diff options
| author | Yi Liu <yi.l.liu@intel.com> | 2025-02-26 02:40:12 -0800 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@nvidia.com> | 2025-03-04 09:34:54 -0400 |
| commit | 1062d81086156e42878d701b816d2f368b53a77c (patch) | |
| tree | 40bf9277d73abc2aaf1b243c8d3da4899f72e718 | |
| parent | 5e9f822c9c683ae884fa5e71df41d1647b2876c6 (diff) | |
iommufd: Disallow allocating nested parent domain with fault ID
Allocating a domain with a fault ID indicates that the domain is faultable.
However, there is a gap for the nested parent domain to support PRI. Some
hardware lacks the capability to distinguish whether PRI occurs at stage 1
or stage 2. This limitation may require software-based page table walking
to resolve. Since no in-tree IOMMU driver currently supports this
functionality, it is disallowed. For more details, refer to the related
discussion at [1].
[1] https://lore.kernel.org/linux-iommu/bd1655c6-8b2f-4cfa-adb1-badc00d01811@intel.com/
Link: https://patch.msgid.link/r/20250226104012.82079-1-yi.l.liu@intel.com
Suggested-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
| -rw-r--r-- | drivers/iommu/iommufd/hw_pagetable.c | 3 | ||||
| -rw-r--r-- | tools/testing/selftests/iommu/iommufd.c | 4 |
2 files changed, 7 insertions, 0 deletions
diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c index 7de6e914232e..268315b1d8bc 100644 --- a/drivers/iommu/iommufd/hw_pagetable.c +++ b/drivers/iommu/iommufd/hw_pagetable.c @@ -126,6 +126,9 @@ iommufd_hwpt_paging_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas, if ((flags & IOMMU_HWPT_ALLOC_DIRTY_TRACKING) && !device_iommu_capable(idev->dev, IOMMU_CAP_DIRTY_TRACKING)) return ERR_PTR(-EOPNOTSUPP); + if ((flags & IOMMU_HWPT_FAULT_ID_VALID) && + (flags & IOMMU_HWPT_ALLOC_NEST_PARENT)) + return ERR_PTR(-EOPNOTSUPP); hwpt_paging = __iommufd_object_alloc( ictx, hwpt_paging, IOMMUFD_OBJ_HWPT_PAGING, common.obj); diff --git a/tools/testing/selftests/iommu/iommufd.c b/tools/testing/selftests/iommu/iommufd.c index a1b2b657999d..618c03bb6509 100644 --- a/tools/testing/selftests/iommu/iommufd.c +++ b/tools/testing/selftests/iommu/iommufd.c @@ -439,6 +439,10 @@ TEST_F(iommufd_ioas, alloc_hwpt_nested) &test_hwpt_id); test_err_hwpt_alloc(EINVAL, self->device_id, self->device_id, 0, &test_hwpt_id); + test_err_hwpt_alloc(EOPNOTSUPP, self->device_id, self->ioas_id, + IOMMU_HWPT_ALLOC_NEST_PARENT | + IOMMU_HWPT_FAULT_ID_VALID, + &test_hwpt_id); test_cmd_hwpt_alloc(self->device_id, self->ioas_id, IOMMU_HWPT_ALLOC_NEST_PARENT, |