tree c76a71926c7d327663d90cd4c3a94f9aaec69b92
parent 4c885c35463fac9e11055ce447de05bc996b4c4c
author Alexey Kardashevskiy <aik@ozlabs.ru> 1490337846 +1100
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1521706671 +0100

vfio/powerpc/spapr_tce: Enforce IOMMU type compatibility check


[ Upstream commit 1282ba7fc28dbc66c3f0e4aaafaaa228361d1ae5 ]

The existing SPAPR TCE driver advertises both VFIO_SPAPR_TCE_IOMMU and
VFIO_SPAPR_TCE_v2_IOMMU types to the userspace and the userspace usually
picks the v2.

Normally the userspace would create a container, attach an IOMMU group
to it and only then set the IOMMU type (which would normally be v2).

However a specific IOMMU group may not support v2, in other words
it may not implement set_window/unset_window/take_ownership/
release_ownership and such a group should not be attached to
a v2 container.

This adds extra checks that a new group can do what the selected IOMMU
type suggests. The userspace can then test the return value from
ioctl(VFIO_SET_IOMMU, VFIO_SPAPR_TCE_v2_IOMMU) and try
VFIO_SPAPR_TCE_IOMMU.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>