iommu/vt-d: Support IOMMU_DEV_FEAT_IOPF

Allow drivers to query and enable IOMMU_DEV_FEAT_IOPF, which amounts to
checking whether PRI is enabled.
Reviewed-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20210401154718.307519-5-jean-philippe@linaro.orgSigned-off-by: NJoerg Roedel <jroedel@suse.de>

drivers/iommu/intel/iommu.c

@@ -5311,6 +5311,8 @@ static int siov_find_pci_dvsec(struct pci_dev *pdev)
 static bool
 intel_iommu_dev_has_feat(struct device *dev, enum iommu_dev_features feat)
 {
+	struct device_domain_info *info = get_domain_info(dev);
+
 	if (feat == IOMMU_DEV_FEAT_AUX) {
 		int ret;
 
@@ -5325,13 +5327,13 @@ intel_iommu_dev_has_feat(struct device *dev, enum iommu_dev_features feat)
 		return !!siov_find_pci_dvsec(to_pci_dev(dev));
 	}
 
-	if (feat == IOMMU_DEV_FEAT_SVA) {
-		struct device_domain_info *info = get_domain_info(dev);
+	if (feat == IOMMU_DEV_FEAT_IOPF)
+		return info && info->pri_supported;
 
+	if (feat == IOMMU_DEV_FEAT_SVA)
 		return info && (info->iommu->flags & VTD_FLAG_SVM_CAPABLE) &&
 			info->pasid_supported && info->pri_supported &&
 			info->ats_supported;
-	}
 
 	return false;
 }
@@ -5342,6 +5344,9 @@ intel_iommu_dev_enable_feat(struct device *dev, enum iommu_dev_features feat)
 	if (feat == IOMMU_DEV_FEAT_AUX)
 		return intel_iommu_enable_auxd(dev);
 
+	if (feat == IOMMU_DEV_FEAT_IOPF)
+		return intel_iommu_dev_has_feat(dev, feat) ? 0 : -ENODEV;
+
 	if (feat == IOMMU_DEV_FEAT_SVA) {
 		struct device_domain_info *info = get_domain_info(dev);