Now both the physical path and the emulated path should 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.
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 --- drivers/vfio/iommufd.c | 11 ++++++----- include/uapi/linux/vfio.h | 6 ++++++ 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 {