP; + if (cmd->length >= ULONG_MAX || cmd->src_iova >= ULONG_MAX || + cmd->dst_iova >= ULONG_MAX) + return -EOVERFLOW; + + src_ioas = iommufd_get_ioas(ucmd, cmd->src_ioas_id); + if (IS_ERR(src_ioas)) + return PTR_ERR(src_ioas); + rc = iopt_get_pages(&src_ioas->iopt, cmd->src_iova, cmd->length, + &pages_list); + iommufd_put_object(&src_ioas->obj); + if (rc) + return rc; + + dst_ioas = iommufd_get_ioas(ucmd, cmd->dst_ioas_id); + if (IS_ERR(dst_ioas)) { + rc = PTR_ERR(dst_ioas); + goto out_pages; + } + + if (!(cmd->flags & IOMMU_IOAS_MAP_FIXED_IOVA)) + flags = IOPT_ALLOC_IOVA; + iova = cmd->dst_iova; + rc = iopt_map_pages(&dst_ioas->iopt, &pages_list, cmd->length, &iova, + conv_iommu_prot(cmd->flags), flags); + if (rc) + goto out_put_dst; + + cmd->dst_iova = iova; + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); +out_put_dst: + iommufd_put_object(&dst_ioas->obj); +out_pages: + iopt_free_pages_list(&pages_list); + return rc; +} + +int iommufd_ioas_unmap(struct iommufd_ucmd *ucmd) +{ + struct iommu_ioas_unmap *cmd = ucmd->cmd; + struct iommufd_ioas *ioas; + unsigned long unmapped = 0; + int rc; + + ioas = iommufd_get_ioas(ucmd, cmd->ioas_id); + if (IS_ERR(ioas)) + return PTR_ERR(ioas); + + if (cmd->iova == 0 && cmd->length == U64_MAX) { + rc = iopt_unmap_all(&ioas->iopt, &unmapped); + if (rc) + goto out_put; + } else { + if (cmd->iova >= ULONG_MAX || cmd->length >= ULONG_MAX) { + rc = -EOVERFLOW; + goto out_put; + } + rc = iopt_unmap_iova(&ioas->iopt, cmd->iova, cmd->length, + &unmapped); + if (rc) + goto out_put; + } + + cmd->length = unmapped; + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); + +out_put: + iommufd_put_object(&ioas->obj); + return rc; +} + +int iommufd_option_rlimit_mode(struct iommu_option *cmd, + struct iommufd_ctx *ictx) +{ + if (cmd->object_id) + return -EOPNOTSUPP; + + if (cmd->op == IOMMU_OPTION_OP_GET) { + cmd->val64 = ictx->account_mode == IOPT_PAGES_ACCOUNT_MM; + return 0; + } + if (cmd->op == IOMMU_OPTION_OP_SET) { + int rc = 0; + + if (!capable(CAP_SYS_RESOURCE)) + return -EPERM; + + xa_lock(&ictx->objects); + if (!xa_empty(&ictx->objects)) { + rc = -EBUSY; + } else { + if (cmd->val64 == 0) + ictx->account_mode = IOPT_PAGES_ACCOUNT_USER; + else if (cmd->val64 == 1) + ictx->account_mode = IOPT_PAGES_ACCOUNT_MM; + else + rc = -EINVAL; + } + xa_unlock(&ictx->objects); + + return rc; + } + return -EOPNOTSUPP; +} + +static int iommufd_ioas_option_huge_pages(struct iommu_option *cmd, + struct iommufd_ioas *ioas) +{ + if (cmd->op == IOMMU_OPTION_OP_GET) { + cmd->val64 = !ioas->iopt.disable_large_pages; + return 0; + } + if (cmd->op == IOMMU_OPTION_OP_SET) { + if (cmd->val64 == 0) + return iopt_disable_large_pages(&ioas->iopt); + if (cmd->val64 == 1) { + iopt_enable_large_pages(&ioas->iopt); + return 0; + } + return -EINVAL; + } + return -EOPNOTSUPP; +} + +int iommufd_ioas_option(struct iommufd_ucmd *ucmd) +{ + struct iommu_option *cmd = ucmd->cmd; + struct iommufd_ioas *ioas; + int rc = 0; + + if (cmd->__reserved) + return -EOPNOTSUPP; + + ioas = iommufd_get_ioas(ucmd, cmd->object_id); + if (IS_ERR(ioas)) + return PTR_ERR(ioas); + + switch (cmd->option_id) { + case IOMMU_OPTION_HUGE_PAGES: + rc = iommufd_ioas_option_huge_pages(cmd, ioas); + break; + default: + rc = -EOPNOTSUPP; + } + + iommufd_put_object(&ioas->obj); + return rc; +} diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index f7ab6c6edafd..1a13c54a8def 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -11,6 +11,7 @@ struct iommu_domain; struct iommu_group; +struct iommu_option; struct iommufd_ctx { struct file *file; @@ -102,6 +103,7 @@ static inline int iommufd_ucmd_respond(struct iommufd_ucmd *ucmd, enum iommufd_object_type { IOMMUFD_OBJ_NONE, IOMMUFD_OBJ_ANY = IOMMUFD_OBJ_NONE, + IOMMUFD_OBJ_IOAS, }; /* Base struct for all objects with a userspace ID handle. */ @@ -174,6 +176,37 @@ struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx, type), \ typeof(*(ptr)), obj) +/* + * The IO Address Space (IOAS) pagetable is a virtual page table backed by the + * io_pagetable object. It is a user controlled mapping of IOVA -> PFNs. The + * mapping is copied into all of the associated domains and made available to + * in-kernel users. + */ +struct iommufd_ioas { + struct iommufd_object obj; + struct io_pagetable iopt; +}; + +static inline struct iommufd_ioas *iommufd_get_ioas(struct iommufd_ucmd *ucmd, + u32 id) +{ + return container_of(iommufd_get_object(ucmd->ictx, id, + IOMMUFD_OBJ_IOAS), + struct iommufd_ioas, obj); +} + +struct iommufd_ioas *iommufd_ioas_alloc(struct iommufd_ctx *ictx); +int iommufd_ioas_alloc_ioctl(struct iommufd_ucmd *ucmd); +void iommufd_ioas_destroy(struct iommufd_object *obj); +int iommufd_ioas_iova_ranges(struct iommufd_ucmd *ucmd); +int iommufd_ioas_allow_iovas(struct iommufd_ucmd *ucmd); +int iommufd_ioas_map(struct iommufd_ucmd *ucmd); +int iommufd_ioas_copy(struct iommufd_ucmd *ucmd); +int iommufd_ioas_unmap(struct iommufd_ucmd *ucmd); +int iommufd_ioas_option(struct iommufd_ucmd *ucmd); +int iommufd_option_rlimit_mode(struct iommu_option *cmd, + struct iommufd_ctx *ictx); + struct iommufd_access { unsigned long iova_alignment; u32 iopt_access_list_id; diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index dfbc68b97506..1c0a1f499378 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -204,8 +204,39 @@ static int iommufd_fops_release(struct inode *inode, struct file *filp) return 0; } +static int iommufd_option(struct iommufd_ucmd *ucmd) +{ + struct iommu_option *cmd = ucmd->cmd; + int rc; + + if (cmd->__reserved) + return -EOPNOTSUPP; + + switch (cmd->option_id) { + case IOMMU_OPTION_RLIMIT_MODE: + rc = iommufd_option_rlimit_mode(cmd, ucmd->ictx); + break; + case IOMMU_OPTION_HUGE_PAGES: + rc = iommufd_ioas_option(ucmd); + break; + default: + return -EOPNOTSUPP; + } + if (rc) + return rc; + if (copy_to_user(&((struct iommu_option __user *)ucmd->ubuffer)->val64, + &cmd->val64, sizeof(cmd->val64))) + return -EFAULT; + return 0; +} + union ucmd_buffer { struct iommu_destroy destroy; + struct iommu_ioas_alloc alloc; + struct iommu_ioas_allow_iovas allow_iovas; + struct iommu_ioas_iova_ranges iova_ranges; + struct iommu_ioas_map map; + struct iommu_ioas_unmap unmap; }; struct iommufd_ioctl_op { @@ -226,6 +257,20 @@ struct iommufd_ioctl_op { } static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = { IOCTL_OP(IOMMU_DESTROY, iommufd_destroy, struct iommu_destroy, id), + IOCTL_OP(IOMMU_IOAS_ALLOC, iommufd_ioas_alloc_ioctl, + struct iommu_ioas_alloc, out_ioas_id), + IOCTL_OP(IOMMU_IOAS_ALLOW_IOVAS, iommufd_ioas_allow_iovas, + struct iommu_ioas_allow_iovas, allowed_iovas), + IOCTL_OP(IOMMU_IOAS_COPY, iommufd_ioas_copy, struct iommu_ioas_copy, + src_iova), + IOCTL_OP(IOMMU_IOAS_IOVA_RANGES, iommufd_ioas_iova_ranges, + struct iommu_ioas_iova_ranges, out_iova_alignment), + IOCTL_OP(IOMMU_IOAS_MAP, iommufd_ioas_map, struct iommu_ioas_map, + iova), + IOCTL_OP(IOMMU_IOAS_UNMAP, iommufd_ioas_unmap, struct iommu_ioas_unmap, + length), + IOCTL_OP(IOMMU_OPTION, iommufd_option, struct iommu_option, + val64), }; static long iommufd_fops_ioctl(struct file *filp, unsigned int cmd, @@ -312,6 +357,9 @@ void iommufd_ctx_put(struct iommufd_ctx *ictx) EXPORT_SYMBOL_NS_GPL(iommufd_ctx_put, IOMMUFD); static const struct iommufd_object_ops iommufd_object_ops[] = { + [IOMMUFD_OBJ_IOAS] = { + .destroy = iommufd_ioas_destroy, + }, }; static struct miscdevice iommu_misc_dev = { diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index 37de92f0534b..30cc5c5e2b34 100644 --- a/include/uapi/linux/iommufd.h +++ b/include/uapi/linux/iommufd.h @@ -37,12 +37,19 @@ enum { IOMMUFD_CMD_BASE = 0x80, IOMMUFD_CMD_DESTROY = IOMMUFD_CMD_BASE, + IOMMUFD_CMD_IOAS_ALLOC, + IOMMUFD_CMD_IOAS_ALLOW_IOVAS, + IOMMUFD_CMD_IOAS_COPY, + IOMMUFD_CMD_IOAS_IOVA_RANGES, + IOMMUFD_CMD_IOAS_MAP, + IOMMUFD_CMD_IOAS_UNMAP, + IOMMUFD_CMD_OPTION, }; /** * struct iommu_destroy - ioctl(IOMMU_DESTROY) * @size: sizeof(struct iommu_destroy) - * @id: iommufd object ID to destroy. Can by any destroyable object type. + * @id: iommufd object ID to destroy. Can be any destroyable object type. * * Destroy any object held within iommufd. */ @@ -52,4 +59,253 @@ struct iommu_destroy { }; #define IOMMU_DESTROY _IO(IOMMUFD_TYPE, IOMMUFD_CMD_DESTROY) +/** + * struct iommu_ioas_alloc - ioctl(IOMMU_IOAS_ALLOC) + * @size: sizeof(struct iommu_ioas_alloc) + * @flags: Must be 0 + * @out_ioas_id: Output IOAS ID for the allocated object + * + * Allocate an IO Address Space (IOAS) which holds an IO Virtual Address (IOVA) + * to memory mapping. + */ +struct iommu_ioas_alloc { + __u32 size; + __u32 flags; + __u32 out_ioas_id; +}; +#define IOMMU_IOAS_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_ALLOC) + +/** + * struct iommu_iova_range - ioctl(IOMMU_IOVA_RANGE) + * @start: First IOVA + * @last: Inclusive last IOVA + * + * An interval in IOVA space. + */ +struct iommu_iova_range { + __aligned_u64 start; + __aligned_u64 last; +}; + +/** + * struct iommu_ioas_iova_ranges - ioctl(IOMMU_IOAS_IOVA_RANGES) + * @size: sizeof(struct iommu_ioas_iova_ranges) + * @ioas_id: IOAS ID to read ranges from + * @num_iovas: Input/Output total number of ranges in the IOAS + * @__reserved: Must be 0 + * @allowed_iovas: Pointer to the output array of struct iommu_iova_range + * @out_iova_alignment: Minimum alignment required for mapping IOVA + * + * Query an IOAS for ranges of allowed IOVAs. Mapping IOVA outside these ranges + * is not allowed. num_iovas will be set to the total number of iovas and + * the allowed_iovas[] will be filled in as space permits. + * + * The allowed ranges are dependent on the HW path the DMA operation takes, and + * can change during the lifetime of the IOAS. A fresh empty IOAS will have a + * full range, and each attached device will narrow the ranges based on that + * device's HW restrictions. Detaching a device can widen the ranges. Userspace + * should query ranges after every attach/detach to know what IOVAs are valid + * for mapping. + * + * On input num_iovas is the length of the allowed_iovas array. On output it is + * the total number of iovas filled in. The ioctl will return -EMSGSIZE and set + * num_iovas to the required value if num_iovas is too small. In this case the + * caller should allocate a larger output array and re-issue the ioctl. + * + * out_iova_alignment returns the minimum IOVA alignment that can be given + * to IOMMU_IOAS_MAP/COPY. IOVA's must satisfy:: + * + * starting_iova % out_iova_alignment == 0 + * (starting_iova + length) % out_iova_alignment == 0 + * + * out_iova_alignment can be 1 indicating any IOVA is allowed. It cannot + * be higher than the system PAGE_SIZE. + */ +struct iommu_ioas_iova_ranges { + __u32 size; + __u32 ioas_id; + __u32 num_iovas; + __u32 __reserved; + __aligned_u64 allowed_iovas; + __aligned_u64 out_iova_alignment; +}; +#define IOMMU_IOAS_IOVA_RANGES _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_IOVA_RANGES) + +/** + * struct iommu_ioas_allow_iovas - ioctl(IOMMU_IOAS_ALLOW_IOVAS) + * @size: sizeof(struct iommu_ioas_allow_iovas) + * @ioas_id: IOAS ID to allow IOVAs from + * @num_iovas: Input/Output total number of ranges in the IOAS + * @__reserved: Must be 0 + * @allowed_iovas: Pointer to array of struct iommu_iova_range + * + * Ensure a range of IOVAs are always available for allocation. If this call + * succeeds then IOMMU_IOAS_IOVA_RANGES will never return a list of IOVA ranges + * that are narrower than the ranges provided here. This call will fail if + * IOMMU_IOAS_IOVA_RANGES is currently narrower than the given ranges. + * + * When an IOAS is first created the IOVA_RANGES will be maximally sized, and as + * devices are attached the IOVA will narrow based on the device restrictions. + * When an allowed range is specified any narrowing will be refused, ie device + * attachment can fail if the device requires limiting within the allowed range. + * + * Automatic IOVA allocation is also impacted by this call. MAP will only + * allocate within the allowed IOVAs if they are present. + * + * This call replaces the entire allowed list with the given list. + */ +struct iommu_ioas_allow_iovas { + __u32 size; + __u32 ioas_id; + __u32 num_iovas; + __u32 __reserved; + __aligned_u64 allowed_iovas; +}; +#define IOMMU_IOAS_ALLOW_IOVAS _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_ALLOW_IOVAS) + +/** + * enum iommufd_ioas_map_flags - Flags for map and copy + * @IOMMU_IOAS_MAP_FIXED_IOVA: If clear the kernel will compute an appropriate + * IOVA to place the mapping at + * @IOMMU_IOAS_MAP_WRITEABLE: DMA is allowed to write to this mapping + * @IOMMU_IOAS_MAP_READABLE: DMA is allowed to read from this mapping + */ +enum iommufd_ioas_map_flags { + IOMMU_IOAS_MAP_FIXED_IOVA = 1 << 0, + IOMMU_IOAS_MAP_WRITEABLE = 1 << 1, + IOMMU_IOAS_MAP_READABLE = 1 << 2, +}; + +/** + * struct iommu_ioas_map - ioctl(IOMMU_IOAS_MAP) + * @size: sizeof(struct iommu_ioas_map) + * @flags: Combination of enum iommufd_ioas_map_flags + * @ioas_id: IOAS ID to change the mapping of + * @__reserved: Must be 0 + * @user_va: Userspace pointer to start mapping from + * @length: Number of bytes to map + * @iova: IOVA the mapping was placed at. If IOMMU_IOAS_MAP_FIXED_IOVA is set + * then this must be provided as input. + * + * Set an IOVA mapping from a user pointer. If FIXED_IOVA is specified then the + * mapping will be established at iova, otherwise a suitable location based on + * the reserved and allowed lists will be automatically selected and returned in + * iova. + * + * If IOMMU_IOAS_MAP_FIXED_IOVA is specified then the iova range must currently + * be unused, existing IOVA cannot be replaced. + */ +struct iommu_ioas_map { + __u32 size; + __u32 flags; + __u32 ioas_id; + __u32 __reserved; + __aligned_u64 user_va; + __aligned_u64 length; + __aligned_u64 iova; +}; +#define IOMMU_IOAS_MAP _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_MAP) + +/** + * struct iommu_ioas_copy - ioctl(IOMMU_IOAS_COPY) + * @size: sizeof(struct iommu_ioas_copy) + * @flags: Combination of enum iommufd_ioas_map_flags + * @dst_ioas_id: IOAS ID to change the mapping of + * @src_ioas_id: IOAS ID to copy from + * @length: Number of bytes to copy and map + * @dst_iova: IOVA the mapping was placed at. If IOMMU_IOAS_MAP_FIXED_IOVA is + * set then this must be provided as input. + * @src_iova: IOVA to start the copy + * + * Copy an already existing mapping from src_ioas_id and establish it in + * dst_ioas_id. The src iova/length must exactly match a range used with + * IOMMU_IOAS_MAP. + * + * This may be used to efficiently clone a subset of an IOAS to another, or as a + * kind of 'cache' to speed up mapping. Copy has an efficiency advantage over + * establishing equivalent new mappings, as internal resources are shared, and + * the kernel will pin the user memory only once. + */ +struct iommu_ioas_copy { + __u32 size; + __u32 flags; + __u32 dst_ioas_id; + __u32 src_ioas_id; + __aligned_u64 length; + __aligned_u64 dst_iova; + __aligned_u64 src_iova; +}; +#define IOMMU_IOAS_COPY _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_COPY) + +/** + * struct iommu_ioas_unmap - ioctl(IOMMU_IOAS_UNMAP) + * @size: sizeof(struct iommu_ioas_unmap) + * @ioas_id: IOAS ID to change the mapping of + * @iova: IOVA to start the unmapping at + * @length: Number of bytes to unmap, and return back the bytes unmapped + * + * Unmap an IOVA range. The iova/length must be a superset of a previously + * mapped range used with IOMMU_IOAS_MAP or IOMMU_IOAS_COPY. Splitting or + * truncating ranges is not allowed. The values 0 to U64_MAX will unmap + * everything. + */ +struct iommu_ioas_unmap { + __u32 size; + __u32 ioas_id; + __aligned_u64 iova; + __aligned_u64 length; +}; +#define IOMMU_IOAS_UNMAP _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_UNMAP) + +/** + * enum iommufd_option - ioctl(IOMMU_OPTION_RLIMIT_MODE) and + * ioctl(IOMMU_OPTION_HUGE_PAGES) + * @IOMMU_OPTION_RLIMIT_MODE: + * Change how RLIMIT_MEMLOCK accounting works. The caller must have privilege + * to invoke this. Value 0 (default) is user based accouting, 1 uses process + * based accounting. Global option, object_id must be 0 + * @IOMMU_OPTION_HUGE_PAGES: + * Value 1 (default) allows contiguous pages to be combined when generating + * iommu mappings. Value 0 disables combining, everything is mapped to + * PAGE_SIZE. This can be useful for benchmarking. This is a per-IOAS + * option, the object_id must be the IOAS ID. + */ +enum iommufd_option { + IOMMU_OPTION_RLIMIT_MODE = 0, + IOMMU_OPTION_HUGE_PAGES = 1, +}; + +/** + * enum iommufd_option_ops - ioctl(IOMMU_OPTION_OP_SET) and + * ioctl(IOMMU_OPTION_OP_GET) + * @IOMMU_OPTION_OP_SET: Set the option's value + * @IOMMU_OPTION_OP_GET: Get the option's value + */ +enum iommufd_option_ops { + IOMMU_OPTION_OP_SET = 0, + IOMMU_OPTION_OP_GET = 1, +}; + +/** + * struct iommu_option - iommu option multiplexer + * @size: sizeof(struct iommu_option) + * @option_id: One of enum iommufd_option + * @op: One of enum iommufd_option_ops + * @__reserved: Must be 0 + * @object_id: ID of the object if required + * @val64: Option value to set or value returned on get + * + * Change a simple option value. This multiplexor allows controlling options + * on objects. IOMMU_OPTION_OP_SET will load an option and IOMMU_OPTION_OP_GET + * will return the current value. + */ +struct iommu_option { + __u32 size; + __u32 option_id; + __u16 op; + __u16 __reserved; + __u32 object_id; + __aligned_u64 val64; +}; +#define IOMMU_OPTION _IO(IOMMUFD_TYPE, IOMMUFD_CMD_OPTION) #endif -- cgit v1.2.3 From ea4acfac57b9dee57a7d5840359a41cc3251de92 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 29 Nov 2022 16:29:35 -0400 Subject: iommufd: Add a HW pagetable object The hw_pagetable object exposes the internal struct iommu_domain's to userspace. An iommu_domain is required when any DMA device attaches to an IOAS to control the io page table through the iommu driver. For compatibility with VFIO the hw_pagetable is automatically created when a DMA device is attached to the IOAS. If a compatible iommu_domain already exists then the hw_pagetable associated with it is used for the attachment. In the initial series there is no iommufd uAPI for the hw_pagetable object. The next patch provides driver facing APIs for IO page table attachment that allows drivers to accept either an IOAS or a hw_pagetable ID and for the driver to return the hw_pagetable ID that was auto-selected from an IOAS. The expectation is the driver will provide uAPI through its own FD for attaching its device to iommufd. This allows userspace to learn the mapping of devices to iommu_domains and to override the automatic attachment. The future HW specific interface will allow userspace to create hw_pagetable objects using iommu_domains with IOMMU driver specific parameters. This infrastructure will allow linking those domains to IOAS's and devices. Link: https://lore.kernel.org/r/12-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Reviewed-by: Kevin Tian Reviewed-by: Eric Auger Tested-by: Nicolin Chen Tested-by: Yi Liu Tested-by: Lixiao Yang Tested-by: Matthew Rosato Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/Makefile | 1 + drivers/iommu/iommufd/hw_pagetable.c | 57 +++++++++++++++++++++++++++++++++ drivers/iommu/iommufd/ioas.c | 3 ++ drivers/iommu/iommufd/iommufd_private.h | 33 +++++++++++++++++++ drivers/iommu/iommufd/main.c | 3 ++ 5 files changed, 97 insertions(+) create mode 100644 drivers/iommu/iommufd/hw_pagetable.c (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommufd/Makefile b/drivers/iommu/iommufd/Makefile index 2b4f36f1b72f..e13e971aa28c 100644 --- a/drivers/iommu/iommufd/Makefile +++ b/drivers/iommu/iommufd/Makefile @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0-only iommufd-y := \ + hw_pagetable.o \ io_pagetable.o \ ioas.o \ main.o \ diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c new file mode 100644 index 000000000000..43d473989a06 --- /dev/null +++ b/drivers/iommu/iommufd/hw_pagetable.c @@ -0,0 +1,57 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES + */ +#include + +#include "iommufd_private.h" + +void iommufd_hw_pagetable_destroy(struct iommufd_object *obj) +{ + struct iommufd_hw_pagetable *hwpt = + container_of(obj, struct iommufd_hw_pagetable, obj); + + WARN_ON(!list_empty(&hwpt->devices)); + + iommu_domain_free(hwpt->domain); + refcount_dec(&hwpt->ioas->obj.users); + mutex_destroy(&hwpt->devices_lock); +} + +/** + * iommufd_hw_pagetable_alloc() - Get an iommu_domain for a device + * @ictx: iommufd context + * @ioas: IOAS to associate the domain with + * @dev: Device to get an iommu_domain for + * + * Allocate a new iommu_domain and return it as a hw_pagetable. + */ +struct iommufd_hw_pagetable * +iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas, + struct device *dev) +{ + struct iommufd_hw_pagetable *hwpt; + int rc; + + hwpt = iommufd_object_alloc(ictx, hwpt, IOMMUFD_OBJ_HW_PAGETABLE); + if (IS_ERR(hwpt)) + return hwpt; + + hwpt->domain = iommu_domain_alloc(dev->bus); + if (!hwpt->domain) { + rc = -ENOMEM; + goto out_abort; + } + + INIT_LIST_HEAD(&hwpt->devices); + INIT_LIST_HEAD(&hwpt->hwpt_item); + mutex_init(&hwpt->devices_lock); + /* Pairs with iommufd_hw_pagetable_destroy() */ + refcount_inc(&ioas->obj.users); + hwpt->ioas = ioas; + return hwpt; + +out_abort: + iommufd_object_abort(ictx, &hwpt->obj); + return ERR_PTR(rc); +} diff --git a/drivers/iommu/iommufd/ioas.c b/drivers/iommu/iommufd/ioas.c index 6ff97dafc891..302779b33bd4 100644 --- a/drivers/iommu/iommufd/ioas.c +++ b/drivers/iommu/iommufd/ioas.c @@ -17,6 +17,7 @@ void iommufd_ioas_destroy(struct iommufd_object *obj) rc = iopt_unmap_all(&ioas->iopt, NULL); WARN_ON(rc && rc != -ENOENT); iopt_destroy_table(&ioas->iopt); + mutex_destroy(&ioas->mutex); } struct iommufd_ioas *iommufd_ioas_alloc(struct iommufd_ctx *ictx) @@ -28,6 +29,8 @@ struct iommufd_ioas *iommufd_ioas_alloc(struct iommufd_ctx *ictx) return ioas; iopt_init_table(&ioas->iopt); + INIT_LIST_HEAD(&ioas->hwpt_list); + mutex_init(&ioas->mutex); return ioas; } diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 1a13c54a8def..6b0448702a95 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -103,6 +103,7 @@ static inline int iommufd_ucmd_respond(struct iommufd_ucmd *ucmd, enum iommufd_object_type { IOMMUFD_OBJ_NONE, IOMMUFD_OBJ_ANY = IOMMUFD_OBJ_NONE, + IOMMUFD_OBJ_HW_PAGETABLE, IOMMUFD_OBJ_IOAS, }; @@ -181,10 +182,20 @@ struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx, * io_pagetable object. It is a user controlled mapping of IOVA -> PFNs. The * mapping is copied into all of the associated domains and made available to * in-kernel users. + * + * Every iommu_domain that is created is wrapped in a iommufd_hw_pagetable + * object. When we go to attach a device to an IOAS we need to get an + * iommu_domain and wrapping iommufd_hw_pagetable for it. + * + * An iommu_domain & iommfd_hw_pagetable will be automatically selected + * for a device based on the hwpt_list. If no suitable iommu_domain + * is found a new iommu_domain will be created. */ struct iommufd_ioas { struct iommufd_object obj; struct io_pagetable iopt; + struct mutex mutex; + struct list_head hwpt_list; }; static inline struct iommufd_ioas *iommufd_get_ioas(struct iommufd_ucmd *ucmd, @@ -207,6 +218,28 @@ int iommufd_ioas_option(struct iommufd_ucmd *ucmd); int iommufd_option_rlimit_mode(struct iommu_option *cmd, struct iommufd_ctx *ictx); +/* + * A HW pagetable is called an iommu_domain inside the kernel. This user object + * allows directly creating and inspecting the domains. Domains that have kernel + * owned page tables will be associated with an iommufd_ioas that provides the + * IOVA to PFN map. + */ +struct iommufd_hw_pagetable { + struct iommufd_object obj; + struct iommufd_ioas *ioas; + struct iommu_domain *domain; + bool auto_domain : 1; + /* Head at iommufd_ioas::hwpt_list */ + struct list_head hwpt_item; + struct mutex devices_lock; + struct list_head devices; +}; + +struct iommufd_hw_pagetable * +iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas, + struct device *dev); +void iommufd_hw_pagetable_destroy(struct iommufd_object *obj); + struct iommufd_access { unsigned long iova_alignment; u32 iopt_access_list_id; diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index 1c0a1f499378..ac6580a7b706 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -360,6 +360,9 @@ static const struct iommufd_object_ops iommufd_object_ops[] = { [IOMMUFD_OBJ_IOAS] = { .destroy = iommufd_ioas_destroy, }, + [IOMMUFD_OBJ_HW_PAGETABLE] = { + .destroy = iommufd_hw_pagetable_destroy, + }, }; static struct miscdevice iommu_misc_dev = { -- cgit v1.2.3 From e8d57210035b6377d424ba964961892d01127cf6 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 29 Nov 2022 16:29:36 -0400 Subject: iommufd: Add kAPI toward external drivers for physical devices Add the four functions external drivers need to connect physical DMA to the IOMMUFD: iommufd_device_bind() / iommufd_device_unbind() Register the device with iommufd and establish security isolation. iommufd_device_attach() / iommufd_device_detach() Connect a bound device to a page table Binding a device creates a device object ID in the uAPI, however the generic API does not yet provide any IOCTLs to manipulate them. Link: https://lore.kernel.org/r/13-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Reviewed-by: Kevin Tian Tested-by: Nicolin Chen Tested-by: Yi Liu Tested-by: Lixiao Yang Tested-by: Matthew Rosato Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/Makefile | 1 + drivers/iommu/iommufd/device.c | 419 ++++++++++++++++++++++++++++++++ drivers/iommu/iommufd/iommufd_private.h | 5 + drivers/iommu/iommufd/main.c | 3 + include/linux/iommufd.h | 9 + 5 files changed, 437 insertions(+) create mode 100644 drivers/iommu/iommufd/device.c (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommufd/Makefile b/drivers/iommu/iommufd/Makefile index e13e971aa28c..ca28a135b967 100644 --- a/drivers/iommu/iommufd/Makefile +++ b/drivers/iommu/iommufd/Makefile @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0-only iommufd-y := \ + device.o \ hw_pagetable.o \ io_pagetable.o \ ioas.o \ diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c new file mode 100644 index 000000000000..67cd00b4d926 --- /dev/null +++ b/drivers/iommu/iommufd/device.c @@ -0,0 +1,419 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES + */ +#include +#include +#include +#include + +#include "iommufd_private.h" + +static bool allow_unsafe_interrupts; +module_param(allow_unsafe_interrupts, bool, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC( + allow_unsafe_interrupts, + "Allow IOMMUFD to bind to devices even if the platform cannot isolate " + "the MSI interrupt window. Enabling this is a security weakness."); + +/* + * A iommufd_device object represents the binding relationship between a + * consuming driver and the iommufd. These objects are created/destroyed by + * external drivers, not by userspace. + */ +struct iommufd_device { + struct iommufd_object obj; + struct iommufd_ctx *ictx; + struct iommufd_hw_pagetable *hwpt; + /* Head at iommufd_hw_pagetable::devices */ + struct list_head devices_item; + /* always the physical device */ + struct device *dev; + struct iommu_group *group; + bool enforce_cache_coherency; +}; + +void iommufd_device_destroy(struct iommufd_object *obj) +{ + struct iommufd_device *idev = + container_of(obj, struct iommufd_device, obj); + + iommu_device_release_dma_owner(idev->dev); + iommu_group_put(idev->group); + iommufd_ctx_put(idev->ictx); +} + +/** + * iommufd_device_bind - Bind a physical device to an iommu fd + * @ictx: iommufd file descriptor + * @dev: Pointer to a physical device struct + * @id: Output ID number to return to userspace for this device + * + * A successful bind establishes an ownership over the device and returns + * struct iommufd_device pointer, otherwise returns error pointer. + * + * A driver using this API must set driver_managed_dma and must not touch + * the device until this routine succeeds and establishes ownership. + * + * Binding a PCI device places the entire RID under iommufd control. + * + * The caller must undo this with iommufd_device_unbind() + */ +struct iommufd_device *iommufd_device_bind(struct iommufd_ctx *ictx, + struct device *dev, u32 *id) +{ + struct iommufd_device *idev; + struct iommu_group *group; + int rc; + + /* + * iommufd always sets IOMMU_CACHE because we offer no way for userspace + * to restore cache coherency. + */ + if (!device_iommu_capable(dev, IOMMU_CAP_CACHE_COHERENCY)) + return ERR_PTR(-EINVAL); + + group = iommu_group_get(dev); + if (!group) + return ERR_PTR(-ENODEV); + + rc = iommu_device_claim_dma_owner(dev, ictx); + if (rc) + goto out_group_put; + + idev = iommufd_object_alloc(ictx, idev, IOMMUFD_OBJ_DEVICE); + if (IS_ERR(idev)) { + rc = PTR_ERR(idev); + goto out_release_owner; + } + idev->ictx = ictx; + iommufd_ctx_get(ictx); + idev->dev = dev; + idev->enforce_cache_coherency = + device_iommu_capable(dev, IOMMU_CAP_ENFORCE_CACHE_COHERENCY); + /* The calling driver is a user until iommufd_device_unbind() */ + refcount_inc(&idev->obj.users); + /* group refcount moves into iommufd_device */ + idev->group = group; + + /* + * If the caller fails after this success it must call + * iommufd_unbind_device() which is safe since we hold this refcount. + * This also means the device is a leaf in the graph and no other object + * can take a reference on it. + */ + iommufd_object_finalize(ictx, &idev->obj); + *id = idev->obj.id; + return idev; + +out_release_owner: + iommu_device_release_dma_owner(dev); +out_group_put: + iommu_group_put(group); + return ERR_PTR(rc); +} +EXPORT_SYMBOL_NS_GPL(iommufd_device_bind, IOMMUFD); + +/** + * iommufd_device_unbind - Undo iommufd_device_bind() + * @idev: Device returned by iommufd_device_bind() + * + * Release the device from iommufd control. The DMA ownership will return back + * to unowned with DMA controlled by the DMA API. This invalidates the + * iommufd_device pointer, other APIs that consume it must not be called + * concurrently. + */ +void iommufd_device_unbind(struct iommufd_device *idev) +{ + bool was_destroyed; + + was_destroyed = iommufd_object_destroy_user(idev->ictx, &idev->obj); + WARN_ON(!was_destroyed); +} +EXPORT_SYMBOL_NS_GPL(iommufd_device_unbind, IOMMUFD); + +static int iommufd_device_setup_msi(struct iommufd_device *idev, + struct iommufd_hw_pagetable *hwpt, + phys_addr_t sw_msi_start) +{ + int rc; + + /* + * IOMMU_CAP_INTR_REMAP means that the platform is isolating MSI, and it + * creates the MSI window by default in the iommu domain. Nothing + * further to do. + */ + if (device_iommu_capable(idev->dev, IOMMU_CAP_INTR_REMAP)) + return 0; + + /* + * On ARM systems that set the global IRQ_DOMAIN_FLAG_MSI_REMAP every + * allocated iommu_domain will block interrupts by default and this + * special flow is needed to turn them back on. iommu_dma_prepare_msi() + * will install pages into our domain after request_irq() to make this + * work. + * + * FIXME: This is conceptually broken for iommufd since we want to allow + * userspace to change the domains, eg switch from an identity IOAS to a + * DMA IOAS. There is currently no way to create a MSI window that + * matches what the IRQ layer actually expects in a newly created + * domain. + */ + if (irq_domain_check_msi_remap()) { + if (WARN_ON(!sw_msi_start)) + return -EPERM; + /* + * iommu_get_msi_cookie() can only be called once per domain, + * it returns -EBUSY on later calls. + */ + if (hwpt->msi_cookie) + return 0; + rc = iommu_get_msi_cookie(hwpt->domain, sw_msi_start); + if (rc) + return rc; + hwpt->msi_cookie = true; + return 0; + } + + /* + * Otherwise the platform has a MSI window that is not isolated. For + * historical compat with VFIO allow a module parameter to ignore the + * insecurity. + */ + if (!allow_unsafe_interrupts) + return -EPERM; + + dev_warn( + idev->dev, + "MSI interrupt window cannot be isolated by the IOMMU, this platform is insecure. Use the \"allow_unsafe_interrupts\" module parameter to override\n"); + return 0; +} + +static bool iommufd_hw_pagetable_has_group(struct iommufd_hw_pagetable *hwpt, + struct iommu_group *group) +{ + struct iommufd_device *cur_dev; + + list_for_each_entry(cur_dev, &hwpt->devices, devices_item) + if (cur_dev->group == group) + return true; + return false; +} + +static int iommufd_device_do_attach(struct iommufd_device *idev, + struct iommufd_hw_pagetable *hwpt) +{ + phys_addr_t sw_msi_start = 0; + int rc; + + mutex_lock(&hwpt->devices_lock); + + /* + * Try to upgrade the domain we have, it is an iommu driver bug to + * report IOMMU_CAP_ENFORCE_CACHE_COHERENCY but fail + * enforce_cache_coherency when there are no devices attached to the + * domain. + */ + if (idev->enforce_cache_coherency && !hwpt->enforce_cache_coherency) { + if (hwpt->domain->ops->enforce_cache_coherency) + hwpt->enforce_cache_coherency = + hwpt->domain->ops->enforce_cache_coherency( + hwpt->domain); + if (!hwpt->enforce_cache_coherency) { + WARN_ON(list_empty(&hwpt->devices)); + rc = -EINVAL; + goto out_unlock; + } + } + + rc = iopt_table_enforce_group_resv_regions(&hwpt->ioas->iopt, idev->dev, + idev->group, &sw_msi_start); + if (rc) + goto out_unlock; + + rc = iommufd_device_setup_msi(idev, hwpt, sw_msi_start); + if (rc) + goto out_iova; + + /* + * FIXME: Hack around missing a device-centric iommu api, only attach to + * the group once for the first device that is in the group. + */ + if (!iommufd_hw_pagetable_has_group(hwpt, idev->group)) { + rc = iommu_attach_group(hwpt->domain, idev->group); + if (rc) + goto out_iova; + + if (list_empty(&hwpt->devices)) { + rc = iopt_table_add_domain(&hwpt->ioas->iopt, + hwpt->domain); + if (rc) + goto out_detach; + } + } + + idev->hwpt = hwpt; + refcount_inc(&hwpt->obj.users); + list_add(&idev->devices_item, &hwpt->devices); + mutex_unlock(&hwpt->devices_lock); + return 0; + +out_detach: + iommu_detach_group(hwpt->domain, idev->group); +out_iova: + iopt_remove_reserved_iova(&hwpt->ioas->iopt, idev->dev); +out_unlock: + mutex_unlock(&hwpt->devices_lock); + return rc; +} + +/* + * When automatically managing the domains we search for a compatible domain in + * the iopt and if one is found use it, otherwise create a new domain. + * Automatic domain selection will never pick a manually created domain. + */ +static int iommufd_device_auto_get_domain(struct iommufd_device *idev, + struct iommufd_ioas *ioas) +{ + struct iommufd_hw_pagetable *hwpt; + int rc; + + /* + * There is no differentiation when domains are allocated, so any domain + * that is willing to attach to the device is interchangeable with any + * other. + */ + mutex_lock(&ioas->mutex); + list_for_each_entry(hwpt, &ioas->hwpt_list, hwpt_item) { + if (!hwpt->auto_domain) + continue; + + rc = iommufd_device_do_attach(idev, hwpt); + + /* + * -EINVAL means the domain is incompatible with the device. + * Other error codes should propagate to userspace as failure. + * Success means the domain is attached. + */ + if (rc == -EINVAL) + continue; + goto out_unlock; + } + + hwpt = iommufd_hw_pagetable_alloc(idev->ictx, ioas, idev->dev); + if (IS_ERR(hwpt)) { + rc = PTR_ERR(hwpt); + goto out_unlock; + } + hwpt->auto_domain = true; + + rc = iommufd_device_do_attach(idev, hwpt); + if (rc) + goto out_abort; + list_add_tail(&hwpt->hwpt_item, &ioas->hwpt_list); + + mutex_unlock(&ioas->mutex); + iommufd_object_finalize(idev->ictx, &hwpt->obj); + return 0; + +out_abort: + iommufd_object_abort_and_destroy(idev->ictx, &hwpt->obj); +out_unlock: + mutex_unlock(&ioas->mutex); + return rc; +} + +/** + * iommufd_device_attach - Connect a device from an iommu_domain + * @idev: device to attach + * @pt_id: Input a IOMMUFD_OBJ_IOAS, or IOMMUFD_OBJ_HW_PAGETABLE + * Output the IOMMUFD_OBJ_HW_PAGETABLE ID + * + * This connects the device to an iommu_domain, either automatically or manually + * selected. Once this completes the device could do DMA. + * + * The caller should return the resulting pt_id back to userspace. + * This function is undone by calling iommufd_device_detach(). + */ +int iommufd_device_attach(struct iommufd_device *idev, u32 *pt_id) +{ + struct iommufd_object *pt_obj; + int rc; + + pt_obj = iommufd_get_object(idev->ictx, *pt_id, IOMMUFD_OBJ_ANY); + if (IS_ERR(pt_obj)) + return PTR_ERR(pt_obj); + + switch (pt_obj->type) { + case IOMMUFD_OBJ_HW_PAGETABLE: { + struct iommufd_hw_pagetable *hwpt = + container_of(pt_obj, struct iommufd_hw_pagetable, obj); + + rc = iommufd_device_do_attach(idev, hwpt); + if (rc) + goto out_put_pt_obj; + + mutex_lock(&hwpt->ioas->mutex); + list_add_tail(&hwpt->hwpt_item, &hwpt->ioas->hwpt_list); + mutex_unlock(&hwpt->ioas->mutex); + break; + } + case IOMMUFD_OBJ_IOAS: { + struct iommufd_ioas *ioas = + container_of(pt_obj, struct iommufd_ioas, obj); + + rc = iommufd_device_auto_get_domain(idev, ioas); + if (rc) + goto out_put_pt_obj; + break; + } + default: + rc = -EINVAL; + goto out_put_pt_obj; + } + + refcount_inc(&idev->obj.users); + *pt_id = idev->hwpt->obj.id; + rc = 0; + +out_put_pt_obj: + iommufd_put_object(pt_obj); + return rc; +} +EXPORT_SYMBOL_NS_GPL(iommufd_device_attach, IOMMUFD); + +/** + * iommufd_device_detach - Disconnect a device to an iommu_domain + * @idev: device to detach + * + * Undo iommufd_device_attach(). This disconnects the idev from the previously + * attached pt_id. The device returns back to a blocked DMA translation. + */ +void iommufd_device_detach(struct iommufd_device *idev) +{ + struct iommufd_hw_pagetable *hwpt = idev->hwpt; + + mutex_lock(&hwpt->ioas->mutex); + mutex_lock(&hwpt->devices_lock); + list_del(&idev->devices_item); + if (!iommufd_hw_pagetable_has_group(hwpt, idev->group)) { + if (list_empty(&hwpt->devices)) { + iopt_table_remove_domain(&hwpt->ioas->iopt, + hwpt->domain); + list_del(&hwpt->hwpt_item); + } + iommu_detach_group(hwpt->domain, idev->group); + } + iopt_remove_reserved_iova(&hwpt->ioas->iopt, idev->dev); + mutex_unlock(&hwpt->devices_lock); + mutex_unlock(&hwpt->ioas->mutex); + + if (hwpt->auto_domain) + iommufd_object_destroy_user(idev->ictx, &hwpt->obj); + else + refcount_dec(&hwpt->obj.users); + + idev->hwpt = NULL; + + refcount_dec(&idev->obj.users); +} +EXPORT_SYMBOL_NS_GPL(iommufd_device_detach, IOMMUFD); diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 6b0448702a95..72a0c805be23 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -103,6 +103,7 @@ static inline int iommufd_ucmd_respond(struct iommufd_ucmd *ucmd, enum iommufd_object_type { IOMMUFD_OBJ_NONE, IOMMUFD_OBJ_ANY = IOMMUFD_OBJ_NONE, + IOMMUFD_OBJ_DEVICE, IOMMUFD_OBJ_HW_PAGETABLE, IOMMUFD_OBJ_IOAS, }; @@ -229,6 +230,8 @@ struct iommufd_hw_pagetable { struct iommufd_ioas *ioas; struct iommu_domain *domain; bool auto_domain : 1; + bool enforce_cache_coherency : 1; + bool msi_cookie : 1; /* Head at iommufd_ioas::hwpt_list */ struct list_head hwpt_item; struct mutex devices_lock; @@ -240,6 +243,8 @@ iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas, struct device *dev); void iommufd_hw_pagetable_destroy(struct iommufd_object *obj); +void iommufd_device_destroy(struct iommufd_object *obj); + struct iommufd_access { unsigned long iova_alignment; u32 iopt_access_list_id; diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index ac6580a7b706..fe98912bab0e 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -357,6 +357,9 @@ void iommufd_ctx_put(struct iommufd_ctx *ictx) EXPORT_SYMBOL_NS_GPL(iommufd_ctx_put, IOMMUFD); static const struct iommufd_object_ops iommufd_object_ops[] = { + [IOMMUFD_OBJ_DEVICE] = { + .destroy = iommufd_device_destroy, + }, [IOMMUFD_OBJ_IOAS] = { .destroy = iommufd_ioas_destroy, }, diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h index 26e09d539737..185dff3eb32f 100644 --- a/include/linux/iommufd.h +++ b/include/linux/iommufd.h @@ -9,10 +9,19 @@ #include #include #include +#include +struct iommufd_device; struct iommufd_ctx; struct file; +struct iommufd_device *iommufd_device_bind(struct iommufd_ctx *ictx, + struct device *dev, u32 *id); +void iommufd_device_unbind(struct iommufd_device *idev); + +int iommufd_device_attach(struct iommufd_device *idev, u32 *pt_id); +void iommufd_device_detach(struct iommufd_device *idev); + enum { IOMMUFD_ACCESS_RW_READ = 0, IOMMUFD_ACCESS_RW_WRITE = 1 << 0, -- cgit v1.2.3 From 8d40205f6093f18e07fe3dc5920fc85e9f82b8b3 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 29 Nov 2022 16:29:37 -0400 Subject: iommufd: Add kAPI toward external drivers for kernel access Kernel access is the mode that VFIO "mdevs" use. In this case there is no struct device and no IOMMU connection. iommufd acts as a record keeper for accesses and returns the actual struct pages back to the caller to use however they need. eg with kmap or the DMA API. Each caller must create a struct iommufd_access with iommufd_access_create(), similar to how iommufd_device_bind() works. Using this struct the caller can access blocks of IOVA using iommufd_access_pin_pages() or iommufd_access_rw(). Callers must provide a callback that immediately unpins any IOVA being used within a range. This happens if userspace unmaps the IOVA under the pin. The implementation forwards the access requests directly to the iopt infrastructure that manages the iopt_pages_access. Link: https://lore.kernel.org/r/14-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Reviewed-by: Kevin Tian Tested-by: Nicolin Chen Tested-by: Yi Liu Tested-by: Lixiao Yang Tested-by: Matthew Rosato Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/device.c | 316 ++++++++++++++++++++++++++++++++ drivers/iommu/iommufd/io_pagetable.c | 8 +- drivers/iommu/iommufd/iommufd_private.h | 10 + drivers/iommu/iommufd/main.c | 3 + include/linux/iommufd.h | 43 ++++- 5 files changed, 377 insertions(+), 3 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c index 67cd00b4d926..06b6894b7706 100644 --- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -6,6 +6,7 @@ #include #include +#include "io_pagetable.h" #include "iommufd_private.h" static bool allow_unsafe_interrupts; @@ -417,3 +418,318 @@ void iommufd_device_detach(struct iommufd_device *idev) refcount_dec(&idev->obj.users); } EXPORT_SYMBOL_NS_GPL(iommufd_device_detach, IOMMUFD); + +void iommufd_access_destroy_object(struct iommufd_object *obj) +{ + struct iommufd_access *access = + container_of(obj, struct iommufd_access, obj); + + iopt_remove_access(&access->ioas->iopt, access); + iommufd_ctx_put(access->ictx); + refcount_dec(&access->ioas->obj.users); +} + +/** + * iommufd_access_create - Create an iommufd_access + * @ictx: iommufd file descriptor + * @ioas_id: ID for a IOMMUFD_OBJ_IOAS + * @ops: Driver's ops to associate with the access + * @data: Opaque data to pass into ops functions + * + * An iommufd_access allows a driver to read/write to the IOAS without using + * DMA. The underlying CPU memory can be accessed using the + * iommufd_access_pin_pages() or iommufd_access_rw() functions. + * + * The provided ops are required to use iommufd_access_pin_pages(). + */ +struct iommufd_access * +iommufd_access_create(struct iommufd_ctx *ictx, u32 ioas_id, + const struct iommufd_access_ops *ops, void *data) +{ + struct iommufd_access *access; + struct iommufd_object *obj; + int rc; + + /* + * There is no uAPI for the access object, but to keep things symmetric + * use the object infrastructure anyhow. + */ + access = iommufd_object_alloc(ictx, access, IOMMUFD_OBJ_ACCESS); + if (IS_ERR(access)) + return access; + + access->data = data; + access->ops = ops; + + obj = iommufd_get_object(ictx, ioas_id, IOMMUFD_OBJ_IOAS); + if (IS_ERR(obj)) { + rc = PTR_ERR(obj); + goto out_abort; + } + access->ioas = container_of(obj, struct iommufd_ioas, obj); + iommufd_ref_to_users(obj); + + if (ops->needs_pin_pages) + access->iova_alignment = PAGE_SIZE; + else + access->iova_alignment = 1; + rc = iopt_add_access(&access->ioas->iopt, access); + if (rc) + goto out_put_ioas; + + /* The calling driver is a user until iommufd_access_destroy() */ + refcount_inc(&access->obj.users); + access->ictx = ictx; + iommufd_ctx_get(ictx); + iommufd_object_finalize(ictx, &access->obj); + return access; +out_put_ioas: + refcount_dec(&access->ioas->obj.users); +out_abort: + iommufd_object_abort(ictx, &access->obj); + return ERR_PTR(rc); +} +EXPORT_SYMBOL_NS_GPL(iommufd_access_create, IOMMUFD); + +/** + * iommufd_access_destroy - Destroy an iommufd_access + * @access: The access to destroy + * + * The caller must stop using the access before destroying it. + */ +void iommufd_access_destroy(struct iommufd_access *access) +{ + bool was_destroyed; + + was_destroyed = iommufd_object_destroy_user(access->ictx, &access->obj); + WARN_ON(!was_destroyed); +} +EXPORT_SYMBOL_NS_GPL(iommufd_access_destroy, IOMMUFD); + +/** + * iommufd_access_notify_unmap - Notify users of an iopt to stop using it + * @iopt: iopt to work on + * @iova: Starting iova in the iopt + * @length: Number of bytes + * + * After this function returns there should be no users attached to the pages + * linked to this iopt that intersect with iova,length. Anyone that has attached + * a user through iopt_access_pages() needs to detach it through + * iommufd_access_unpin_pages() before this function returns. + * + * iommufd_access_destroy() will wait for any outstanding unmap callback to + * complete. Once iommufd_access_destroy() no unmap ops are running or will + * run in the future. Due to this a driver must not create locking that prevents + * unmap to complete while iommufd_access_destroy() is running. + */ +void iommufd_access_notify_unmap(struct io_pagetable *iopt, unsigned long iova, + unsigned long length) +{ + struct iommufd_ioas *ioas = + container_of(iopt, struct iommufd_ioas, iopt); + struct iommufd_access *access; + unsigned long index; + + xa_lock(&ioas->iopt.access_list); + xa_for_each(&ioas->iopt.access_list, index, access) { + if (!iommufd_lock_obj(&access->obj)) + continue; + xa_unlock(&ioas->iopt.access_list); + + access->ops->unmap(access->data, iova, length); + + iommufd_put_object(&access->obj); + xa_lock(&ioas->iopt.access_list); + } + xa_unlock(&ioas->iopt.access_list); +} + +/** + * iommufd_access_unpin_pages() - Undo iommufd_access_pin_pages + * @access: IOAS access to act on + * @iova: Starting IOVA + * @length: Number of bytes to access + * + * Return the struct page's. The caller must stop accessing them before calling + * this. The iova/length must exactly match the one provided to access_pages. + */ +void iommufd_access_unpin_pages(struct iommufd_access *access, + unsigned long iova, unsigned long length) +{ + struct io_pagetable *iopt = &access->ioas->iopt; + struct iopt_area_contig_iter iter; + unsigned long last_iova; + struct iopt_area *area; + + if (WARN_ON(!length) || + WARN_ON(check_add_overflow(iova, length - 1, &last_iova))) + return; + + down_read(&iopt->iova_rwsem); + iopt_for_each_contig_area(&iter, area, iopt, iova, last_iova) + iopt_area_remove_access( + area, iopt_area_iova_to_index(area, iter.cur_iova), + iopt_area_iova_to_index( + area, + min(last_iova, iopt_area_last_iova(area)))); + up_read(&iopt->iova_rwsem); + WARN_ON(!iopt_area_contig_done(&iter)); +} +EXPORT_SYMBOL_NS_GPL(iommufd_access_unpin_pages, IOMMUFD); + +static bool iopt_area_contig_is_aligned(struct iopt_area_contig_iter *iter) +{ + if (iopt_area_start_byte(iter->area, iter->cur_iova) % PAGE_SIZE) + return false; + + if (!iopt_area_contig_done(iter) && + (iopt_area_start_byte(iter->area, iopt_area_last_iova(iter->area)) % + PAGE_SIZE) != (PAGE_SIZE - 1)) + return false; + return true; +} + +static bool check_area_prot(struct iopt_area *area, unsigned int flags) +{ + if (flags & IOMMUFD_ACCESS_RW_WRITE) + return area->iommu_prot & IOMMU_WRITE; + return area->iommu_prot & IOMMU_READ; +} + +/** + * iommufd_access_pin_pages() - Return a list of pages under the iova + * @access: IOAS access to act on + * @iova: Starting IOVA + * @length: Number of bytes to access + * @out_pages: Output page list + * @flags: IOPMMUFD_ACCESS_RW_* flags + * + * Reads @length bytes starting at iova and returns the struct page * pointers. + * These can be kmap'd by the caller for CPU access. + * + * The caller must perform iommufd_access_unpin_pages() when done to balance + * this. + * + * This API always requires a page aligned iova. This happens naturally if the + * ioas alignment is >= PAGE_SIZE and the iova is PAGE_SIZE aligned. However + * smaller alignments have corner cases where this API can fail on otherwise + * aligned iova. + */ +int iommufd_access_pin_pages(struct iommufd_access *access, unsigned long iova, + unsigned long length, struct page **out_pages, + unsigned int flags) +{ + struct io_pagetable *iopt = &access->ioas->iopt; + struct iopt_area_contig_iter iter; + unsigned long last_iova; + struct iopt_area *area; + int rc; + + if (!length) + return -EINVAL; + if (check_add_overflow(iova, length - 1, &last_iova)) + return -EOVERFLOW; + + down_read(&iopt->iova_rwsem); + iopt_for_each_contig_area(&iter, area, iopt, iova, last_iova) { + unsigned long last = min(last_iova, iopt_area_last_iova(area)); + unsigned long last_index = iopt_area_iova_to_index(area, last); + unsigned long index = + iopt_area_iova_to_index(area, iter.cur_iova); + + if (area->prevent_access || + !iopt_area_contig_is_aligned(&iter)) { + rc = -EINVAL; + goto err_remove; + } + + if (!check_area_prot(area, flags)) { + rc = -EPERM; + goto err_remove; + } + + rc = iopt_area_add_access(area, index, last_index, out_pages, + flags); + if (rc) + goto err_remove; + out_pages += last_index - index + 1; + } + if (!iopt_area_contig_done(&iter)) { + rc = -ENOENT; + goto err_remove; + } + + up_read(&iopt->iova_rwsem); + return 0; + +err_remove: + if (iova < iter.cur_iova) { + last_iova = iter.cur_iova - 1; + iopt_for_each_contig_area(&iter, area, iopt, iova, last_iova) + iopt_area_remove_access( + area, + iopt_area_iova_to_index(area, iter.cur_iova), + iopt_area_iova_to_index( + area, min(last_iova, + iopt_area_last_iova(area)))); + } + up_read(&iopt->iova_rwsem); + return rc; +} +EXPORT_SYMBOL_NS_GPL(iommufd_access_pin_pages, IOMMUFD); + +/** + * iommufd_access_rw - Read or write data under the iova + * @access: IOAS access to act on + * @iova: Starting IOVA + * @data: Kernel buffer to copy to/from + * @length: Number of bytes to access + * @flags: IOMMUFD_ACCESS_RW_* flags + * + * Copy kernel to/from data into the range given by IOVA/length. If flags + * indicates IOMMUFD_ACCESS_RW_KTHREAD then a large copy can be optimized + * by changing it into copy_to/from_user(). + */ +int iommufd_access_rw(struct iommufd_access *access, unsigned long iova, + void *data, size_t length, unsigned int flags) +{ + struct io_pagetable *iopt = &access->ioas->iopt; + struct iopt_area_contig_iter iter; + struct iopt_area *area; + unsigned long last_iova; + int rc; + + if (!length) + return -EINVAL; + if (check_add_overflow(iova, length - 1, &last_iova)) + return -EOVERFLOW; + + down_read(&iopt->iova_rwsem); + iopt_for_each_contig_area(&iter, area, iopt, iova, last_iova) { + unsigned long last = min(last_iova, iopt_area_last_iova(area)); + unsigned long bytes = (last - iter.cur_iova) + 1; + + if (area->prevent_access) { + rc = -EINVAL; + goto err_out; + } + + if (!check_area_prot(area, flags)) { + rc = -EPERM; + goto err_out; + } + + rc = iopt_pages_rw_access( + area->pages, iopt_area_start_byte(area, iter.cur_iova), + data, bytes, flags); + if (rc) + goto err_out; + data += bytes; + } + if (!iopt_area_contig_done(&iter)) + rc = -ENOENT; +err_out: + up_read(&iopt->iova_rwsem); + return rc; +} +EXPORT_SYMBOL_NS_GPL(iommufd_access_rw, IOMMUFD); diff --git a/drivers/iommu/iommufd/io_pagetable.c b/drivers/iommu/iommufd/io_pagetable.c index 756d347948f0..4f4a9d9aac57 100644 --- a/drivers/iommu/iommufd/io_pagetable.c +++ b/drivers/iommu/iommufd/io_pagetable.c @@ -458,6 +458,7 @@ static int iopt_unmap_iova_range(struct io_pagetable *iopt, unsigned long start, * is NULL. This prevents domain attach/detatch from running * concurrently with cleaning up the area. */ +again: down_read(&iopt->domains_rwsem); down_write(&iopt->iova_rwsem); while ((area = iopt_area_iter_first(iopt, start, last))) { @@ -486,8 +487,11 @@ static int iopt_unmap_iova_range(struct io_pagetable *iopt, unsigned long start, area->prevent_access = true; up_write(&iopt->iova_rwsem); up_read(&iopt->domains_rwsem); - /* Later patch calls back to drivers to unmap */ - return -EBUSY; + iommufd_access_notify_unmap(iopt, area_first, + iopt_area_length(area)); + if (WARN_ON(READ_ONCE(area->num_accesses))) + return -EDEADLOCK; + goto again; } pages = area->pages; diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 72a0c805be23..40302cc0da36 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -65,6 +65,8 @@ int iopt_unmap_iova(struct io_pagetable *iopt, unsigned long iova, unsigned long length, unsigned long *unmapped); int iopt_unmap_all(struct io_pagetable *iopt, unsigned long *unmapped); +void iommufd_access_notify_unmap(struct io_pagetable *iopt, unsigned long iova, + unsigned long length); int iopt_table_add_domain(struct io_pagetable *iopt, struct iommu_domain *domain); void iopt_table_remove_domain(struct io_pagetable *iopt, @@ -106,6 +108,7 @@ enum iommufd_object_type { IOMMUFD_OBJ_DEVICE, IOMMUFD_OBJ_HW_PAGETABLE, IOMMUFD_OBJ_IOAS, + IOMMUFD_OBJ_ACCESS, }; /* Base struct for all objects with a userspace ID handle. */ @@ -246,6 +249,11 @@ void iommufd_hw_pagetable_destroy(struct iommufd_object *obj); void iommufd_device_destroy(struct iommufd_object *obj); struct iommufd_access { + struct iommufd_object obj; + struct iommufd_ctx *ictx; + struct iommufd_ioas *ioas; + const struct iommufd_access_ops *ops; + void *data; unsigned long iova_alignment; u32 iopt_access_list_id; }; @@ -253,4 +261,6 @@ struct iommufd_access { int iopt_add_access(struct io_pagetable *iopt, struct iommufd_access *access); void iopt_remove_access(struct io_pagetable *iopt, struct iommufd_access *access); +void iommufd_access_destroy_object(struct iommufd_object *obj); + #endif diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index fe98912bab0e..4153f6a20255 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -357,6 +357,9 @@ void iommufd_ctx_put(struct iommufd_ctx *ictx) EXPORT_SYMBOL_NS_GPL(iommufd_ctx_put, IOMMUFD); static const struct iommufd_object_ops iommufd_object_ops[] = { + [IOMMUFD_OBJ_ACCESS] = { + .destroy = iommufd_access_destroy_object, + }, [IOMMUFD_OBJ_DEVICE] = { .destroy = iommufd_device_destroy, }, diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h index 185dff3eb32f..46c481a26d79 100644 --- a/include/linux/iommufd.h +++ b/include/linux/iommufd.h @@ -9,10 +9,12 @@ #include #include #include -#include +struct device; struct iommufd_device; +struct page; struct iommufd_ctx; +struct iommufd_access; struct file; struct iommufd_device *iommufd_device_bind(struct iommufd_ctx *ictx, @@ -22,6 +24,11 @@ void iommufd_device_unbind(struct iommufd_device *idev); int iommufd_device_attach(struct iommufd_device *idev, u32 *pt_id); void iommufd_device_detach(struct iommufd_device *idev); +struct iommufd_access_ops { + u8 needs_pin_pages : 1; + void (*unmap)(void *data, unsigned long iova, unsigned long length); +}; + enum { IOMMUFD_ACCESS_RW_READ = 0, IOMMUFD_ACCESS_RW_WRITE = 1 << 0, @@ -29,11 +36,24 @@ enum { IOMMUFD_ACCESS_RW_KTHREAD = 1 << 1, }; +struct iommufd_access * +iommufd_access_create(struct iommufd_ctx *ictx, u32 ioas_id, + const struct iommufd_access_ops *ops, void *data); +void iommufd_access_destroy(struct iommufd_access *access); + void iommufd_ctx_get(struct iommufd_ctx *ictx); #if IS_ENABLED(CONFIG_IOMMUFD) struct iommufd_ctx *iommufd_ctx_from_file(struct file *file); void iommufd_ctx_put(struct iommufd_ctx *ictx); + +int iommufd_access_pin_pages(struct iommufd_access *access, unsigned long iova, + unsigned long length, struct page **out_pages, + unsigned int flags); +void iommufd_access_unpin_pages(struct iommufd_access *access, + unsigned long iova, unsigned long length); +int iommufd_access_rw(struct iommufd_access *access, unsigned long iova, + void *data, size_t len, unsigned int flags); #else /* !CONFIG_IOMMUFD */ static inline struct iommufd_ctx *iommufd_ctx_from_file(struct file *file) { @@ -43,5 +63,26 @@ static inline struct iommufd_ctx *iommufd_ctx_from_file(struct file *file) static inline void iommufd_ctx_put(struct iommufd_ctx *ictx) { } + +static inline int iommufd_access_pin_pages(struct iommufd_access *access, + unsigned long iova, + unsigned long length, + struct page **out_pages, + unsigned int flags) +{ + return -EOPNOTSUPP; +} + +static inline void iommufd_access_unpin_pages(struct iommufd_access *access, + unsigned long iova, + unsigned long length) +{ +} + +static inline int iommufd_access_rw(struct iommufd_access *access, unsigned long iova, + void *data, size_t len, unsigned int flags) +{ + return -EOPNOTSUPP; +} #endif /* CONFIG_IOMMUFD */ #endif -- cgit v1.2.3 From d624d6652a65ad4f47a58b8651a1ec1163bb81d3 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 29 Nov 2022 16:29:38 -0400 Subject: iommufd: vfio container FD ioctl compatibility iommufd can directly implement the /dev/vfio/vfio container IOCTLs by mapping them into io_pagetable operations. A userspace application can test against iommufd and confirm compatibility then simply make a small change to open /dev/iommu instead of /dev/vfio/vfio. For testing purposes /dev/vfio/vfio can be symlinked to /dev/iommu and then all applications will use the compatibility path with no code changes. A later series allows /dev/vfio/vfio to be directly provided by iommufd, which allows the rlimit mode to work the same as well. This series just provides the iommufd side of compatibility. Actually linking this to VFIO_SET_CONTAINER is a followup series, with a link in the cover letter. Internally the compatibility API uses a normal IOAS object that, like vfio, is automatically allocated when the first device is attached. Userspace can also query or set this IOAS object directly using the IOMMU_VFIO_IOAS ioctl. This allows mixing and matching new iommufd only features while still using the VFIO style map/unmap ioctls. While this is enough to operate qemu, it has a few differences: - Resource limits rely on memory cgroups to bound what userspace can do instead of the module parameter dma_entry_limit. - VFIO P2P is not implemented. The DMABUF patches for vfio are a start at a solution where iommufd would import a special DMABUF. This is to avoid further propogating the follow_pfn() security problem. - A full audit for pedantic compatibility details (eg errnos, etc) has not yet been done - powerpc SPAPR is left out, as it is not connected to the iommu_domain framework. It seems interest in SPAPR is minimal as it is currently non-working in v6.1-rc1. They will have to convert to the iommu subsystem framework to enjoy iommfd. The following are not going to be implemented and we expect to remove them from VFIO type1: - SW access 'dirty tracking'. As discussed in the cover letter this will be done in VFIO. - VFIO_TYPE1_NESTING_IOMMU https://lore.kernel.org/all/0-v1-0093c9b0e345+19-vfio_no_nesting_jgg@nvidia.com/ - VFIO_DMA_MAP_FLAG_VADDR https://lore.kernel.org/all/Yz777bJZjTyLrHEQ@nvidia.com/ Link: https://lore.kernel.org/r/15-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Tested-by: Nicolin Chen Tested-by: Yi Liu Tested-by: Lixiao Yang Tested-by: Matthew Rosato Reviewed-by: Kevin Tian Reviewed-by: Eric Auger Signed-off-by: Nicolin Chen Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/Makefile | 3 +- drivers/iommu/iommufd/iommufd_private.h | 6 + drivers/iommu/iommufd/main.c | 16 +- drivers/iommu/iommufd/vfio_compat.c | 472 ++++++++++++++++++++++++++++++++ include/linux/iommufd.h | 7 + include/uapi/linux/iommufd.h | 36 +++ 6 files changed, 534 insertions(+), 6 deletions(-) create mode 100644 drivers/iommu/iommufd/vfio_compat.c (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommufd/Makefile b/drivers/iommu/iommufd/Makefile index ca28a135b967..2fdff04000b3 100644 --- a/drivers/iommu/iommufd/Makefile +++ b/drivers/iommu/iommufd/Makefile @@ -5,6 +5,7 @@ iommufd-y := \ io_pagetable.o \ ioas.o \ main.o \ - pages.o + pages.o \ + vfio_compat.o obj-$(CONFIG_IOMMUFD) += iommufd.o diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 40302cc0da36..8fe5f162ccbc 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -18,6 +18,7 @@ struct iommufd_ctx { struct xarray objects; u8 account_mode; + struct iommufd_ioas *vfio_ioas; }; /* @@ -92,6 +93,9 @@ struct iommufd_ucmd { void *cmd; }; +int iommufd_vfio_ioctl(struct iommufd_ctx *ictx, unsigned int cmd, + unsigned long arg); + /* Copy the response in ucmd->cmd back to userspace. */ static inline int iommufd_ucmd_respond(struct iommufd_ucmd *ucmd, size_t cmd_len) @@ -222,6 +226,8 @@ int iommufd_ioas_option(struct iommufd_ucmd *ucmd); int iommufd_option_rlimit_mode(struct iommu_option *cmd, struct iommufd_ctx *ictx); +int iommufd_vfio_ioas(struct iommufd_ucmd *ucmd); + /* * A HW pagetable is called an iommu_domain inside the kernel. This user object * allows directly creating and inspecting the domains. Domains that have kernel diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index 4153f6a20255..5cf69c4d591d 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -133,6 +133,8 @@ bool iommufd_object_destroy_user(struct iommufd_ctx *ictx, return false; } __xa_erase(&ictx->objects, obj->id); + if (ictx->vfio_ioas && &ictx->vfio_ioas->obj == obj) + ictx->vfio_ioas = NULL; xa_unlock(&ictx->objects); up_write(&obj->destroy_rwsem); @@ -271,27 +273,31 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = { length), IOCTL_OP(IOMMU_OPTION, iommufd_option, struct iommu_option, val64), + IOCTL_OP(IOMMU_VFIO_IOAS, iommufd_vfio_ioas, struct iommu_vfio_ioas, + __reserved), }; static long iommufd_fops_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { + struct iommufd_ctx *ictx = filp->private_data; const struct iommufd_ioctl_op *op; struct iommufd_ucmd ucmd = {}; union ucmd_buffer buf; unsigned int nr; int ret; - ucmd.ictx = filp->private_data; + nr = _IOC_NR(cmd); + if (nr < IOMMUFD_CMD_BASE || + (nr - IOMMUFD_CMD_BASE) >= ARRAY_SIZE(iommufd_ioctl_ops)) + return iommufd_vfio_ioctl(ictx, cmd, arg); + + ucmd.ictx = ictx; ucmd.ubuffer = (void __user *)arg; ret = get_user(ucmd.user_size, (u32 __user *)ucmd.ubuffer); if (ret) return ret; - nr = _IOC_NR(cmd); - if (nr < IOMMUFD_CMD_BASE || - (nr - IOMMUFD_CMD_BASE) >= ARRAY_SIZE(iommufd_ioctl_ops)) - return -ENOIOCTLCMD; op = &iommufd_ioctl_ops[nr - IOMMUFD_CMD_BASE]; if (op->ioctl_num != cmd) return -ENOIOCTLCMD; diff --git a/drivers/iommu/iommufd/vfio_compat.c b/drivers/iommu/iommufd/vfio_compat.c new file mode 100644 index 000000000000..3ceca0e8311c --- /dev/null +++ b/drivers/iommu/iommufd/vfio_compat.c @@ -0,0 +1,472 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES + */ +#include +#include +#include +#include +#include +#include +#include +#include + +#include "iommufd_private.h" + +static struct iommufd_ioas *get_compat_ioas(struct iommufd_ctx *ictx) +{ + struct iommufd_ioas *ioas = ERR_PTR(-ENODEV); + + xa_lock(&ictx->objects); + if (!ictx->vfio_ioas || !iommufd_lock_obj(&ictx->vfio_ioas->obj)) + goto out_unlock; + ioas = ictx->vfio_ioas; +out_unlock: + xa_unlock(&ictx->objects); + return ioas; +} + +/** + * iommufd_vfio_compat_ioas_id - Return the IOAS ID that vfio should use + * @ictx: Context to operate on + * @out_ioas_id: The ioas_id the caller should use + * + * The compatibility IOAS is the IOAS that the vfio compatibility ioctls operate + * on since they do not have an IOAS ID input in their ABI. Only attaching a + * group should cause a default creation of the internal ioas, this returns the + * existing ioas if it has already been assigned somehow. + */ +int iommufd_vfio_compat_ioas_id(struct iommufd_ctx *ictx, u32 *out_ioas_id) +{ + struct iommufd_ioas *ioas = NULL; + struct iommufd_ioas *out_ioas; + + ioas = iommufd_ioas_alloc(ictx); + if (IS_ERR(ioas)) + return PTR_ERR(ioas); + + xa_lock(&ictx->objects); + if (ictx->vfio_ioas && iommufd_lock_obj(&ictx->vfio_ioas->obj)) + out_ioas = ictx->vfio_ioas; + else { + out_ioas = ioas; + ictx->vfio_ioas = ioas; + } + xa_unlock(&ictx->objects); + + *out_ioas_id = out_ioas->obj.id; + if (out_ioas != ioas) { + iommufd_put_object(&out_ioas->obj); + iommufd_object_abort(ictx, &ioas->obj); + return 0; + } + /* + * An automatically created compat IOAS is treated as a userspace + * created object. Userspace can learn the ID via IOMMU_VFIO_IOAS_GET, + * and if not manually destroyed it will be destroyed automatically + * at iommufd release. + */ + iommufd_object_finalize(ictx, &ioas->obj); + return 0; +} +EXPORT_SYMBOL_NS_GPL(iommufd_vfio_compat_ioas_id, IOMMUFD_VFIO); + +int iommufd_vfio_ioas(struct iommufd_ucmd *ucmd) +{ + struct iommu_vfio_ioas *cmd = ucmd->cmd; + struct iommufd_ioas *ioas; + + if (cmd->__reserved) + return -EOPNOTSUPP; + switch (cmd->op) { + case IOMMU_VFIO_IOAS_GET: + ioas = get_compat_ioas(ucmd->ictx); + if (IS_ERR(ioas)) + return PTR_ERR(ioas); + cmd->ioas_id = ioas->obj.id; + iommufd_put_object(&ioas->obj); + return iommufd_ucmd_respond(ucmd, sizeof(*cmd)); + + case IOMMU_VFIO_IOAS_SET: + ioas = iommufd_get_ioas(ucmd, cmd->ioas_id); + if (IS_ERR(ioas)) + return PTR_ERR(ioas); + xa_lock(&ucmd->ictx->objects); + ucmd->ictx->vfio_ioas = ioas; + xa_unlock(&ucmd->ictx->objects); + iommufd_put_object(&ioas->obj); + return 0; + + case IOMMU_VFIO_IOAS_CLEAR: + xa_lock(&ucmd->ictx->objects); + ucmd->ictx->vfio_ioas = NULL; + xa_unlock(&ucmd->ictx->objects); + return 0; + default: + return -EOPNOTSUPP; + } +} + +static int iommufd_vfio_map_dma(struct iommufd_ctx *ictx, unsigned int cmd, + void __user *arg) +{ + u32 supported_flags = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE; + size_t minsz = offsetofend(struct vfio_iommu_type1_dma_map, size); + struct vfio_iommu_type1_dma_map map; + int iommu_prot = IOMMU_CACHE; + struct iommufd_ioas *ioas; + unsigned long iova; + int rc; + + if (copy_from_user(&map, arg, minsz)) + return -EFAULT; + + if (map.argsz < minsz || map.flags & ~supported_flags) + return -EINVAL; + + if (map.flags & VFIO_DMA_MAP_FLAG_READ) + iommu_prot |= IOMMU_READ; + if (map.flags & VFIO_DMA_MAP_FLAG_WRITE) + iommu_prot |= IOMMU_WRITE; + + ioas = get_compat_ioas(ictx); + if (IS_ERR(ioas)) + return PTR_ERR(ioas); + + /* + * Maps created through the legacy interface always use VFIO compatible + * rlimit accounting. If the user wishes to use the faster user based + * rlimit accounting then they must use the new interface. + */ + iova = map.iova; + rc = iopt_map_user_pages(ictx, &ioas->iopt, &iova, u64_to_user_ptr(map.vaddr), + map.size, iommu_prot, 0); + iommufd_put_object(&ioas->obj); + return rc; +} + +static int iommufd_vfio_unmap_dma(struct iommufd_ctx *ictx, unsigned int cmd, + void __user *arg) +{ + size_t minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size); + /* + * VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP is obsoleted by the new + * dirty tracking direction: + * https://lore.kernel.org/kvm/20220731125503.142683-1-yishaih@nvidia.com/ + * https://lore.kernel.org/kvm/20220428210933.3583-1-joao.m.martins@oracle.com/ + */ + u32 supported_flags = VFIO_DMA_UNMAP_FLAG_ALL; + struct vfio_iommu_type1_dma_unmap unmap; + unsigned long unmapped = 0; + struct iommufd_ioas *ioas; + int rc; + + if (copy_from_user(&unmap, arg, minsz)) + return -EFAULT; + + if (unmap.argsz < minsz || unmap.flags & ~supported_flags) + return -EINVAL; + + ioas = get_compat_ioas(ictx); + if (IS_ERR(ioas)) + return PTR_ERR(ioas); + + if (unmap.flags & VFIO_DMA_UNMAP_FLAG_ALL) { + if (unmap.iova != 0 || unmap.size != 0) { + rc = -EINVAL; + goto err_put; + } + rc = iopt_unmap_all(&ioas->iopt, &unmapped); + } else { + if (READ_ONCE(ioas->iopt.disable_large_pages)) { + /* + * Create cuts at the start and last of the requested + * range. If the start IOVA is 0 then it doesn't need to + * be cut. + */ + unsigned long iovas[] = { unmap.iova + unmap.size - 1, + unmap.iova - 1 }; + + rc = iopt_cut_iova(&ioas->iopt, iovas, + unmap.iova ? 2 : 1); + if (rc) + goto err_put; + } + rc = iopt_unmap_iova(&ioas->iopt, unmap.iova, unmap.size, + &unmapped); + } + unmap.size = unmapped; + if (copy_to_user(arg, &unmap, minsz)) + rc = -EFAULT; + +err_put: + iommufd_put_object(&ioas->obj); + return rc; +} + +static int iommufd_vfio_cc_iommu(struct iommufd_ctx *ictx) +{ + struct iommufd_hw_pagetable *hwpt; + struct iommufd_ioas *ioas; + int rc = 1; + + ioas = get_compat_ioas(ictx); + if (IS_ERR(ioas)) + return PTR_ERR(ioas); + + mutex_lock(&ioas->mutex); + list_for_each_entry(hwpt, &ioas->hwpt_list, hwpt_item) { + if (!hwpt->enforce_cache_coherency) { + rc = 0; + break; + } + } + mutex_unlock(&ioas->mutex); + + iommufd_put_object(&ioas->obj); + return rc; +} + +static int iommufd_vfio_check_extension(struct iommufd_ctx *ictx, + unsigned long type) +{ + switch (type) { + case VFIO_TYPE1_IOMMU: + case VFIO_TYPE1v2_IOMMU: + case VFIO_UNMAP_ALL: + return 1; + + case VFIO_DMA_CC_IOMMU: + return iommufd_vfio_cc_iommu(ictx); + + /* + * This is obsolete, and to be removed from VFIO. It was an incomplete + * idea that got merged. + * https://lore.kernel.org/kvm/0-v1-0093c9b0e345+19-vfio_no_nesting_jgg@nvidia.com/ + */ + case VFIO_TYPE1_NESTING_IOMMU: + return 0; + + /* + * VFIO_DMA_MAP_FLAG_VADDR + * https://lore.kernel.org/kvm/1611939252-7240-1-git-send-email-steven.sistare@oracle.com/ + * https://lore.kernel.org/all/Yz777bJZjTyLrHEQ@nvidia.com/ + * + * It is hard to see how this could be implemented safely. + */ + case VFIO_UPDATE_VADDR: + default: + return 0; + } +} + +static int iommufd_vfio_set_iommu(struct iommufd_ctx *ictx, unsigned long type) +{ + struct iommufd_ioas *ioas = NULL; + int rc = 0; + + if (type != VFIO_TYPE1_IOMMU && type != VFIO_TYPE1v2_IOMMU) + return -EINVAL; + + /* VFIO fails the set_iommu if there is no group */ + ioas = get_compat_ioas(ictx); + if (IS_ERR(ioas)) + return PTR_ERR(ioas); + + /* + * The difference between TYPE1 and TYPE1v2 is the ability to unmap in + * the middle of mapped ranges. This is complicated by huge page support + * which creates single large IOPTEs that cannot be split by the iommu + * driver. TYPE1 is very old at this point and likely nothing uses it, + * however it is simple enough to emulate by simply disabling the + * problematic large IOPTEs. Then we can safely unmap within any range. + */ + if (type == VFIO_TYPE1_IOMMU) + rc = iopt_disable_large_pages(&ioas->iopt); + iommufd_put_object(&ioas->obj); + return rc; +} + +static unsigned long iommufd_get_pagesizes(struct iommufd_ioas *ioas) +{ + struct io_pagetable *iopt = &ioas->iopt; + unsigned long pgsize_bitmap = ULONG_MAX; + struct iommu_domain *domain; + unsigned long index; + + down_read(&iopt->domains_rwsem); + xa_for_each(&iopt->domains, index, domain) + pgsize_bitmap &= domain->pgsize_bitmap; + + /* See vfio_update_pgsize_bitmap() */ + if (pgsize_bitmap & ~PAGE_MASK) { + pgsize_bitmap &= PAGE_MASK; + pgsize_bitmap |= PAGE_SIZE; + } + pgsize_bitmap = max(pgsize_bitmap, ioas->iopt.iova_alignment); + up_read(&iopt->domains_rwsem); + return pgsize_bitmap; +} + +static int iommufd_fill_cap_iova(struct iommufd_ioas *ioas, + struct vfio_info_cap_header __user *cur, + size_t avail) +{ + struct vfio_iommu_type1_info_cap_iova_range __user *ucap_iovas = + container_of(cur, + struct vfio_iommu_type1_info_cap_iova_range __user, + header); + struct vfio_iommu_type1_info_cap_iova_range cap_iovas = { + .header = { + .id = VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE, + .version = 1, + }, + }; + struct interval_tree_span_iter span; + + interval_tree_for_each_span(&span, &ioas->iopt.reserved_itree, 0, + ULONG_MAX) { + struct vfio_iova_range range; + + if (!span.is_hole) + continue; + range.start = span.start_hole; + range.end = span.last_hole; + if (avail >= struct_size(&cap_iovas, iova_ranges, + cap_iovas.nr_iovas + 1) && + copy_to_user(&ucap_iovas->iova_ranges[cap_iovas.nr_iovas], + &range, sizeof(range))) + return -EFAULT; + cap_iovas.nr_iovas++; + } + if (avail >= struct_size(&cap_iovas, iova_ranges, cap_iovas.nr_iovas) && + copy_to_user(ucap_iovas, &cap_iovas, sizeof(cap_iovas))) + return -EFAULT; + return struct_size(&cap_iovas, iova_ranges, cap_iovas.nr_iovas); +} + +static int iommufd_fill_cap_dma_avail(struct iommufd_ioas *ioas, + struct vfio_info_cap_header __user *cur, + size_t avail) +{ + struct vfio_iommu_type1_info_dma_avail cap_dma = { + .header = { + .id = VFIO_IOMMU_TYPE1_INFO_DMA_AVAIL, + .version = 1, + }, + /* + * iommufd's limit is based on the cgroup's memory limit. + * Normally vfio would return U16_MAX here, and provide a module + * parameter to adjust it. Since S390 qemu userspace actually + * pays attention and needs a value bigger than U16_MAX return + * U32_MAX. + */ + .avail = U32_MAX, + }; + + if (avail >= sizeof(cap_dma) && + copy_to_user(cur, &cap_dma, sizeof(cap_dma))) + return -EFAULT; + return sizeof(cap_dma); +} + +static int iommufd_vfio_iommu_get_info(struct iommufd_ctx *ictx, + void __user *arg) +{ + typedef int (*fill_cap_fn)(struct iommufd_ioas *ioas, + struct vfio_info_cap_header __user *cur, + size_t avail); + static const fill_cap_fn fill_fns[] = { + iommufd_fill_cap_dma_avail, + iommufd_fill_cap_iova, + }; + size_t minsz = offsetofend(struct vfio_iommu_type1_info, iova_pgsizes); + struct vfio_info_cap_header __user *last_cap = NULL; + struct vfio_iommu_type1_info info; + struct iommufd_ioas *ioas; + size_t total_cap_size; + int rc; + int i; + + if (copy_from_user(&info, arg, minsz)) + return -EFAULT; + + if (info.argsz < minsz) + return -EINVAL; + minsz = min_t(size_t, info.argsz, sizeof(info)); + + ioas = get_compat_ioas(ictx); + if (IS_ERR(ioas)) + return PTR_ERR(ioas); + + info.flags = VFIO_IOMMU_INFO_PGSIZES; + info.iova_pgsizes = iommufd_get_pagesizes(ioas); + info.cap_offset = 0; + + down_read(&ioas->iopt.iova_rwsem); + total_cap_size = sizeof(info); + for (i = 0; i != ARRAY_SIZE(fill_fns); i++) { + int cap_size; + + if (info.argsz > total_cap_size) + cap_size = fill_fns[i](ioas, arg + total_cap_size, + info.argsz - total_cap_size); + else + cap_size = fill_fns[i](ioas, NULL, 0); + if (cap_size < 0) { + rc = cap_size; + goto out_put; + } + if (last_cap && info.argsz >= total_cap_size && + put_user(total_cap_size, &last_cap->next)) { + rc = -EFAULT; + goto out_put; + } + last_cap = arg + total_cap_size; + total_cap_size += cap_size; + } + + /* + * If the user did not provide enough space then only some caps are + * returned and the argsz will be updated to the correct amount to get + * all caps. + */ + if (info.argsz >= total_cap_size) + info.cap_offset = sizeof(info); + info.argsz = total_cap_size; + info.flags |= VFIO_IOMMU_INFO_CAPS; + if (copy_to_user(arg, &info, minsz)) { + rc = -EFAULT; + goto out_put; + } + rc = 0; + +out_put: + up_read(&ioas->iopt.iova_rwsem); + iommufd_put_object(&ioas->obj); + return rc; +} + +int iommufd_vfio_ioctl(struct iommufd_ctx *ictx, unsigned int cmd, + unsigned long arg) +{ + void __user *uarg = (void __user *)arg; + + switch (cmd) { + case VFIO_GET_API_VERSION: + return VFIO_API_VERSION; + case VFIO_SET_IOMMU: + return iommufd_vfio_set_iommu(ictx, arg); + case VFIO_CHECK_EXTENSION: + return iommufd_vfio_check_extension(ictx, arg); + case VFIO_IOMMU_GET_INFO: + return iommufd_vfio_iommu_get_info(ictx, uarg); + case VFIO_IOMMU_MAP_DMA: + return iommufd_vfio_map_dma(ictx, cmd, uarg); + case VFIO_IOMMU_UNMAP_DMA: + return iommufd_vfio_unmap_dma(ictx, cmd, uarg); + case VFIO_IOMMU_DIRTY_PAGES: + default: + return -ENOIOCTLCMD; + } + return -ENOIOCTLCMD; +} diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h index 46c481a26d79..84af9a239769 100644 --- a/include/linux/iommufd.h +++ b/include/linux/iommufd.h @@ -54,6 +54,7 @@ void iommufd_access_unpin_pages(struct iommufd_access *access, unsigned long iova, unsigned long length); int iommufd_access_rw(struct iommufd_access *access, unsigned long iova, void *data, size_t len, unsigned int flags); +int iommufd_vfio_compat_ioas_id(struct iommufd_ctx *ictx, u32 *out_ioas_id); #else /* !CONFIG_IOMMUFD */ static inline struct iommufd_ctx *iommufd_ctx_from_file(struct file *file) { @@ -84,5 +85,11 @@ static inline int iommufd_access_rw(struct iommufd_access *access, unsigned long { return -EOPNOTSUPP; } + +static inline int iommufd_vfio_compat_ioas_id(struct iommufd_ctx *ictx, + u32 *out_ioas_id) +{ + return -EOPNOTSUPP; +} #endif /* CONFIG_IOMMUFD */ #endif diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index 30cc5c5e2b34..98ebba80cfa1 100644 --- a/include/uapi/linux/iommufd.h +++ b/include/uapi/linux/iommufd.h @@ -44,6 +44,7 @@ enum { IOMMUFD_CMD_IOAS_MAP, IOMMUFD_CMD_IOAS_UNMAP, IOMMUFD_CMD_OPTION, + IOMMUFD_CMD_VFIO_IOAS, }; /** @@ -308,4 +309,39 @@ struct iommu_option { __aligned_u64 val64; }; #define IOMMU_OPTION _IO(IOMMUFD_TYPE, IOMMUFD_CMD_OPTION) + +/** + * enum iommufd_vfio_ioas_op - IOMMU_VFIO_IOAS_* ioctls + * @IOMMU_VFIO_IOAS_GET: Get the current compatibility IOAS + * @IOMMU_VFIO_IOAS_SET: Change the current compatibility IOAS + * @IOMMU_VFIO_IOAS_CLEAR: Disable VFIO compatibility + */ +enum iommufd_vfio_ioas_op { + IOMMU_VFIO_IOAS_GET = 0, + IOMMU_VFIO_IOAS_SET = 1, + IOMMU_VFIO_IOAS_CLEAR = 2, +}; + +/** + * struct iommu_vfio_ioas - ioctl(IOMMU_VFIO_IOAS) + * @size: sizeof(struct iommu_vfio_ioas) + * @ioas_id: For IOMMU_VFIO_IOAS_SET the input IOAS ID to set + * For IOMMU_VFIO_IOAS_GET will output the IOAS ID + * @op: One of enum iommufd_vfio_ioas_op + * @__reserved: Must be 0 + * + * The VFIO compatibility support uses a single ioas because VFIO APIs do not + * support the ID field. Set or Get the IOAS that VFIO compatibility will use. + * When VFIO_GROUP_SET_CONTAINER is used on an iommufd it will get the + * compatibility ioas, either by taking what is already set, or auto creating + * one. From then on VFIO will continue to use that ioas and is not effected by + * this ioctl. SET or CLEAR does not destroy any auto-created IOAS. + */ +struct iommu_vfio_ioas { + __u32 size; + __u32 ioas_id; + __u16 op; + __u16 __reserved; +}; +#define IOMMU_VFIO_IOAS _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VFIO_IOAS) #endif -- cgit v1.2.3 From f4b20bb34c83dceade5470288f48f94ce3598ada Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 29 Nov 2022 16:29:39 -0400 Subject: iommufd: Add kernel support for testing iommufd Provide a mock kernel module for the iommu_domain that allows it to run without any HW and the mocking provides a way to directly validate that the PFNs loaded into the iommu_domain are correct. This exposes the access kAPI toward userspace to allow userspace to explore the functionality of pages.c and io_pagetable.c The mock also simulates the rare case of PAGE_SIZE > iommu page size as the mock will operate at a 2K iommu page size. This allows exercising all of the calculations to support this mismatch. This is also intended to support syzkaller exploring the same space. However, it is an unusually invasive config option to enable all of this. The config option should not be enabled in a production kernel. Link: https://lore.kernel.org/r/16-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Tested-by: Matthew Rosato # s390 Tested-by: Eric Auger # aarch64 Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/Kconfig | 12 + drivers/iommu/iommufd/Makefile | 2 + drivers/iommu/iommufd/device.c | 38 ++ drivers/iommu/iommufd/ioas.c | 3 + drivers/iommu/iommufd/iommufd_private.h | 35 ++ drivers/iommu/iommufd/iommufd_test.h | 93 ++++ drivers/iommu/iommufd/main.c | 14 + drivers/iommu/iommufd/pages.c | 8 + drivers/iommu/iommufd/selftest.c | 853 ++++++++++++++++++++++++++++++++ include/linux/iommufd.h | 3 + 10 files changed, 1061 insertions(+) create mode 100644 drivers/iommu/iommufd/iommufd_test.h create mode 100644 drivers/iommu/iommufd/selftest.c (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommufd/Kconfig b/drivers/iommu/iommufd/Kconfig index 164812084a67..871244f2443f 100644 --- a/drivers/iommu/iommufd/Kconfig +++ b/drivers/iommu/iommufd/Kconfig @@ -10,3 +10,15 @@ config IOMMUFD it relates to managing IO page tables that point at user space memory. If you don't know what to do here, say N. + +if IOMMUFD +config IOMMUFD_TEST + bool "IOMMU Userspace API Test support" + depends on DEBUG_KERNEL + depends on FAULT_INJECTION + depends on RUNTIME_TESTING_MENU + default n + help + This is dangerous, do not enable unless running + tools/testing/selftests/iommu +endif diff --git a/drivers/iommu/iommufd/Makefile b/drivers/iommu/iommufd/Makefile index 2fdff04000b3..8aeba81800c5 100644 --- a/drivers/iommu/iommufd/Makefile +++ b/drivers/iommu/iommufd/Makefile @@ -8,4 +8,6 @@ iommufd-y := \ pages.o \ vfio_compat.o +iommufd-$(CONFIG_IOMMUFD_TEST) += selftest.o + obj-$(CONFIG_IOMMUFD) += iommufd.o diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c index 06b6894b7706..67ce36152e8a 100644 --- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -733,3 +733,41 @@ err_out: return rc; } EXPORT_SYMBOL_NS_GPL(iommufd_access_rw, IOMMUFD); + +#ifdef CONFIG_IOMMUFD_TEST +/* + * Creating a real iommufd_device is too hard, bypass creating a iommufd_device + * and go directly to attaching a domain. + */ +struct iommufd_hw_pagetable * +iommufd_device_selftest_attach(struct iommufd_ctx *ictx, + struct iommufd_ioas *ioas, + struct device *mock_dev) +{ + struct iommufd_hw_pagetable *hwpt; + int rc; + + hwpt = iommufd_hw_pagetable_alloc(ictx, ioas, mock_dev); + if (IS_ERR(hwpt)) + return hwpt; + + rc = iopt_table_add_domain(&hwpt->ioas->iopt, hwpt->domain); + if (rc) + goto out_hwpt; + + refcount_inc(&hwpt->obj.users); + iommufd_object_finalize(ictx, &hwpt->obj); + return hwpt; + +out_hwpt: + iommufd_object_abort_and_destroy(ictx, &hwpt->obj); + return ERR_PTR(rc); +} + +void iommufd_device_selftest_detach(struct iommufd_ctx *ictx, + struct iommufd_hw_pagetable *hwpt) +{ + iopt_table_remove_domain(&hwpt->ioas->iopt, hwpt->domain); + refcount_dec(&hwpt->obj.users); +} +#endif diff --git a/drivers/iommu/iommufd/ioas.c b/drivers/iommu/iommufd/ioas.c index 302779b33bd4..31577e9d434f 100644 --- a/drivers/iommu/iommufd/ioas.c +++ b/drivers/iommu/iommufd/ioas.c @@ -242,6 +242,9 @@ int iommufd_ioas_copy(struct iommufd_ucmd *ucmd) unsigned long iova; int rc; + iommufd_test_syz_conv_iova_id(ucmd, cmd->src_ioas_id, &cmd->src_iova, + &cmd->flags); + if ((cmd->flags & ~(IOMMU_IOAS_MAP_FIXED_IOVA | IOMMU_IOAS_MAP_WRITEABLE | IOMMU_IOAS_MAP_READABLE))) diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 8fe5f162ccbc..222e86591f8a 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -113,6 +113,9 @@ enum iommufd_object_type { IOMMUFD_OBJ_HW_PAGETABLE, IOMMUFD_OBJ_IOAS, IOMMUFD_OBJ_ACCESS, +#ifdef CONFIG_IOMMUFD_TEST + IOMMUFD_OBJ_SELFTEST, +#endif }; /* Base struct for all objects with a userspace ID handle. */ @@ -269,4 +272,36 @@ void iopt_remove_access(struct io_pagetable *iopt, struct iommufd_access *access); void iommufd_access_destroy_object(struct iommufd_object *obj); +#ifdef CONFIG_IOMMUFD_TEST +struct iommufd_hw_pagetable * +iommufd_device_selftest_attach(struct iommufd_ctx *ictx, + struct iommufd_ioas *ioas, + struct device *mock_dev); +void iommufd_device_selftest_detach(struct iommufd_ctx *ictx, + struct iommufd_hw_pagetable *hwpt); +int iommufd_test(struct iommufd_ucmd *ucmd); +void iommufd_selftest_destroy(struct iommufd_object *obj); +extern size_t iommufd_test_memory_limit; +void iommufd_test_syz_conv_iova_id(struct iommufd_ucmd *ucmd, + unsigned int ioas_id, u64 *iova, u32 *flags); +bool iommufd_should_fail(void); +void __init iommufd_test_init(void); +void iommufd_test_exit(void); +#else +static inline void iommufd_test_syz_conv_iova_id(struct iommufd_ucmd *ucmd, + unsigned int ioas_id, + u64 *iova, u32 *flags) +{ +} +static inline bool iommufd_should_fail(void) +{ + return false; +} +static inline void __init iommufd_test_init(void) +{ +} +static inline void iommufd_test_exit(void) +{ +} +#endif #endif diff --git a/drivers/iommu/iommufd/iommufd_test.h b/drivers/iommu/iommufd/iommufd_test.h new file mode 100644 index 000000000000..1d96a8f466fd --- /dev/null +++ b/drivers/iommu/iommufd/iommufd_test.h @@ -0,0 +1,93 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES. + */ +#ifndef _UAPI_IOMMUFD_TEST_H +#define _UAPI_IOMMUFD_TEST_H + +#include +#include + +enum { + IOMMU_TEST_OP_ADD_RESERVED = 1, + IOMMU_TEST_OP_MOCK_DOMAIN, + IOMMU_TEST_OP_MD_CHECK_MAP, + IOMMU_TEST_OP_MD_CHECK_REFS, + IOMMU_TEST_OP_CREATE_ACCESS, + IOMMU_TEST_OP_DESTROY_ACCESS_PAGES, + IOMMU_TEST_OP_ACCESS_PAGES, + IOMMU_TEST_OP_ACCESS_RW, + IOMMU_TEST_OP_SET_TEMP_MEMORY_LIMIT, +}; + +enum { + MOCK_APERTURE_START = 1UL << 24, + MOCK_APERTURE_LAST = (1UL << 31) - 1, +}; + +enum { + MOCK_FLAGS_ACCESS_WRITE = 1 << 0, + MOCK_FLAGS_ACCESS_SYZ = 1 << 16, +}; + +enum { + MOCK_ACCESS_RW_WRITE = 1 << 0, + MOCK_ACCESS_RW_SLOW_PATH = 1 << 2, +}; + +enum { + MOCK_FLAGS_ACCESS_CREATE_NEEDS_PIN_PAGES = 1 << 0, +}; + +struct iommu_test_cmd { + __u32 size; + __u32 op; + __u32 id; + __u32 __reserved; + union { + struct { + __aligned_u64 start; + __aligned_u64 length; + } add_reserved; + struct { + __u32 out_device_id; + __u32 out_hwpt_id; + } mock_domain; + struct { + __aligned_u64 iova; + __aligned_u64 length; + __aligned_u64 uptr; + } check_map; + struct { + __aligned_u64 length; + __aligned_u64 uptr; + __u32 refs; + } check_refs; + struct { + __u32 out_access_fd; + __u32 flags; + } create_access; + struct { + __u32 access_pages_id; + } destroy_access_pages; + struct { + __u32 flags; + __u32 out_access_pages_id; + __aligned_u64 iova; + __aligned_u64 length; + __aligned_u64 uptr; + } access_pages; + struct { + __aligned_u64 iova; + __aligned_u64 length; + __aligned_u64 uptr; + __u32 flags; + } access_rw; + struct { + __u32 limit; + } memory_limit; + }; + __u32 last; +}; +#define IOMMU_TEST_CMD _IO(IOMMUFD_TYPE, IOMMUFD_CMD_BASE + 32) + +#endif diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index 5cf69c4d591d..7c8f40bc8d98 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -19,6 +19,7 @@ #include #include "iommufd_private.h" +#include "iommufd_test.h" struct iommufd_object_ops { void (*destroy)(struct iommufd_object *obj); @@ -239,6 +240,9 @@ union ucmd_buffer { struct iommu_ioas_iova_ranges iova_ranges; struct iommu_ioas_map map; struct iommu_ioas_unmap unmap; +#ifdef CONFIG_IOMMUFD_TEST + struct iommu_test_cmd test; +#endif }; struct iommufd_ioctl_op { @@ -275,6 +279,9 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = { val64), IOCTL_OP(IOMMU_VFIO_IOAS, iommufd_vfio_ioas, struct iommu_vfio_ioas, __reserved), +#ifdef CONFIG_IOMMUFD_TEST + IOCTL_OP(IOMMU_TEST_CMD, iommufd_test, struct iommu_test_cmd, last), +#endif }; static long iommufd_fops_ioctl(struct file *filp, unsigned int cmd, @@ -375,6 +382,11 @@ static const struct iommufd_object_ops iommufd_object_ops[] = { [IOMMUFD_OBJ_HW_PAGETABLE] = { .destroy = iommufd_hw_pagetable_destroy, }, +#ifdef CONFIG_IOMMUFD_TEST + [IOMMUFD_OBJ_SELFTEST] = { + .destroy = iommufd_selftest_destroy, + }, +#endif }; static struct miscdevice iommu_misc_dev = { @@ -392,11 +404,13 @@ static int __init iommufd_init(void) ret = misc_register(&iommu_misc_dev); if (ret) return ret; + iommufd_test_init(); return 0; } static void __exit iommufd_exit(void) { + iommufd_test_exit(); misc_deregister(&iommu_misc_dev); } diff --git a/drivers/iommu/iommufd/pages.c b/drivers/iommu/iommufd/pages.c index bafeee9d73e8..640331b8a079 100644 --- a/drivers/iommu/iommufd/pages.c +++ b/drivers/iommu/iommufd/pages.c @@ -56,7 +56,11 @@ #include "io_pagetable.h" #include "double_span.h" +#ifndef CONFIG_IOMMUFD_TEST #define TEMP_MEMORY_LIMIT 65536 +#else +#define TEMP_MEMORY_LIMIT iommufd_test_memory_limit +#endif #define BATCH_BACKUP_SIZE 32 /* @@ -1756,6 +1760,10 @@ int iopt_pages_rw_access(struct iopt_pages *pages, unsigned long start_byte, bool change_mm = current->mm != pages->source_mm; int rc = 0; + if (IS_ENABLED(CONFIG_IOMMUFD_TEST) && + (flags & __IOMMUFD_ACCESS_RW_SLOW_PATH)) + change_mm = true; + if ((flags & IOMMUFD_ACCESS_RW_WRITE) && !pages->writable) return -EPERM; diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c new file mode 100644 index 000000000000..cfb5fe9a5e0e --- /dev/null +++ b/drivers/iommu/iommufd/selftest.c @@ -0,0 +1,853 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES. + * + * Kernel side components to support tools/testing/selftests/iommu + */ +#include +#include +#include +#include +#include +#include +#include + +#include "io_pagetable.h" +#include "iommufd_private.h" +#include "iommufd_test.h" + +static DECLARE_FAULT_ATTR(fail_iommufd); +static struct dentry *dbgfs_root; + +size_t iommufd_test_memory_limit = 65536; + +enum { + MOCK_IO_PAGE_SIZE = PAGE_SIZE / 2, + + /* + * Like a real page table alignment requires the low bits of the address + * to be zero. xarray also requires the high bit to be zero, so we store + * the pfns shifted. The upper bits are used for metadata. + */ + MOCK_PFN_MASK = ULONG_MAX / MOCK_IO_PAGE_SIZE, + + _MOCK_PFN_START = MOCK_PFN_MASK + 1, + MOCK_PFN_START_IOVA = _MOCK_PFN_START, + MOCK_PFN_LAST_IOVA = _MOCK_PFN_START, +}; + +/* + * Syzkaller has trouble randomizing the correct iova to use since it is linked + * to the map ioctl's output, and it has no ide about that. So, simplify things. + * In syzkaller mode the 64 bit IOVA is converted into an nth area and offset + * value. This has a much smaller randomization space and syzkaller can hit it. + */ +static unsigned long iommufd_test_syz_conv_iova(struct io_pagetable *iopt, + u64 *iova) +{ + struct syz_layout { + __u32 nth_area; + __u32 offset; + }; + struct syz_layout *syz = (void *)iova; + unsigned int nth = syz->nth_area; + struct iopt_area *area; + + down_read(&iopt->iova_rwsem); + for (area = iopt_area_iter_first(iopt, 0, ULONG_MAX); area; + area = iopt_area_iter_next(area, 0, ULONG_MAX)) { + if (nth == 0) { + up_read(&iopt->iova_rwsem); + return iopt_area_iova(area) + syz->offset; + } + nth--; + } + up_read(&iopt->iova_rwsem); + + return 0; +} + +void iommufd_test_syz_conv_iova_id(struct iommufd_ucmd *ucmd, + unsigned int ioas_id, u64 *iova, u32 *flags) +{ + struct iommufd_ioas *ioas; + + if (!(*flags & MOCK_FLAGS_ACCESS_SYZ)) + return; + *flags &= ~(u32)MOCK_FLAGS_ACCESS_SYZ; + + ioas = iommufd_get_ioas(ucmd, ioas_id); + if (IS_ERR(ioas)) + return; + *iova = iommufd_test_syz_conv_iova(&ioas->iopt, iova); + iommufd_put_object(&ioas->obj); +} + +struct mock_iommu_domain { + struct iommu_domain domain; + struct xarray pfns; +}; + +enum selftest_obj_type { + TYPE_IDEV, +}; + +struct selftest_obj { + struct iommufd_object obj; + enum selftest_obj_type type; + + union { + struct { + struct iommufd_hw_pagetable *hwpt; + struct iommufd_ctx *ictx; + struct device mock_dev; + } idev; + }; +}; + +static struct iommu_domain *mock_domain_alloc(unsigned int iommu_domain_type) +{ + struct mock_iommu_domain *mock; + + if (WARN_ON(iommu_domain_type != IOMMU_DOMAIN_UNMANAGED)) + return NULL; + + mock = kzalloc(sizeof(*mock), GFP_KERNEL); + if (!mock) + return NULL; + mock->domain.geometry.aperture_start = MOCK_APERTURE_START; + mock->domain.geometry.aperture_end = MOCK_APERTURE_LAST; + mock->domain.pgsize_bitmap = MOCK_IO_PAGE_SIZE; + xa_init(&mock->pfns); + return &mock->domain; +} + +static void mock_domain_free(struct iommu_domain *domain) +{ + struct mock_iommu_domain *mock = + container_of(domain, struct mock_iommu_domain, domain); + + WARN_ON(!xa_empty(&mock->pfns)); + kfree(mock); +} + +static int mock_domain_map_pages(struct iommu_domain *domain, + unsigned long iova, phys_addr_t paddr, + size_t pgsize, size_t pgcount, int prot, + gfp_t gfp, size_t *mapped) +{ + struct mock_iommu_domain *mock = + container_of(domain, struct mock_iommu_domain, domain); + unsigned long flags = MOCK_PFN_START_IOVA; + unsigned long start_iova = iova; + + /* + * xarray does not reliably work with fault injection because it does a + * retry allocation, so put our own failure point. + */ + if (iommufd_should_fail()) + return -ENOENT; + + WARN_ON(iova % MOCK_IO_PAGE_SIZE); + WARN_ON(pgsize % MOCK_IO_PAGE_SIZE); + for (; pgcount; pgcount--) { + size_t cur; + + for (cur = 0; cur != pgsize; cur += MOCK_IO_PAGE_SIZE) { + void *old; + + if (pgcount == 1 && cur + MOCK_IO_PAGE_SIZE == pgsize) + flags = MOCK_PFN_LAST_IOVA; + old = xa_store(&mock->pfns, iova / MOCK_IO_PAGE_SIZE, + xa_mk_value((paddr / MOCK_IO_PAGE_SIZE) | + flags), + gfp); + if (xa_is_err(old)) { + for (; start_iova != iova; + start_iova += MOCK_IO_PAGE_SIZE) + xa_erase(&mock->pfns, + start_iova / + MOCK_IO_PAGE_SIZE); + return xa_err(old); + } + WARN_ON(old); + iova += MOCK_IO_PAGE_SIZE; + paddr += MOCK_IO_PAGE_SIZE; + *mapped += MOCK_IO_PAGE_SIZE; + flags = 0; + } + } + return 0; +} + +static size_t mock_domain_unmap_pages(struct iommu_domain *domain, + unsigned long iova, size_t pgsize, + size_t pgcount, + struct iommu_iotlb_gather *iotlb_gather) +{ + struct mock_iommu_domain *mock = + container_of(domain, struct mock_iommu_domain, domain); + bool first = true; + size_t ret = 0; + void *ent; + + WARN_ON(iova % MOCK_IO_PAGE_SIZE); + WARN_ON(pgsize % MOCK_IO_PAGE_SIZE); + + for (; pgcount; pgcount--) { + size_t cur; + + for (cur = 0; cur != pgsize; cur += MOCK_IO_PAGE_SIZE) { + ent = xa_erase(&mock->pfns, iova / MOCK_IO_PAGE_SIZE); + WARN_ON(!ent); + /* + * iommufd generates unmaps that must be a strict + * superset of the map's performend So every starting + * IOVA should have been an iova passed to map, and the + * + * First IOVA must be present and have been a first IOVA + * passed to map_pages + */ + if (first) { + WARN_ON(!(xa_to_value(ent) & + MOCK_PFN_START_IOVA)); + first = false; + } + if (pgcount == 1 && cur + MOCK_IO_PAGE_SIZE == pgsize) + WARN_ON(!(xa_to_value(ent) & + MOCK_PFN_LAST_IOVA)); + + iova += MOCK_IO_PAGE_SIZE; + ret += MOCK_IO_PAGE_SIZE; + } + } + return ret; +} + +static phys_addr_t mock_domain_iova_to_phys(struct iommu_domain *domain, + dma_addr_t iova) +{ + struct mock_iommu_domain *mock = + container_of(domain, struct mock_iommu_domain, domain); + void *ent; + + WARN_ON(iova % MOCK_IO_PAGE_SIZE); + ent = xa_load(&mock->pfns, iova / MOCK_IO_PAGE_SIZE); + WARN_ON(!ent); + return (xa_to_value(ent) & MOCK_PFN_MASK) * MOCK_IO_PAGE_SIZE; +} + +static const struct iommu_ops mock_ops = { + .owner = THIS_MODULE, + .pgsize_bitmap = MOCK_IO_PAGE_SIZE, + .domain_alloc = mock_domain_alloc, + .default_domain_ops = + &(struct iommu_domain_ops){ + .free = mock_domain_free, + .map_pages = mock_domain_map_pages, + .unmap_pages = mock_domain_unmap_pages, + .iova_to_phys = mock_domain_iova_to_phys, + }, +}; + +static inline struct iommufd_hw_pagetable * +get_md_pagetable(struct iommufd_ucmd *ucmd, u32 mockpt_id, + struct mock_iommu_domain **mock) +{ + struct iommufd_hw_pagetable *hwpt; + struct iommufd_object *obj; + + obj = iommufd_get_object(ucmd->ictx, mockpt_id, + IOMMUFD_OBJ_HW_PAGETABLE); + if (IS_ERR(obj)) + return ERR_CAST(obj); + hwpt = container_of(obj, struct iommufd_hw_pagetable, obj); + if (hwpt->domain->ops != mock_ops.default_domain_ops) { + iommufd_put_object(&hwpt->obj); + return ERR_PTR(-EINVAL); + } + *mock = container_of(hwpt->domain, struct mock_iommu_domain, domain); + return hwpt; +} + +/* Create an hw_pagetable with the mock domain so we can test the domain ops */ +static int iommufd_test_mock_domain(struct iommufd_ucmd *ucmd, + struct iommu_test_cmd *cmd) +{ + static struct bus_type mock_bus = { .iommu_ops = &mock_ops }; + struct iommufd_hw_pagetable *hwpt; + struct selftest_obj *sobj; + struct iommufd_ioas *ioas; + int rc; + + ioas = iommufd_get_ioas(ucmd, cmd->id); + if (IS_ERR(ioas)) + return PTR_ERR(ioas); + + sobj = iommufd_object_alloc(ucmd->ictx, sobj, IOMMUFD_OBJ_SELFTEST); + if (IS_ERR(sobj)) { + rc = PTR_ERR(sobj); + goto out_ioas; + } + sobj->idev.ictx = ucmd->ictx; + sobj->type = TYPE_IDEV; + sobj->idev.mock_dev.bus = &mock_bus; + + hwpt = iommufd_device_selftest_attach(ucmd->ictx, ioas, + &sobj->idev.mock_dev); + if (IS_ERR(hwpt)) { + rc = PTR_ERR(hwpt); + goto out_sobj; + } + sobj->idev.hwpt = hwpt; + + /* Userspace must destroy both of these IDs to destroy the object */ + cmd->mock_domain.out_hwpt_id = hwpt->obj.id; + cmd->mock_domain.out_device_id = sobj->obj.id; + iommufd_object_finalize(ucmd->ictx, &sobj->obj); + iommufd_put_object(&ioas->obj); + return iommufd_ucmd_respond(ucmd, sizeof(*cmd)); + +out_sobj: + iommufd_object_abort(ucmd->ictx, &sobj->obj); +out_ioas: + iommufd_put_object(&ioas->obj); + return rc; +} + +/* Add an additional reserved IOVA to the IOAS */ +static int iommufd_test_add_reserved(struct iommufd_ucmd *ucmd, + unsigned int mockpt_id, + unsigned long start, size_t length) +{ + struct iommufd_ioas *ioas; + int rc; + + ioas = iommufd_get_ioas(ucmd, mockpt_id); + if (IS_ERR(ioas)) + return PTR_ERR(ioas); + down_write(&ioas->iopt.iova_rwsem); + rc = iopt_reserve_iova(&ioas->iopt, start, start + length - 1, NULL); + up_write(&ioas->iopt.iova_rwsem); + iommufd_put_object(&ioas->obj); + return rc; +} + +/* Check that every pfn under each iova matches the pfn under a user VA */ +static int iommufd_test_md_check_pa(struct iommufd_ucmd *ucmd, + unsigned int mockpt_id, unsigned long iova, + size_t length, void __user *uptr) +{ + struct iommufd_hw_pagetable *hwpt; + struct mock_iommu_domain *mock; + int rc; + + if (iova % MOCK_IO_PAGE_SIZE || length % MOCK_IO_PAGE_SIZE || + (uintptr_t)uptr % MOCK_IO_PAGE_SIZE) + return -EINVAL; + + hwpt = get_md_pagetable(ucmd, mockpt_id, &mock); + if (IS_ERR(hwpt)) + return PTR_ERR(hwpt); + + for (; length; length -= MOCK_IO_PAGE_SIZE) { + struct page *pages[1]; + unsigned long pfn; + long npages; + void *ent; + + npages = get_user_pages_fast((uintptr_t)uptr & PAGE_MASK, 1, 0, + pages); + if (npages < 0) { + rc = npages; + goto out_put; + } + if (WARN_ON(npages != 1)) { + rc = -EFAULT; + goto out_put; + } + pfn = page_to_pfn(pages[0]); + put_page(pages[0]); + + ent = xa_load(&mock->pfns, iova / MOCK_IO_PAGE_SIZE); + if (!ent || + (xa_to_value(ent) & MOCK_PFN_MASK) * MOCK_IO_PAGE_SIZE != + pfn * PAGE_SIZE + ((uintptr_t)uptr % PAGE_SIZE)) { + rc = -EINVAL; + goto out_put; + } + iova += MOCK_IO_PAGE_SIZE; + uptr += MOCK_IO_PAGE_SIZE; + } + rc = 0; + +out_put: + iommufd_put_object(&hwpt->obj); + return rc; +} + +/* Check that the page ref count matches, to look for missing pin/unpins */ +static int iommufd_test_md_check_refs(struct iommufd_ucmd *ucmd, + void __user *uptr, size_t length, + unsigned int refs) +{ + if (length % PAGE_SIZE || (uintptr_t)uptr % PAGE_SIZE) + return -EINVAL; + + for (; length; length -= PAGE_SIZE) { + struct page *pages[1]; + long npages; + + npages = get_user_pages_fast((uintptr_t)uptr, 1, 0, pages); + if (npages < 0) + return npages; + if (WARN_ON(npages != 1)) + return -EFAULT; + if (!PageCompound(pages[0])) { + unsigned int count; + + count = page_ref_count(pages[0]); + if (count / GUP_PIN_COUNTING_BIAS != refs) { + put_page(pages[0]); + return -EIO; + } + } + put_page(pages[0]); + uptr += PAGE_SIZE; + } + return 0; +} + +struct selftest_access { + struct iommufd_access *access; + struct file *file; + struct mutex lock; + struct list_head items; + unsigned int next_id; + bool destroying; +}; + +struct selftest_access_item { + struct list_head items_elm; + unsigned long iova; + size_t length; + unsigned int id; +}; + +static const struct file_operations iommfd_test_staccess_fops; + +static struct selftest_access *iommufd_access_get(int fd) +{ + struct file *file; + + file = fget(fd); + if (!file) + return ERR_PTR(-EBADFD); + + if (file->f_op != &iommfd_test_staccess_fops) { + fput(file); + return ERR_PTR(-EBADFD); + } + return file->private_data; +} + +static void iommufd_test_access_unmap(void *data, unsigned long iova, + unsigned long length) +{ + unsigned long iova_last = iova + length - 1; + struct selftest_access *staccess = data; + struct selftest_access_item *item; + struct selftest_access_item *tmp; + + mutex_lock(&staccess->lock); + list_for_each_entry_safe(item, tmp, &staccess->items, items_elm) { + if (iova > item->iova + item->length - 1 || + iova_last < item->iova) + continue; + list_del(&item->items_elm); + iommufd_access_unpin_pages(staccess->access, item->iova, + item->length); + kfree(item); + } + mutex_unlock(&staccess->lock); +} + +static int iommufd_test_access_item_destroy(struct iommufd_ucmd *ucmd, + unsigned int access_id, + unsigned int item_id) +{ + struct selftest_access_item *item; + struct selftest_access *staccess; + + staccess = iommufd_access_get(access_id); + if (IS_ERR(staccess)) + return PTR_ERR(staccess); + + mutex_lock(&staccess->lock); + list_for_each_entry(item, &staccess->items, items_elm) { + if (item->id == item_id) { + list_del(&item->items_elm); + iommufd_access_unpin_pages(staccess->access, item->iova, + item->length); + mutex_unlock(&staccess->lock); + kfree(item); + fput(staccess->file); + return 0; + } + } + mutex_unlock(&staccess->lock); + fput(staccess->file); + return -ENOENT; +} + +static int iommufd_test_staccess_release(struct inode *inode, + struct file *filep) +{ + struct selftest_access *staccess = filep->private_data; + + if (staccess->access) { + iommufd_test_access_unmap(staccess, 0, ULONG_MAX); + iommufd_access_destroy(staccess->access); + } + mutex_destroy(&staccess->lock); + kfree(staccess); + return 0; +} + +static const struct iommufd_access_ops selftest_access_ops_pin = { + .needs_pin_pages = 1, + .unmap = iommufd_test_access_unmap, +}; + +static const struct iommufd_access_ops selftest_access_ops = { + .unmap = iommufd_test_access_unmap, +}; + +static const struct file_operations iommfd_test_staccess_fops = { + .release = iommufd_test_staccess_release, +}; + +static struct selftest_access *iommufd_test_alloc_access(void) +{ + struct selftest_access *staccess; + struct file *filep; + + staccess = kzalloc(sizeof(*staccess), GFP_KERNEL_ACCOUNT); + if (!staccess) + return ERR_PTR(-ENOMEM); + INIT_LIST_HEAD(&staccess->items); + mutex_init(&staccess->lock); + + filep = anon_inode_getfile("[iommufd_test_staccess]", + &iommfd_test_staccess_fops, staccess, + O_RDWR); + if (IS_ERR(filep)) { + kfree(staccess); + return ERR_CAST(filep); + } + staccess->file = filep; + return staccess; +} + +static int iommufd_test_create_access(struct iommufd_ucmd *ucmd, + unsigned int ioas_id, unsigned int flags) +{ + struct iommu_test_cmd *cmd = ucmd->cmd; + struct selftest_access *staccess; + struct iommufd_access *access; + int fdno; + int rc; + + if (flags & ~MOCK_FLAGS_ACCESS_CREATE_NEEDS_PIN_PAGES) + return -EOPNOTSUPP; + + staccess = iommufd_test_alloc_access(); + if (IS_ERR(staccess)) + return PTR_ERR(staccess); + + fdno = get_unused_fd_flags(O_CLOEXEC); + if (fdno < 0) { + rc = -ENOMEM; + goto out_free_staccess; + } + + access = iommufd_access_create( + ucmd->ictx, ioas_id, + (flags & MOCK_FLAGS_ACCESS_CREATE_NEEDS_PIN_PAGES) ? + &selftest_access_ops_pin : + &selftest_access_ops, + staccess); + if (IS_ERR(access)) { + rc = PTR_ERR(access); + goto out_put_fdno; + } + cmd->create_access.out_access_fd = fdno; + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); + if (rc) + goto out_destroy; + + staccess->access = access; + fd_install(fdno, staccess->file); + return 0; + +out_destroy: + iommufd_access_destroy(access); +out_put_fdno: + put_unused_fd(fdno); +out_free_staccess: + fput(staccess->file); + return rc; +} + +/* Check that the pages in a page array match the pages in the user VA */ +static int iommufd_test_check_pages(void __user *uptr, struct page **pages, + size_t npages) +{ + for (; npages; npages--) { + struct page *tmp_pages[1]; + long rc; + + rc = get_user_pages_fast((uintptr_t)uptr, 1, 0, tmp_pages); + if (rc < 0) + return rc; + if (WARN_ON(rc != 1)) + return -EFAULT; + put_page(tmp_pages[0]); + if (tmp_pages[0] != *pages) + return -EBADE; + pages++; + uptr += PAGE_SIZE; + } + return 0; +} + +static int iommufd_test_access_pages(struct iommufd_ucmd *ucmd, + unsigned int access_id, unsigned long iova, + size_t length, void __user *uptr, + u32 flags) +{ + struct iommu_test_cmd *cmd = ucmd->cmd; + struct selftest_access_item *item; + struct selftest_access *staccess; + struct page **pages; + size_t npages; + int rc; + + /* Prevent syzkaller from triggering a WARN_ON in kvzalloc() */ + if (length > 16*1024*1024) + return -ENOMEM; + + if (flags & ~(MOCK_FLAGS_ACCESS_WRITE | MOCK_FLAGS_ACCESS_SYZ)) + return -EOPNOTSUPP; + + staccess = iommufd_access_get(access_id); + if (IS_ERR(staccess)) + return PTR_ERR(staccess); + + if (staccess->access->ops != &selftest_access_ops_pin) { + rc = -EOPNOTSUPP; + goto out_put; + } + + if (flags & MOCK_FLAGS_ACCESS_SYZ) + iova = iommufd_test_syz_conv_iova(&staccess->access->ioas->iopt, + &cmd->access_pages.iova); + + npages = (ALIGN(iova + length, PAGE_SIZE) - + ALIGN_DOWN(iova, PAGE_SIZE)) / + PAGE_SIZE; + pages = kvcalloc(npages, sizeof(*pages), GFP_KERNEL_ACCOUNT); + if (!pages) { + rc = -ENOMEM; + goto out_put; + } + + /* + * Drivers will need to think very carefully about this locking. The + * core code can do multiple unmaps instantaneously after + * iommufd_access_pin_pages() and *all* the unmaps must not return until + * the range is unpinned. This simple implementation puts a global lock + * around the pin, which may not suit drivers that want this to be a + * performance path. drivers that get this wrong will trigger WARN_ON + * races and cause EDEADLOCK failures to userspace. + */ + mutex_lock(&staccess->lock); + rc = iommufd_access_pin_pages(staccess->access, iova, length, pages, + flags & MOCK_FLAGS_ACCESS_WRITE); + if (rc) + goto out_unlock; + + /* For syzkaller allow uptr to be NULL to skip this check */ + if (uptr) { + rc = iommufd_test_check_pages( + uptr - (iova - ALIGN_DOWN(iova, PAGE_SIZE)), pages, + npages); + if (rc) + goto out_unaccess; + } + + item = kzalloc(sizeof(*item), GFP_KERNEL_ACCOUNT); + if (!item) { + rc = -ENOMEM; + goto out_unaccess; + } + + item->iova = iova; + item->length = length; + item->id = staccess->next_id++; + list_add_tail(&item->items_elm, &staccess->items); + + cmd->access_pages.out_access_pages_id = item->id; + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); + if (rc) + goto out_free_item; + goto out_unlock; + +out_free_item: + list_del(&item->items_elm); + kfree(item); +out_unaccess: + iommufd_access_unpin_pages(staccess->access, iova, length); +out_unlock: + mutex_unlock(&staccess->lock); + kvfree(pages); +out_put: + fput(staccess->file); + return rc; +} + +static int iommufd_test_access_rw(struct iommufd_ucmd *ucmd, + unsigned int access_id, unsigned long iova, + size_t length, void __user *ubuf, + unsigned int flags) +{ + struct iommu_test_cmd *cmd = ucmd->cmd; + struct selftest_access *staccess; + void *tmp; + int rc; + + /* Prevent syzkaller from triggering a WARN_ON in kvzalloc() */ + if (length > 16*1024*1024) + return -ENOMEM; + + if (flags & ~(MOCK_ACCESS_RW_WRITE | MOCK_ACCESS_RW_SLOW_PATH | + MOCK_FLAGS_ACCESS_SYZ)) + return -EOPNOTSUPP; + + staccess = iommufd_access_get(access_id); + if (IS_ERR(staccess)) + return PTR_ERR(staccess); + + tmp = kvzalloc(length, GFP_KERNEL_ACCOUNT); + if (!tmp) { + rc = -ENOMEM; + goto out_put; + } + + if (flags & MOCK_ACCESS_RW_WRITE) { + if (copy_from_user(tmp, ubuf, length)) { + rc = -EFAULT; + goto out_free; + } + } + + if (flags & MOCK_FLAGS_ACCESS_SYZ) + iova = iommufd_test_syz_conv_iova(&staccess->access->ioas->iopt, + &cmd->access_rw.iova); + + rc = iommufd_access_rw(staccess->access, iova, tmp, length, flags); + if (rc) + goto out_free; + if (!(flags & MOCK_ACCESS_RW_WRITE)) { + if (copy_to_user(ubuf, tmp, length)) { + rc = -EFAULT; + goto out_free; + } + } + +out_free: + kvfree(tmp); +out_put: + fput(staccess->file); + return rc; +} +static_assert((unsigned int)MOCK_ACCESS_RW_WRITE == IOMMUFD_ACCESS_RW_WRITE); +static_assert((unsigned int)MOCK_ACCESS_RW_SLOW_PATH == + __IOMMUFD_ACCESS_RW_SLOW_PATH); + +void iommufd_selftest_destroy(struct iommufd_object *obj) +{ + struct selftest_obj *sobj = container_of(obj, struct selftest_obj, obj); + + switch (sobj->type) { + case TYPE_IDEV: + iommufd_device_selftest_detach(sobj->idev.ictx, + sobj->idev.hwpt); + break; + } +} + +int iommufd_test(struct iommufd_ucmd *ucmd) +{ + struct iommu_test_cmd *cmd = ucmd->cmd; + + switch (cmd->op) { + case IOMMU_TEST_OP_ADD_RESERVED: + return iommufd_test_add_reserved(ucmd, cmd->id, + cmd->add_reserved.start, + cmd->add_reserved.length); + case IOMMU_TEST_OP_MOCK_DOMAIN: + return iommufd_test_mock_domain(ucmd, cmd); + case IOMMU_TEST_OP_MD_CHECK_MAP: + return iommufd_test_md_check_pa( + ucmd, cmd->id, cmd->check_map.iova, + cmd->check_map.length, + u64_to_user_ptr(cmd->check_map.uptr)); + case IOMMU_TEST_OP_MD_CHECK_REFS: + return iommufd_test_md_check_refs( + ucmd, u64_to_user_ptr(cmd->check_refs.uptr), + cmd->check_refs.length, cmd->check_refs.refs); + case IOMMU_TEST_OP_CREATE_ACCESS: + return iommufd_test_create_access(ucmd, cmd->id, + cmd->create_access.flags); + case IOMMU_TEST_OP_ACCESS_PAGES: + return iommufd_test_access_pages( + ucmd, cmd->id, cmd->access_pages.iova, + cmd->access_pages.length, + u64_to_user_ptr(cmd->access_pages.uptr), + cmd->access_pages.flags); + case IOMMU_TEST_OP_ACCESS_RW: + return iommufd_test_access_rw( + ucmd, cmd->id, cmd->access_rw.iova, + cmd->access_rw.length, + u64_to_user_ptr(cmd->access_rw.uptr), + cmd->access_rw.flags); + case IOMMU_TEST_OP_DESTROY_ACCESS_PAGES: + return iommufd_test_access_item_destroy( + ucmd, cmd->id, cmd->destroy_access_pages.access_pages_id); + case IOMMU_TEST_OP_SET_TEMP_MEMORY_LIMIT: + /* Protect _batch_init(), can not be less than elmsz */ + if (cmd->memory_limit.limit < + sizeof(unsigned long) + sizeof(u32)) + return -EINVAL; + iommufd_test_memory_limit = cmd->memory_limit.limit; + return 0; + default: + return -EOPNOTSUPP; + } +} + +bool iommufd_should_fail(void) +{ + return should_fail(&fail_iommufd, 1); +} + +void __init iommufd_test_init(void) +{ + dbgfs_root = + fault_create_debugfs_attr("fail_iommufd", NULL, &fail_iommufd); +} + +void iommufd_test_exit(void) +{ + debugfs_remove_recursive(dbgfs_root); +} diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h index 84af9a239769..650d45629647 100644 --- a/include/linux/iommufd.h +++ b/include/linux/iommufd.h @@ -34,6 +34,9 @@ enum { IOMMUFD_ACCESS_RW_WRITE = 1 << 0, /* Set if the caller is in a kthread then rw will use kthread_use_mm() */ IOMMUFD_ACCESS_RW_KTHREAD = 1 << 1, + + /* Only for use by selftest */ + __IOMMUFD_ACCESS_RW_SLOW_PATH = 1 << 2, }; struct iommufd_access * -- cgit v1.2.3 From e26eed4f623da70913b535631a29764d108efe98 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 29 Nov 2022 16:29:40 -0400 Subject: iommufd: Add some fault injection points This increases the coverage the fail_nth test gets, as well as via syzkaller. Link: https://lore.kernel.org/r/17-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Tested-by: Matthew Rosato # s390 Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/main.c | 3 +++ drivers/iommu/iommufd/pages.c | 26 ++++++++++++++++++++++++++ 2 files changed, 29 insertions(+) (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index 7c8f40bc8d98..bcb463e58100 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -102,6 +102,9 @@ struct iommufd_object *iommufd_get_object(struct iommufd_ctx *ictx, u32 id, { struct iommufd_object *obj; + if (iommufd_should_fail()) + return ERR_PTR(-ENOENT); + xa_lock(&ictx->objects); obj = xa_load(&ictx->objects, id); if (!obj || (type != IOMMUFD_OBJ_ANY && obj->type != type) || diff --git a/drivers/iommu/iommufd/pages.c b/drivers/iommu/iommufd/pages.c index 640331b8a079..c5d2d9a8c562 100644 --- a/drivers/iommu/iommufd/pages.c +++ b/drivers/iommu/iommufd/pages.c @@ -80,6 +80,10 @@ static void *temp_kmalloc(size_t *size, void *backup, size_t backup_len) if (*size < backup_len) return backup; + + if (!backup && iommufd_should_fail()) + return NULL; + *size = min_t(size_t, *size, TEMP_MEMORY_LIMIT); res = kmalloc(*size, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY); if (res) @@ -544,6 +548,7 @@ static int pages_to_xarray(struct xarray *xa, unsigned long start_index, unsigned long last_index, struct page **pages) { struct page **end_pages = pages + (last_index - start_index) + 1; + struct page **half_pages = pages + (end_pages - pages) / 2; XA_STATE(xas, xa, start_index); do { @@ -551,6 +556,15 @@ static int pages_to_xarray(struct xarray *xa, unsigned long start_index, xas_lock(&xas); while (pages != end_pages) { + /* xarray does not participate in fault injection */ + if (pages == half_pages && iommufd_should_fail()) { + xas_set_err(&xas, -EINVAL); + xas_unlock(&xas); + /* aka xas_destroy() */ + xas_nomem(&xas, GFP_KERNEL); + goto err_clear; + } + old = xas_store(&xas, xa_mk_value(page_to_pfn(*pages))); if (xas_error(&xas)) break; @@ -561,6 +575,7 @@ static int pages_to_xarray(struct xarray *xa, unsigned long start_index, xas_unlock(&xas); } while (xas_nomem(&xas, GFP_KERNEL)); +err_clear: if (xas_error(&xas)) { if (xas.xa_index != start_index) clear_xarray(xa, start_index, xas.xa_index - 1); @@ -728,6 +743,10 @@ static int pfn_reader_user_pin(struct pfn_reader_user *user, npages = min_t(unsigned long, last_index - start_index + 1, user->upages_len / sizeof(*user->upages)); + + if (iommufd_should_fail()) + return -EFAULT; + uptr = (uintptr_t)(pages->uptr + start_index * PAGE_SIZE); if (!remote_mm) rc = pin_user_pages_fast(uptr, npages, user->gup_flags, @@ -872,6 +891,8 @@ static int pfn_reader_user_update_pinned(struct pfn_reader_user *user, npages = pages->last_npinned - pages->npinned; inc = false; } else { + if (iommufd_should_fail()) + return -ENOMEM; npages = pages->npinned - pages->last_npinned; inc = true; } @@ -1721,6 +1742,11 @@ static int iopt_pages_rw_page(struct iopt_pages *pages, unsigned long index, return iopt_pages_rw_slow(pages, index, index, offset, data, length, flags); + if (iommufd_should_fail()) { + rc = -EINVAL; + goto out_mmput; + } + mmap_read_lock(pages->source_mm); rc = pin_user_pages_remote( pages->source_mm, (uintptr_t)(pages->uptr + index * PAGE_SIZE), -- cgit v1.2.3 From 52f528583bb395495f7dd35e6e4d548bccbf8a73 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 29 Nov 2022 16:29:41 -0400 Subject: iommufd: Add additional invariant assertions These are on performance paths so we protect them using the CONFIG_IOMMUFD_TEST to not take a hit during normal operation. These are useful when running the test suite and syzkaller to find data structure inconsistencies early. Link: https://lore.kernel.org/r/18-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com Tested-by: Yi Liu Tested-by: Matthew Rosato # s390 Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/device.c | 5 +++++ drivers/iommu/iommufd/io_pagetable.c | 22 +++++++++++++++++++ drivers/iommu/iommufd/io_pagetable.h | 3 +++ drivers/iommu/iommufd/pages.c | 42 ++++++++++++++++++++++++++++++++++-- 4 files changed, 70 insertions(+), 2 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c index 67ce36152e8a..dd2a415b603e 100644 --- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -625,6 +625,11 @@ int iommufd_access_pin_pages(struct iommufd_access *access, unsigned long iova, struct iopt_area *area; int rc; + /* Driver's ops don't support pin_pages */ + if (IS_ENABLED(CONFIG_IOMMUFD_TEST) && + WARN_ON(access->iova_alignment != PAGE_SIZE || !access->ops->unmap)) + return -EINVAL; + if (!length) return -EINVAL; if (check_add_overflow(iova, length - 1, &last_iova)) diff --git a/drivers/iommu/iommufd/io_pagetable.c b/drivers/iommu/iommufd/io_pagetable.c index 4f4a9d9aac57..3467cea79568 100644 --- a/drivers/iommu/iommufd/io_pagetable.c +++ b/drivers/iommu/iommufd/io_pagetable.c @@ -251,6 +251,11 @@ static int iopt_alloc_area_pages(struct io_pagetable *iopt, (uintptr_t)elm->pages->uptr + elm->start_byte, length); if (rc) goto out_unlock; + if (IS_ENABLED(CONFIG_IOMMUFD_TEST) && + WARN_ON(iopt_check_iova(iopt, *dst_iova, length))) { + rc = -EINVAL; + goto out_unlock; + } } else { rc = iopt_check_iova(iopt, *dst_iova, length); if (rc) @@ -277,6 +282,8 @@ out_unlock: static void iopt_abort_area(struct iopt_area *area) { + if (IS_ENABLED(CONFIG_IOMMUFD_TEST)) + WARN_ON(area->pages); if (area->iopt) { down_write(&area->iopt->iova_rwsem); interval_tree_remove(&area->node, &area->iopt->area_itree); @@ -642,6 +649,9 @@ void iopt_destroy_table(struct io_pagetable *iopt) { struct interval_tree_node *node; + if (IS_ENABLED(CONFIG_IOMMUFD_TEST)) + iopt_remove_reserved_iova(iopt, NULL); + while ((node = interval_tree_iter_first(&iopt->allowed_itree, 0, ULONG_MAX))) { interval_tree_remove(node, &iopt->allowed_itree); @@ -688,6 +698,8 @@ static void iopt_unfill_domain(struct io_pagetable *iopt, continue; mutex_lock(&pages->mutex); + if (IS_ENABLED(CONFIG_IOMMUFD_TEST)) + WARN_ON(!area->storage_domain); if (area->storage_domain == domain) area->storage_domain = storage_domain; mutex_unlock(&pages->mutex); @@ -792,6 +804,16 @@ static int iopt_check_iova_alignment(struct io_pagetable *iopt, (iopt_area_length(area) & align_mask) || (area->page_offset & align_mask)) return -EADDRINUSE; + + if (IS_ENABLED(CONFIG_IOMMUFD_TEST)) { + struct iommufd_access *access; + unsigned long index; + + xa_for_each(&iopt->access_list, index, access) + if (WARN_ON(access->iova_alignment > + new_iova_alignment)) + return -EADDRINUSE; + } return 0; } diff --git a/drivers/iommu/iommufd/io_pagetable.h b/drivers/iommu/iommufd/io_pagetable.h index 2ee6942c3ef4..83e7c175f2a2 100644 --- a/drivers/iommu/iommufd/io_pagetable.h +++ b/drivers/iommu/iommufd/io_pagetable.h @@ -101,6 +101,9 @@ static inline size_t iopt_area_length(struct iopt_area *area) static inline unsigned long iopt_area_start_byte(struct iopt_area *area, unsigned long iova) { + if (IS_ENABLED(CONFIG_IOMMUFD_TEST)) + WARN_ON(iova < iopt_area_iova(area) || + iova > iopt_area_last_iova(area)); return (iova - iopt_area_iova(area)) + area->page_offset + iopt_area_index(area) * PAGE_SIZE; } diff --git a/drivers/iommu/iommufd/pages.c b/drivers/iommu/iommufd/pages.c index c5d2d9a8c562..429fa3b0a239 100644 --- a/drivers/iommu/iommufd/pages.c +++ b/drivers/iommu/iommufd/pages.c @@ -162,12 +162,20 @@ void interval_tree_double_span_iter_next( static void iopt_pages_add_npinned(struct iopt_pages *pages, size_t npages) { - pages->npinned += npages; + int rc; + + rc = check_add_overflow(pages->npinned, npages, &pages->npinned); + if (IS_ENABLED(CONFIG_IOMMUFD_TEST)) + WARN_ON(rc || pages->npinned > pages->npages); } static void iopt_pages_sub_npinned(struct iopt_pages *pages, size_t npages) { - pages->npinned -= npages; + int rc; + + rc = check_sub_overflow(pages->npinned, npages, &pages->npinned); + if (IS_ENABLED(CONFIG_IOMMUFD_TEST)) + WARN_ON(rc || pages->npinned > pages->npages); } static void iopt_pages_err_unpin(struct iopt_pages *pages, @@ -189,6 +197,9 @@ static void iopt_pages_err_unpin(struct iopt_pages *pages, static unsigned long iopt_area_index_to_iova(struct iopt_area *area, unsigned long index) { + if (IS_ENABLED(CONFIG_IOMMUFD_TEST)) + WARN_ON(index < iopt_area_index(area) || + index > iopt_area_last_index(area)); index -= iopt_area_index(area); if (index == 0) return iopt_area_iova(area); @@ -198,6 +209,9 @@ static unsigned long iopt_area_index_to_iova(struct iopt_area *area, static unsigned long iopt_area_index_to_iova_last(struct iopt_area *area, unsigned long index) { + if (IS_ENABLED(CONFIG_IOMMUFD_TEST)) + WARN_ON(index < iopt_area_index(area) || + index > iopt_area_last_index(area)); if (index == iopt_area_last_index(area)) return iopt_area_last_iova(area); return iopt_area_iova(area) - area->page_offset + @@ -286,6 +300,8 @@ static void batch_skip_carry(struct pfn_batch *batch, unsigned int skip_pfns) { if (!batch->total_pfns) return; + if (IS_ENABLED(CONFIG_IOMMUFD_TEST)) + WARN_ON(batch->total_pfns != batch->npfns[0]); skip_pfns = min(batch->total_pfns, skip_pfns); batch->pfns[0] += skip_pfns; batch->npfns[0] -= skip_pfns; @@ -301,6 +317,8 @@ static int __batch_init(struct pfn_batch *batch, size_t max_pages, void *backup, batch->pfns = temp_kmalloc(&size, backup, backup_len); if (!batch->pfns) return -ENOMEM; + if (IS_ENABLED(CONFIG_IOMMUFD_TEST) && WARN_ON(size < elmsz)) + return -EINVAL; batch->array_size = size / elmsz; batch->npfns = (u32 *)(batch->pfns + batch->array_size); batch_clear(batch); @@ -429,6 +447,10 @@ static int batch_iommu_map_small(struct iommu_domain *domain, unsigned long start_iova = iova; int rc; + if (IS_ENABLED(CONFIG_IOMMUFD_TEST)) + WARN_ON(paddr % PAGE_SIZE || iova % PAGE_SIZE || + size % PAGE_SIZE); + while (size) { rc = iommu_map(domain, iova, paddr, PAGE_SIZE, prot); if (rc) @@ -718,6 +740,10 @@ static int pfn_reader_user_pin(struct pfn_reader_user *user, uintptr_t uptr; long rc; + if (IS_ENABLED(CONFIG_IOMMUFD_TEST) && + WARN_ON(last_index < start_index)) + return -EINVAL; + if (!user->upages) { /* All undone in pfn_reader_destroy() */ user->upages_len = @@ -956,6 +982,10 @@ static int pfn_reader_fill_span(struct pfn_reader *pfns) struct iopt_area *area; int rc; + if (IS_ENABLED(CONFIG_IOMMUFD_TEST) && + WARN_ON(span->last_used < start_index)) + return -EINVAL; + if (span->is_used == 1) { batch_from_xarray(&pfns->batch, &pfns->pages->pinned_pfns, start_index, span->last_used); @@ -1008,6 +1038,10 @@ static int pfn_reader_next(struct pfn_reader *pfns) while (pfns->batch_end_index != pfns->last_index + 1) { unsigned int npfns = pfns->batch.total_pfns; + if (IS_ENABLED(CONFIG_IOMMUFD_TEST) && + WARN_ON(interval_tree_double_span_iter_done(&pfns->span))) + return -EINVAL; + rc = pfn_reader_fill_span(pfns); if (rc) return rc; @@ -1091,6 +1125,10 @@ static int pfn_reader_first(struct pfn_reader *pfns, struct iopt_pages *pages, { int rc; + if (IS_ENABLED(CONFIG_IOMMUFD_TEST) && + WARN_ON(last_index < start_index)) + return -EINVAL; + rc = pfn_reader_init(pfns, pages, start_index, last_index); if (rc) return rc; -- cgit v1.2.3 From 01f70cbb26eadb5959344598977cb7159948263a Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 29 Nov 2022 16:31:55 -0400 Subject: iommufd: Allow iommufd to supply /dev/vfio/vfio If the VFIO container is compiled out, give a kconfig option for iommufd to provide the miscdev node with the same name and permissions as vfio uses. The compatibility node supports the same ioctls as VFIO and automatically enables the VFIO compatible pinned page accounting mode. Link: https://lore.kernel.org/r/10-v4-42cd2eb0e3eb+335a-vfio_iommufd_jgg@nvidia.com Reviewed-by: Kevin Tian Reviewed-by: Yi Liu Reviewed-by: Alex Williamson Tested-by: Alex Williamson Tested-by: Nicolin Chen Tested-by: Yi Liu Tested-by: Lixiao Yang Tested-by: Matthew Rosato Tested-by: Yu He Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/Kconfig | 20 ++++++++++++++++++++ drivers/iommu/iommufd/main.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 56 insertions(+) (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommufd/Kconfig b/drivers/iommu/iommufd/Kconfig index 871244f2443f..8306616b6d81 100644 --- a/drivers/iommu/iommufd/Kconfig +++ b/drivers/iommu/iommufd/Kconfig @@ -12,6 +12,26 @@ config IOMMUFD If you don't know what to do here, say N. if IOMMUFD +config IOMMUFD_VFIO_CONTAINER + bool "IOMMUFD provides the VFIO container /dev/vfio/vfio" + depends on VFIO && !VFIO_CONTAINER + default VFIO && !VFIO_CONTAINER + help + IOMMUFD will provide /dev/vfio/vfio instead of VFIO. This relies on + IOMMUFD providing compatibility emulation to give the same ioctls. + It provides an option to build a kernel with legacy VFIO components + removed. + + IOMMUFD VFIO container emulation is known to lack certain features + of the native VFIO container, such as no-IOMMU support, peer-to-peer + DMA mapping, PPC IOMMU support, as well as other potentially + undiscovered gaps. This option is currently intended for the + purpose of testing IOMMUFD with unmodified userspace supporting VFIO + and making use of the Type1 VFIO IOMMU backend. General purpose + enabling of this option is currently discouraged. + + Unless testing IOMMUFD, say N here. + config IOMMUFD_TEST bool "IOMMU Userspace API Test support" depends on DEBUG_KERNEL diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index bcb463e58100..083e6fcbe10a 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -18,6 +18,7 @@ #include #include +#include "io_pagetable.h" #include "iommufd_private.h" #include "iommufd_test.h" @@ -25,6 +26,7 @@ struct iommufd_object_ops { void (*destroy)(struct iommufd_object *obj); }; static const struct iommufd_object_ops iommufd_object_ops[]; +static struct miscdevice vfio_misc_dev; struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size, @@ -170,6 +172,16 @@ static int iommufd_fops_open(struct inode *inode, struct file *filp) if (!ictx) return -ENOMEM; + /* + * For compatibility with VFIO when /dev/vfio/vfio is opened we default + * to the same rlimit accounting as vfio uses. + */ + if (IS_ENABLED(CONFIG_IOMMUFD_VFIO_CONTAINER) && + filp->private_data == &vfio_misc_dev) { + ictx->account_mode = IOPT_PAGES_ACCOUNT_MM; + pr_info_once("IOMMUFD is providing /dev/vfio/vfio, not VFIO.\n"); + } + xa_init_flags(&ictx->objects, XA_FLAGS_ALLOC1 | XA_FLAGS_ACCOUNT); ictx->file = filp; filp->private_data = ictx; @@ -400,6 +412,15 @@ static struct miscdevice iommu_misc_dev = { .mode = 0660, }; + +static struct miscdevice vfio_misc_dev = { + .minor = VFIO_MINOR, + .name = "vfio", + .fops = &iommufd_fops, + .nodename = "vfio/vfio", + .mode = 0666, +}; + static int __init iommufd_init(void) { int ret; @@ -407,18 +428,33 @@ static int __init iommufd_init(void) ret = misc_register(&iommu_misc_dev); if (ret) return ret; + + if (IS_ENABLED(CONFIG_IOMMUFD_VFIO_CONTAINER)) { + ret = misc_register(&vfio_misc_dev); + if (ret) + goto err_misc; + } iommufd_test_init(); return 0; +err_misc: + misc_deregister(&iommu_misc_dev); + return ret; } static void __exit iommufd_exit(void) { iommufd_test_exit(); + if (IS_ENABLED(CONFIG_IOMMUFD_VFIO_CONTAINER)) + misc_deregister(&vfio_misc_dev); misc_deregister(&iommu_misc_dev); } module_init(iommufd_init); module_exit(iommufd_exit); +#if IS_ENABLED(CONFIG_IOMMUFD_VFIO_CONTAINER) +MODULE_ALIAS_MISCDEV(VFIO_MINOR); +MODULE_ALIAS("devname:vfio/vfio"); +#endif MODULE_DESCRIPTION("I/O Address Space Management for passthrough devices"); MODULE_LICENSE("GPL"); -- cgit v1.2.3 From c9b8a83a8f2dca9f82288a621595a6a5970cdc5e Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Wed, 7 Dec 2022 16:44:41 -0400 Subject: iommufd: Fix comment typos Repair some typos in comments that were noticed late in the review cycle. Fixes: f394576eb11d ("iommufd: PFN handling for iopt_pages") Link: https://lore.kernel.org/r/1-v1-0362a1a1c034+98-iommufd_fixes1_jgg@nvidia.com Reviewed-by: Kevin Tian Reviewed-by: Eric Auger Reported-by: Binbin Wu Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/io_pagetable.h | 2 +- drivers/iommu/iommufd/pages.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommufd/io_pagetable.h b/drivers/iommu/iommufd/io_pagetable.h index 83e7c175f2a2..0ec3509b7e33 100644 --- a/drivers/iommu/iommufd/io_pagetable.h +++ b/drivers/iommu/iommufd/io_pagetable.h @@ -33,7 +33,7 @@ struct iommu_domain; * * The io_pagetable::iova_rwsem protects node * The iopt_pages::mutex protects pages_node - * iopt and immu_prot are immutable + * iopt and iommu_prot are immutable * The pages::mutex protects num_accesses */ struct iopt_area { diff --git a/drivers/iommu/iommufd/pages.c b/drivers/iommu/iommufd/pages.c index 429fa3b0a239..fccdba782cb6 100644 --- a/drivers/iommu/iommufd/pages.c +++ b/drivers/iommu/iommufd/pages.c @@ -342,7 +342,7 @@ static void batch_destroy(struct pfn_batch *batch, void *backup) kfree(batch->pfns); } -/* true if the pfn could be added, false otherwise */ +/* true if the pfn was added, false otherwise */ static bool batch_add_pfn(struct pfn_batch *batch, unsigned long pfn) { const unsigned int MAX_NPFNS = type_max(typeof(*batch->npfns)); @@ -418,7 +418,7 @@ static struct page **raw_pages_from_domain(struct iommu_domain *domain, return out_pages; } -/* Continues reading a domain until we reach a discontiguity in the pfns. */ +/* Continues reading a domain until we reach a discontinuity in the pfns. */ static void batch_from_domain_continue(struct pfn_batch *batch, struct iommu_domain *domain, struct iopt_area *area, -- cgit v1.2.3 From a26fa392068d1dcdf781397b7a7dd908dd68f030 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Wed, 7 Dec 2022 16:44:42 -0400 Subject: iommufd: Improve a few unclear bits of code Correct a few items noticed late in review: - We should assert that the math in batch_clear_carry() doesn't underflow - user->locked should be -1 not 0 sicne we just did mmput - npages should not have been recalculated, it already has that value No functional change. Fixes: 8d160cd4d506 ("iommufd: Algorithms for PFN storage") Link: https://lore.kernel.org/r/2-v1-0362a1a1c034+98-iommufd_fixes1_jgg@nvidia.com Reviewed-by: Kevin Tian Reviewed-by: Eric Auger Reported-by: Binbin Wu Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/pages.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommufd/pages.c b/drivers/iommu/iommufd/pages.c index fccdba782cb6..c77177229648 100644 --- a/drivers/iommu/iommufd/pages.c +++ b/drivers/iommu/iommufd/pages.c @@ -289,6 +289,10 @@ static void batch_clear_carry(struct pfn_batch *batch, unsigned int keep_pfns) if (!keep_pfns) return batch_clear(batch); + if (IS_ENABLED(CONFIG_IOMMUFD_TEST)) + WARN_ON(!batch->end || + batch->npfns[batch->end - 1] < keep_pfns); + batch->total_pfns = keep_pfns; batch->npfns[0] = keep_pfns; batch->pfns[0] = batch->pfns[batch->end - 1] + @@ -723,7 +727,7 @@ static void pfn_reader_user_destroy(struct pfn_reader_user *user, mmap_read_unlock(pages->source_mm); if (pages->source_mm != current->mm) mmput(pages->source_mm); - user->locked = 0; + user->locked = -1; } kfree(user->upages); @@ -810,7 +814,6 @@ static int incr_user_locked_vm(struct iopt_pages *pages, unsigned long npages) lock_limit = task_rlimit(pages->source_task, RLIMIT_MEMLOCK) >> PAGE_SHIFT; - npages = pages->npinned - pages->last_npinned; do { cur_pages = atomic_long_read(&pages->source_user->locked_vm); new_pages = cur_pages + npages; -- cgit v1.2.3 From d6c55c0a20e5059abdde81713ddf6324a946eb3c Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Wed, 7 Dec 2022 16:44:43 -0400 Subject: iommufd: Change the order of MSI setup Eric points out this is wrong for the rare case of someone using allow_unsafe_interrupts on ARM. We always have to setup the MSI window in the domain if the iommu driver asks for it. Move the iommu_get_msi_cookie() setup to the top of the function and always do it, regardless of the security mode. Add checks to iommufd_device_setup_msi() to ensure the driver is not doing something incomprehensible. No current driver will set both a HW and SW MSI window, or have more than one SW MSI window. Fixes: e8d57210035b ("iommufd: Add kAPI toward external drivers for physical devices") Link: https://lore.kernel.org/r/3-v1-0362a1a1c034+98-iommufd_fixes1_jgg@nvidia.com Reviewed-by: Kevin Tian Reported-by: Eric Auger Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/device.c | 56 ++++++++++++++++-------------------- drivers/iommu/iommufd/io_pagetable.c | 24 +++++++++------- 2 files changed, 39 insertions(+), 41 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c index dd2a415b603e..d81f93a321af 100644 --- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -139,19 +139,11 @@ static int iommufd_device_setup_msi(struct iommufd_device *idev, int rc; /* - * IOMMU_CAP_INTR_REMAP means that the platform is isolating MSI, and it - * creates the MSI window by default in the iommu domain. Nothing - * further to do. - */ - if (device_iommu_capable(idev->dev, IOMMU_CAP_INTR_REMAP)) - return 0; - - /* - * On ARM systems that set the global IRQ_DOMAIN_FLAG_MSI_REMAP every - * allocated iommu_domain will block interrupts by default and this - * special flow is needed to turn them back on. iommu_dma_prepare_msi() - * will install pages into our domain after request_irq() to make this - * work. + * If the IOMMU driver gives a IOMMU_RESV_SW_MSI then it is asking us to + * call iommu_get_msi_cookie() on its behalf. This is necessary to setup + * the MSI window so iommu_dma_prepare_msi() can install pages into our + * domain after request_irq(). If it is not done interrupts will not + * work on this domain. * * FIXME: This is conceptually broken for iommufd since we want to allow * userspace to change the domains, eg switch from an identity IOAS to a @@ -159,33 +151,35 @@ static int iommufd_device_setup_msi(struct iommufd_device *idev, * matches what the IRQ layer actually expects in a newly created * domain. */ - if (irq_domain_check_msi_remap()) { - if (WARN_ON(!sw_msi_start)) - return -EPERM; + if (sw_msi_start != PHYS_ADDR_MAX && !hwpt->msi_cookie) { + rc = iommu_get_msi_cookie(hwpt->domain, sw_msi_start); + if (rc) + return rc; + /* * iommu_get_msi_cookie() can only be called once per domain, * it returns -EBUSY on later calls. */ - if (hwpt->msi_cookie) - return 0; - rc = iommu_get_msi_cookie(hwpt->domain, sw_msi_start); - if (rc) - return rc; hwpt->msi_cookie = true; - return 0; } /* - * Otherwise the platform has a MSI window that is not isolated. For - * historical compat with VFIO allow a module parameter to ignore the - * insecurity. + * For historical compat with VFIO the insecure interrupt path is + * allowed if the module parameter is set. Insecure means that a MemWr + * operation from the device (eg a simple DMA) cannot trigger an + * interrupt outside this iommufd context. */ - if (!allow_unsafe_interrupts) - return -EPERM; + if (!device_iommu_capable(idev->dev, IOMMU_CAP_INTR_REMAP) && + !irq_domain_check_msi_remap()) { + if (!allow_unsafe_interrupts) + return -EPERM; - dev_warn( - idev->dev, - "MSI interrupt window cannot be isolated by the IOMMU, this platform is insecure. Use the \"allow_unsafe_interrupts\" module parameter to override\n"); + dev_warn( + idev->dev, + "MSI interrupts are not secure, they cannot be isolated by the platform. " + "Check that platform features like interrupt remapping are enabled. " + "Use the \"allow_unsafe_interrupts\" module parameter to override\n"); + } return 0; } @@ -203,7 +197,7 @@ static bool iommufd_hw_pagetable_has_group(struct iommufd_hw_pagetable *hwpt, static int iommufd_device_do_attach(struct iommufd_device *idev, struct iommufd_hw_pagetable *hwpt) { - phys_addr_t sw_msi_start = 0; + phys_addr_t sw_msi_start = PHYS_ADDR_MAX; int rc; mutex_lock(&hwpt->devices_lock); diff --git a/drivers/iommu/iommufd/io_pagetable.c b/drivers/iommu/iommufd/io_pagetable.c index 3467cea79568..e0ae72b9e67f 100644 --- a/drivers/iommu/iommufd/io_pagetable.c +++ b/drivers/iommu/iommufd/io_pagetable.c @@ -1170,6 +1170,8 @@ int iopt_table_enforce_group_resv_regions(struct io_pagetable *iopt, struct iommu_resv_region *resv; struct iommu_resv_region *tmp; LIST_HEAD(group_resv_regions); + unsigned int num_hw_msi = 0; + unsigned int num_sw_msi = 0; int rc; down_write(&iopt->iova_rwsem); @@ -1181,23 +1183,25 @@ int iopt_table_enforce_group_resv_regions(struct io_pagetable *iopt, if (resv->type == IOMMU_RESV_DIRECT_RELAXABLE) continue; - /* - * The presence of any 'real' MSI regions should take precedence - * over the software-managed one if the IOMMU driver happens to - * advertise both types. - */ - if (sw_msi_start && resv->type == IOMMU_RESV_MSI) { - *sw_msi_start = 0; - sw_msi_start = NULL; - } - if (sw_msi_start && resv->type == IOMMU_RESV_SW_MSI) + if (sw_msi_start && resv->type == IOMMU_RESV_MSI) + num_hw_msi++; + if (sw_msi_start && resv->type == IOMMU_RESV_SW_MSI) { *sw_msi_start = resv->start; + num_sw_msi++; + } rc = iopt_reserve_iova(iopt, resv->start, resv->length - 1 + resv->start, device); if (rc) goto out_reserved; } + + /* Drivers must offer sane combinations of regions */ + if (WARN_ON(num_sw_msi && num_hw_msi) || WARN_ON(num_sw_msi > 1)) { + rc = -EINVAL; + goto out_reserved; + } + rc = 0; goto out_free_resv; -- cgit v1.2.3