diff --git a/blockdev.c b/blockdev.c
index 9480dbb..df8ce14 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -709,6 +709,18 @@ void qmp_drive_reopen(const char *device, const char *new_image_file,
                           has_format ? format : "qcow2", errp);
 }
 
+static void blockdev_do_action(int kind, void *data, Error **errp)
+{
+    BlockdevAction action;
+    BlockdevActionList list;
+
+    action.kind = kind;
+    action.data = data;
+    list.value = &action;
+    list.next = NULL;
+    qmp_transaction(&list, errp);
+}
+
 void qmp_blockdev_snapshot_sync(const char *device, const char *snapshot_file,
                                 bool has_format, const char *format,
                                 bool has_mode, enum NewImageMode mode,
@@ -722,16 +734,8 @@ void qmp_blockdev_snapshot_sync(const char *device, const char *snapshot_file,
         .has_mode = has_mode,
         .mode = mode,
     };
-    BlockdevAction action = {
-        .kind = BLOCKDEV_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC,
-        .blockdev_snapshot_sync = &snapshot,
-    };
-    BlockdevActionList list = {
-        .value = &action,
-        .next = NULL
-    };
-
-    qmp_transaction(&list, errp);
+    blockdev_do_action(BLOCKDEV_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC, &snapshot,
+                       errp);
 }
 
 void qmp_drive_mirror(const char *device, const char *target,
@@ -746,16 +750,7 @@ void qmp_drive_mirror(const char *device, const char *target,
         .has_mode = has_mode,
         .mode = mode,
     };
-    BlockdevAction action = {
-        .kind = BLOCKDEV_ACTION_KIND_DRIVE_MIRROR,
-        .drive_mirror = &mirror,
-    };
-    BlockdevActionList list = {
-        .value = &action,
-        .next = NULL
-    };
-
-    qmp_transaction(&list, errp);
+    blockdev_do_action(BLOCKDEV_ACTION_KIND_DRIVE_MIRROR, &mirror, errp);
 }
 
 
diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py
index 6968e7f..727fb77 100644
--- a/scripts/qapi-types.py
+++ b/scripts/qapi-types.py
@@ -117,6 +117,7 @@ struct %(name)s
 {
     %(name)sKind kind;
     union {
+        void *data;
 ''',
                 name=name)