Wayland - hpaluch/hpaluch.github.io GitHub Wiki

Wayland

Here are my notes on Wayland (mostly issues).

Wayland KVM problems

virtio-gl acceleration problems

Under KVM we have 3 options for graphics acceleration of Guest (VM):

  • QXL - works best (2D+Video streaming acceleration), therefore RedHat dropped it from RHEL 9: https://bugzilla.redhat.com/show_bug.cgi?id=2030592 There is real risk that other distributions will follow them...
  • Virtio without GL (OpenGL acceleration): OpenGL terminal alacritty is terribly slow (after ENTER it takes 1 second before it will scroll with command results). However other applications (Firefox, LibreOffice) work good enough
  • Virtio with GL support (also knownn as virgl):
    • alacritty terminal is fast. But other applications (non OpenGL) - Firefox, etc. are terribly slow (like 1 fps)
    • additionally mouse is completely screwed - very sluggish and at wrong position (click will target different position than mouse cursor)

There already exists honest and sad story regarding these issues on YouTube:

Found workaround for VirGL + 3D:

  • GTK4 applications (ptyxis, etc.) shows many rendering artifacts
  • here is workaround that works for me (tested under Fedora 42 Beta + GNOME): 
    # GDK_DEBUG is optional - the fix is in GDK_GL_DISABLE
GDK_DEBUG=opengl GDK_GL_DISABLE=base-instance ptyxis

virt-viewer does not release mouse

Hit with that on Fedora 41 GNOME (Wayland) + virt-viewer (VM running on remote Proxmox VE host)

  • Ctrl-Alt-R will release keyboard focus but still holds mouse (pointer not visible)
  • only way to escape that trap is to press Alt-Tab (right after keyboard release) and kill virt-viewer from other terminal (!)

Related reports: