Bug 514084 - Can't change resolution in a Qemu VM
Summary: Can't change resolution in a Qemu VM
Status: RESOLVED FIXED
Alias: None
Product: kwin
Classification: Plasma
Component: general (other bugs)
Version First Reported In: 6.5.4
Platform: Arch Linux Linux
: NOR minor
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2026-01-02 18:30 UTC by Jonathan
Modified: 2026-01-07 16:41 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed/Implemented In:
Sentry Crash Report:


Attachments
screenshot of settings page in x11 (33.65 KB, image/png)
2026-01-02 18:30 UTC, Jonathan
Details

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Description Jonathan 2026-01-02 18:30:47 UTC
Created attachment 188162 [details]
screenshot of settings page in x11

warning: i am a teen (15) so i do not have much experience in writing formal things.

SUMMARY

Cant change resolution in KDE-plasma X11 and Wayland despite xrandr advertising multiple modes

important note: This is done in a Qemu VM, both virtio and qxl has the same problem and i did not test the others. This has used to work and other older VM's that i have with older KDE versions still do. 

This is not an x11 bug! despite i am primarily showing x11 the same issue happens on Wayland too.

STEPS TO REPRODUCE
1. Install arch linux in a regular way (arch wiki install guide), this includes networking 
2. Update system and install plasma-desktop and select pipewire jack and ffmpeg media.
3. install and enable sddm and launch KDE

OBSERVED RESULT

The screen is locked to the resolution 1280 x 800 and the settings screen does not show alternatives to change, infact it removes the entire display configuration page leaving only nightlight (and compositor in the x11 session). installing gnome and/or other DE/gui's still have working resolution management on the same installation. checking (on the x11 session) xrandr says that the virtual screen actually does support different solutions.

EXPECTED RESULT


SOFTWARE/OS VERSIONS

info center:
Operating System: Arch Linux 
KDE Plasma Version: 6.5.4
KDE Frameworks Version: 6.21.0
Qt Version: 6.10.1
Kernel Version: 6.18.2-zen2-1-zen (64-bit)
Graphics Platform: X11
Processors: 8 Γ— AMD Ryzen 7 7800X3D 8-Core Processor
Memory: 8 GiB of RAM (7.7 GiB usable)
Graphics Processor: llvmpipe
Manufacturer: QEMU
Product Name: Standard PC (Q35 + ICH9, 2009)
System Version: pc-q35-10.1

ADDITIONAL INFORMATION

xrandr output:

Screen 0: minimum 320 x 200, current 1280 x 800, maximum 8192 x 8192
Virtual-1 connected primary 1280x800+0+0 (normal left inverted right x axis y axis) 325mm x 203mm
   1280x800      74.99*+
   5120x2160     50.00  
   4096x2160     50.00  
   3840x2160     60.00    50.00    59.94  
   1920x1440     60.00  
   2560x1080     50.00  
   1856x1392     60.00  
   1792x1344     60.00  
   2048x1152     60.00  
   1920x1200     59.88  
   1920x1080     60.00    50.00  
   1600x1200     60.00  
   1680x1050     59.95  
   1400x1050     59.98  
   1280x1024     60.02  
   1440x900      59.89  
   1280x960      60.00  
   1360x768      60.02  
   1280x768      59.87  
   1024x768      60.00  
   800x600       60.32  
   640x480       60.00    59.94
Comment 1 Jonathan 2026-01-02 18:47:37 UTC
i realize now i forgot the expected result page, im sorry. the expected result is the get the fully functional settings page for display management in kde plasma on both Wayland and x11 and it should be able to change the resolution to all/almost all of the resolutions reported by xrandr
Comment 2 Zamundaaa 2026-01-07 15:41:15 UTC
That looks like you simply forgot to install kscreen?
Comment 3 Jonathan 2026-01-07 15:54:23 UTC
(In reply to Zamundaaa from comment #2)
> That looks like you simply forgot to install kscreen?

thanks, in prevous installations kscreen was installed with the plasma-desktop package. did something change?
Comment 4 Zamundaaa 2026-01-07 16:16:38 UTC
Not that I know of, kscreen has been an "optional" dependency in Arch for a while.
Comment 5 Jonathan 2026-01-07 16:38:43 UTC
(In reply to Zamundaaa from comment #4)
> Not that I know of, kscreen has been an "optional" dependency in Arch for a
> while.

weird, then how come ive never had this issue? ive never needed to install kscreen before
Comment 6 Zamundaaa 2026-01-07 16:40:03 UTC
I don't know. You'll have to ask Arch people about it, we don't do packaging here.
Comment 7 Jonathan 2026-01-07 16:41:08 UTC
(In reply to Zamundaaa from comment #6)
> I don't know. You'll have to ask Arch people about it, we don't do packaging
> here.

Thanks again for your helpπŸ‘‹