Re: [virtio-comment] virtio-sound linux driver conformance to spec

[Matias Ezequiel Vara Larsen <mvaralar@redhat.com>]

On Wed, Sep 13, 2023 at 06:58:30PM +0300, Manos Pitsidianakis wrote:
> Hello Matias,
> 
> Please show and refer to code snippets from the kernel tree that you
> think are related to your question. It'd help us make sure we all talk
> about the same thing.
> 

In this discussion, I am referring to the way in which the virtio-sound
driver is manipulating buffers that have been consumed by the device,
e.g., used-ring in the tx queue. My understanding is the driver builds a
ring-buffer that is shared with the user application in the guest. As
soon as the device returns a buffer to the used ring, the driver puts
the request in the available ring again. This is my understanding from
sound/virtio/virtio_pcm_msg.c#L324. The user application updates the
content of the buffer at sound/virtio/virtio_pcm_msg.c#L322, but this
task is deferred by using schedule_work(). The update of the buffer may
happen once the buffers are already in the available ring.

Thanks, Matias.