Implement VirtIO sound device #53

Cuda-Chen · 2024-08-31T08:17:47Z

Implement VirtIO sound device supporting these operations (the item with checked box checked means it is implemented right now):

For setting up the device:
- VIRTIO_SND_R_JACK_INFO
- VIRTIO_SND_R_PCM_INFO
- VIRTIO_SND_R_CHMAP_INFO
For playing the sound (PCM):
- VIRTIO_SND_R_PCM_SET_PARAMS
- VIRTIO_SND_R_PCM_PREPARE
- VIRTIO_SND_R_PCM_RELEASE
- VIRTIO_SND_R_PCM_START
- VIRTIO_SND_R_PCM_STOP

Test Cases

The test cases are subjected to be altered.

boot up test

test procedures

Execute make check to run semu.
Check kernel message (dmesg).

expected results

The following message should appear while booting up:

[    4.011962] ALSA device list:
[    4.015962]   #0: Loopback 1
[    4.015962]   #1: VirtIO SoundCard at platform/f4400000.virtio/virtio2

check driver configuration

test procedures

Execute aplay -l in emulator.
Check the output messages.

expected results

The following message should appear after Step 1:

$ aplay -l          
**** List of PLAYBACK Hardware Devices ****

<other sound device here>

card 1: SoundCard [VirtIO SoundCard], device 0: virtio-snd [VirtIO PCM 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

play sound

test procedures

Execute speaker-test in emulator.
Check the host speaker.

expected results

A white noise will be played by host speaker while speaker-test is executing.

shengwen-tw · 2024-08-31T09:06:12Z

Please provide testing procedures once the change is ready.

CNFA_sf.h

virtio-snd.c

configs/linux.config

os_generic.h

Makefile

configs/linux.config

virtio-snd.c

jserv

Run clang-format before submitting.

.gitmodules

Makefile

jserv

Consult https://github.com/cntools/cnfa/blob/master/.github/workflows/build-cnfa.yml and mention the build dependency in top-level README.md.

configs/linux.config

feature.h

README.md

configs/linux.config

jserv · 2024-10-02T03:59:08Z

Execute speaker-test in emulator.
Check the host speaker.
expected results
A white noise will be played by host speaker while speaker-test is executing.

What features or functionalities are missing that prevent aplay from playing wave files?

Cuda-Chen · 2024-10-02T08:14:47Z

What features or functionalities are missing that prevent aplay from playing wave files?

For my understanding and observation, two things are missing:

sound card: While aplay selects a sound card, there is no information regarding the VirtIO SoundCard at platform/f4400000.virtio/virtio2.
PCM: aplay triggers PCM related function to play sound. However, for virtio-snd, I am still working on the PCM part (VIRTIO_SND_R_PCM_*) especially filling the buffer to ALSA.

virtio-snd.c

jserv · 2024-11-16T15:21:47Z

virtio-snd.c

@@ -799,6 +790,8 @@ static int virtio_snd_tx_desc_handler(virtio_snd_state_t *vsnd,
    /* End of critical seciont. */
    pthread_mutex_unlock(&virtio_snd_mutex);

+    sleep(1);


Why sleep(1) here?

Just for debugging usage, and I will remove the sleep(1) once I find the root cause of infinite loop of receiving frames from driver.

Enable ALSA driver and System V IPC in Linux Kernel. For ALSA, the debug is enabled and will be removed once this commit is ready. Add description of descriptor chaining, yet need refactoring the description as well as code (exists uncertainty of the query struct). Succeed to initialize virtio-snd. Handle requests in control and TX queue, and print the address and length of each virtq element to check the validness of self-implement queue. For macOS, an experimental core audio library check is implemented. As the driver sends the PCM frames asynchronously, use a dedicated thread for receiving frames from driver. Need to let the thread become a thread pool so that we don't need to create the thread everytime when we try to receive frames from driver. As such, the pcm_release state is sent asynchronously, need to address this later.

Consume incoming PCM frames and save nothing for debug.

Cuda-Chen force-pushed the add-virtio-snd branch from 4a8a6fc to 0902227 Compare August 31, 2024 08:21

jserv requested a review from shengwen-tw August 31, 2024 08:59

jserv reviewed Aug 31, 2024

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jserv reviewed Aug 31, 2024

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Cuda-Chen force-pushed the add-virtio-snd branch from 0902227 to ebba2c7 Compare September 1, 2024 06:05