Am 13.09.23 um 09:33 schrieb Emmanouil Pitsidianakis:
> To perform audio capture we duplicate the TX logic of the previous
> commit with the following difference: we receive data from the QEMU
> audio backend and write it in the virt queue IO buffers the guest sends
> to QEMU. When they are full (i.e. they have `period_bytes` amount of
> data) or when recording stops in QEMU's audio backend, the buffer is
> returned to the guest by notifying it.
>
> Signed-off-by: Emmanouil Pitsidianakis <manos.pitsidiana...@linaro.org>
> ---
> hw/virtio/trace-events | 3 +-
> hw/virtio/virtio-snd.c | 233 +++++++++++++++++++++++++++++++++++++----
> 2 files changed, 213 insertions(+), 23 deletions(-)
> diff --git a/hw/virtio/virtio-snd.c b/hw/virtio/virtio-snd.c
> index 6fe03f9790..1d3a001371 100644
> --- a/hw/virtio/virtio-snd.c
> +++ b/hw/virtio/virtio-snd.c
> @@ -1048,26 +1131,133 @@ static void virtio_snd_pcm_out_cb(void *data, int
> available)
> }
>
> /*
> - * Flush all buffer data from this stream's queue into the driver's virtual
> - * queue.
> + * AUD_* input callback.
> *
> - * @stream: VirtIOSoundPCMStream *stream
> + * @data: VirtIOSoundPCMStream stream
> + * @available: number of bytes that can be read with AUD_read()
> */
> -static void virtio_snd_pcm_flush(VirtIOSoundPCMStream *stream)
> +static void virtio_snd_pcm_in_cb(void *data, int available)
> {
> + VirtIOSoundPCMStream *stream = data;
> VirtIOSoundPCMBlock *block;
> - VirtIOSoundPCMBlock *next;
> + virtio_snd_pcm_status resp = { 0 };
> + size_t size;
>
> WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
> - QSIMPLEQ_FOREACH_SAFE(block, &stream->queue, entry, next) {
> - AUD_write(stream->voice.out, block->data + block->offset,
> block->size);
> - virtqueue_push(block->vq, block->elem, sizeof(block->elem));
> - virtio_notify(VIRTIO_DEVICE(stream->s), block->vq);
> - QSIMPLEQ_REMOVE(&stream->queue, block, VirtIOSoundPCMBlock,
> entry);
> + while (!QSIMPLEQ_EMPTY(&stream->queue)) {
> + block = QSIMPLEQ_FIRST(&stream->queue);
> +
> + for (;;) {
> + size = AUD_read(stream->voice.in,
> + block->data + block->size,
> + MIN(available, (stream->params.period_bytes -
> block->size)));
> + if (!size) {
> + available = 0;
> + break;
> + }
> + block->size += size;
> + available -= size;
> + if (block->size >= stream->params.period_bytes) {
> + resp.status = cpu_to_le32(VIRTIO_SND_S_OK);
> + resp.latency_bytes = 0;
> + /* Copy data -if any- to guest */
> + iov_from_buf(block->elem->in_sg,
> + block->elem->in_num,
> + 0,
> + block->data,
> + stream->params.period_bytes);
> + iov_from_buf(block->elem->in_sg,
> + block->elem->in_num,
> + block->size,
> + &resp,
> + sizeof(resp));
> + virtqueue_push(block->vq,
> + block->elem,
> + sizeof(block->elem));
Hi Manos,
if I'm not completely mistaken, the third argument of a virtqueue_push()
call is the size of the message copied into the virtio ring buffer, not
the size of a pointer. As I wrote for the v8 series, the other
virtqueue_push() calls also don't look right.
With best regards,
Volker
> + virtio_notify(VIRTIO_DEVICE(stream->s),
> + block->vq);
> + QSIMPLEQ_REMOVE_HEAD(&stream->queue, entry);
> + virtio_snd_pcm_block_free(block);
> + break;
> + }
> + if (!available) {
> + break;
> + }
> + }
> + if (!available) {
> + break;
> + }
> }
> }
> }
>
