[PATCH V9 10/10] iommu/vt-d: Report PASID format as domain attribute

[Jacob Pan]

Report the domain attribute of PASID table format. As multiple formats
of PASID table entry are supported, it is important for the guest to
know which format to use in virtual IOMMU. The result will be used for
binding device with guest PASID.

Signed-off-by: Liu Yi L <yi.l.liu@xxxxxxxxx>
Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
---
 drivers/iommu/intel-iommu.c | 22 ++++++++++++++++++++++
 include/linux/iommu.h       |  1 +
 2 files changed, 23 insertions(+)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 2f0bf7cc70ce..b3778e86dc32 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -6413,6 +6413,27 @@ intel_iommu_domain_set_attr(struct iommu_domain *domain,
 	return ret;
 }
 
+static int intel_iommu_domain_get_attr(struct iommu_domain *domain,
+				       enum iommu_attr attr, void *data)
+{
+	/* Only used for guest */
+	switch (domain->type) {
+	case IOMMU_DOMAIN_DMA:
+		return -ENODEV;
+	case IOMMU_DOMAIN_UNMANAGED:
+		switch (attr) {
+		case DOMAIN_ATTR_PASID_FORMAT:
+			*(int *)data = IOMMU_PASID_FORMAT_INTEL_VTD;
+			return 0;
+		default:
+			return -ENODEV;
+		}
+		break;
+	default:
+		return -EINVAL;
+	}
+}
+
 const struct iommu_ops intel_iommu_ops = {
 	.capable		= intel_iommu_capable,
 	.domain_alloc		= intel_iommu_domain_alloc,
@@ -6432,6 +6453,7 @@ const struct iommu_ops intel_iommu_ops = {
 	.put_resv_regions	= intel_iommu_put_resv_regions,
 	.apply_resv_region	= intel_iommu_apply_resv_region,
 	.device_group		= pci_device_group,
+	.domain_get_attr	= intel_iommu_domain_get_attr,
 	.dev_has_feat		= intel_iommu_dev_has_feat,
 	.dev_feat_enabled	= intel_iommu_dev_feat_enabled,
 	.dev_enable_feat	= intel_iommu_dev_enable_feat,
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index f2223cbb5fd5..9718c109ea0a 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -126,6 +126,7 @@ enum iommu_attr {
 	DOMAIN_ATTR_FSL_PAMUV1,
 	DOMAIN_ATTR_NESTING,	/* two stages of translation */
 	DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE,
+	DOMAIN_ATTR_PASID_FORMAT,
 	DOMAIN_ATTR_MAX,
 };
 
-- 
2.7.4