Re: [PATCH v4 11/24] net: Use virtual time for net announce

[Pavel Dovgalyuk]

On 12.03.2024 14:05, Nicholas Piggin wrote:
> On Tue Mar 12, 2024 at 7:09 PM AEST, Pavel Dovgalyuk wrote:
> > This won't work, as needed. Announce timer can't be enabled, because
> > it is set in post_load function. Therefore announce callbacks break
> > the replay, when virtio-net is used with snapshots.
>
> I see. Is that somehow marked as being incompatible with rr?

Here's the prior discussion on it: 
https://lore.kernel.org/qemu-devel/8735ovx0zd.fsf@linaro.org/t/


> Thanks,
> Nick
>
> > On 11.03.2024 20:40, Nicholas Piggin wrote:
> > > Using virtual time for announce ensures that guest visible effects
> > > are deterministic and don't break replay.
> > >
> > > Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> > > ---
> > >    net/announce.c | 2 +-
> > >    1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/net/announce.c b/net/announce.c
> > > index 9e99044422..70b5d5e822 100644
> > > --- a/net/announce.c
> > > +++ b/net/announce.c
> > > @@ -187,7 +187,7 @@ static void qemu_announce_self_once(void *opaque)
> > >    
> > >    void qemu_announce_self(AnnounceTimer *timer, AnnounceParameters *params)
> > >    {
> > > -    qemu_announce_timer_reset(timer, params, QEMU_CLOCK_REALTIME,
> > > +    qemu_announce_timer_reset(timer, params, QEMU_CLOCK_VIRTUAL,
> > >                                  qemu_announce_self_once, timer);
> > >        if (params->rounds) {
> > >            qemu_announce_self_once(timer);