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path: root/drivers/vfio/pci/vfio_pci.c
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2021-04-29Merge tag 'vfio-v5.13-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds1-134/+140
Pull VFIO updates from Alex Williamson: - Embed struct vfio_device into vfio driver structures (Jason Gunthorpe) - Make vfio_mdev type safe (Jason Gunthorpe) - Remove vfio-pci NVLink2 extensions for POWER9 (Christoph Hellwig) - Update vfio-pci IGD extensions for OpRegion 2.1+ (Fred Gao) - Various spelling/blank line fixes (Zhen Lei, Zhou Wang, Bhaskar Chowdhury) - Simplify unpin_pages error handling (Shenming Lu) - Fix i915 mdev Kconfig dependency (Arnd Bergmann) - Remove unused structure member (Keqian Zhu) * tag 'vfio-v5.13-rc1' of git://github.com/awilliam/linux-vfio: (43 commits) vfio/gvt: fix DRM_I915_GVT dependency on VFIO_MDEV vfio/iommu_type1: Remove unused pinned_page_dirty_scope in vfio_iommu vfio/mdev: Correct the function signatures for the mdev_type_attributes vfio/mdev: Remove kobj from mdev_parent_ops->create() vfio/gvt: Use mdev_get_type_group_id() vfio/gvt: Make DRM_I915_GVT depend on VFIO_MDEV vfio/mbochs: Use mdev_get_type_group_id() vfio/mdpy: Use mdev_get_type_group_id() vfio/mtty: Use mdev_get_type_group_id() vfio/mdev: Add mdev/mtype_get_type_group_id() vfio/mdev: Remove duplicate storage of parent in mdev_device vfio/mdev: Add missing error handling to dev_set_name() vfio/mdev: Reorganize mdev_device_create() vfio/mdev: Add missing reference counting to mdev_type vfio/mdev: Expose mdev_get/put_parent to mdev_private.h vfio/mdev: Use struct mdev_type in struct mdev_device vfio/mdev: Simplify driver registration vfio/mdev: Add missing typesafety around mdev_device vfio/mdev: Do not allow a mdev_type to have a NULL parent pointer vfio/mdev: Fix missing static's on MDEV_TYPE_ATTR's ...
2021-04-13vfio/pci: Add missing range check in vfio_pci_mmapChristian A. Ehrhardt1-1/+3
When mmaping an extra device region verify that the region index derived from the mmap offset is valid. Fixes: a15b1883fee1 ("vfio_pci: Allow mapping extra regions") Cc: stable@vger.kernel.org Signed-off-by: Christian A. Ehrhardt <lk@c--e.de> Message-Id: <20210412214124.GA241759@lisa.in-ulm.de> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-04-06Merge branches 'v5.13/vfio/embed-vfio_device', 'v5.13/vfio/misc' and ↵Alex Williamson1-20/+1
'v5.13/vfio/nvlink' into v5.13/vfio/next Spelling fixes merged with file deletion. Conflicts: drivers/vfio/pci/vfio_pci_nvlink2.c Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-04-06vfio: Remove device_data from the vfio bus driver APIJason Gunthorpe1-1/+1
There are no longer any users, so it can go away. Everything is using container_of now. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Message-Id: <14-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-04-06vfio/pci: Replace uses of vfio_device_data() with container_ofJason Gunthorpe1-43/+24
This tidies a few confused places that think they can have a refcount on the vfio_device but the device_data could be NULL, that isn't possible by design. Most of the change falls out when struct vfio_devices is updated to just store the struct vfio_pci_device itself. This wasn't possible before because there was no easy way to get from the 'struct vfio_pci_device' to the 'struct vfio_device' to put back the refcount. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Message-Id: <13-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-04-06vfio: Make vfio_device_ops pass a 'struct vfio_device *' instead of 'void *'Jason Gunthorpe1-18/+29
This is the standard kernel pattern, the ops associated with a struct get the struct pointer in for typesafety. The expected design is to use container_of to cleanly go from the subsystem level type to the driver level type without having any type erasure in a void *. Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Message-Id: <12-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-04-06vfio/pci: Use vfio_init/register/unregister_group_devJason Gunthorpe1-5/+5
pci already allocates a struct vfio_pci_device with exactly the same lifetime as vfio_device, switch to the new API and embed vfio_device in vfio_pci_device. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Liu Yi L <yi.l.liu@intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Message-Id: <9-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-04-06vfio/pci: Re-order vfio_pci_probe()Jason Gunthorpe1-8/+9
vfio_add_group_dev() must be called only after all of the private data in vdev is fully setup and ready, otherwise there could be races with user space instantiating a device file descriptor and starting to call ops. For instance vfio_pci_reflck_attach() sets vdev->reflck and vfio_pci_open(), called by fops open, unconditionally derefs it, which will crash if things get out of order. Fixes: cc20d7999000 ("vfio/pci: Introduce VF token") Fixes: e309df5b0c9e ("vfio/pci: Parallelize device open and release") Fixes: 6eb7018705de ("vfio-pci: Move idle devices to D3hot power state") Fixes: ecaa1f6a0154 ("vfio-pci: Add VGA arbiter client") Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Message-Id: <8-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-04-06vfio/pci: Move VGA and VF initialization to functionsJason Gunthorpe1-42/+74
vfio_pci_probe() is quite complicated, with optional VF and VGA sub components. Move these into clear init/uninit functions and have a linear flow in probe/remove. This fixes a few little buglets: - vfio_pci_remove() is in the wrong order, vga_client_register() removes a notifier and is after kfree(vdev), but the notifier refers to vdev, so it can use after free in a race. - vga_client_register() can fail but was ignored Organize things so destruction order is the reverse of creation order. Fixes: ecaa1f6a0154 ("vfio-pci: Add VGA arbiter client") Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Message-Id: <7-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-04-06vfio/pci: remove vfio_pci_nvlink2Christoph Hellwig1-18/+0
This driver never had any open userspace (which for VFIO would include VM kernel drivers) that use it, and thus should never have been added by our normal userspace ABI rules. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Message-Id: <20210326061311.1497642-2-hch@lst.de> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-04-06vfio/pci: Remove an unnecessary blank line in vfio_pci_enableZhou Wang1-1/+0
This blank line is unnecessary, so remove it. Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com> Message-Id: <1615808073-178604-1-git-send-email-wangzhou1@hisilicon.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-04-06vfio: pci: Spello fix in the file vfio_pci.cBhaskar Chowdhury1-1/+1
s/permision/permission/ Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Message-Id: <20210314052925.3560-1-unixbhaskar@gmail.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-02-19vfio/pci: remove CONFIG_VFIO_PCI_ZDEV from KconfigMax Gurtovoy1-7/+5
In case we're running on s390 system always expose the capabilities for configuration of zPCI devices. In case we're running on different platform, continue as usual. Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-12-02vfio-pci: Use io_remap_pfn_range() for PCI IO memoryJason Gunthorpe1-2/+2
commit f8f6ae5d077a ("mm: always have io_remap_pfn_range() set pgprot_decrypted()") allows drivers using mmap to put PCI memory mapped BAR space into userspace to work correctly on AMD SME systems that default to all memory encrypted. Since vfio_pci_mmap_fault() is working with PCI memory mapped BAR space it should be calling io_remap_pfn_range() otherwise it will not work on SME systems. Fixes: 11c4cd07ba11 ("vfio-pci: Fault mmaps to enable vma tracking") Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Peter Xu <peterx@redhat.com> Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-12-02vfio/pci: Move dummy_resources_list init in vfio_pci_probe()Eric Auger1-2/+1
In case an error occurs in vfio_pci_enable() before the call to vfio_pci_probe_mmaps(), vfio_pci_disable() will try to iterate on an uninitialized list and cause a kernel panic. Lets move to the initialization to vfio_pci_probe() to fix the issue. Signed-off-by: Eric Auger <eric.auger@redhat.com> Fixes: 05f0c03fbac1 ("vfio-pci: Allow to mmap sub-page MMIO BARs if the mmio page is exclusive") CC: Stable <stable@vger.kernel.org> # v4.7+ Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-11-03vfio/pci: Bypass IGD init in case of -ENODEVFred Gao1-1/+1
Bypass the IGD initialization when -ENODEV returns, that should be the case if opregion is not available for IGD or within discrete graphics device's option ROM, or host/lpc bridge is not found. Then use of -ENODEV here means no special device resources found which needs special care for VFIO, but we still allow other normal device resource access. Cc: Zhenyu Wang <zhenyuw@linux.intel.com> Cc: Xiong Zhang <xiong.y.zhang@intel.com> Cc: Hang Yuan <hang.yuan@linux.intel.com> Cc: Stuart Summers <stuart.summers@intel.com> Signed-off-by: Fred Gao <fred.gao@intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-10-22Merge tag 'vfio-v5.10-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds1-1/+37
Pull VFIO updates from Alex Williamson: - New fsl-mc vfio bus driver supporting userspace drivers of objects within NXP's DPAA2 architecture (Diana Craciun) - Support for exposing zPCI information on s390 (Matthew Rosato) - Fixes for "detached" VFs on s390 (Matthew Rosato) - Fixes for pin-pages and dma-rw accesses (Yan Zhao) - Cleanups and optimize vconfig regen (Zenghui Yu) - Fix duplicate irq-bypass token registration (Alex Williamson) * tag 'vfio-v5.10-rc1' of git://github.com/awilliam/linux-vfio: (30 commits) vfio iommu type1: Fix memory leak in vfio_iommu_type1_pin_pages vfio/pci: Clear token on bypass registration failure vfio/fsl-mc: fix the return of the uninitialized variable ret vfio/fsl-mc: Fix the dead code in vfio_fsl_mc_set_irq_trigger vfio/fsl-mc: Fixed vfio-fsl-mc driver compilation on 32 bit MAINTAINERS: Add entry for s390 vfio-pci vfio-pci/zdev: Add zPCI capabilities to VFIO_DEVICE_GET_INFO vfio/fsl-mc: Add support for device reset vfio/fsl-mc: Add read/write support for fsl-mc devices vfio/fsl-mc: trigger an interrupt via eventfd vfio/fsl-mc: Add irq infrastructure for fsl-mc devices vfio/fsl-mc: Added lock support in preparation for interrupt handling vfio/fsl-mc: Allow userspace to MMAP fsl-mc device MMIO regions vfio/fsl-mc: Implement VFIO_DEVICE_GET_REGION_INFO ioctl call vfio/fsl-mc: Implement VFIO_DEVICE_GET_INFO ioctl vfio/fsl-mc: Scan DPRC objects on vfio-fsl-mc driver bind vfio: Introduce capability definitions for VFIO_DEVICE_GET_INFO s390/pci: track whether util_str is valid in the zpci_dev s390/pci: stash version in the zpci_dev vfio/fsl-mc: Add VFIO framework skeleton for fsl-mc devices ...
2020-10-16mm: remove the now-unnecessary mmget_still_valid() hackJann Horn1-20/+18
The preceding patches have ensured that core dumping properly takes the mmap_lock. Thanks to that, we can now remove mmget_still_valid() and all its users. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Link: http://lkml.kernel.org/r/20200827114932.3572699-8-jannh@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-12Merge branches 'v5.10/vfio/fsl-mc-v6' and 'v5.10/vfio/zpci-info-v3' into ↵Alex Williamson1-0/+37
v5.10/vfio/next
2020-10-12vfio-pci/zdev: Add zPCI capabilities to VFIO_DEVICE_GET_INFOMatthew Rosato1-0/+37
Define a new configuration entry VFIO_PCI_ZDEV for VFIO/PCI. When this s390-only feature is configured we add capabilities to the VFIO_DEVICE_GET_INFO ioctl that describe features of the associated zPCI device and its underlying hardware. This patch is based on work previously done by Pierre Morel. Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-09-21vfio/pci: Remove redundant declaration of vfio_pci_driverZenghui Yu1-1/+0
It was added by commit 137e5531351d ("vfio/pci: Add sriov_configure support") but duplicates a forward declaration earlier in the file. Remove it. Signed-off-by: Zenghui Yu <yuzenghui@huawei.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-08-24treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva1-1/+1
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-07-27vfio/pci: Add QAT devices to denylistGiovanni Cabiddu1-0/+15
The current generation of Intel® QuickAssist Technology devices are not designed to run in an untrusted environment because of the following issues reported in the document "Intel® QuickAssist Technology (Intel® QAT) Software for Linux" (document number 336211-014): QATE-39220 - GEN - Intel® QAT API submissions with bad addresses that trigger DMA to invalid or unmapped addresses can cause a platform hang QATE-7495 - GEN - An incorrectly formatted request to Intel® QAT can hang the entire Intel® QAT Endpoint The document is downloadable from https://01.org/intel-quickassist-technology at the following link: https://01.org/sites/default/files/downloads/336211-014-qatforlinux-releasenotes-hwv1.7_0.pdf This patch adds the following QAT devices to the denylist: DH895XCC, C3XXX and C62X. Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com> Reviewed-by: Fiona Trahe <fiona.trahe@intel.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-07-27vfio/pci: Add device denylistGiovanni Cabiddu1-0/+33
Add denylist of devices that by default are not probed by vfio-pci. Devices in this list may be susceptible to untrusted application, even if the IOMMU is enabled. To be accessed via vfio-pci, the user has to explicitly disable the denylist. The denylist can be disabled via the module parameter disable_denylist. Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Fiona Trahe <fiona.trahe@intel.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-07-27vfio/pci: Hold igate across releasing eventfd contextsAlex Williamson1-3/+1
No need to release and immediately re-acquire igate while clearing out the eventfd ctxs. Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-07-27vfio/pci: Add Intel X550 to hidden INTx devicesAlex Williamson1-0/+2
Intel document 333717-008, "Intel® Ethernet Controller X550 Specification Update", version 2.7, dated June 2020, includes errata #22, added in version 2.1, May 2016, indicating X550 NICs suffer from the same implementation deficiency as the 700-series NICs: "The Interrupt Status bit in the Status register of the PCIe configuration space is not implemented and is not set as described in the PCIe specification." Without the interrupt status bit, vfio-pci cannot determine when these devices signal INTx. They are therefore added to the nointx quirk. Cc: Jesse Brandeburg <jesse.brandeburg@intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-07-17vfio/pci: fix racy on error and request eventfd ctxZeng Tao1-0/+5
The vfio_pci_release call will free and clear the error and request eventfd ctx while these ctx could be in use at the same time in the function like vfio_pci_request, and it's expected to protect them under the vdev->igate mutex, which is missing in vfio_pci_release. This issue is introduced since commit 1518ac272e78 ("vfio/pci: fix memory leaks of eventfd ctx"),and since commit 5c5866c593bb ("vfio/pci: Clear error and request eventfd ctx after releasing"), it's very easily to trigger the kernel panic like this: [ 9513.904346] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 [ 9513.913091] Mem abort info: [ 9513.915871] ESR = 0x96000006 [ 9513.918912] EC = 0x25: DABT (current EL), IL = 32 bits [ 9513.924198] SET = 0, FnV = 0 [ 9513.927238] EA = 0, S1PTW = 0 [ 9513.930364] Data abort info: [ 9513.933231] ISV = 0, ISS = 0x00000006 [ 9513.937048] CM = 0, WnR = 0 [ 9513.940003] user pgtable: 4k pages, 48-bit VAs, pgdp=0000007ec7d12000 [ 9513.946414] [0000000000000008] pgd=0000007ec7d13003, p4d=0000007ec7d13003, pud=0000007ec728c003, pmd=0000000000000000 [ 9513.956975] Internal error: Oops: 96000006 [#1] PREEMPT SMP [ 9513.962521] Modules linked in: vfio_pci vfio_virqfd vfio_iommu_type1 vfio hclge hns3 hnae3 [last unloaded: vfio_pci] [ 9513.972998] CPU: 4 PID: 1327 Comm: bash Tainted: G W 5.8.0-rc4+ #3 [ 9513.980443] Hardware name: Huawei TaiShan 2280 V2/BC82AMDC, BIOS 2280-V2 CS V3.B270.01 05/08/2020 [ 9513.989274] pstate: 80400089 (Nzcv daIf +PAN -UAO BTYPE=--) [ 9513.994827] pc : _raw_spin_lock_irqsave+0x48/0x88 [ 9513.999515] lr : eventfd_signal+0x6c/0x1b0 [ 9514.003591] sp : ffff800038a0b960 [ 9514.006889] x29: ffff800038a0b960 x28: ffff007ef7f4da10 [ 9514.012175] x27: ffff207eefbbfc80 x26: ffffbb7903457000 [ 9514.017462] x25: ffffbb7912191000 x24: ffff007ef7f4d400 [ 9514.022747] x23: ffff20be6e0e4c00 x22: 0000000000000008 [ 9514.028033] x21: 0000000000000000 x20: 0000000000000000 [ 9514.033321] x19: 0000000000000008 x18: 0000000000000000 [ 9514.038606] x17: 0000000000000000 x16: ffffbb7910029328 [ 9514.043893] x15: 0000000000000000 x14: 0000000000000001 [ 9514.049179] x13: 0000000000000000 x12: 0000000000000002 [ 9514.054466] x11: 0000000000000000 x10: 0000000000000a00 [ 9514.059752] x9 : ffff800038a0b840 x8 : ffff007ef7f4de60 [ 9514.065038] x7 : ffff007fffc96690 x6 : fffffe01faffb748 [ 9514.070324] x5 : 0000000000000000 x4 : 0000000000000000 [ 9514.075609] x3 : 0000000000000000 x2 : 0000000000000001 [ 9514.080895] x1 : ffff007ef7f4d400 x0 : 0000000000000000 [ 9514.086181] Call trace: [ 9514.088618] _raw_spin_lock_irqsave+0x48/0x88 [ 9514.092954] eventfd_signal+0x6c/0x1b0 [ 9514.096691] vfio_pci_request+0x84/0xd0 [vfio_pci] [ 9514.101464] vfio_del_group_dev+0x150/0x290 [vfio] [ 9514.106234] vfio_pci_remove+0x30/0x128 [vfio_pci] [ 9514.111007] pci_device_remove+0x48/0x108 [ 9514.115001] device_release_driver_internal+0x100/0x1b8 [ 9514.120200] device_release_driver+0x28/0x38 [ 9514.124452] pci_stop_bus_device+0x68/0xa8 [ 9514.128528] pci_stop_and_remove_bus_device+0x20/0x38 [ 9514.133557] pci_iov_remove_virtfn+0xb4/0x128 [ 9514.137893] sriov_disable+0x3c/0x108 [ 9514.141538] pci_disable_sriov+0x28/0x38 [ 9514.145445] hns3_pci_sriov_configure+0x48/0xb8 [hns3] [ 9514.150558] sriov_numvfs_store+0x110/0x198 [ 9514.154724] dev_attr_store+0x44/0x60 [ 9514.158373] sysfs_kf_write+0x5c/0x78 [ 9514.162018] kernfs_fop_write+0x104/0x210 [ 9514.166010] __vfs_write+0x48/0x90 [ 9514.169395] vfs_write+0xbc/0x1c0 [ 9514.172694] ksys_write+0x74/0x100 [ 9514.176079] __arm64_sys_write+0x24/0x30 [ 9514.179987] el0_svc_common.constprop.4+0x110/0x200 [ 9514.184842] do_el0_svc+0x34/0x98 [ 9514.188144] el0_svc+0x14/0x40 [ 9514.191185] el0_sync_handler+0xb0/0x2d0 [ 9514.195088] el0_sync+0x140/0x180 [ 9514.198389] Code: b9001020 d2800000 52800022 f9800271 (885ffe61) [ 9514.204455] ---[ end trace 648de00c8406465f ]--- [ 9514.212308] note: bash[1327] exited with preempt_count 1 Cc: Qian Cai <cai@lca.pw> Cc: Alex Williamson <alex.williamson@redhat.com> Fixes: 1518ac272e78 ("vfio/pci: fix memory leaks of eventfd ctx") Signed-off-by: Zeng Tao <prime.zeng@hisilicon.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-06-18vfio/pci: Clear error and request eventfd ctx after releasingAlex Williamson1-2/+6
The next use of the device will generate an underflow from the stale reference. Cc: Qian Cai <cai@lca.pw> Fixes: 1518ac272e78 ("vfio/pci: fix memory leaks of eventfd ctx") Reported-by: Daniel Wagner <dwagner@suse.de> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Tested-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-06-09mmap locking API: convert mmap_sem commentsMichel Lespinasse1-7/+7
Convert comments that reference mmap_sem to reference mmap_lock instead. [akpm@linux-foundation.org: fix up linux-next leftovers] [akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil] [akpm@linux-foundation.org: more linux-next fixups, per Michel] Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09mmap locking API: convert mmap_sem call sites missed by coccinelleMichel Lespinasse1-4/+4
Convert the last few remaining mmap_sem rwsem calls to use the new mmap locking API. These were missed by coccinelle for some reason (I think coccinelle does not support some of the preprocessor constructs in these files ?) [akpm@linux-foundation.org: convert linux-next leftovers] [akpm@linux-foundation.org: more linux-next leftovers] [akpm@linux-foundation.org: more linux-next leftovers] Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-6-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-05-26Merge branches 'v5.8/vfio/alex-block-mmio-v3', 'v5.8/vfio/alex-zero-cap-v2' ↵Alex Williamson1-26/+327
and 'v5.8/vfio/qian-leak-fixes' into v5.8/vfio/next
2020-05-26vfio/pci: fix memory leaks of eventfd ctxQian Cai1-0/+4
Finished a qemu-kvm (-device vfio-pci,host=0001:01:00.0) triggers a few memory leaks after a while because vfio_pci_set_ctx_trigger_single() calls eventfd_ctx_fdget() without the matching eventfd_ctx_put() later. Fix it by calling eventfd_ctx_put() for those memory in vfio_pci_release() before vfio_device_release(). unreferenced object 0xebff008981cc2b00 (size 128): comm "qemu-kvm", pid 4043, jiffies 4294994816 (age 9796.310s) hex dump (first 32 bytes): 01 00 00 00 6b 6b 6b 6b 00 00 00 00 ad 4e ad de ....kkkk.....N.. ff ff ff ff 6b 6b 6b 6b ff ff ff ff ff ff ff ff ....kkkk........ backtrace: [<00000000917e8f8d>] slab_post_alloc_hook+0x74/0x9c [<00000000df0f2aa2>] kmem_cache_alloc_trace+0x2b4/0x3d4 [<000000005fcec025>] do_eventfd+0x54/0x1ac [<0000000082791a69>] __arm64_sys_eventfd2+0x34/0x44 [<00000000b819758c>] do_el0_svc+0x128/0x1dc [<00000000b244e810>] el0_sync_handler+0xd0/0x268 [<00000000d495ef94>] el0_sync+0x164/0x180 unreferenced object 0x29ff008981cc4180 (size 128): comm "qemu-kvm", pid 4043, jiffies 4294994818 (age 9796.290s) hex dump (first 32 bytes): 01 00 00 00 6b 6b 6b 6b 00 00 00 00 ad 4e ad de ....kkkk.....N.. ff ff ff ff 6b 6b 6b 6b ff ff ff ff ff ff ff ff ....kkkk........ backtrace: [<00000000917e8f8d>] slab_post_alloc_hook+0x74/0x9c [<00000000df0f2aa2>] kmem_cache_alloc_trace+0x2b4/0x3d4 [<000000005fcec025>] do_eventfd+0x54/0x1ac [<0000000082791a69>] __arm64_sys_eventfd2+0x34/0x44 [<00000000b819758c>] do_el0_svc+0x128/0x1dc [<00000000b244e810>] el0_sync_handler+0xd0/0x268 [<00000000d495ef94>] el0_sync+0x164/0x180 Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-05-18vfio-pci: Invalidate mmaps and block MMIO access on disabled memoryAlex Williamson1-33/+258
Accessing the disabled memory space of a PCI device would typically result in a master abort response on conventional PCI, or an unsupported request on PCI express. The user would generally see these as a -1 response for the read return data and the write would be silently discarded, possibly with an uncorrected, non-fatal AER error triggered on the host. Some systems however take it upon themselves to bring down the entire system when they see something that might indicate a loss of data, such as this discarded write to a disabled memory space. To avoid this, we want to try to block the user from accessing memory spaces while they're disabled. We start with a semaphore around the memory enable bit, where writers modify the memory enable state and must be serialized, while readers make use of the memory region and can access in parallel. Writers include both direct manipulation via the command register, as well as any reset path where the internal mechanics of the reset may both explicitly and implicitly disable memory access, and manipulation of the MSI-X configuration, where the MSI-X vector table resides in MMIO space of the device. Readers include the read and write file ops to access the vfio device fd offsets as well as memory mapped access. In the latter case, we make use of our new vma list support to zap, or invalidate, those memory mappings in order to force them to be faulted back in on access. Our semaphore usage will stall user access to MMIO spaces across internal operations like reset, but the user might experience new behavior when trying to access the MMIO space while disabled via the PCI command register. Access via read or write while disabled will return -EIO and access via memory maps will result in a SIGBUS. This is expected to be compatible with known use cases and potentially provides better error handling capabilities than present in the hardware, while avoiding the more readily accessible and severe platform error responses that might otherwise occur. Fixes: CVE-2020-12888 Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-05-18vfio-pci: Fault mmaps to enable vma trackingAlex Williamson1-2/+74
Rather than calling remap_pfn_range() when a region is mmap'd, setup a vm_ops handler to support dynamic faulting of the range on access. This allows us to manage a list of vmas actively mapping the area that we can later use to invalidate those mappings. The open callback invalidates the vma range so that all tracking is inserted in the fault handler and removed in the close handler. Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-03-24vfio/pci: Cleanup .probe() exit pathsAlex Williamson1-29/+25
The cleanup is getting a tad long. Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-03-24vfio/pci: Remove dev_fmt definitionAlex Williamson1-1/+0
It currently results in messages like: "vfio-pci 0000:03:00.0: vfio_pci: ..." Which is quite a bit redundant. Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-03-24vfio/pci: Add sriov_configure supportAlex Williamson1-11/+95
With the VF Token interface we can now expect that a vfio userspace driver must be in collaboration with the PF driver, an unwitting userspace driver will not be able to get past the GET_DEVICE_FD step in accessing the device. We can now move on to actually allowing SR-IOV to be enabled by vfio-pci on the PF. Support for this is not enabled by default in this commit, but it does provide a module option for this to be enabled (enable_sriov=1). Enabling VFs is rather straightforward, except we don't want to risk that a VF might get autoprobed and bound to other drivers, so a bus notifier is used to "capture" VFs to vfio-pci using the driver_override support. We assume any later action to bind the device to other drivers is condoned by the system admin and allow it with a log warning. vfio-pci will disable SR-IOV on a PF before releasing the device, allowing a VF driver to be assured other drivers cannot take over the PF and that any other userspace driver must know the shared VF token. This support also does not provide a mechanism for the PF userspace driver itself to manipulate SR-IOV through the vfio API. With this patch SR-IOV can only be enabled via the host sysfs interface and the PF driver user cannot create or remove VFs. Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-03-24vfio: Introduce VFIO_DEVICE_FEATURE ioctl and first userAlex Williamson1-0/+59
The VFIO_DEVICE_FEATURE ioctl is meant to be a general purpose, device agnostic ioctl for setting, retrieving, and probing device features. This implementation provides a 16-bit field for specifying a feature index, where the data porition of the ioctl is determined by the semantics for the given feature. Additional flag bits indicate the direction and nature of the operation; SET indicates user data is provided into the device feature, GET indicates the device feature is written out into user data. The PROBE flag augments determining whether the given feature is supported, and if provided, whether the given operation on the feature is supported. The first user of this ioctl is for setting the vfio-pci VF token, where the user provides a shared secret key (UUID) on a SR-IOV PF device, which users must provide when opening associated VF devices. Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-03-24vfio/pci: Introduce VF tokenAlex Williamson1-1/+197
If we enable SR-IOV on a vfio-pci owned PF, the resulting VFs are not fully isolated from the PF. The PF can always cause a denial of service to the VF, even if by simply resetting itself. The degree to which a PF can access the data passed through a VF or interfere with its operation is dependent on a given SR-IOV implementation. Therefore we want to avoid a scenario where an existing vfio-pci based userspace driver might assume the PF driver is trusted, for example assigning a PF to one VM and VF to another with some expectation of isolation. IOMMU grouping could be a solution to this, but imposes an unnecessarily strong relationship between PF and VF drivers if they need to operate with the same IOMMU context. Instead we introduce a "VF token", which is essentially just a shared secret between PF and VF drivers, implemented as a UUID. The VF token can be set by a vfio-pci based PF driver and must be known by the vfio-pci based VF driver in order to gain access to the device. This allows the degree to which this VF token is considered secret to be determined by the applications and environment. For example a VM might generate a random UUID known only internally to the hypervisor while a userspace networking appliance might use a shared, or even well know, UUID among the application drivers. To incorporate this VF token, the VFIO_GROUP_GET_DEVICE_FD interface is extended to accept key=value pairs in addition to the device name. This allows us to most easily deny user access to the device without risk that existing userspace drivers assume region offsets, IRQs, and other device features, leading to more elaborate error paths. The format of these options are expected to take the form: "$DEVICE_NAME $OPTION1=$VALUE1 $OPTION2=$VALUE2" Where the device name is always provided first for compatibility and additional options are specified in a space separated list. The relation between and requirements for the additional options will be vfio bus driver dependent, however unknown or unused option within this schema should return error. This allow for future use of unknown options as well as a positive indication to the user that an option is used. An example VF token option would take this form: "0000:03:00.0 vf_token=2ab74924-c335-45f4-9b16-8569e5b08258" When accessing a VF where the PF is making use of vfio-pci, the user MUST provide the current vf_token. When accessing a PF, the user MUST provide the current vf_token IF there are active VF users or MAY provide a vf_token in order to set the current VF token when no VF users are active. The former requirement assures VF users that an unassociated driver cannot usurp the PF device. These semantics also imply that a VF token MUST be set by a PF driver before VF drivers can access their device, the default token is random and mechanisms to read the token are not provided in order to protect the VF token of previous users. Use of the vf_token option outside of these cases will return an error, as discussed above. Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-03-24vfio/pci: Implement match opsAlex Williamson1-0/+8
This currently serves the same purpose as the default implementation but will be expanded for additional functionality. Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-10-14PCI: Add PCI_STD_NUM_BARS for the number of standard BARsDenis Efremov1-4/+7
Code that iterates over all standard PCI BARs typically uses PCI_STD_RESOURCE_END. However, that requires the unusual test "i <= PCI_STD_RESOURCE_END" rather than something the typical "i < PCI_STD_NUM_BARS". Add a definition for PCI_STD_NUM_BARS and change loops to use the more idiomatic C style to help avoid fencepost errors. Link: https://lore.kernel.org/r/20190927234026.23342-1-efremov@linux.com Link: https://lore.kernel.org/r/20190927234308.23935-1-efremov@linux.com Link: https://lore.kernel.org/r/20190916204158.6889-3-efremov@linux.com Signed-off-by: Denis Efremov <efremov@linux.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Sebastian Ott <sebott@linux.ibm.com> # arch/s390/ Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> # video/fbdev/ Acked-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com> # pci/controller/dwc/ Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com> # scsi/pm8001/ Acked-by: Martin K. Petersen <martin.petersen@oracle.com> # scsi/pm8001/ Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # memstick/
2019-08-22vfio_pci: Restore original state on releasehexin1-4/+13
vfio_pci_enable() saves the device's initial configuration information with the intent that it is restored in vfio_pci_disable(). However, the commit referenced in Fixes: below replaced the call to __pci_reset_function_locked(), which is not wrapped in a state save and restore, with pci_try_reset_function(), which overwrites the restored device state with the current state before applying it to the device. Reinstate use of __pci_reset_function_locked() to return to the desired behavior. Fixes: 890ed578df82 ("vfio-pci: Use pci "try" reset interface") Signed-off-by: hexin <hexin15@baidu.com> Signed-off-by: Liu Qi <liuqi16@baidu.com> Signed-off-by: Zhang Yu <zhangyu31@baidu.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner1-4/+1
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-22vfio: Use dev_printk() when possibleBjorn Helgaas1-13/+10
Use dev_printk() when possible to make messages consistent with other device-related messages. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-04-03vfio/pci: use correct format charactersLouis Taylor1-2/+2
When compiling with -Wformat, clang emits the following warnings: drivers/vfio/pci/vfio_pci.c:1601:5: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~ drivers/vfio/pci/vfio_pci.c:1601:13: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~ drivers/vfio/pci/vfio_pci.c:1601:21: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~~~~ drivers/vfio/pci/vfio_pci.c:1601:32: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~~~~ drivers/vfio/pci/vfio_pci.c:1605:5: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~ drivers/vfio/pci/vfio_pci.c:1605:13: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~ drivers/vfio/pci/vfio_pci.c:1605:21: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~~~~ drivers/vfio/pci/vfio_pci.c:1605:32: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] vendor, device, subvendor, subdevice, ^~~~~~~~~ The types of these arguments are unconditionally defined, so this patch updates the format character to the correct ones for unsigned ints. Link: https://github.com/ClangBuiltLinux/linux/issues/378 Signed-off-by: Louis Taylor <louis@kragniz.eu> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-02-19vfio_pci: Enable memory accesses before calling pci_map_romEric Auger1-5/+14
pci_map_rom/pci_get_rom_size() performs memory access in the ROM. In case the Memory Space accesses were disabled, readw() is likely to trigger a synchronous external abort on some platforms. In case memory accesses were disabled, re-enable them before the call and disable them back again just after. Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver") Signed-off-by: Eric Auger <eric.auger@redhat.com> Suggested-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-02-19vfio/pci: Restore device state on PM transitionAlex Williamson1-8/+63
PCI core handles save and restore of device state around reset, but when using pci_set_power_state() we can unintentionally trigger a soft reset of the device, where PCI core only restores the BAR state. If we're using vfio-pci's idle D3 support to try to put devices into low power when unused, this might trigger a reset when the device is woken for use. Also power state management by the user, or within a guest, can put the device into D3 power state with potentially limited ability to restore the device if it should undergo a reset. The PCI spec does not define the extent of a soft reset and many devices reporting soft reset on D3->D0 transition do not undergo a PCI config space reset. It's therefore assumed safe to unconditionally restore the remainder of the state if the device indicates soft reset support, even on a user initiated wakeup. Implement a wrapper in vfio-pci to tag devices reporting PM reset support, save their state on transitions into D3 and restore on transitions back to D0. Reported-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-12-29Merge tag 'vfio-v4.21-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds1-24/+136
Pull VFIO updates from Alex Williamson: - Replace global vfio-pci lock with per bus lock to allow concurrent open and release (Alex Williamson) - Declare mdev function as static (Paolo Cretaro) - Convert char to u8 in mdev/mtty sample driver (Nathan Chancellor) * tag 'vfio-v4.21-rc1' of git://github.com/awilliam/linux-vfio: vfio-mdev/samples: Use u8 instead of char for handle functions vfio/mdev: add static modifier to add_mdev_supported_type vfio/pci: Parallelize device open and release
2018-12-21vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriverAlexey Kardashevskiy1-2/+25
POWER9 Witherspoon machines come with 4 or 6 V100 GPUs which are not pluggable PCIe devices but still have PCIe links which are used for config space and MMIO. In addition to that the GPUs have 6 NVLinks which are connected to other GPUs and the POWER9 CPU. POWER9 chips have a special unit on a die called an NPU which is an NVLink2 host bus adapter with p2p connections to 2 to 3 GPUs, 3 or 2 NVLinks to each. These systems also support ATS (address translation services) which is a part of the NVLink2 protocol. Such GPUs also share on-board RAM (16GB or 32GB) to the system via the same NVLink2 so a CPU has cache-coherent access to a GPU RAM. This exports GPU RAM to the userspace as a new VFIO device region. This preregisters the new memory as device memory as it might be used for DMA. This inserts pfns from the fault handler as the GPU memory is not onlined until the vendor driver is loaded and trained the NVLinks so doing this earlier causes low level errors which we fence in the firmware so it does not hurt the host system but still better be avoided; for the same reason this does not map GPU RAM into the host kernel (usual thing for emulated access otherwise). This exports an ATSD (Address Translation Shootdown) register of NPU which allows TLB invalidations inside GPU for an operating system. The register conveniently occupies a single 64k page. It is also presented to the userspace as a new VFIO device region. One NPU has 8 ATSD registers, each of them can be used for TLB invalidation in a GPU linked to this NPU. This allocates one ATSD register per an NVLink bridge allowing passing up to 6 registers. Due to the host firmware bug (just recently fixed), only 1 ATSD register per NPU was actually advertised to the host system so this passes that alone register via the first NVLink bridge device in the group which is still enough as QEMU collects them all back and presents to the guest via vPHB to mimic the emulated NPU PHB on the host. In order to provide the userspace with the information about GPU-to-NVLink connections, this exports an additional capability called "tgt" (which is an abbreviated host system bus address). The "tgt" property tells the GPU its own system address and allows the guest driver to conglomerate the routing information so each GPU knows how to get directly to the other GPUs. For ATS to work, the nest MMU (an NVIDIA block in a P9 CPU) needs to know LPID (a logical partition ID or a KVM guest hardware ID in other words) and PID (a memory context ID of a userspace process, not to be confused with a linux pid). This assigns a GPU to LPID in the NPU and this is why this adds a listener for KVM on an IOMMU group. A PID comes via NVLink from a GPU and NPU uses a PID wildcard to pass it through. This requires coherent memory and ATSD to be available on the host as the GPU vendor only supports configurations with both features enabled and other configurations are known not to work. Because of this and because of the ways the features are advertised to the host system (which is a device tree with very platform specific properties), this requires enabled POWERNV platform. The V100 GPUs do not advertise any of these capabilities via the config space and there are more than just one device ID so this relies on the platform to tell whether these GPUs have special abilities such as NVLinks. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21vfio_pci: Allow regions to add own capabilitiesAlexey Kardashevskiy1-0/+6
VFIO regions already support region capabilities with a limited set of fields. However the subdriver might have to report to the userspace additional bits. This adds an add_capability() hook to vfio_pci_regops. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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