[Qemu-devel] [PATCH RESEND 6/9] virtio-serial: fix virtio-serial child refcount in transports

[<arei.gonglei@huawei.com>]

From: Gonglei <arei.gonglei@huawei.com>

object_initialize() leaves the object with a refcount of 1.
object_property_add_child() adds its own reference which is dropped
again when the property is deleted.

The upshot of this is that we always have a refcount >= 1.  Upon hot
unplug the virtio-serial child is not finalized!

Drop our reference after the child property has been added to the
parent.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
---
 hw/s390x/s390-virtio-bus.c | 1 +
 hw/s390x/virtio-ccw.c      | 1 +
 hw/virtio/virtio-pci.c     | 1 +
 3 files changed, 3 insertions(+)

diff --git a/hw/s390x/s390-virtio-bus.c b/hw/s390x/s390-virtio-bus.c
index 31f5286..422402e 100644
--- a/hw/s390x/s390-virtio-bus.c
+++ b/hw/s390x/s390-virtio-bus.c
@@ -227,6 +227,7 @@ static void s390_virtio_serial_instance_init(Object *obj)
     object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_SERIAL);
     object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
     qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
+    object_unref(OBJECT(&dev->vdev));
 }
 
 static int s390_virtio_scsi_init(VirtIOS390Device *s390_dev)
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index 271104d..5d7f3a6 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -853,6 +853,7 @@ static void virtio_ccw_serial_instance_init(Object *obj)
     object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_SERIAL);
     object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
     qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
+    object_unref(OBJECT(&dev->vdev));
 }
 
 static int virtio_ccw_balloon_init(VirtioCcwDevice *ccw_dev)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 3c1f37b..4446d79 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1410,6 +1410,7 @@ static void virtio_serial_pci_instance_init(Object *obj)
     object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_SERIAL);
     object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
     qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
+    object_unref(OBJECT(&dev->vdev));
 }
 
 static const TypeInfo virtio_serial_pci_info = {
-- 
1.7.12.4