QEMU surface contents not updating when immediately unfocused

[cedws]

• Sway Version:
  v1.5

• Configuration File:
  Reproducible with default.

• Description:
  When QEMU (v5.1.0) is started and immediately unfocused, the surface contents do not update again until the surface is focused again or fullscreened. QEMU will continue to display Guest has not initialized the display (yet). As far as I can tell, it is running under Wayland because I see "shell": "xdg_shell" from swaymsg -t get_tree.

Steps to reproduce:

• Run qemu-system-x86_64
• Ensure the QEMU window is unfocused immediately
• Observe that the QEMU window continues to display Guest has not initialized the display (yet) until it is refocused

[emersion]

Can you post a WAYLAND_DEBUG=client log?

[cedws]

https://gist.github.com/cedws/d9c4de5ecfd6dd207ee550a2359e9601

The output hangs around line 122 until refocused. Also,

[863008.205]  -> xdg_toplevel@29.set_title("QEMU [Paused]")

looks interesting. Could it be that this is because QEMU is pausing itself (or maybe that's just because I'm initialising a VM with nothing to do),