[PATCH V1 3/5] vfio: detect closed container

[Steve Sistare <steven.sistare@oracle.com>]

Add a function that detects if an iommu_group has a valid container.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
---
 drivers/vfio/vfio.c  | 12 ++++++++++++
 include/linux/vfio.h |  1 +
 2 files changed, 13 insertions(+)

diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 262ab0e..f89ab80 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -61,6 +61,7 @@ struct vfio_container {
 	struct vfio_iommu_driver	*iommu_driver;
 	void				*iommu_data;
 	bool				noiommu;
+	bool				closed;
 };
 
 struct vfio_unbound_dev {
@@ -1223,6 +1224,7 @@ static int vfio_fops_release(struct inode *inode, struct file *filep)
 
 	filep->private_data = NULL;
 
+	container->closed = true;
 	vfio_container_put(container);
 
 	return 0;
@@ -2216,6 +2218,16 @@ void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
 }
 EXPORT_SYMBOL_GPL(vfio_group_set_kvm);
 
+bool vfio_iommu_group_contained(struct iommu_group *iommu_group)
+{
+	struct vfio_group *group = vfio_group_get_from_iommu(iommu_group);
+	bool ret = group && group->container && !group->container->closed;
+
+	vfio_group_put(group);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(vfio_iommu_group_contained);
+
 static int vfio_register_group_notifier(struct vfio_group *group,
 					unsigned long *events,
 					struct notifier_block *nb)
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 38d3c6a..b2724e7 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -148,6 +148,7 @@ extern int vfio_unregister_notifier(struct device *dev,
 
 struct kvm;
 extern void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm);
+extern bool vfio_iommu_group_contained(struct iommu_group *group);
 
 /*
  * Sub-module helpers
-- 
1.8.3.1