Re: [Qemu-devel] [PATCH v3] balloon: Fix failure of updating guest memory status

[Stefan Hajnoczi]

On Mon, Aug 15, 2016 at 1:35 PM, Ladi Prosek <address@hidden> wrote:
> On Mon, Aug 15, 2016 at 2:09 PM, Stefan Hajnoczi <address@hidden> wrote:
>> On Fri, Aug 05, 2016 at 01:36:32PM +0200, Ladi Prosek wrote:
>>> diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
>>> index 5af429a..65457e9 100644
>>> --- a/hw/virtio/virtio-balloon.c
>>> +++ b/hw/virtio/virtio-balloon.c
>>> @@ -423,6 +423,26 @@ static int virtio_balloon_load_device(VirtIODevice 
>>> *vdev, QEMUFile *f,
>>>      return 0;
>>>  }
>>>
>>> +static void virtio_balloon_vmstate_cb(void *opaque, int running,
>>> +                                      RunState state)
>>> +{
>>> +    VirtIOBalloon *s = opaque;
>>> +
>>> +    if (!running) {
>>> +        /* put the stats element back if the VM is not running */
>>> +        if (s->stats_vq_elem != NULL) {
>>> +            virtqueue_discard(s->svq, s->stats_vq_elem, 
>>> s->stats_vq_offset);
>>
>> The third argument should be 0 because we did not write anything into
>> in_sg[].
>
> Thanks! Then it looks like the regular virtqueue_push in
> balloon_stats_poll_cb should also be called with 0 and the
> stats_vq_offset field can be deleted altogether. We never write to
> in_sg.

Yes.

Stefan