[Qemu-devel] [PATCH v3 07/28] vhost: make vhost_dev_cleanup() idempotent

[marcandre . lureau]

From: Marc-André Lureau <address@hidden>

May be called on multiple code path, so it's easier to make it safe in
the first place.

Signed-off-by: Marc-André Lureau <address@hidden>
---
 hw/virtio/vhost.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index ebdd1da..9fc6e4d 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1085,19 +1085,27 @@ fail:
 void vhost_dev_cleanup(struct vhost_dev *hdev)
 {
     int i;
+
     for (i = 0; i < hdev->nvqs; ++i) {
         vhost_virtqueue_cleanup(hdev->vqs + i);
     }
-    memory_listener_unregister(&hdev->memory_listener);
+    if (hdev->mem) {
+        /* those are only safe after successful init */
+        memory_listener_unregister(&hdev->memory_listener);
+        QLIST_REMOVE(hdev, entry);
+    }
     if (hdev->migration_blocker) {
         migrate_del_blocker(hdev->migration_blocker);
         error_free(hdev->migration_blocker);
     }
     g_free(hdev->mem);
     g_free(hdev->mem_sections);
-    hdev->vhost_ops->vhost_backend_cleanup(hdev);
+    if (hdev->vhost_ops) {
+        hdev->vhost_ops->vhost_backend_cleanup(hdev);
+    }
     vhost_log_put(hdev, false);
-    QLIST_REMOVE(hdev, entry);
+
+    memset(hdev, 0, sizeof(struct vhost_dev));
 }
 
 /* Stop processing guest IO notifications in qemu.
-- 
2.9.0