Re: [Qemu-devel] [Spice-devel] seamless migration with spice

From: Alon Levy <alevy@redhat.com>
To: Gerd Hoffmann <kraxel@redhat.com>,
	Hans de Goede <hdegoede@redhat.com>,
	"spice-devel@freedesktop.org" <spice-devel@freedesktop.org>,
	qemu-devel <qemu-devel@nongnu.org>,
	Anthony Liguori <anthony@codemonkey.ws>
Subject: Re: [Qemu-devel] [Spice-devel]    seamless migration with spice
Date: Mon, 12 Mar 2012 16:35:23 +0200	[thread overview]
Message-ID: <20120312143523.GP6256@garlic> (raw)
In-Reply-To: <20120312142416.GO6256@garlic>

On Mon, Mar 12, 2012 at 04:24:16PM +0200, Alon Levy wrote:
> On Mon, Mar 12, 2012 at 01:44:47PM +0100, Gerd Hoffmann wrote:
> > On 03/12/12 12:45, Alon Levy wrote:
> > > On Mon, Mar 12, 2012 at 12:34:42PM +0100, Gerd Hoffmann wrote:
> > >> On 03/12/12 12:29, Alon Levy wrote:
> > >>>
> > >>> Actually the agent protocol does extend nicely to multiple clients - I
> > >>> forgot the name but there is an additional wrapper between the
> > >>> client/server originating message and the guest received message, that
> > >>> is currently used for server or client originating messages, and can be
> > >>> reused to have multiple in flight different client messages.
> > >>
> > >> I think you'll have issues in the layer above though.  Two spice clients
> > >> doing cut+paste operations at the same time?  Two spice clients
> > >> requesting different screen resolutions?
> > > 
> > > Yeah, you're right of course, this needs to be dealt with somehow.
> > >  cut+paste: maps nicely to a number of different buffers. Would need
> > >  some policy, and the session agent becomes closer to a buffer manager.
> > >  resolutions: again policy, perhaps have a master client, or if none
> > >  defined let the last or just the first choose. Not sure.
> > > 
> > > But these issues don't need to be solved now, do they?
> > 
> > Surely not.  But better keep it in mind when figuring how to handle
> > migration, so we are prepared to xfer all needed state in case we
> > implement that some day.
> > 
> > How does multi-client handle this today?
> 
> Just a single agent iirc. Or perhaps it breaks..
s/agent/client/, i.e. just one of the clients gets to have client mouse,
c&p, resolution changes (well, all the rest get affected by the
triggered resolution changes). IOW, left as a todo.

> 
> > 
> > cheers,
> >   Gerd
> > _______________________________________________
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>