[PATCH v4 1/5] iommu: Add optional subdev in aux_at(de)tach ops

[Lu Baolu]

In the vfio/mdev use case of aux-domain, the subdevices are created from
the physical devices with IOMMU_DEV_FEAT_AUX enabled and the aux-domains
are attached to the subdevices through the iommu_ops.aux_attach_dev()
interface.

Current iommu_ops.aux_at(de)tach_dev() design only takes the aux-domain
and the physical device as the parameters, this is insufficient if we
want the vendor iommu drivers to learn the knowledge about relationships
between the aux-domains and the subdevices. Add a @subdev parameter to
iommu_ops.aux_at(de)tach_dev() interfaces so that a subdevice could be
opt-in.

Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
 drivers/iommu/intel/iommu.c | 10 ++++++----
 drivers/iommu/iommu.c       |  4 ++--
 include/linux/iommu.h       |  6 ++++--
 3 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index bce158468abf..3c12fd06856c 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -5338,8 +5338,9 @@ static int intel_iommu_attach_device(struct iommu_domain *domain,
 	return domain_add_dev_info(to_dmar_domain(domain), dev);
 }
 
-static int intel_iommu_aux_attach_device(struct iommu_domain *domain,
-					 struct device *dev)
+static int
+intel_iommu_aux_attach_device(struct iommu_domain *domain,
+			      struct device *dev, struct device *subdev)
 {
 	int ret;
 
@@ -5359,8 +5360,9 @@ static void intel_iommu_detach_device(struct iommu_domain *domain,
 	dmar_remove_one_dev_info(dev);
 }
 
-static void intel_iommu_aux_detach_device(struct iommu_domain *domain,
-					  struct device *dev)
+static void
+intel_iommu_aux_detach_device(struct iommu_domain *domain, struct device *dev,
+			      struct device *subdev)
 {
 	aux_domain_remove_dev(to_dmar_domain(domain), dev);
 }
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 609bd25bf154..38cdfeb887e1 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2728,7 +2728,7 @@ int iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev)
 	int ret = -ENODEV;
 
 	if (domain->ops->aux_attach_dev)
-		ret = domain->ops->aux_attach_dev(domain, dev);
+		ret = domain->ops->aux_attach_dev(domain, dev, NULL);
 
 	if (!ret)
 		trace_attach_device_to_domain(dev);
@@ -2740,7 +2740,7 @@ EXPORT_SYMBOL_GPL(iommu_aux_attach_device);
 void iommu_aux_detach_device(struct iommu_domain *domain, struct device *dev)
 {
 	if (domain->ops->aux_detach_dev) {
-		domain->ops->aux_detach_dev(domain, dev);
+		domain->ops->aux_detach_dev(domain, dev, NULL);
 		trace_detach_device_from_domain(dev);
 	}
 }
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index fee209efb756..871267104915 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -279,8 +279,10 @@ struct iommu_ops {
 	int (*dev_disable_feat)(struct device *dev, enum iommu_dev_features f);
 
 	/* Aux-domain specific attach/detach entries */
-	int (*aux_attach_dev)(struct iommu_domain *domain, struct device *dev);
-	void (*aux_detach_dev)(struct iommu_domain *domain, struct device *dev);
+	int (*aux_attach_dev)(struct iommu_domain *domain, struct device *dev,
+			      struct device *subdev);
+	void (*aux_detach_dev)(struct iommu_domain *domain, struct device *dev,
+			       struct device *subdev);
 	int (*aux_get_pasid)(struct iommu_domain *domain, struct device *dev);
 
 	struct iommu_sva *(*sva_bind)(struct device *dev, struct mm_struct *mm,
-- 
2.17.1