[Qemu-devel] [PATCH 31/88] virtio-net: fix virtio-net child refcount in transports

[Michael Roth]

From: Gonglei <address@hidden>

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-net child is not finalized!

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

Signed-off-by: Gonglei <address@hidden>
Reviewed-by: Cornelia Huck <address@hidden>
Cc: address@hidden
Signed-off-by: Paolo Bonzini <address@hidden>
(cherry picked from commit 6a0c6b59788627541faf70864464f1e155dc18d7)
Signed-off-by: Michael Roth <address@hidden>
---
 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 5b5d595..297eac2 100644
--- a/hw/s390x/s390-virtio-bus.c
+++ b/hw/s390x/s390-virtio-bus.c
@@ -161,6 +161,7 @@ static void s390_virtio_net_instance_init(Object *obj)
     VirtIONetS390 *dev = VIRTIO_NET_S390(obj);
     object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_NET);
     object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
+    object_unref(OBJECT(&dev->vdev));
     qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
 }
 
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index 7d67577..bb699f2 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -794,6 +794,7 @@ static void virtio_ccw_net_instance_init(Object *obj)
     VirtIONetCcw *dev = VIRTIO_NET_CCW(obj);
     object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_NET);
     object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
+    object_unref(OBJECT(&dev->vdev));
     qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
 }
 
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 2452db9..eb1d138 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1467,6 +1467,7 @@ static void virtio_net_pci_instance_init(Object *obj)
     VirtIONetPCI *dev = VIRTIO_NET_PCI(obj);
     object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_NET);
     object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
+    object_unref(OBJECT(&dev->vdev));
     qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
 }
 
-- 
1.9.1