Re: [Qemu-devel] [PATCH 2/2] virtio-balloon: resume collecting stats on vmload

[Roman Kagan]

On Sat, Sep 03, 2016 at 01:53:53AM +0300, Michael S. Tsirkin wrote:
> On Fri, Sep 02, 2016 at 10:21:58AM +0300, Roman Kagan wrote:
> > On Thu, Sep 01, 2016 at 10:26:54PM +0300, Michael S. Tsirkin wrote:
> > > I'm sorry - I don't like this patch. This means that
> > > virtio_balloon_receive_stats will be called and will poke
> > > at the ring even if the ring was never kicked.
> > 
> > I'm not sure I understand what the problem is with that:
> > virtio_balloon_receive_stats just returns early if virtio_queue_empty(),
> > which is no more poking at the ring than is already done in virtio_load.
> 
> Generally we should not look at ring until there was a kick.

How else would you recover ->inuse?

Roman.