On Thu, 2018-08-23 at 22:42 +0200, Gerd Hoffmann wrote: > Hi, > > > "we only support" seems to just state the use cases before adding > > vGPU but we are trying to support vGPU cases. > > If even we decide that for vGPU cards we always have monitor_id == 0 > > Yes, we want this for sure. One channel per display. For sure? This deserves a justification. > > (that is multiple DisplayChannels for each vGPU) we still have the > > issue of id matching with the agent which these patches are trying to > > deal with. > > Yes. *That* is the underlying problem. There is no guest-visible link > between display device and spice channel. It is one of two problems. We are discussing this over and over though. I'll wait for Jonathon to post a summary of yesterday's IRC discussion, as he may do a better job explaining it (I've explained it several times throughout the discussion, given that we are still discussing it, I probably wasn't very successful ;)) > Except when the device is > qxl, because qxl has a channel-id field somewhere (in qxl rom IIRC) > which the guest can read. Really? Can you describe how the guest could read that? Thanks. > And it is not limited to vGPU. Try place two emulated display devices > into one guest (not using qxl). You'll face the very same issue. > > Placing both channel_id and monitor_id into the messages isn't going to > solve this. No, the way I solve this is by having a hash table on the server, which maps (channel_id, monitor_id) -> guest_output_id. The reason for using (channel_id, monitor_id) is that it is the only unambiguous unique identifier of a monitor on the server. The guest_output_id is sent to the server from the streaming agent and it is the xrandr output id. Therefore we obviously have it only for streamed monitors. For other, old-style monitors, we still fall back to channel_id + monitor_id. This is obviously quite sub-optimal, but it seems to me it's the best we can do. The details are in the patches... Cheers, Lukas > cheers, > Gerd > > _______________________________________________ > Spice-devel mailing list > Spice-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/spice-devel _______________________________________________ Spice-devel mailing list Spice-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/spice-devel