Since asserting dma ownership now causes the group to have its DMA blocked
the iommu layer requires a working iommu. This means the dma_owner APIs
cannot be used on the fake groups that VFIO creates. Test for this and
avoid calling them.
Otherwise asserting dma ownership will fail for VFIO mdev devices as a
BLOCKING iommu_domain cannot be allocated due to the NULL iommu ops.
Fixes: 0286300e6045 ("iommu: iommu_group_claim_dma_owner() must always assign a
domain")
Reported-by: Eric Farman <[email protected]>
Tested-by: Eric Farman <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>
---
drivers/vfio/vfio.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
Sort of a v2 from here:
https://lore.kernel.org/all/[email protected]/
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index cfcff7764403fc..f5ed03897210c3 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -927,7 +927,8 @@ static void __vfio_group_unset_container(struct vfio_group
*group)
driver->ops->detach_group(container->iommu_data,
group->iommu_group);
- iommu_group_release_dma_owner(group->iommu_group);
+ if (group->type == VFIO_IOMMU)
+ iommu_group_release_dma_owner(group->iommu_group);
group->container = NULL;
group->container_users = 0;
@@ -1001,9 +1002,11 @@ static int vfio_group_set_container(struct vfio_group
*group, int container_fd)
goto unlock_out;
}
- ret = iommu_group_claim_dma_owner(group->iommu_group, f.file);
- if (ret)
- goto unlock_out;
+ if (group->type == VFIO_IOMMU) {
+ ret = iommu_group_claim_dma_owner(group->iommu_group, f.file);
+ if (ret)
+ goto unlock_out;
+ }
driver = container->iommu_driver;
if (driver) {
@@ -1011,7 +1014,9 @@ static int vfio_group_set_container(struct vfio_group
*group, int container_fd)
group->iommu_group,
group->type);
if (ret) {
- iommu_group_release_dma_owner(group->iommu_group);
+ if (group->type == VFIO_IOMMU)
+ iommu_group_release_dma_owner(
+ group->iommu_group);
goto unlock_out;
}
}
base-commit: 7ab5e10eda02da1d9562ffde562c51055d368e9c
--
2.36.0
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