Can't find any ALSA soundcard

[tdesaules]

Hello everyone,

I'm developing a small application that requires access to a sound card.

From what I see in the experimental features, there's an option to add an audio device:

audio:
  # EXPERIMENTAL
  # QEMU audiodev, e.g., "none", "coreaudio", "pa", "alsa", "oss".
  # VZ driver, use "vz" as device name
  # Choosing "none" will mute the audio output, and not play any sound.
  # Choosing "default" will pick a suitable choice of: coreaudio, pa, dsound, oss.
  # As of QEMU v6.2 the default is to create a disconnected sound device
  # that is still visible in the guest but not connected to the host.
  # 🟢 Builtin default: ""
  device: null

I'm using a MacBook M3, and I've tested with both vz and qemu, trying the different options available for device without ever getting a sound card in my VM (running Ubuntu and Debian).

I'm using a basic template:

images:
  - location: https://cloud.debian.org/images/cloud/bookworm/latest/debian-12-genericcloud-amd64.qcow2
    arch: x86_64
  - location: https://cloud.debian.org/images/cloud/bookworm/latest/debian-12-genericcloud-arm64.qcow2
    arch: aarch64

vmType: qemu

cpus: 4
memory: 4GiB
disk: 32GiB
networks:
  - lima: bridged

containerd:
  system: false
  user: false

audio:
  device: coreaudio

aplay -L
null
    Discard all samples (playback) or generate zero samples (capture)

Am I missing a configuration step? Or is the feature simply unavailable?

[afbjorklund]

The "device" is what it will use on the host, so it will probably always be "coreaudio" (unless you are running Lima on Linux)

That adds the sound hardware*, then you need to add the sound software inside your distribution of choice - like Ubuntu.

* For now it is hardcoded to "Intel HD Audio", ich9-intel-hda

• Pulseaudio on container #1107

There is a more complete example in template://experimental/alsa, but it probably deserves more info in the manual?

I don't really know what sound hardware that VZ is emulating, but that should probably be added too (device: default)

https://github.com/lima-vm/lima/blob/master/templates/experimental/alsa.yaml

There is one kernel module, and one system package.

---

EDIT: VZ uses virtio for sound / audio (duh). Should add virtio-sound and CONFIG_SND_VIRTIO also to QEMU

-audio driver=coreaudio,model=virtio

[tdesaules]

Indeed, I haven't run all the tests on Ubuntu; I've been searching on Debian... The device is correctly detected with lspci, but I don't have the snd-hda-intel module. I'll look into it, otherwise I'll switch to Ubuntu.
Thank you

[afbjorklund]

Not having much luck with the debian cloud image (as in template://debian), you might have to switch to another image

# CONFIG_SOUND is not set

EDIT: If you switch from "genericcloud" to "generic" image, you will get support for emulation but not paravirtualization:

CONFIG_SOUND=m
CONFIG_SND=m
CONFIG_SND_HDA_INTEL=m
# CONFIG_SND_VIRTIO is not set

commit f92f1a2

- location: https://cloud.debian.org/images/cloud/bookworm/latest/debian-12-generic-arm64.qcow2
  arch: aarch64

[afbjorklund]

It might change in the future, though.

location: https://cloud.debian.org/images/cloud/sid/daily/latest/debian-sid-generic-arm64-daily.qcow2

CONFIG_SND_VIRTIO=m

linux-image-6.12.33+deb13-arm64: /usr/lib/modules/6.12.33+deb13-arm64/kernel/sound/virtio/virtio_snd.ko.xz

---

afb@lima-debian:~$ sudo arecord -l
**** List of CAPTURE Hardware Devices ****
card 0: SoundCard [VirtIO SoundCard], device 0: virtio-snd [VirtIO PCM 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
afb@lima-debian:~$ sudo aplay -l
**** List of PLAYBACK Hardware Devices ****
card 1: SoundCard_1 [VirtIO SoundCard], device 0: virtio-snd [VirtIO PCM 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

I get some trouble when configuring alsa in VZ, though. I get two soundcards, but gets a I/O error on play.

afb@lima-debian:~$ lspci -k
00:0b.0 Multimedia audio controller: Red Hat, Inc. Virtio 1.0 sound (rev 01)
	Subsystem: Red Hat, Inc. Device 0059
	Kernel driver in use: virtio-pci
00:0c.0 Multimedia audio controller: Red Hat, Inc. Virtio 1.0 sound (rev 01)
	Subsystem: Red Hat, Inc. Device 0059
	Kernel driver in use: virtio-pci
afb@lima-debian:~$ cat /proc/asound/card0/id
SoundCard
afb@lima-debian:~$ cat /proc/asound/card1/id
SoundCard_1

/dev/snd/pcmC0D0c
/dev/snd/pcmC1D0p

[afbjorklund]

Hmm, didn't think that through. There is no sound over a SSH connection! It did work in the macOS GUI.
Only in mono (-c 1) and not in stereo (-c 2), but I haven't looked at the VZ config - maybe that is normal.

Certain things are only created in macOS when you log in through the GUI, and doesn't work headless.
So I can't even do a package installation (with installer) on the Mac Mini, without creating a session...

[tdesaules]

I was using the debian image, but using the ubuntu one is also fine in my use case and it seems to work fine (at the end I'm able to emit some sound)