qdev: Assert onboard devices all get realized properly

This would have caught some of the bugs I just fixed.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200609122339.937862-25-armbru@redhat.com>

hw/core/qdev.c

@@ -427,6 +427,19 @@ void qdev_init_nofail(DeviceState *dev)
     object_unref(OBJECT(dev));
 }
 
+static int qdev_assert_realized_properly(Object *obj, void *opaque)
+{
+    DeviceState *dev = DEVICE(object_dynamic_cast(obj, TYPE_DEVICE));
+    DeviceClass *dc;
+
+    if (dev) {
+        dc = DEVICE_GET_CLASS(dev);
+        assert(dev->realized);
+        assert(dev->parent_bus || !dc->bus_type);
+    }
+    return 0;
+}
+
 void qdev_machine_creation_done(void)
 {
     /*
@@ -434,6 +447,9 @@ void qdev_machine_creation_done(void)
      * only create hotpluggable devices
      */
     qdev_hotplug = true;
+
+    object_child_foreach_recursive(object_get_root(),
+                                   qdev_assert_realized_properly, NULL);
 }
 
 bool qdev_machine_modified(void)