Feature Request: Support multi codec for qemu's usb-audio device.
Goal
Support qemu's usb-audio multi
mode for multi-channel audio.
Technical details
Since about 4 years ago qemu's usb-audio device has a multi
mode which supports 7.1 surround sound audio:
https://github.com/qemu/qemu/commit/3e44607e9394ca08f8672bffa045d2462a371bbc
Currently the only way to use this from libvirt is by configuring something along the lines of
<qemu:commandline>
<qemu:arg value='-device'/>
<qemu:arg value='{"driver":"usb-audio","id":"sound1","bus":"usb.0","port":"15","audiodev":"audio1","multi":true}'/>
</qemu:commandline>
The XHCI USB controller and the audio1
device are configured through normal libvirt XML.
One annoying issue with this is figuring out the name of the USB bus. Another is that libvirt does not track the usage of the USB port that this usb-audio device occupies, leading to errors if you set up (in this case) more than 14 other USB devices in libvirt XML.
Libvirt already supports the usb-audio device in stereo mode.
It would be nice if we could simply configure the usb-audio device with a multi
codec in libvirt XML.