I have been playing with looking glass and have it mostly working but there are a couple of issues I have not been able to solve myself.
When I use spice to pass through the mouse and keyboard it works but the mouse becomes bound to a box much smaller than the display. In other words, I can move the mouse around but it hits the “edge” long before it gets to the actual edge of the display.
I have audio working but as soon as the looking glass client connects, I lose audio.
The host is Windows 10. The client is Arch Linux.
If there is any additional information you need, please let me know.
Qemu can output audio to ALSA or Pulseaudio directly when using the Intel HDA virtial sound device. SCREAM is also an option which there is even a guide for on the LG wiki. Please have a look around these forums as Qemu and audio have been a problem for many for a long time now and as such there is a ton of threads here on this topic.