[Spice-devel] [RFC PATCH v2 00/20] Monitor ID rework

[Lukáš Hrázký]

Hello,

On Wed, 2018-09-19 at 11:24 +0200, Gerd Hoffmann wrote:
>   Hi,
> 
> > this is the reworked second version of the Monitor ID series.
> 
> Ping.  What is the status here?  v3 coming?

Sorry about the radio silence. We discussed the possibilities and came
up with roughly the following:

- From now on we will only use one monitor per display channel.

- Given the above, we don't need to fix the channel_id + monitor_id
problem immediately, so we'll leave that as it is now.

- We're going to try to implement you suggestion of identifying the
monitors in the guest basically according to your outline in
https://lists.freedesktop.org/archives/spice-devel/2018-August/045465.html

> Another lousely related thing:  While debugging another issue I've
> noticed that QXLMonitorsConfig has a surface_id field.  What this is
> intended for?  Map non-primary surface to a head?

I just did a brief investigation, I am not sure. It seems the field is
not used in the QEMU <-> SPICE part of the exchange?

In the SPICE protocol the field is used to refer to the surface on
which the monitor is located. I think it can only be a primary surface
and due to implementation limitations this means only surface ID 0, but
I may be wrong here. Maybe Frediano has more insight.

> And one more:  I'm trying to get edid support into qemu and linux kms
> drivers.  This might also help identify monitors in the guest (edid data
> blobs can have serial numbers).  Not short-term though as this will need
> updated guest drivers to work.

We also considered EDID as a possibility for identification, but in the
end discarded it as not fitting well. The main reason I think was that
EDID is actually data from the physical monitor, not a graphics device
output.

An example was mentioned when you have a physical graphics card
directly assigned to a VM, which has two outputs and a user would
unplug his monitor from the first output and plug it into the other.

Cheers,
Lukas

> cheers,
>   Gerd