hw/virtio/virtio-balloon: move adding property to virtio_balloon_instance_init

This is in preparation for using alias property in virtio-balloon-pci
and virtio-balloon-ccw.
Signed-off-by: NShannon Zhao <zhaoshenglong@huawei.com>
Signed-off-by: NShannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>

hw/virtio/virtio-balloon.c

@@ -396,14 +396,6 @@ static void virtio_balloon_device_realize(DeviceState *dev, Error **errp)
 
     register_savevm(dev, "virtio-balloon", -1, 1,
                     virtio_balloon_save, virtio_balloon_load, s);
-
-    object_property_add(OBJECT(dev), "guest-stats", "guest statistics",
-                        balloon_stats_get_all, NULL, NULL, s, NULL);
-
-    object_property_add(OBJECT(dev), "guest-stats-polling-interval", "int",
-                        balloon_stats_get_poll_interval,
-                        balloon_stats_set_poll_interval,
-                        NULL, s, NULL);
 }
 
 static void virtio_balloon_device_unrealize(DeviceState *dev, Error **errp)
@@ -417,6 +409,19 @@ static void virtio_balloon_device_unrealize(DeviceState *dev, Error **errp)
     virtio_cleanup(vdev);
 }
 
+static void virtio_balloon_instance_init(Object *obj)
+{
+    VirtIOBalloon *s = VIRTIO_BALLOON(obj);
+
+    object_property_add(obj, "guest-stats", "guest statistics",
+                        balloon_stats_get_all, NULL, NULL, s, NULL);
+
+    object_property_add(obj, "guest-stats-polling-interval", "int",
+                        balloon_stats_get_poll_interval,
+                        balloon_stats_set_poll_interval,
+                        NULL, s, NULL);
+}
+
 static Property virtio_balloon_properties[] = {
     DEFINE_PROP_END_OF_LIST(),
 };
@@ -441,6 +446,7 @@ static const TypeInfo virtio_balloon_info = {
     .name = TYPE_VIRTIO_BALLOON,
     .parent = TYPE_VIRTIO_DEVICE,
     .instance_size = sizeof(VirtIOBalloon),
+    .instance_init = virtio_balloon_instance_init,
     .class_init = virtio_balloon_class_init,
 };