Added the callback for writing audio using AUD_write. The callback uses two helper functions for reading the buffers from the streams and handling the buffers that were written. initialized the SWVoiceOut using this callback.
Signed-off-by: Shreyansh Chouhan <chouhan.shreyansh2...@gmail.com> --- hw/audio/virtio-snd.c | 254 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 248 insertions(+), 6 deletions(-) diff --git a/hw/audio/virtio-snd.c b/hw/audio/virtio-snd.c index 5ed8e524a6..b74c9e4a1f 100644 --- a/hw/audio/virtio-snd.c +++ b/hw/audio/virtio-snd.c @@ -476,6 +476,248 @@ static int virtio_snd_pcm_get_nelems(virtio_snd_pcm_stream *st) + !!(st->buffer_bytes % st->period_bytes); } +static uint32_t virtio_snd_pcm_get_buf_pos(virtio_snd_pcm_stream *st, + uint32_t dir) +{ + return (dir == VIRTIO_SND_D_OUTPUT) ? st->w_pos : st->r_pos; +} + +static uint32_t virtio_snd_pcm_get_curr_elem(virtio_snd_pcm_stream *st, + uint32_t dir) +{ + uint32_t pos; + int nelems; + + nelems = virtio_snd_pcm_get_nelems(st); + pos = virtio_snd_pcm_get_buf_pos(st, dir); + + return (pos / st->period_bytes) % nelems; +} + +static uint32_t virtio_snd_pcm_get_curr_elem_cap(virtio_snd_pcm_stream *st, + uint32_t dir) +{ + uint32_t cap_bytes; + int i; + + i = virtio_snd_pcm_get_curr_elem(st, dir); + + if (dir == VIRTIO_SND_D_OUTPUT) + cap_bytes = iov_size(st->elems[i]->out_sg, st->elems[i]->out_num) + - sizeof(virtio_snd_pcm_xfer); + else + cap_bytes = iov_size(st->elems[i]->in_sg, st->elems[i]->in_num) + - sizeof(virtio_snd_pcm_status); + + return cap_bytes; +} + +static uint32_t virtio_snd_pcm_get_curr_elem_used(virtio_snd_pcm_stream *st, + uint32_t dir) +{ + uint32_t pos; + + pos = virtio_snd_pcm_get_buf_pos(st, dir); + + return pos % st->period_bytes; +} + +static uint32_t virtio_snd_pcm_get_curr_elem_free(virtio_snd_pcm_stream *st, + uint32_t dir) +{ + uint32_t free_bytes, used; + + used = virtio_snd_pcm_get_curr_elem_used(st, dir); + free_bytes = virtio_snd_pcm_get_curr_elem_cap(st, dir) - used; + + return free_bytes; +} + +/* + * Get the size in bytes of the buffer that still has to be written. + * + * @st: virtio sound pcm stream + */ +static uint32_t virtio_snd_pcm_get_pending_bytes(virtio_snd_pcm_stream *st) +{ + return (st->direction == VIRTIO_SND_D_OUTPUT) ? + st->r_pos - st->w_pos : + st->w_pos - st->r_pos; +} + +static uint32_t virtio_snd_pcm_get_buf_to_proc(virtio_snd_pcm_stream *st, + size_t size) +{ + uint32_t to_proc, elem_free; + + elem_free = virtio_snd_pcm_get_curr_elem_free(st, st->direction); + to_proc = MIN(elem_free, size); + + return to_proc; +} + +static void virtio_snd_pcm_update_buf_pos(virtio_snd_pcm_stream *st, uint32_t dir, + uint32_t size) +{ + if (dir == VIRTIO_SND_D_OUTPUT) + st->w_pos += size; + else + st->r_pos += size; +} + +/* + * Get data from a stream of the virtio sound device. Only reads upto the + * end of the current virtqueue element. Returns the number of bytes read. + * + * @buffer: Write to this buffer + * @size: The number of bytes to read + * @st: VirtIOSound card stream + * @offset: Start reading from this offseta in the stream (in bytes) + */ +static size_t virtio_snd_pcm_buf_read(void *buf, size_t to_read, + virtio_snd_pcm_stream *st) +{ + size_t sz; + int i, used; + + used = virtio_snd_pcm_get_curr_elem_used(st, st->direction); + i = virtio_snd_pcm_get_curr_elem(st, st->direction); + + sz = iov_to_buf(st->elems[i]->out_sg, st->elems[i]->out_num, + sizeof(virtio_snd_pcm_xfer) + used, buf, to_read); + + assert(sz == to_read); + return sz; +} + +/* + * Marks an element as used, pushes it to queue and notifies the device. + * Also frees the element + */ +static void virtio_snd_pcm_handle_elem_used(virtio_snd_pcm_stream *st) +{ + int elem_size, i; + size_t sz, offset; + + virtio_snd_pcm_status status; + status.status = VIRTIO_SND_S_OK; + status.latency_bytes = 0; + + i = virtio_snd_pcm_get_curr_elem(st, st->direction); + elem_size = iov_size(st->elems[i]->out_sg, st->elems[i]->out_num) + + iov_size(st->elems[i]->in_sg, st->elems[i]->in_num); + offset = iov_size(st->elems[i]->in_sg, st->elems[i]->in_num) + - sizeof(virtio_snd_pcm_status); + + sz = iov_from_buf(st->elems[i]->in_sg, st->elems[i]->in_num, offset, + &status, sizeof(status)); + assert(sz == sizeof(virtio_snd_pcm_status)); + + virtqueue_push(st->s->tx_vq, st->elems[i], elem_size); + virtio_notify(VIRTIO_DEVICE(st->s), st->s->tx_vq); + + g_free(st->elems[i]); + st->elems[i] = NULL; +} + +/* + * Handle a buffer after it has been written by AUD_write. + * It writes the status for the I/O messages that have been completed and + * marks the tx virtqueue elmenets as used. It notifies the device + * about I/O completion. Returns the number of bytes handled. + * + * @st: VirtIOSound card stream + * @size: Size that was written by AUD_write + * If size = 0, write for the last element failed + */ +static size_t virtio_snd_pcm_handle_used(virtio_snd_pcm_stream *st, + size_t size) +{ + if (size == 0) + // error + return 0; + + size_t used, elem_buf_size; + + used = virtio_snd_pcm_get_curr_elem_used(st, st->direction); + elem_buf_size = virtio_snd_pcm_get_curr_elem_cap(st, st->direction); + + if (used + size == elem_buf_size) + virtio_snd_pcm_handle_elem_used(st); + + virtio_snd_pcm_update_buf_pos(st, st->direction, size); + + return size; +} + +/* + * Writes upto the end of the current virtqueue element. + * Returns the numbre of bytes written. + * + * @st: Virtio sound card stream + * @size: Number of bytes to write to HWVoiceOut + */ +static size_t write_audio(virtio_snd_pcm_stream *st, + uint32_t size) +{ + size_t to_write, handled, written; + void *mixbuf; + + to_write = virtio_snd_pcm_get_buf_to_proc(st, size); + mixbuf = g_malloc0(to_write); + to_write = virtio_snd_pcm_buf_read(mixbuf, to_write, st); + written = AUD_write(st->voice.out, mixbuf, to_write); + handled = virtio_snd_pcm_handle_used(st, written); + assert(handled == written); + + g_free(mixbuf); + return written; +} + +/* + * Callback for AUD_open_out. + * Reads a buffer from the VirtIOSound card stream and writes it + * using AUD_write. + * + * @opaque: VirtIOSound card stream + * @free: Size in bytes that can be written via AUD_write + */ +static void virtio_snd_output_cb(void *opaque, int free) +{ + int to_play, pending; + virtio_snd_pcm_stream *st = opaque; + int written = 0; + + pending = virtio_snd_pcm_get_pending_bytes(st); + + if (!pending && st->flushing) { + st->flushing = false; + + if (st->direction == VIRTIO_SND_D_OUTPUT) + AUD_set_active_out(st->voice.out, false); + else + AUD_set_active_in(st->voice.in, false); + return; + } + + to_play = MIN(free, pending); + + virtio_snd_log("to_play: %d, free: %d, pending: %d\n", to_play, free, pending); + while (to_play) { + int wbytes = write_audio(st, to_play); + + if (!wbytes) + break; + + to_play -= wbytes; + free -= wbytes; + written += wbytes; + pending -= wbytes; + } + + virtio_snd_log("written: %d\n", written); +} + /* * Prepares a VirtIOSound card stream. * Returns a virtio sound status (VIRTIO_SND_S_*). @@ -537,12 +779,12 @@ static uint32_t virtio_snd_pcm_prepare_impl(VirtIOSound *s, uint32_t stream) virtio_snd_get_qemu_audsettings(&as, params); if (st->direction == VIRTIO_SND_D_OUTPUT) { - /* st->voice.out = AUD_open_out(&s->card, - * st->voice.out, - * "virtio_snd_card", - * st, - * virtio_snd_output_cb, &as); - */ + st->voice.out = AUD_open_out(&s->card, + st->voice.out, + "virtio_snd_card", + st, + virtio_snd_output_cb, &as); + } else { /* st->voice.in = AUD_open_in(&s->card, * st->voice.in, -- 2.31.1