[Spice-devel] [spice-server] sound: do not change volume or mute state on migration

[Frediano Ziglio]

> 
> Hi,
> 
> On Thu, Nov 16, 2017 at 10:58:03AM -0500, Frediano Ziglio wrote:
> > > 
> > > From: Victor Toso <me at victortoso.com>
> > > 
> > > On migration, we are resending the current volume and mute state in
> > > the Guest.
> > 
> > Maybe is just me but this sentence is confusing. By "we" I think you
> > mean spice-server but the confusion came from the fact that is Qemu
> > that on the new machine try to send the volume to spice-server causing
> > a potential volume/mute message to be sent to the client.
> > Another part that is not clear is the "state in the Guest" I think you
> > are meaning we are sending the "current Guest state value".
> > I'll try to rephrase:
> > "On migration, Qemu notify spice-server with the current Guest volume
> > and mute state values which currently is handled forwarding these values
> > to the client."
> 
> Yes, that's correct ~ sorry for the confusion.
> 
> Is the rest of commit log clear enough? Spice should mimic what happens
> in the guest but a volume/mute change on migration is not happening per
> user request which can cause odd volume/mute changes in the client.
> 
> Thanks,
>     Victor
> 

Was looking at these settings, maybe the fix would be better in
snd_channel_set_mute and snd_channel_set_volume (not setting the
mask) ?
What about record_channel_client_constructed? There is a similar
check (for migration) in playback_channel_client_constructed but
not in record_channel_client_constructed.

> > 
> > >             If the client user has change its master volume in the
> > > guest it might change the client application volume too and the volume
> > > jump (increase or decrease) might happen on migration.
> > > 
> > > This patch is a complement of f10de4bc084fcc - Here, volume was
> > > jumping regardless of guest's volume value.
> > > 
> > > Resolves: rhbz#1425443
> > > Signed-off-by: Victor Toso <victortoso at redhat.com>
> > > ---
> > >  server/sound.c | 12 ++++++++++++
> > >  1 file changed, 12 insertions(+)
> > > 
> > > diff --git a/server/sound.c b/server/sound.c
> > > index b1bfaaaa..c6c8bdc8 100644
> > > --- a/server/sound.c
> > > +++ b/server/sound.c
> > > @@ -414,6 +414,12 @@ static bool snd_send_volume(SndChannelClient
> > > *client,
> > > uint32_t cap, int msg)
> > >          return false;
> > >      }
> > >  
> > > +    /* Never changes volume or mute state on migration */
> > > +    if
> > > (red_client_during_migrate_at_target(red_channel_client_get_client(rcc)))
> > > {
> > > +        spice_debug("Do not change volume during migration");
> > > +        return FALSE;
> > > +    }
> > > +
> > >      vol = alloca(sizeof (SpiceMsgAudioVolume) +
> > >                   st->volume_nchannels * sizeof (uint16_t));
> > >      red_channel_client_init_send_data(rcc, msg);
> > > @@ -445,6 +451,12 @@ static bool snd_send_mute(SndChannelClient *client,
> > > uint32_t cap, int msg)
> > >          return false;
> > >      }
> > >  
> > > +   /* Never changes volume or mute state on migration */
> > > +   if
> > > (red_client_during_migrate_at_target(red_channel_client_get_client(rcc)))
> > > {
> > > +       spice_debug("Do not change mute during migration");
> > > +       return FALSE;
> > > +   }
> > > +
> > >      red_channel_client_init_send_data(rcc, msg);
> > >      mute.mute = st->mute;
> > >      spice_marshall_SpiceMsgAudioMute(m, &mute);
> > 
> > Frediano
>