vfio: Unregister IOMMU notifiers when container is destroyed

On systems with guest visible IOMMU, adding a new memory region onto
PCI bus calls vfio_listener_region_add() for every DMA window. This
installs a notifier for IOMMU memory regions. The notifier is supposed
to be removed vfio_listener_region_del(), however in the case of mixed
PHB (emulated + VFIO devices) when last VFIO device is unplugged and
container gets destroyed, all existing DMA windows stay alive altogether
with the notifiers which are on the linked list which head was in
the destroyed container.

This unregisters IOMMU memory region notifier when a container is
destroyed.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index b1045da857aa162e37caa30329e3c19ed2941467..85ee9b005edc7a46c109e91dd69fd3898edf4e62 100644 (file)
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -772,11 +772,19 @@ static void vfio_disconnect_container(VFIOGroup *group)
 
     if (QLIST_EMPTY(&container->group_list)) {
         VFIOAddressSpace *space = container->space;
+        VFIOGuestIOMMU *giommu, *tmp;
 
         if (container->iommu_data.release) {
             container->iommu_data.release(container);
         }
         QLIST_REMOVE(container, next);
+
+        QLIST_FOREACH_SAFE(giommu, &container->giommu_list, giommu_next, tmp) {
+            memory_region_unregister_iommu_notifier(&giommu->n);
+            QLIST_REMOVE(giommu, giommu_next);
+            g_free(giommu);
+        }
+
         trace_vfio_disconnect_container(container->fd);
         close(container->fd);
         g_free(container);