Commit a3da1ab6 authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Alex Williamson

vfio: Do not manipulate iommu dma_owner for fake iommu groups

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: 0286300e ("iommu: iommu_group_claim_dma_owner() must always assign a domain")
Reported-by: default avatarEric Farman <farman@linux.ibm.com>
Tested-by: default avatarEric Farman <farman@linux.ibm.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/0-v1-9cfc47edbcd4+13546-vfio_dma_owner_fix_jgg@nvidia.comSigned-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent 7ab5e10e
......@@ -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;
}
}
......
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