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authorNicolin Chen <nicolinc@nvidia.com>2023-07-27 23:33:29 -0700
committerJason Gunthorpe <jgg@nvidia.com>2023-07-28 13:31:24 -0300
commitc157fd88619946cd62af47c45214c479749dad8d (patch)
tree20ea10c24eaa8f93163c30d1c668fb8a0a63f97d
parentc154660b6e26c3f0670a49f43f1fafa5d65f6d39 (diff)
vfio: Support IO page table replacement
Now both the physical path and the emulated path can support an IO page table replacement. Call iommufd_device_replace/iommufd_access_replace(), when vdev->iommufd_attached is true. Also update the VFIO_DEVICE_ATTACH_IOMMUFD_PT kdoc in the uAPI header. Link: https://lore.kernel.org/r/b5f01956ff161f76aa52c95b0fa1ad6eaca95c4a.1690523699.git.nicolinc@nvidia.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
-rw-r--r--drivers/vfio/iommufd.c11
-rw-r--r--include/uapi/linux/vfio.h6
2 files changed, 12 insertions, 5 deletions
diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c
index 4d84904fd927..82eba6966fa5 100644
--- a/drivers/vfio/iommufd.c
+++ b/drivers/vfio/iommufd.c
@@ -146,9 +146,9 @@ int vfio_iommufd_physical_attach_ioas(struct vfio_device *vdev, u32 *pt_id)
return -EINVAL;
if (vdev->iommufd_attached)
- return -EBUSY;
-
- rc = iommufd_device_attach(vdev->iommufd_device, pt_id);
+ rc = iommufd_device_replace(vdev->iommufd_device, pt_id);
+ else
+ rc = iommufd_device_attach(vdev->iommufd_device, pt_id);
if (rc)
return rc;
vdev->iommufd_attached = true;
@@ -223,8 +223,9 @@ int vfio_iommufd_emulated_attach_ioas(struct vfio_device *vdev, u32 *pt_id)
lockdep_assert_held(&vdev->dev_set->lock);
if (vdev->iommufd_attached)
- return -EBUSY;
- rc = iommufd_access_attach(vdev->iommufd_access, *pt_id);
+ rc = iommufd_access_replace(vdev->iommufd_access, *pt_id);
+ else
+ rc = iommufd_access_attach(vdev->iommufd_access, *pt_id);
if (rc)
return rc;
vdev->iommufd_attached = true;
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index fa06e3eb4955..537157ff8670 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -939,6 +939,12 @@ struct vfio_device_bind_iommufd {
* Undo by VFIO_DEVICE_DETACH_IOMMUFD_PT or device fd close. This is only
* allowed on cdev fds.
*
+ * If a vfio device is currently attached to a valid hw_pagetable, without doing
+ * a VFIO_DEVICE_DETACH_IOMMUFD_PT, a second VFIO_DEVICE_ATTACH_IOMMUFD_PT ioctl
+ * passing in another hw_pagetable (hwpt) id is allowed. This action, also known
+ * as a hw_pagetable replacement, will replace the device's currently attached
+ * hw_pagetable with a new hw_pagetable corresponding to the given pt_id.
+ *
* Return: 0 on success, -errno on failure.
*/
struct vfio_device_attach_iommufd_pt {