Windows QEMU/KVM VM display is not resized with the window

Ask Fedora
1

Hi! I’ve successfully (almost) installed Windows 11 using virt-manager on my Fedora 41 AMD laptop. I did install storage and network virtio drivers as well as virtio guest tools. Clipboard sharing between host and VM works, but unfortunately changing display resolution does not. Resolution within Windows is fixed to 2242x1476 and does not change as I resize the window (I did set “Auto resize VM with window” but that does not change the effect). In my VM settings I have “Video QXL” entry with

<video>
  <model type="qxl" ram="65536" vram="65536" vgamem="16384" heads="1" primary="yes"/>
  <alias name="video0"/>
  <address type="pci" domain="0x0000" bus="0x00" slot="0x01" function="0x0"/>
</video>

In guest Windows 11 device manager I have an entry “Generic Monitor (QXL0001)”, so it seems that the QXL drivers are installed but something is not working. Could anyone help me troubleshoot this? Thank you!

2

Is your monitor a widescreen ? If so, you can increase vgamem:

vgamem="65536"
3

My monitor is a laptop monitor 1920x1200. I just managed to figure it out - I was wrong and the resolution changes when windows is resized, it’s just too large. The reason is that I previously configured Display scaling in my host OS (KDE Plasma) to 125% - which also messes up scaling for the Virtual Machine! If I set scaling back to 100% in the host, and then put the VM into full-screen mode - it correctly resizes it to the native resolution of my physical display - 1920x1200. This is probably a bug in virtmanager/qemu/kvm - I don’t think it should respect the display scaling of the host OS and use the actual pixel size of the viewport. I’m on Wayland.