[RFC PATCH v2 08/10] vfio/type1: Add domain at(de)taching group helpers

[Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>]

If a domain is attaching to a group which includes the
mediated devices, it should attach to the mdev parent
of each mdev. This adds a helper for attaching domain
to group, no matter a PCI physical device or mediated
devices which are derived from a PCI physical device.

Cc: Ashok Raj <ashok.raj@xxxxxxxxx>
Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
Cc: Liu Yi L <yi.l.liu@xxxxxxxxx>
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
 drivers/vfio/vfio_iommu_type1.c | 77 ++++++++++++++++++++++++++++++---
 1 file changed, 70 insertions(+), 7 deletions(-)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index d9fd3188615d..89e2e6123223 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -91,6 +91,9 @@ struct vfio_dma {
 struct vfio_group {
 	struct iommu_group	*iommu_group;
 	struct list_head	next;
+	bool			attach_parent;	/* An mdev group with domain
+						 * attached to parent
+						 */
 };
 
 /*
@@ -1327,6 +1330,66 @@ static bool vfio_iommu_has_sw_msi(struct iommu_group *group, phys_addr_t *base)
 	return ret;
 }
 
+static int vfio_mdev_set_aux_domain(struct device *dev,
+				    struct iommu_domain *domain)
+{
+	int (*fn)(struct device *dev, void *domain);
+	int ret;
+
+	fn = symbol_get(mdev_set_domain);
+	if (fn) {
+		ret = fn(dev, domain);
+		symbol_put(mdev_set_domain);
+
+		return ret;
+	}
+
+	return -EINVAL;
+}
+
+static int vfio_attach_aux_domain(struct device *dev, void *data)
+{
+	struct iommu_domain *domain = data;
+	int ret;
+
+	ret = vfio_mdev_set_aux_domain(dev, domain);
+	if (ret)
+		return ret;
+
+	return iommu_attach_device(domain, dev->parent);
+}
+
+static int vfio_detach_aux_domain(struct device *dev, void *data)
+{
+	struct iommu_domain *domain = data;
+
+	vfio_mdev_set_aux_domain(dev, NULL);
+	iommu_detach_device(domain, dev->parent);
+
+	return 0;
+}
+
+static int vfio_iommu_attach_group(struct vfio_domain *domain,
+				   struct vfio_group *group)
+{
+	if (group->attach_parent)
+		return iommu_group_for_each_dev(group->iommu_group,
+						domain->domain,
+						vfio_attach_aux_domain);
+	else
+		return iommu_attach_group(domain->domain, group->iommu_group);
+}
+
+static void vfio_iommu_detach_group(struct vfio_domain *domain,
+				    struct vfio_group *group)
+{
+	if (group->attach_parent)
+		iommu_group_for_each_dev(group->iommu_group, domain->domain,
+					 vfio_detach_aux_domain);
+	else
+		iommu_detach_group(domain->domain, group->iommu_group);
+}
+
 static int vfio_iommu_type1_attach_group(void *iommu_data,
 					 struct iommu_group *iommu_group)
 {
@@ -1402,7 +1465,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 			goto out_domain;
 	}
 
-	ret = iommu_attach_group(domain->domain, iommu_group);
+	ret = vfio_iommu_attach_group(domain, group);
 	if (ret)
 		goto out_domain;
 
@@ -1434,8 +1497,8 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 	list_for_each_entry(d, &iommu->domain_list, next) {
 		if (d->domain->ops == domain->domain->ops &&
 		    d->prot == domain->prot) {
-			iommu_detach_group(domain->domain, iommu_group);
-			if (!iommu_attach_group(d->domain, iommu_group)) {
+			vfio_iommu_detach_group(domain, group);
+			if (!vfio_iommu_attach_group(d, group)) {
 				list_add(&group->next, &d->group_list);
 				iommu_domain_free(domain->domain);
 				kfree(domain);
@@ -1443,7 +1506,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 				return 0;
 			}
 
-			ret = iommu_attach_group(domain->domain, iommu_group);
+			ret = vfio_iommu_attach_group(domain, group);
 			if (ret)
 				goto out_domain;
 		}
@@ -1469,7 +1532,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 	return 0;
 
 out_detach:
-	iommu_detach_group(domain->domain, iommu_group);
+	vfio_iommu_detach_group(domain, group);
 out_domain:
 	iommu_domain_free(domain->domain);
 out_free:
@@ -1560,7 +1623,7 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
 		if (!group)
 			continue;
 
-		iommu_detach_group(domain->domain, iommu_group);
+		vfio_iommu_detach_group(domain, group);
 		list_del(&group->next);
 		kfree(group);
 		/*
@@ -1625,7 +1688,7 @@ static void vfio_release_domain(struct vfio_domain *domain, bool external)
 	list_for_each_entry_safe(group, group_tmp,
 				 &domain->group_list, next) {
 		if (!external)
-			iommu_detach_group(domain->domain, group->iommu_group);
+			vfio_iommu_detach_group(domain, group);
 		list_del(&group->next);
 		kfree(group);
 	}
-- 
2.17.1