From 2a3dab19a0a6c1823645764188776f271de1b3cf Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 29 Nov 2022 16:31:50 -0400 Subject: 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/5-v4-42cd2eb0e3eb+335a-vfio_iommufd_jgg@nvidia.com Reviewed-by: Kevin Tian Reviewed-by: Alex Williamson Tested-by: Alex Williamson Tested-by: Nicolin Chen Tested-by: Yi Liu Tested-by: Lixiao Yang Tested-by: Matthew Rosato Tested-by: Yu He Signed-off-by: Jason Gunthorpe --- drivers/vfio/container.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'drivers/vfio/container.c') diff --git a/drivers/vfio/container.c b/drivers/vfio/container.c index d97747dfb05d..8772dad68085 100644 --- a/drivers/vfio/container.c +++ b/drivers/vfio/container.c @@ -516,8 +516,11 @@ int vfio_group_use_container(struct vfio_group *group) { lockdep_assert_held(&group->group_lock); - if (!group->container || !group->container->iommu_driver || - WARN_ON(!group->container_users)) + /* + * The container fd has been assigned with VFIO_GROUP_SET_CONTAINER but + * VFIO_SET_IOMMU hasn't been done yet. + */ + if (!group->container->iommu_driver) return -EINVAL; if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO)) -- cgit v1.2.3