4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Alexey Kardashevskiy <aik@xxxxxxxxx>
[ 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@xxxxxxxxx>
Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/vfio/vfio_iommu_spapr_tce.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -1332,8 +1332,16 @@ static int tce_iommu_attach_group(void *
if (!table_group->ops || !table_group->ops->take_ownership ||
!table_group->ops->release_ownership) {
+ if (container->v2) {
+ ret = -EPERM;
+ goto unlock_exit;
+ }
ret = tce_iommu_take_ownership(container, table_group);
} else {
+ if (!container->v2) {
+ ret = -EPERM;
+ goto unlock_exit;
+ }
ret = tce_iommu_take_ownership_ddw(container, table_group);
if (!tce_groups_attached(container) && !container->tables[0])
container->def_window_pending = true;