iommufd: Deal with IOMMU_HWPT_FAULT_ID_VALID in iommufd core

IOMMU_HWPT_FAULT_ID_VALID is used to mark if the fault_id field of
iommu_hwp_alloc is valid or not. As the fault_id field is handled in
the iommufd core, so it makes sense to sanitize the
IOMMU_HWPT_FAULT_ID_VALID flag in the iommufd core, and mask it out
before passing the user flags to the iommu drivers.

Link: https://patch.msgid.link/r/20241207120108.5640-1-yi.l.liu@intel.com
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Author: yiliu1765

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c

@@ -178,18 +178,12 @@ arm_vsmmu_alloc_domain_nested(struct iommufd_viommu *viommu, u32 flags,
 			      const struct iommu_user_data *user_data)
 {
 	struct arm_vsmmu *vsmmu = container_of(viommu, struct arm_vsmmu, core);
-	const u32 SUPPORTED_FLAGS = IOMMU_HWPT_FAULT_ID_VALID;
 	struct arm_smmu_nested_domain *nested_domain;
 	struct iommu_hwpt_arm_smmuv3 arg;
 	bool enable_ats = false;
 	int ret;
 
-	/*
-	 * Faults delivered to the nested domain are faults that originated by
-	 * the S1 in the domain. The core code will match all PASIDs when
-	 * delivering the fault due to user_pasid_table
-	 */
-	if (flags & ~SUPPORTED_FLAGS)
+	if (flags)
 		return ERR_PTR(-EOPNOTSUPP);
 
 	ret = iommu_copy_struct_from_user(&arg, user_data,

drivers/iommu/intel/iommu.c

@@ -3340,8 +3340,7 @@ intel_iommu_domain_alloc_paging_flags(struct device *dev, u32 flags,
 	bool first_stage;
 
 	if (flags &
-	    (~(IOMMU_HWPT_ALLOC_NEST_PARENT | IOMMU_HWPT_ALLOC_DIRTY_TRACKING
-	       | IOMMU_HWPT_FAULT_ID_VALID)))
+	    (~(IOMMU_HWPT_ALLOC_NEST_PARENT | IOMMU_HWPT_ALLOC_DIRTY_TRACKING)))
 		return ERR_PTR(-EOPNOTSUPP);
 	if (nested_parent && !nested_supported(iommu))
 		return ERR_PTR(-EOPNOTSUPP);

drivers/iommu/iommufd/hw_pagetable.c

@@ -140,8 +140,8 @@ iommufd_hwpt_paging_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
 	hwpt_paging->nest_parent = flags & IOMMU_HWPT_ALLOC_NEST_PARENT;
 
 	if (ops->domain_alloc_paging_flags) {
-		hwpt->domain = ops->domain_alloc_paging_flags(idev->dev, flags,
-							      user_data);
+		hwpt->domain = ops->domain_alloc_paging_flags(idev->dev,
+				flags & ~IOMMU_HWPT_FAULT_ID_VALID, user_data);
 		if (IS_ERR(hwpt->domain)) {
 			rc = PTR_ERR(hwpt->domain);
 			hwpt->domain = NULL;
@@ -280,6 +280,8 @@ iommufd_viommu_alloc_hwpt_nested(struct iommufd_viommu *viommu, u32 flags,
 	struct iommufd_hw_pagetable *hwpt;
 	int rc;
 
+	if (flags & ~IOMMU_HWPT_FAULT_ID_VALID)
+		return ERR_PTR(-EOPNOTSUPP);
 	if (!user_data->len)
 		return ERR_PTR(-EOPNOTSUPP);
 	if (!viommu->ops || !viommu->ops->alloc_domain_nested)
@@ -296,7 +298,9 @@ iommufd_viommu_alloc_hwpt_nested(struct iommufd_viommu *viommu, u32 flags,
 	hwpt_nested->parent = viommu->hwpt;
 
 	hwpt->domain =
-		viommu->ops->alloc_domain_nested(viommu, flags, user_data);
+		viommu->ops->alloc_domain_nested(viommu,
+				flags & ~IOMMU_HWPT_FAULT_ID_VALID,
+				user_data);
 	if (IS_ERR(hwpt->domain)) {
 		rc = PTR_ERR(hwpt->domain);
 		hwpt->domain = NULL;

drivers/iommu/iommufd/selftest.c

@@ -585,7 +585,7 @@ mock_viommu_alloc_domain_nested(struct iommufd_viommu *viommu, u32 flags,
 	struct mock_viommu *mock_viommu = to_mock_viommu(viommu);
 	struct mock_iommu_domain_nested *mock_nested;
 
-	if (flags & ~IOMMU_HWPT_FAULT_ID_VALID)
+	if (flags)
 		return ERR_PTR(-EOPNOTSUPP);
 
 	mock_nested = __mock_domain_alloc_nested(user_data);