vfio-iommufd: Allow iommufd to be used in place of a container fd

This makes VFIO_GROUP_SET_CONTAINER accept both a vfio container FD and an
iommufd.

In iommufd mode an IOAS will exist after the SET_CONTAINER, but it will
not be attached to any groups.

For VFIO this means that the VFIO_GROUP_GET_STATUS and
VFIO_GROUP_FLAGS_VIABLE works subtly differently. With the container FD
the iommu_group_claim_dma_owner() is done during SET_CONTAINER but for
IOMMUFD this is done during VFIO_GROUP_GET_DEVICE_FD. Meaning that
VFIO_GROUP_FLAGS_VIABLE could be set but GET_DEVICE_FD will fail due to
viability.

As GET_DEVICE_FD can fail for many reasons already this is not expected to
be a meaningful difference.

Reorganize the tests for if the group has an assigned container or iommu
into a vfio_group_has_iommu() function and consolidate all the duplicated
WARN_ON's etc related to this.

Call container functions only if a container is actually present on the
group.

Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Kevin Tian <[email protected]>
Reviewed-by: Alex Williamson <[email protected]>
Tested-by: Alex Williamson <[email protected]>
Tested-by: Nicolin Chen <[email protected]>
Tested-by: Yi Liu <[email protected]>
Tested-by: Lixiao Yang <[email protected]>
Tested-by: Matthew Rosato <[email protected]>
Tested-by: Yu He <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>

0 files changed, 0 insertions, 0 deletions