SVM loading with VIRTIO-SND

[aniantre]

1. When launching the Secondary Virtual Machine (SVM) using Crosvm, I encounter the message "No soundcards found" despite having recompiled the Linux kernel (Image) with the CONFIG_SND_VIRTIO=y flag enabled. Does Crosvm lack support for VirtIO sound, or are additional backend configurations required in the Primary Virtual Machine (PVM) to enable VirtIO sound?

2. Instead of Crosvm, can I use Libvirt/Virt-install in the PVM to create and launch the SVM? If yes, would I need to install Libvirt/Virt-install on the PVM? Note that the PVM does not support installing packages via apt.

[eberman-quic]

1. When launching the Secondary Virtual Machine (SVM) using Crosvm, I encounter the message "No soundcards found" despite having recompiled the Linux kernel (Image) with the CONFIG_SND_VIRTIO=y flag enabled. Does Crosvm lack support for VirtIO sound, or are additional backend configurations required in the Primary Virtual Machine (PVM) to enable VirtIO sound?

I haven't tried using virtio-snd, but it seems like it should be supported with crosvm:

https://chromium.googlesource.com/crosvm/crosvm/+/refs/heads/main/devices/src/virtio/snd/

2. Instead of Crosvm, can I use Libvirt/Virt-install in the PVM to create and launch the SVM? If yes, would I need to install Libvirt/Virt-install on the PVM? Note that the PVM does not support installing packages via apt.

We haven't started any efforts yet to add support for Gunyah in libvirt/virt-install.

We have sent a couple RFCs for QEMU, although we'd have to check with Srivatsa about how functional it is with these patches: https://lore.kernel.org/all/20240516143356.1739402-1-quic_svaddagi@quicinc.com/

[quic-pheragu]

1. When launching the Secondary Virtual Machine (SVM) using Crosvm, I encounter the message "No soundcards found" despite having recompiled the Linux kernel (Image) with the CONFIG_SND_VIRTIO=y flag enabled. Does Crosvm lack support for VirtIO sound, or are additional backend configurations required in the Primary Virtual Machine (PVM) to enable VirtIO sound?

I was able to boot a VM with a virtual sound device via crosvm with the above steps.
[ 0.360628][ T1] ALSA device list:
[ 0.360748][ T1] #0: VirtIO SoundCard at pci/0000:00:02.0/virtio1

Can you confirm if the CONFIG_SND_VIRTIO was indeed enabled in the VM image you are using? Also, could you please provide the command you are using to launch the VM via crosvm with virtio-snd?

[aniantre]

@quic-pheragu

When I'm trying to boot up PVM using VM Image (CONFIG_SND_VIRTIO enabled), then I can see:
[ 2.963037] ALSA device list:
[ 2.963686] #0: VirtIO SoundCard at pci/0000:00:02.0/virtio1

But within the PVM, while booting up GVM I'm using the same VM Image( which I used to boot up PVM) , then I can see:
[ 24.952272] ALSA device list:
[ 24.965106] No soundcards found.

The crosvm command I'm using:

/usr/gunyah/crosvm --no-syslog run --disable-sandbox \
--serial=type=stdout,hardware=virtio-console,console,stdin,num=1 \
--serial=type=stdout,hardware=serial,earlycon,num=1 \
--initrd /usr/gunyah/initrd.img --no-rng \
--params "rw root=/dev/ram rdinit=/sbin/init earlyprintk=serial panic=0" \
/usr/gunyah/Image 

I also tried to execute:

/usr/gunyah/crosvm --no-syslog run --disable-sandbox \
--serial=type=stdout,hardware=virtio-console,console,stdin,num=1 \
--serial=type=stdout,hardware=serial,earlycon,num=1 \
--initrd /usr/gunyah/initrd.img --no-rng \
--params "rw root=/dev/ram rdinit=/sbin/init earlyprintk=serial panic=0" \
--device virtio-sound-pci,audiodev=my_audiodev \
--audiodev alsa,id=my_audiodev \
/usr/gunyah/Image

but crosvm doesn't support --device argument

[2024-06-06T04:49:29.240714080+00:00 ERROR crosvm] arg parsing failed: Unrecognized argument: --device
[2024-06-06T04:49:29.253384944+00:00 INFO  crosvm] invalid argument

Also, can we boot up Comprehensive Linux OS in GVM? So that can play audio files (aplay tool) in GVM using aplay tools.

Thanks

[quic-pheragu]

@quic-pheragu

When I'm trying to boot up PVM using VM Image (CONFIG_SND_VIRTIO enabled), then I can see: [ 2.963037] ALSA device list: [ 2.963686] #0: VirtIO SoundCard at pci/0000:00:02.0/virtio1

But within the PVM, while booting up GVM I'm using the same VM Image( which I used to boot up PVM) , then I can see: [ 24.952272] ALSA device list: [ 24.965106] No soundcards found.

The crosvm command I'm using:

/usr/gunyah/crosvm --no-syslog run --disable-sandbox \
--serial=type=stdout,hardware=virtio-console,console,stdin,num=1 \
--serial=type=stdout,hardware=serial,earlycon,num=1 \
--initrd /usr/gunyah/initrd.img --no-rng \
--params "rw root=/dev/ram rdinit=/sbin/init earlyprintk=serial panic=0" \
/usr/gunyah/Image 

I also tried to execute:

/usr/gunyah/crosvm --no-syslog run --disable-sandbox \
--serial=type=stdout,hardware=virtio-console,console,stdin,num=1 \
--serial=type=stdout,hardware=serial,earlycon,num=1 \
--initrd /usr/gunyah/initrd.img --no-rng \
--params "rw root=/dev/ram rdinit=/sbin/init earlyprintk=serial panic=0" \
--device virtio-sound-pci,audiodev=my_audiodev \
--audiodev alsa,id=my_audiodev \
/usr/gunyah/Image

but crosvm doesn't support --device argument

[2024-06-06T04:49:29.240714080+00:00 ERROR crosvm] arg parsing failed: Unrecognized argument: --device
[2024-06-06T04:49:29.253384944+00:00 INFO  crosvm] invalid argument

/usr/gunyah/crosvm --no-syslog run --disable-sandbox --hypervisor gunyah --serial=type=stdout,hardware=virtio-console,console,stdin,num=1 --serial=type=stdout,hardware=serial,earlycon,num=1 --initrd /data/gunyah/initrd.img --hugepages --no-balloon --no-rng --protected-vm-without-firmware --swiotlb 10 --virtio-snd backend=file,playback_path=/data/gunyah,playback_size=400000 --params "rw root=/dev/ram rdinit=/sbin/init\

Can you try using this command with virtio-snd arg instead?

Also, can we boot up Comprehensive Linux OS in GVM? So that can play audio files (aplay tool) in GVM using aplay tools.

With limited memory, I don't think you will be able to boot a full blown linux as a secondary VM.

Thanks

Best Regards!

[aniantre]

@quic-pheragu

Thanks for your quick reply!!

/usr/gunyah/crosvm --no-syslog run --disable-sandbox --hypervisor gunyah --serial=type=stdout,hardware=virtio-console,console,stdin,num=1 --serial=type=stdout,hardware=serial,earlycon,num=1 --initrd /data/gunyah/initrd.img --hugepages --no-balloon --no-rng --protected-vm-without-firmware --swiotlb 10 --virtio-snd backend=file,playback_path=/data/gunyah,playback_size=400000 --params "rw root=/dev/ram rdinit=/sbin/init\

Can you try using this command with virtio-snd arg instead?

Three doubts:

1. in your command, I cannot see the kernel image (Image)
2. --no-balloon arg is not supported
   [2024-06-08T05:25:28.796012240+00:00 ERROR crosvm] arg parsing failed: Unrecognized argument: --no-balloon
3. --virtio-snd arg is not supported

root@qemuarm64:/usr/gunyah# /usr/gunyah/crosvm --no-syslog run --disable-sandbox \
> --hypervisor gunyah \
> --serial=type=stdout,hardware=virtio-console,console,stdin,num=1 \
> --serial=type=stdout,hardware=serial,earlycon,num=1 \
> --initrd ./initrd.img --hugepages --no-rng \
> --protected-vm-without-firmware --swiotlb 10 \
> --params "rw root=/dev/ram rdinit=/sbin/init earlyprintk=serial panic=0" \
> --virtio-snd backend=file,playback_path=/data/gunyah,playback_size=400000 \
> /usr/gunyah/Image
[2024-06-08T05:27:02.268950848+00:00 ERROR crosvm] arg parsing failed: Unrecognized argument: --virtio-snd
[2024-06-08T05:27:02.271552640+00:00 INFO  crosvm] invalid argument

I don't know why --no-balloon and --virtio-snd is not supports here. Is it the crosvm version issue? For me it is crosvm 0.1.0

I followed the scripts (clone and build_crosvm.sh) to build and install crosvm.

But when I tried to build and run crosvm on my host (for x86_64), --virtio-snd arg supports.

I'm curious now, whether --virtio-snd arg is not supported for aarch64?

Best Regards!

[eberman-quic]

Is it the crosvm version issue? For me it is crosvm 0.1.0

FYI -- crosvm devs don't update the version, it's been 0.1.0 since 2017. We'd be compiling from a decently recent source version of crosvm. Source SHA from chromium's repo would be best point of comparison.

The build_crosvm.sh in the support scripts is just enough to demo the existence of Gunyah virtual machines; you probably will want to adjust the build command to add additional features to the VMM. Notably, there's --no-default-features in that build command, which disables audio and balloon support.

[chenshiqin]

Hi, now host is linux and use alsa，guest is linux too，How do I configure crosvm and --virtio-snd so I can play directly in the guest side?

[chenshiqin]

Hi,The sound card information on the host is /dev/snd/pcmC0D0p.How do I configure crosvm and --virtio-snd?

[quic-pheragu]

Hi,The sound card information on the host is /dev/snd/pcmC0D0p.How do I configure crosvm and --virtio-snd?

I quickly tried passing --virtio-snd playback_path=/dev/snd/pcmC0D0p,playback_size=400000 to the crosvm cmd. It seems to enumerate a Soundcard on the VM
[ 0.341903][ T1] ALSA device list:
[ 0.342056][ T1] #0: VirtIO SoundCard at pci/0000:00:02.0/virtio1

Can you try your experiment with this?

[chenshiqin]

您好，您的邮件我已经收到！谢谢！

[chenshiqin]

Hi ，
1、My host environment is as follows：
root@ubuntu:/# ls /dev/snd/pcmC0D0p
/dev/snd/pcmC0D0p
root@ubuntu:/# cat /proc/asound/cards
0 [rockchipes8388 ]: rockchip-es8388 - rockchip-es8388
rockchip-es8388
2、And my croswm cmd as below:
--virtio-snd playback_path=/dev/snd/pcmC0D0p,playback_size=400000

3、my guest side as below:
root@ubuntu:/home/rockchip# ls /dev/snd/
by-path controlC0 pcmC0D0c pcmC0D0p timer

4、When I play music in the guest side: aplay sn.wav, there is no sound, but I play it directly in the host side is normal。

[chenshiqin]

When I play music in the guest side: aplay sn.wav, the sound card in the host side is turned off

[aniantre]

Is it the crosvm version issue? For me it is crosvm 0.1.0

FYI -- crosvm devs don't update the version, it's been 0.1.0 since 2017. We'd be compiling from a decently recent source version of crosvm. Source SHA from chromium's repo would be best point of comparison.

The build_crosvm.sh in the support scripts is just enough to demo the existence of Gunyah virtual machines; you probably will want to adjust the build command to add additional features to the VMM. Notably, there's --no-default-features in that build command, which disables audio and balloon support.

Yes @eberman-quic , You was right. Because --no-default-features was used while building crosvm, audio and balloon support was disabled.

Additionally, crosvm will require shared libraries: libwayland-client and libffi. To get it, did some modifications in build-rootfs-img.sh

I used below command to up GVM using crosvm:

/usr/gunyah/crosvm --no-syslog run --disable-sandbox \
--hypervisor gunyah \
--serial=type=stdout,hardware=virtio-console,console,stdin,num=1 \
--serial=type=stdout,hardware=serial,earlycon,num=1 \
--initrd /usr/gunyah/initrd.img --hugepages --no-balloon --no-rng \
--virtio-snd backend=file,playback_path=/data/gunyah,playback_size=400000 \
--params "rw root=/dev/ram rdinit=/sbin/init earlyprintk=serial panic=0" \
/usr/gunyah/Image

Thanks and Best Regards!!

[quic-pheragu]

When I play music in the guest side: aplay sn.wav, the sound card in the host side is turned off

There could be some input parameters to CrosVM that might have to be tweaked. I am not very familiar with that. Could you please ask this directly on the CrosVM mailing list?

[aniantre]

When I play music in the guest side: aplay sn.wav, the sound card in the host side is turned off

Hi @chenshiqin, are you using aplay tool in PVM or in GVM? If yes, how you managed it to install it on these VMs?
Note: I'm using the Linux kernel image which is generated by scripts provided in repository.