[Qemu-devel] [PATCH 8/9] qdev: make qdev_set_parent_bus() just set a link property

[Anthony Liguori]

Also make setting the link to NULL break the bus link

Signed-off-by: Anthony Liguori <aligu...@us.ibm.com>
---
 hw/qdev.c |   48 ++++++++++++++++++++++++++++++++++++++++++------
 1 files changed, 42 insertions(+), 6 deletions(-)

diff --git a/hw/qdev.c b/hw/qdev.c
index 86e1337..525a0cb 100644
--- a/hw/qdev.c
+++ b/hw/qdev.c
@@ -100,8 +100,7 @@ static void bus_add_child(BusState *bus, DeviceState *child)
 
 void qdev_set_parent_bus(DeviceState *dev, BusState *bus)
 {
-    dev->parent_bus = bus;
-    bus_add_child(bus, dev);
+    object_property_set_link(OBJECT(dev), OBJECT(bus), "parent_bus", NULL);
 }
 
 /* Create a new device.  This only initializes the device state structure
@@ -241,8 +240,8 @@ void qbus_reset_all_fn(void *opaque)
 /* can be used as ->unplug() callback for the simple cases */
 int qdev_simple_unplug_cb(DeviceState *dev)
 {
-    /* just zap it */
-    qdev_free(dev);
+    /* Unplug from parent bus via a forced eject */
+    qdev_set_parent_bus(dev, NULL);
     return 0;
 }
 
@@ -646,6 +645,40 @@ void qdev_property_add_static(DeviceState *dev, Property 
*prop,
     assert_no_error(local_err);
 }
 
+static void qdev_set_link_property(Object *obj, Visitor *v, void *opaque,
+                                   const char *name, Error **errp)
+{
+    DeviceState *dev = DEVICE(obj);
+    BusState *parent_bus = dev->parent_bus;
+
+    object_set_link_property(obj, v, opaque, name, errp);
+
+    if (parent_bus) {
+        bus_remove_child(parent_bus, dev);
+    }
+
+    if (dev->parent_bus) {
+        bus_add_child(dev->parent_bus, dev);
+    }
+
+    if (!dev->parent_bus) {
+        notifier_list_notify(&dev->eject_notifier, dev);
+    }
+}
+
+static void qdev_release_link_property(Object *obj, const char *name,
+                                       void *opaque)
+{
+    DeviceState *dev = DEVICE(obj);
+
+    if (dev->parent_bus) {
+        bus_remove_child(dev->parent_bus, dev);
+        object_unref(OBJECT(dev->parent_bus));
+    }
+
+    dev->parent_bus = NULL;
+}
+
 static void device_initfn(Object *obj)
 {
     DeviceState *dev = DEVICE(obj);
@@ -670,8 +703,11 @@ static void device_initfn(Object *obj)
     } while (class != object_class_by_name(TYPE_DEVICE));
     qdev_prop_set_globals(dev);
 
-    object_property_add_link(OBJECT(dev), "parent_bus", TYPE_BUS,
-                             (Object **)&dev->parent_bus, NULL);
+    object_property_add(OBJECT(dev), "parent_bus", "link<" TYPE_BUS ">",
+                        object_get_link_property,
+                        qdev_set_link_property,
+                        qdev_release_link_property,
+                        &dev->parent_bus, NULL);
 
     notifier_list_init(&dev->eject_notifier);
 }
-- 
1.7.5.4