Re: [PATCH v2 2/3] virtio-net: add missing object_unref()

[Jason Wang]

On 2021/2/11 上午1:45, Laurent Vivier wrote:
> failover_add_primary() calls qdev_device_add() and doesn't unref
> the device. Because of that, when the device is unplugged a reference
> is remaining and prevents the cleanup of the object.
>
> This prevents to be able to plugin back the failover primary device,
> with errors like:
>
>    (qemu) device_add 
> vfio-pci,host=0000:41:00.0,id=hostdev0,bus=root.3,failover_pair_id=net0
>    (qemu) device_del hostdev0
>
> We can check with "info qtree" and "info pci" that the device has been removed, 
> and then:
>
>    (qemu) device_add 
> vfio-pci,host=0000:41:00.0,id=hostdev1,bus=root.3,failover_pair_id=net0
>    Error: vfio 0000:41:00.0: device is already attached
>    (qemu) device_add 
> vfio-pci,host=0000:41:00.0,id=hostdev0,bus=root.3,failover_pair_id=net0
>    qemu-kvm: Duplicate ID 'hostdev0' for device
>
> Fixes: 21e8709b29cd ("failover: Remove primary_dev member")
> Cc: quintela@redhat.com
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
> Reviewed-by: Jens Freimann <jfreimann@redhat.com>


Acked-by: Jason Wang <jasowang@redhat.com>


> ---
>   hw/net/virtio-net.c | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index 5150f295e8c5..1c5af08dc556 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -862,6 +862,8 @@ static void failover_add_primary(VirtIONet *n, Error **errp)
>           dev = qdev_device_add(opts, &err);
>           if (err) {
>               qemu_opts_del(opts);
> +        } else {
> +            object_unref(OBJECT(dev));
>           }
>       } else {
>           error_setg(errp, "Primary device not found");