diff mbox series

[v15,10/12] iommu/smmuv3: Enforce incompatibility between nested mode and HW MSI regions

Message ID 20210411111228.14386-11-eric.auger@redhat.com (mailing list archive)
State New, archived
Headers show
Series SMMUv3 Nested Stage Setup (IOMMU part) | expand

Commit Message

Eric Auger April 11, 2021, 11:12 a.m. UTC
Nested mode currently is not compatible with HW MSI reserved regions.
Indeed MSI transactions targeting this MSI doorbells bypass the SMMU.

Let's check nested mode is not attempted in such configuration.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 23 +++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index c4794c21c35f..ec75219d6a52 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2472,6 +2472,23 @@  static bool arm_smmu_share_msi_domain(struct iommu_domain *domain,
 	return share;
 }
 
+static bool arm_smmu_has_hw_msi_resv_region(struct device *dev)
+{
+	struct iommu_resv_region *region;
+	bool has_msi_resv_region = false;
+	LIST_HEAD(resv_regions);
+
+	iommu_get_resv_regions(dev, &resv_regions);
+	list_for_each_entry(region, &resv_regions, list) {
+		if (region->type == IOMMU_RESV_MSI) {
+			has_msi_resv_region = true;
+			break;
+		}
+	}
+	iommu_put_resv_regions(dev, &resv_regions);
+	return has_msi_resv_region;
+}
+
 static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 {
 	int ret = 0;
@@ -2532,10 +2549,12 @@  static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 	/*
 	 * In nested mode we must check all devices belonging to the
 	 * domain share the same physical MSI doorbell. Otherwise nested
-	 * stage MSI binding is not supported.
+	 * stage MSI binding is not supported. Also nested mode is not
+	 * compatible with MSI HW reserved regions.
 	 */
 	if (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED &&
-		!arm_smmu_share_msi_domain(domain, dev)) {
+		(!arm_smmu_share_msi_domain(domain, dev) ||
+		 arm_smmu_has_hw_msi_resv_region(dev))) {
 		ret = -EINVAL;
 		goto out_unlock;
 	}