I used this guide when first created sys-audio with f37:
combining with my approach of using minimal templates after creating sys-audio and comparing with other resources here. After that, with f38 and f39, I use simple export list of packages from such created f37-minimal sys-audio template, and install that list into newer fedora-minimal version. After that create new sys-audio based on it with autostart pulseaudio .desktop files in it from the guide above, delete the old one, and no problem.
It always worked out of the box when playback was. I never needed to use microphone until now, though. I have Headphone/microphone combo port and web camera with integrated microphone. I need the latter one to work, obviously. Web camera works when attached to VM: video and playback, but the other part can’t hear me, because no microphone is detected in sys-audio’s pavucontrol.
But, ran into new issues while wildly experimenting. Now I have f39 sys-audio, and it doesn’t receive any stream from outside. Tried with f38 backup, with xfce, nope. At least with f38 I didn’t change anything, so it should work, but no. Which makes me think it’s now something with dom0, and I didn’t do there anything except changing audiovm prefs of other VMs while trying… Even tried to recreate sys-audio from scratch following the guide above. Nope. So, now nothing works except sound in sys-audio itself.
But please if you have any ideas regarding microphone meanwhile, post it here.
EDIT: playback resolved. Somehow, now I needed this line 50-sys-audio.policy, although can’t remember why would I touch the policy, let alone the line at all
admin.vm.feature.CheckWithTemplate +audio-model sys-audio @tag:audiovm-sys-audio allow target=dom0