Re: [Qemu-devel] [PATCH] virtio-pci: fix virtio-net child refcount in transports

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Sep 04, 2014 at 07:41:32PM +0800, arei.gonglei@huawei.com wrote:
> 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-net 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>

Aren't other virtio devices affected? what about virtio-scsi?

> ---
> Stefan had post virtio-blk in commit c5d49db4, but virtio-net has 
> the same problem. Maybe the other virtio devices have too.
> ---
>  hw/virtio/virtio-pci.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index ddb5da1..78dcd68 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -1456,6 +1456,7 @@ 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));
>  }
>  
>  static const TypeInfo virtio_net_pci_info = {
> -- 
> 1.7.12.4
>