VirtIO-GPU resolutions

[karypid]

Hello,

I run an Arch Linux VM using a VirtIO-GPU adapter. I connect to it mostly through RDP (I use Gnome's screen sharing) but also with the windows virt-viewer client. My problem is that I have a 27" monitor at 21:9 ratio and I want to run it at 2560x1440 resolution, yet that is not advertised in Display Settings (even though I can reach much higher resolutions).

These are the modes listed:

$ cat /sys/class/drm/card1-Virtual-1/modes
3840x2160
5120x2160
4096x2160
3840x2160
3840x2160
3840x2160
1920x1440
2560x1080
1856x1392
1792x1344
2048x1152
1920x1200
1920x1080
1920x1080
1600x1200
...

The parse EDID tool seems to not understand the contents of the virtual monitor EDID:

$ cat /sys/class/drm/card1-Virtual-1/edid | parse-edid
You seem to have too many extension blocks. Will not continue to parse
Something strange happened. Please contact the author,
Matthew Kern at <pyrophobicman@gmail.com>

How can I add 2560x1440 and 2560x1600 to this list?

 

[karypid]

I have managed to solve this problem. The solution depends on whether you are using X11 or Wayland.

I use Wayland so the solution in my case was to add the following kernel parameter:

video=Virtual-1:2560x1440@60

After rebooting I was able to select my desired mode.

Source of fix: Dave Jansen's blog post on "Add custom resolution and refresh rate when using Wayland"