diff options
author | Yi Liu <yi.l.liu@intel.com> | 2023-07-18 13:55:41 +0300 |
---|---|---|
committer | Alex Williamson <alex.williamson@redhat.com> | 2023-07-25 19:18:09 +0300 |
commit | b56b7aabcf3cfde57559d3ab06567b94f348f13c (patch) | |
tree | 8f0188975f9c6349f6c4e89230e4b188f96f707d | |
parent | 9062ff405b49769c04f00373de2c9cefab91b600 (diff) | |
download | linux-b56b7aabcf3cfde57559d3ab06567b94f348f13c.tar.xz |
vfio/pci: Copy hot-reset device info to userspace in the devices loop
This copies the vfio_pci_dependent_device to userspace during looping each
affected device for reporting vfio_pci_hot_reset_info. This avoids counting
the affected devices and allocating a potential large buffer to store the
vfio_pci_dependent_device of all the affected devices before copying them
to userspace.
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230718105542.4138-10-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
-rw-r--r-- | drivers/vfio/pci/vfio_pci_core.c | 93 |
1 files changed, 33 insertions, 60 deletions
diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c index 32506c5539b9..f4a0ea01559e 100644 --- a/drivers/vfio/pci/vfio_pci_core.c +++ b/drivers/vfio/pci/vfio_pci_core.c @@ -777,19 +777,25 @@ static int vfio_pci_count_devs(struct pci_dev *pdev, void *data) } struct vfio_pci_fill_info { - int max; - int cur; - struct vfio_pci_dependent_device *devices; + struct vfio_pci_dependent_device __user *devices; + struct vfio_pci_dependent_device __user *devices_end; struct vfio_device *vdev; + u32 count; u32 flags; }; static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data) { + struct vfio_pci_dependent_device info = { + .segment = pci_domain_nr(pdev->bus), + .bus = pdev->bus->number, + .devfn = pdev->devfn, + }; struct vfio_pci_fill_info *fill = data; - if (fill->cur == fill->max) - return -EAGAIN; /* Something changed, try again */ + fill->count++; + if (fill->devices >= fill->devices_end) + return 0; if (fill->flags & VFIO_PCI_HOT_RESET_FLAG_DEV_ID) { struct iommufd_ctx *iommufd = vfio_iommufd_device_ictx(fill->vdev); @@ -802,19 +808,19 @@ static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data) */ vdev = vfio_find_device_in_devset(dev_set, &pdev->dev); if (!vdev) { - fill->devices[fill->cur].devid = VFIO_PCI_DEVID_NOT_OWNED; + info.devid = VFIO_PCI_DEVID_NOT_OWNED; } else { int id = vfio_iommufd_get_dev_id(vdev, iommufd); if (id > 0) - fill->devices[fill->cur].devid = id; + info.devid = id; else if (id == -ENOENT) - fill->devices[fill->cur].devid = VFIO_PCI_DEVID_OWNED; + info.devid = VFIO_PCI_DEVID_OWNED; else - fill->devices[fill->cur].devid = VFIO_PCI_DEVID_NOT_OWNED; + info.devid = VFIO_PCI_DEVID_NOT_OWNED; } /* If devid is VFIO_PCI_DEVID_NOT_OWNED, clear owned flag. */ - if (fill->devices[fill->cur].devid == VFIO_PCI_DEVID_NOT_OWNED) + if (info.devid == VFIO_PCI_DEVID_NOT_OWNED) fill->flags &= ~VFIO_PCI_HOT_RESET_FLAG_DEV_ID_OWNED; } else { struct iommu_group *iommu_group; @@ -823,13 +829,13 @@ static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data) if (!iommu_group) return -EPERM; /* Cannot reset non-isolated devices */ - fill->devices[fill->cur].group_id = iommu_group_id(iommu_group); + info.group_id = iommu_group_id(iommu_group); iommu_group_put(iommu_group); } - fill->devices[fill->cur].segment = pci_domain_nr(pdev->bus); - fill->devices[fill->cur].bus = pdev->bus->number; - fill->devices[fill->cur].devfn = pdev->devfn; - fill->cur++; + + if (copy_to_user(fill->devices, &info, sizeof(info))) + return -EFAULT; + fill->devices++; return 0; } @@ -1259,8 +1265,7 @@ static int vfio_pci_ioctl_get_pci_hot_reset_info( unsigned long minsz = offsetofend(struct vfio_pci_hot_reset_info, count); struct vfio_pci_hot_reset_info hdr; - struct vfio_pci_fill_info fill = { 0 }; - struct vfio_pci_dependent_device *devices = NULL; + struct vfio_pci_fill_info fill = {}; bool slot = false; int ret = 0; @@ -1278,29 +1283,9 @@ static int vfio_pci_ioctl_get_pci_hot_reset_info( else if (pci_probe_reset_bus(vdev->pdev->bus)) return -ENODEV; - /* How many devices are affected? */ - ret = vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_count_devs, - &fill.max, slot); - if (ret) - return ret; - - WARN_ON(!fill.max); /* Should always be at least one */ - - /* - * If there's enough space, fill it now, otherwise return -ENOSPC and - * the number of devices affected. - */ - if (hdr.argsz < sizeof(hdr) + (fill.max * sizeof(*devices))) { - ret = -ENOSPC; - hdr.count = fill.max; - goto reset_info_exit; - } - - devices = kcalloc(fill.max, sizeof(*devices), GFP_KERNEL); - if (!devices) - return -ENOMEM; - - fill.devices = devices; + fill.devices = arg->devices; + fill.devices_end = arg->devices + + (hdr.argsz - sizeof(hdr)) / sizeof(arg->devices[0]); fill.vdev = &vdev->vdev; if (vfio_device_cdev_opened(&vdev->vdev)) @@ -1311,29 +1296,17 @@ static int vfio_pci_ioctl_get_pci_hot_reset_info( ret = vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_fill_devs, &fill, slot); mutex_unlock(&vdev->vdev.dev_set->lock); + if (ret) + return ret; - /* - * If a device was removed between counting and filling, we may come up - * short of fill.max. If a device was added, we'll have a return of - * -EAGAIN above. - */ - if (!ret) { - hdr.count = fill.cur; - hdr.flags = fill.flags; - } - -reset_info_exit: + hdr.count = fill.count; + hdr.flags = fill.flags; if (copy_to_user(arg, &hdr, minsz)) - ret = -EFAULT; - - if (!ret) { - if (copy_to_user(&arg->devices, devices, - hdr.count * sizeof(*devices))) - ret = -EFAULT; - } + return -EFAULT; - kfree(devices); - return ret; + if (fill.count > fill.devices - arg->devices) + return -ENOSPC; + return 0; } static int |