Whonix 17 screen resolution issue

Qubes-Whonix
1

Hello, I recently installed Qubes 4.2-rc4 from ISO so I have whonix 17 installed. I noticed that my applications window were appearing in the middle of my 2 monitors instead of the middle of the monitor where my cursor is like it used to be with Whonix 16.

I checked xrandr on an AppVM based on Whonix 17 and this is what I got:

Screen 0: minimum 64 x 64, current 3840 x 1080, maximum 32767 x 32767
DUMMY0 connected primary 3840x1080+0+0 0mm x 0mm
   QB3840x1080   46.13*+
DUMMY1 disconnected
DUMMY2 disconnected
DUMMY3 disconnected
DUMMY4 disconnected
DUMMY5 disconnected
DUMMY6 disconnected
DUMMY7 disconnected
DUMMY8 disconnected
DUMMY9 disconnected
DUMMY10 disconnected
DUMMY11 disconnected
DUMMY12 disconnected
DUMMY13 disconnected
DUMMY14 disconnected
DUMMY15 disconnected

For example, debian 12 returns this (Whonix 16 was returning the same thing on 4.1):

Screen 0: minimum 64 x 64, current 3840 x 1080, maximum 32767 x 32767
DUMMY0 connected primary 1920x1080+1920+0 0mm x 0mm
   QB3840x1080   46.13 +
   QB1920x1080   59.96* 
DUMMY1 connected 1920x1080+0+0 0mm x 0mm
   QB3840x1080   46.13 +
   QB1920x1080   59.96* 
DUMMY2 disconnected
DUMMY3 disconnected
DUMMY4 disconnected
DUMMY5 disconnected
DUMMY6 disconnected
DUMMY7 disconnected
DUMMY8 disconnected
DUMMY9 disconnected
DUMMY10 disconnected
DUMMY11 disconnected
DUMMY12 disconnected
DUMMY13 disconnected
DUMMY14 disconnected
DUMMY15 disconnected

Whonix 17 is merging my monitors in one and I don’t know why. Is it supposed to do that on that version? I’m not sure if this is a Whonix feature or just a bug from Qubes itself.

2

Most likely a Qubes issue. As Qubes handles X server. Whonix does not mess with that.

Can you reproduce this outside of Qubes-Whonix using a Debian bookworm based App Qube?

3

I tested both Debian 12 (debian-12-xfce based AppVM) and Fedora 38 (fedora-38-xfce based AppVM) and they both return the same values:

Screen 0: minimum 64 x 64, current 3840 x 1080, maximum 32767 x 32767
DUMMY0 connected primary 1920x1080+1920+0 0mm x 0mm
   QB3840x1080   46.13 +
   QB1920x1080   59.96* 
DUMMY1 connected 1920x1080+0+0 0mm x 0mm
   QB3840x1080   46.13 +
   QB1920x1080   59.96* 
DUMMY2 disconnected
...

Only Whonix 17 is different:

Screen 0: minimum 64 x 64, current 3840 x 1080, maximum 32767 x 32767
DUMMY0 connected primary 3840x1080+0+0 0mm x 0mm
   QB3840x1080   46.13*+
DUMMY1 disconnected
...
4

Weird. Please report this upstream to Qubes.

5

I just found why in the logs. xcvt is not installed in the template but it’s used by Qubes to set the monitors layout. I installed it in my test StandaloneVM and it’s fixed. Is this Qubes related or is it Whonix related?

qubes-gui[866]: Ok, somebody connected.
qubes.SetMonitorLayout-dom0[927]: /etc/qubes-rpc/qubes.SetMonitorLayout: line 20: cvt: command not found
qubes.SetMonitorLayout-dom0[927]: xrandr: failed to parse 'QB1920x1080' as a mode specification
qubes.SetMonitorLayout-dom0[927]: Try 'xrandr --help' for more information.
qubes.SetMonitorLayout-dom0[927]: xrandr: cannot find mode "QB1920x1080"
qubes.SetMonitorLayout-dom0[927]: /etc/qubes-rpc/qubes.SetMonitorLayout: line 20: cvt: command not found
qubes.SetMonitorLayout-dom0[927]: xrandr: failed to parse 'QB1920x1080' as a mode specification
qubes.SetMonitorLayout-dom0[927]: Try 'xrandr --help' for more information.
qubes.SetMonitorLayout-dom0[927]: xrandr: cannot find mode "QB1920x1080"
qubes.SetMonitorLayout-dom0[927]: xrandr: cannot find mode QB1920x1080
6

Not sure. Could be Qubes related as some Qubes meta package is lacking a dependency on xcvt or could be Qubes-Whonix related if it lacks a dependency on a Qubes meta packages which is responsible for this.

So best reported against Qubes to get some input from the developers of this functionality.