[gentoo-user] Audio stopped working in KVM with libvirtmanager

[gentoo-user] Audio stopped working in KVM with libvirtmanager

[Nikos Chantziaras]

Audio in KVM (qemu) launched through libvirtmanager used to work fine 
last time I used it (about 3 months ago.) There has been lots of updates 
since then, including a switch from Pulseaudio to Pipewire, and 
something along the way broke it. Now I get no sound whatsoever. qemu 
doesn't even show up as an application in the audio mixer, nor in the 
output of "pw-top".

If I launch the VM directly through qemu with:

   qemu-system-x86_64 [...] -audiodev id=audio1,driver=pa

then it works fine. But if I launch it through libvirtmanager, it 
doesn't. Even if I force the use of "-audiodev id=audio1,driver=pa" in 
the XML of the VM in /etc/libvirt/qemu/, it still doesn't work. There's 
no error anywhere, no warning, nothing in the logs.

Does anyone have any idea what to do?

Re: [gentoo-user] Audio stopped working in KVM with libvirtmanager

[Michael]

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On Saturday, 7 May 2022 14:45:06 BST Nikos Chantziaras wrote:
> Audio in KVM (qemu) launched through libvirtmanager used to work fine
> last time I used it (about 3 months ago.) There has been lots of updates
> since then, including a switch from Pulseaudio to Pipewire, and
> something along the way broke it. Now I get no sound whatsoever. qemu
> doesn't even show up as an application in the audio mixer, nor in the
> output of "pw-top".
> 
> If I launch the VM directly through qemu with:
> 
>    qemu-system-x86_64 [...] -audiodev id=audio1,driver=pa
> 
> then it works fine. But if I launch it through libvirtmanager, it
> doesn't. Even if I force the use of "-audiodev id=audio1,driver=pa" in
> the XML of the VM in /etc/libvirt/qemu/, it still doesn't work. There's
> no error anywhere, no warning, nothing in the logs.
> 
> Does anyone have any idea what to do?

I don't use libvirt, but use QEMU from a console.  For the last couple of 
versions I have been getting these sort of notices when I launch a Win10 VM:

ALSA lib /var/tmp/portage/media-libs/alsa-lib-1.2.6.1/work/alsa-lib-1.2.6.1/
src/pcm/pcm.c:8568:(snd_pcm_recover) underrun occurred

I don't have pulseaudio on this PC, only alsa modules and pipewire with 
default settings.  The VM audio works, but it clips.  I haven't looked into it 
yet, because audio in VM is less of an issue for my use case, hence I have no 
useful suggestions (yet).  :-)

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