Re: [Qemu-devel] multihead & multiseat in qemu

[Gerd Hoffmann]

On Mo, 2014-03-24 at 09:36 +0000, Dr. David Alan Gilbert wrote:
> * Gerd Hoffmann (address@hidden) wrote:
> >   Hi,
> > 
> > > > I'd like to have some way to assign tags such as seat=foo or head=1 to
> > > > devices.  Preferably in some way which can easily picked up with udev
> > > > rules, so it is easily usable by system-logind and Xorg server.
> > > 
> > > Can't you just do this in the serial number strings for both monitor EDID
> > > and USB device, I'm assuming that's how current multiseat setups figure
> > > stuff out.
> > 
> > We don't emulate monitor EDID ...
> > 
> > Also the serial number for HID devices is (ab-)used to signal remote
> > wakeup support (see commit 7b074a22dab4bdda9864b933f1bc811a3db42845).
> 
> Oh dear, that's a shame to use a field like that for a single bit of info.

Indeed.  Patch sent to systemd-devel to get that fixed.

Matching by serial number certainly makes sense.  EDID emulation /
pass-through has been discussed before, so we might get that some day.
Also for virtio-gpu (which is the most important case) we have the
option to simply pass on serial numbers without the edid, maybe in
virtgpu_display_info.

cheers,
  Gerd