vfio/type1: implement notify callback

Implement a notify callback that remembers if the container's file
descriptor has been closed.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

drivers/vfio/vfio_iommu_type1.c

@@ -75,6 +75,7 @@ struct vfio_iommu {
 	bool			nesting;
 	bool			dirty_page_tracking;
 	bool			pinned_page_dirty_scope;
+	bool			container_open;
 };
 
 struct vfio_domain {
@@ -2520,6 +2521,7 @@ static void *vfio_iommu_type1_open(unsigned long arg)
 	INIT_LIST_HEAD(&iommu->iova_list);
 	iommu->dma_list = RB_ROOT;
 	iommu->dma_avail = dma_entry_limit;
+	iommu->container_open = true;
 	mutex_init(&iommu->lock);
 	BLOCKING_INIT_NOTIFIER_HEAD(&iommu->notifier);
 
@@ -3087,6 +3089,18 @@ vfio_iommu_type1_group_iommu_domain(void *iommu_data,
 	return domain;
 }
 
+static void vfio_iommu_type1_notify(void *iommu_data,
+				    enum vfio_iommu_notify_type event)
+{
+	struct vfio_iommu *iommu = iommu_data;
+
+	if (event != VFIO_IOMMU_CONTAINER_CLOSE)
+		return;
+	mutex_lock(&iommu->lock);
+	iommu->container_open = false;
+	mutex_unlock(&iommu->lock);
+}
+
 static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = {
 	.name			= "vfio-iommu-type1",
 	.owner			= THIS_MODULE,
@@ -3101,6 +3115,7 @@ static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = {
 	.unregister_notifier	= vfio_iommu_type1_unregister_notifier,
 	.dma_rw			= vfio_iommu_type1_dma_rw,
 	.group_iommu_domain	= vfio_iommu_type1_group_iommu_domain,
+	.notify			= vfio_iommu_type1_notify,
 };
 
 static int __init vfio_iommu_type1_init(void)