-audiodev 'driver=pa' support

[effects_studio]

Dear Proxmox creators and Community,

first of all, thank you for building such a great product. Here is context of what I'm doing
I'm an owner of effects studio in California and am considering buying it to optimize capacity of machinces that my employees use.
They currently run 32 medium-sized boxes(8 core overclocked intels) with operation systems installed dirrectly on them. This creates two kinds of hassle: backups&restores are hard(employees screw up something from time to time) and most of boxes do nothing frequently(the kind of load we do is very bursty and scales well across cores)

I'm looking to replace current set of boxes with 8 boxes of ThreadRipper 3970x with Proxmox installed on them that would be virtualizing OS-es for employees, making it easy to do backups and replication as well as providing more burst capacity for computations.

I'm currently assembling the first box for this and I ran into a problem: it seems that the qemu provided in Proxmox doesn't support pulseaudio output, only alsa, despite pulseadio getting substantial improvements for low-latency applications in qemu 4.1.
Would it be possible to enable build flag by proxmox to support pulseaudio? This is literally the last thing stopping me deploying Proxmox(and buying 8 licences).

 

[effects_studio]

Here is why I believe it was disabled at build time.

$ /usr/bin/qemu-system-x86_64 -audio-help


Environment variable based configuration deprecated.

Please use the new -audiodev option.


Equivalent -audiodev to your current environment variables:

(Since you didn't specify QEMU_AUDIO_DRV, I'll list all possibilities)

-audiodev id=alsa,driver=alsa

-audiodev id=none,driver=none

Compared with current ubuntu box where it also shows `id=pa` one.

https://github.com/qemu/qemu/blob/8e5943260a8f765216674ee87ce8588cc4e7463e/qemu-options.hx#L477-L481

suggests that CONFIG_AUDIO_PA wasn't passed at build time, unlike in ubuntu qemu.
Would it be possible to enable this flag in Proxmox build system?

 

[spirit]

@effects_studio

Hi,

I have rebuild qemu package with adding pa backend

- --audio-drv-list="alsa" \
+ --audio-drv-list="alsa,pa" \


http://odisoweb1.odiso.net:/pve-qemu-kvm_4.1.1-2_amd64.deb

can you test it ?

 

[d_swague]

Hi, I'm also trying to get sound from my guests to the host via pulseaudio.

@spirit : I've tried your build, which by now is a downgrade to 4.1.1_4, but I don't expect it to matter a lot.

My findings:

1) The package depends on 2 binaries in /usr/sbin: start-stop-daemon and ldconfig, while /usr/sbin isn't a part of $PATH. I symlinked them to /usr/bin to allow dpkg to continue.

2) The driver seems to have been added, but it can't initialize:
pulseaudio: pa_context_connect() failed
pulseaudio: Reason: Connection refused
pulseaudio: Failed to initialize PA contextaudio: Could not init pa audio driver

I've followed the advice from a reddit page to get it to initialize.

Then qemu complained about not being able to apply my hda device rule:

-device ich9-intel-hda,bus=pcie.0,addr=0x1b

I just copied this from the Arch wiki, honestly not knowing exactly what it's supposed to do, other than adding a virtual sound card to the guest.

I thought that I cached the exact error message, but I didn't... If it's useful to you, I can do it again (for now I've already reverted to the stock pve-qemu-kvm).

3) Not related to your package: I've tried with -soundhw and this shows an extra soundcard in the guest, however I'm not able to get it through the hosts's speakers. I got this from another thread on this forum, but without success in my case.

@effects_studio: have you got this working, and if so, do you mind sharing the args you've used for this so I can compare it to mine?

Thank you both!

 

[fabian]

@aaron did some work recently on integrating more audio hardware into our qemu-server package, maybe he can take a look at PA as well