[PATCH v7 7/8] iommu/vt-d: Add nested domain allocation

[Yi Liu]

From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>

This adds the support for IOMMU_HWPT_DATA_VTD_S1 type. And 'nested_parent'
is added to mark the nested parent domain to sanitize the input parent domain.

Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
---
 drivers/iommu/intel/iommu.c | 67 +++++++++++++++++++++++++------------
 drivers/iommu/intel/iommu.h |  1 +
 2 files changed, 46 insertions(+), 22 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 292baa64188b..85366862fb5e 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4077,46 +4077,69 @@ intel_iommu_domain_alloc_user(struct device *dev, u32 flags,
 			      struct iommu_domain *parent,
 			      const struct iommu_user_data *user_data)
 {
-	struct iommu_domain *domain;
 	struct intel_iommu *iommu;
 	bool dirty_tracking;
+	bool nested_parent;
 
 	if (flags &
 	    (~(IOMMU_HWPT_ALLOC_NEST_PARENT | IOMMU_HWPT_ALLOC_DIRTY_TRACKING)))
 		return ERR_PTR(-EOPNOTSUPP);
 
-	if (parent || user_data)
-		return ERR_PTR(-EOPNOTSUPP);
-
 	iommu = device_to_iommu(dev, NULL, NULL);
 	if (!iommu)
 		return ERR_PTR(-ENODEV);
 
-	if ((flags & IOMMU_HWPT_ALLOC_NEST_PARENT) && !nested_supported(iommu))
-		return ERR_PTR(-EOPNOTSUPP);
-
+	nested_parent = flags & IOMMU_HWPT_ALLOC_NEST_PARENT;
 	dirty_tracking = (flags & IOMMU_HWPT_ALLOC_DIRTY_TRACKING);
-	if (dirty_tracking && !ssads_supported(iommu))
-		return ERR_PTR(-EOPNOTSUPP);
 
-	/*
-	 * domain_alloc_user op needs to fully initialize a domain
-	 * before return, so uses iommu_domain_alloc() here for
-	 * simple.
-	 */
-	domain = iommu_domain_alloc(dev->bus);
-	if (!domain)
-		domain = ERR_PTR(-ENOMEM);
+	if (!user_data) { /* Must be PAGING domain */
+		struct iommu_domain *domain;
 
-	if (!IS_ERR(domain) && dirty_tracking) {
-		if (to_dmar_domain(domain)->use_first_level) {
-			iommu_domain_free(domain);
+		if (nested_parent && !nested_supported(iommu))
 			return ERR_PTR(-EOPNOTSUPP);
+		if (dirty_tracking && !ssads_supported(iommu))
+			return ERR_PTR(-EOPNOTSUPP);
+		if (parent)
+			return ERR_PTR(-EINVAL);
+
+		/*
+		 * domain_alloc_user op needs to fully initialize a domain
+		 * before return, so uses iommu_domain_alloc() here for
+		 * simple.
+		 */
+		domain = iommu_domain_alloc(dev->bus);
+		if (!domain)
+			return ERR_PTR(-ENOMEM);
+
+		if (nested_parent)
+			to_dmar_domain(domain)->nested_parent = true;
+
+		if (dirty_tracking) {
+			if (to_dmar_domain(domain)->use_first_level) {
+				iommu_domain_free(domain);
+				return ERR_PTR(-EOPNOTSUPP);
+			}
+			domain->dirty_ops = &intel_dirty_ops;
 		}
-		domain->dirty_ops = &intel_dirty_ops;
+
+		return domain;
 	}
 
-	return domain;
+	/* Must be nested domain */
+	if (user_data->type != IOMMU_HWPT_DATA_VTD_S1)
+		return ERR_PTR(-EOPNOTSUPP);
+	if (!nested_supported(iommu))
+		return ERR_PTR(-EOPNOTSUPP);
+	if (!parent || parent->ops != intel_iommu_ops.default_domain_ops)
+		return ERR_PTR(-EINVAL);
+	if (!to_dmar_domain(parent)->nested_parent)
+		return ERR_PTR(-EINVAL);
+	if (nested_parent)
+		return ERR_PTR(-EINVAL);
+	if (dirty_tracking)
+		return ERR_PTR(-EINVAL);
+
+	return intel_nested_domain_alloc(parent, user_data);
 }
 
 static void intel_iommu_domain_free(struct iommu_domain *domain)
diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index d5aaaedf2094..65e660eb1f47 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -601,6 +601,7 @@ struct dmar_domain {
 					 * level.
 					 */
 	u8 dirty_tracking:1;		/* Dirty tracking is enabled */
+	u8 nested_parent:1;		/* Has other domains nested on it */
 
 	spinlock_t lock;		/* Protect device tracking lists */
 	struct list_head devices;	/* all devices' list */
-- 
2.34.1