[PATCH 3/4] iommu: Introduce IOMMU call-back for processing struct KVM assigned to VFIO

[Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>]

Currently, VFIO provide an kvm_vfio_file_set_kvm() interface for assigning
a KVM structure to a VFIO group. The information in struct KVM is also
useful for IOMMU drivers when setting up VFIO domain.

Introduce struct iommu_domain_ops.set_kvm call-back function to allow
IOMMU drivers to provide call-back to process the struct KVM assigned.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
 drivers/iommu/iommu.c    | 10 ++++++++++
 drivers/vfio/vfio_main.c |  1 +
 include/linux/iommu.h    |  4 ++++
 3 files changed, 15 insertions(+)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 65a3b3d886dc..5116d5fe35f2 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -3231,3 +3231,13 @@ bool iommu_group_dma_owner_claimed(struct iommu_group *group)
 	return user;
 }
 EXPORT_SYMBOL_GPL(iommu_group_dma_owner_claimed);
+
+void iommu_set_kvm(struct iommu_group *group, struct kvm *kvm)
+{
+	if (!group || !group->domain || !group->domain->ops)
+		return;
+
+	if (group->domain->ops->set_kvm)
+		group->domain->ops->set_kvm(group->domain, kvm);
+}
+EXPORT_SYMBOL_GPL(iommu_set_kvm);
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 2d168793d4e1..7641e3a0c986 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -1652,6 +1652,7 @@ void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
 
 	mutex_lock(&group->group_lock);
 	group->kvm = kvm;
+	iommu_set_kvm(group->iommu_group, kvm);
 	mutex_unlock(&group->group_lock);
 }
 EXPORT_SYMBOL_GPL(vfio_file_set_kvm);
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 3c9da1f8979e..43000231d3d7 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -42,6 +42,7 @@ struct notifier_block;
 struct iommu_sva;
 struct iommu_fault_event;
 struct iommu_dma_cookie;
+struct kvm;
 
 /* iommu fault flags */
 #define IOMMU_FAULT_READ	0x0
@@ -314,6 +315,8 @@ struct iommu_domain_ops {
 				  unsigned long quirks);
 
 	void (*free)(struct iommu_domain *domain);
+
+	void (*set_kvm)(struct iommu_domain *domain, struct kvm *kvm);
 };
 
 /**
@@ -391,6 +394,7 @@ void iommu_device_sysfs_remove(struct iommu_device *iommu);
 int  iommu_device_link(struct iommu_device   *iommu, struct device *link);
 void iommu_device_unlink(struct iommu_device *iommu, struct device *link);
 int iommu_deferred_attach(struct device *dev, struct iommu_domain *domain);
+void iommu_set_kvm(struct iommu_group *group, struct kvm *kvm);
 
 static inline struct iommu_device *dev_to_iommu_device(struct device *dev)
 {
-- 
2.32.0