@@ -171,3 +171,5 @@ virtio_snd_handle_pcm_release(uint32_t stream) "VIRTIO_SND_PCM_RELEASE called fo
virtio_snd_handle_code(uint32_t val, const char *code) "ctrl code msg val = %"PRIu32" == %s"
virtio_snd_handle_chmap_info(void) "VIRTIO_SND_CHMAP_INFO called"
virtio_snd_handle_event(void) "event queue callback called"
+virtio_snd_pcm_stream_flush(uint32_t stream) "flushing stream %"PRIu32
+virtio_snd_handle_xfer(void) "tx/rx queue callback called"
@@ -32,6 +32,10 @@
#define VIRTIO_SOUND_CHMAP_DEFAULT 0
#define VIRTIO_SOUND_HDA_FN_NID 0
+static void virtio_snd_pcm_out_cb(void *data, int available);
+static void virtio_snd_process_cmdq(VirtIOSound *s);
+static void virtio_snd_pcm_flush(VirtIOSoundPCMStream *stream);
+
static uint32_t supported_formats = BIT(VIRTIO_SND_PCM_FMT_S8)
| BIT(VIRTIO_SND_PCM_FMT_U8)
| BIT(VIRTIO_SND_PCM_FMT_S16)
@@ -123,6 +127,13 @@ virtio_snd_set_config(VirtIODevice *vdev, const uint8_t *config)
}
+static void
+virtio_snd_pcm_buffer_free(VirtIOSoundPCMBuffer *buffer)
+{
+ g_free(buffer->elem);
+ g_free(buffer);
+}
+
static void
virtio_snd_ctrl_cmd_free(virtio_snd_ctrl_command *cmd)
{
@@ -392,66 +403,88 @@ static void virtio_snd_get_qemu_audsettings(audsettings *as,
/*
* Close a stream and free all its resources.
*
* @stream: VirtIOSoundPCMStream *stream
*/
static void virtio_snd_pcm_close(VirtIOSoundPCMStream *stream)
{
+ if (stream) {
+ if (stream->info.direction == VIRTIO_SND_D_OUTPUT) {
+ virtio_snd_pcm_flush(stream);
+ AUD_close_out(&stream->pcm->snd->card, stream->voice.out);
+ stream->voice.out = NULL;
+ }
+ }
}
/*
* Prepares a VirtIOSound card stream.
* Returns the response status code. (VIRTIO_SND_S_*).
*
* @s: VirtIOSound device
* @stream_id: stream id
*/
static uint32_t virtio_snd_pcm_prepare(VirtIOSound *s, uint32_t stream_id)
{
audsettings as;
virtio_snd_pcm_set_params *params;
VirtIOSoundPCMStream *stream;
if (s->pcm->streams == NULL ||
s->pcm->pcm_params == NULL ||
stream_id >= s->snd_conf.streams) {
return cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
}
params = virtio_snd_pcm_get_params(s, stream_id);
if (params == NULL) {
return cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
}
stream = virtio_snd_pcm_get_stream(s, stream_id);
if (stream == NULL) {
stream = g_new0(VirtIOSoundPCMStream, 1);
stream->active = false;
stream->id = stream_id;
stream->pcm = s->pcm;
stream->s = s;
+ qemu_mutex_init(&stream->queue_mutex);
+ QSIMPLEQ_INIT(&stream->queue);
+ QSIMPLEQ_INIT(&stream->invalid);
/*
* stream_id >= s->snd_conf.streams was checked before so this is
* in-bounds
*/
s->pcm->streams[stream_id] = stream;
}
virtio_snd_get_qemu_audsettings(&as, params);
stream->info.direction = stream_id < s->snd_conf.streams / 2 +
(s->snd_conf.streams & 1) ? VIRTIO_SND_D_OUTPUT : VIRTIO_SND_D_INPUT;
stream->info.hdr.hda_fn_nid = VIRTIO_SOUND_HDA_FN_NID;
stream->info.features = 0;
stream->info.channels_min = 1;
stream->info.channels_max = as.nchannels;
stream->info.formats = supported_formats;
stream->info.rates = supported_rates;
stream->params = *params;
stream->positions[0] = VIRTIO_SND_CHMAP_FL;
stream->positions[1] = VIRTIO_SND_CHMAP_FR;
stream->as = as;
+ if (stream->info.direction == VIRTIO_SND_D_OUTPUT) {
+ stream->voice.out = AUD_open_out(&s->card,
+ stream->voice.out,
+ "virtio-sound.out",
+ stream,
+ virtio_snd_pcm_out_cb,
+ &as);
+ AUD_set_volume_out(stream->voice.out, 0, 255, 255);
+ } else {
+ qemu_log_mask(LOG_UNIMP, "virtio_snd: input/capture is unimplemented.");
+ }
+
return cpu_to_le32(VIRTIO_SND_S_OK);
}
@@ -503,93 +536,136 @@ static void virtio_snd_handle_pcm_prepare(VirtIOSound *s,
/*
* Handles VIRTIO_SND_R_PCM_START.
*
* @s: VirtIOSound device
* @cmd: The request command queue element from VirtIOSound cmdq field
* @start: whether to start or stop the device
*/
static void virtio_snd_handle_pcm_start_stop(VirtIOSound *s,
virtio_snd_ctrl_command *cmd,
bool start)
{
VirtIOSoundPCMStream *stream;
virtio_snd_pcm_hdr req;
uint32_t stream_id;
size_t msg_sz = iov_to_buf(cmd->elem->out_sg,
cmd->elem->out_num,
0,
&req,
sizeof(virtio_snd_pcm_hdr));
if (msg_sz != sizeof(virtio_snd_pcm_hdr)) {
qemu_log_mask(LOG_GUEST_ERROR,
"%s: virtio-snd command size incorrect %zu vs \
%zu\n", __func__, msg_sz, sizeof(virtio_snd_pcm_hdr));
cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
return;
}
stream_id = le32_to_cpu(req.stream_id);
cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_OK);
trace_virtio_snd_handle_pcm_start_stop(start ? "VIRTIO_SND_R_PCM_START" :
"VIRTIO_SND_R_PCM_STOP", stream_id);
+
stream = virtio_snd_pcm_get_stream(s, stream_id);
- if (stream == NULL) {
- error_report("Invalid stream id: %"PRIu32, req.stream_id);
+ if (stream) {
+ WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
+ stream->active = start;
+ }
+ if (stream->info.direction == VIRTIO_SND_D_OUTPUT) {
+ AUD_set_active_out(stream->voice.out, start);
+ }
+ } else {
+ error_report("Invalid stream id: %"PRIu32, stream_id);
cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
return;
}
stream->active = start;
}
/*
- * Handles VIRTIO_SND_R_PCM_RELEASE. Releases the buffer resources allocated to
- * a stream.
+ * Returns the number of I/O messages that are being processed.
+ *
+ * @stream: VirtIOSoundPCMStream
+ */
+static size_t virtio_snd_pcm_get_io_msgs_count(VirtIOSoundPCMStream *stream)
+{
+ VirtIOSoundPCMBuffer *buffer, *next;
+ size_t count = 0;
+
+ WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
+ QSIMPLEQ_FOREACH_SAFE(buffer, &stream->queue, entry, next) {
+ count += 1;
+ }
+ QSIMPLEQ_FOREACH_SAFE(buffer, &stream->invalid, entry, next) {
+ count += 1;
+ }
+ }
+ return count;
+}
+
+/*
+ * Handles VIRTIO_SND_R_PCM_RELEASE.
*
* @s: VirtIOSound device
* @cmd: The request command queue element from VirtIOSound cmdq field
*/
static void virtio_snd_handle_pcm_release(VirtIOSound *s,
virtio_snd_ctrl_command *cmd)
{
uint32_t stream_id;
VirtIOSoundPCMStream *stream;
size_t msg_sz = iov_to_buf(cmd->elem->out_sg,
cmd->elem->out_num,
sizeof(virtio_snd_hdr),
&stream_id,
sizeof(stream_id));
if (msg_sz != sizeof(stream_id)) {
/*
* TODO: do we need to set DEVICE_NEEDS_RESET?
*/
qemu_log_mask(LOG_GUEST_ERROR,
"%s: virtio-snd command size incorrect %zu vs \
%zu\n", __func__, msg_sz, sizeof(stream_id));
cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
return;
}
stream_id = le32_to_cpu(stream_id);
trace_virtio_snd_handle_pcm_release(stream_id);
stream = virtio_snd_pcm_get_stream(s, stream_id);
if (stream == NULL) {
/*
* TODO: do we need to set DEVICE_NEEDS_RESET?
*/
error_report("already released stream %"PRIu32, stream_id);
virtio_error(VIRTIO_DEVICE(s),
"already released stream %"PRIu32,
stream_id);
cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
return;
}
+
+ if (virtio_snd_pcm_get_io_msgs_count(stream)) {
+ /*
+ * virtio-v1.2-csd01, 5.14.6.6.5.1,
+ * Device Requirements: Stream Release
+ *
+ * - The device MUST complete all pending I/O messages for the
+ * specified stream ID.
+ * - The device MUST NOT complete the control request while there
+ * are pending I/O messages for the specified stream ID.
+ */
+ trace_virtio_snd_pcm_stream_flush(stream_id);
+ virtio_snd_pcm_flush(stream);
+ }
+
cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_OK);
}
/*
* The actual processing done in virtio_snd_process_cmdq().
*
* @s: VirtIOSound device
* @cmd: control command request
*/
@@ -728,19 +804,121 @@ static void virtio_snd_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
/*
* The event virtqueue handler.
* Not implemented yet.
*
* @vdev: VirtIOSound device
* @vq: event vq
*/
static void virtio_snd_handle_event(VirtIODevice *vdev, VirtQueue *vq)
{
qemu_log_mask(LOG_UNIMP, "virtio_snd: event queue is unimplemented.\n");
trace_virtio_snd_handle_event();
}
+/*
+ * The tx virtqueue handler. Makes the buffers available to their respective
+ * streams for consumption.
+ *
+ * @vdev: VirtIOSound device
+ * @vq: tx virtqueue
+ */
+static void virtio_snd_handle_tx(VirtIODevice *vdev, VirtQueue *vq)
+{
+ VirtIOSound *s = VIRTIO_SND(vdev);
+ VirtIOSoundPCMStream *stream = NULL;
+ VirtIOSoundPCMBuffer *buffer;
+ VirtQueueElement *elem;
+ size_t msg_sz, size;
+ virtio_snd_pcm_xfer hdr;
+ virtio_snd_pcm_status resp = { 0 };
+ uint32_t stream_id;
+ /*
+ * If any of the I/O messages are invalid, put them in stream->invalid and
+ * return them after the for loop.
+ */
+ bool must_empty_invalid_queue = false;
+
+ if (!virtio_queue_ready(vq)) {
+ return;
+ }
+ trace_virtio_snd_handle_xfer();
+
+ for (;;) {
+ elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
+ if (!elem) {
+ break;
+ }
+ /* get the message hdr object */
+ msg_sz = iov_to_buf(elem->out_sg,
+ elem->out_num,
+ 0,
+ &hdr,
+ sizeof(virtio_snd_pcm_xfer));
+ if (msg_sz != sizeof(virtio_snd_pcm_xfer)) {
+ goto tx_err;
+ }
+ stream_id = le32_to_cpu(hdr.stream_id);
+
+ if (stream_id >= s->snd_conf.streams
+ || s->pcm->streams[stream_id] == NULL) {
+ goto tx_err;
+ }
+
+ stream = s->pcm->streams[stream_id];
+ if (stream->info.direction != VIRTIO_SND_D_OUTPUT) {
+ goto tx_err;
+ }
+
+ WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
+ size = iov_size(elem->out_sg, elem->out_num) - msg_sz;
+
+ buffer = g_malloc0(sizeof(VirtIOSoundPCMBuffer) + size);
+ buffer->elem = elem;
+ buffer->populated = false;
+ buffer->vq = vq;
+ buffer->size = size;
+ buffer->offset = 0;
+
+ QSIMPLEQ_INSERT_TAIL(&stream->queue, buffer, entry);
+ }
+ continue;
+
+tx_err:
+ WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
+ must_empty_invalid_queue = true;
+ buffer = g_malloc0(sizeof(VirtIOSoundPCMBuffer));
+ buffer->elem = elem;
+ buffer->vq = vq;
+ QSIMPLEQ_INSERT_TAIL(&stream->invalid, buffer, entry);
+ }
+ }
+
+ if (must_empty_invalid_queue) {
+ WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
+ while (!QSIMPLEQ_EMPTY(&stream->invalid)) {
+ buffer = QSIMPLEQ_FIRST(&stream->invalid);
+
+ resp.status = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
+ iov_from_buf(buffer->elem->in_sg,
+ buffer->elem->in_num,
+ 0,
+ &resp,
+ sizeof(virtio_snd_pcm_status));
+ virtqueue_push(vq, buffer->elem, sizeof(virtio_snd_pcm_status));
+ QSIMPLEQ_REMOVE_HEAD(&stream->invalid, entry);
+ virtio_snd_pcm_buffer_free(buffer);
+ }
+ /*
+ * Notify vq about virtio_snd_pcm_status responses.
+ * Buffer responses must be notified separately later.
+ */
+ virtio_notify(vdev, vq);
+ }
+ }
+}
+
/*
* Stub buffer virtqueue handler.
*
* @vdev: VirtIOSound device
* @vq: virtqueue
*/
@@ -776,116 +954,216 @@ virtio_snd_vm_state_change(void *opaque, bool running,
static void virtio_snd_realize(DeviceState *dev, Error **errp)
{
ERRP_GUARD();
VirtIOSound *vsnd = VIRTIO_SND(dev);
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
virtio_snd_pcm_set_params default_params = { 0 };
uint32_t status;
vsnd->pcm = NULL;
vsnd->vmstate =
qemu_add_vm_change_state_handler(virtio_snd_vm_state_change, vsnd);
trace_virtio_snd_realize(vsnd);
vsnd->pcm = g_new0(VirtIOSoundPCM, 1);
vsnd->pcm->snd = vsnd;
vsnd->pcm->streams =
g_new0(VirtIOSoundPCMStream *, vsnd->snd_conf.streams);
vsnd->pcm->pcm_params =
g_new0(virtio_snd_pcm_set_params, vsnd->snd_conf.streams);
virtio_init(vdev, VIRTIO_ID_SOUND, sizeof(virtio_snd_config));
virtio_add_feature(&vsnd->features, VIRTIO_F_VERSION_1);
/* set number of jacks and streams */
if (vsnd->snd_conf.jacks > 8) {
error_setg(errp,
"Invalid number of jacks: %"PRIu32,
vsnd->snd_conf.jacks);
return;
}
if (vsnd->snd_conf.streams < 1 || vsnd->snd_conf.streams > 10) {
error_setg(errp,
"Invalid number of streams: %"PRIu32,
vsnd->snd_conf.streams);
return;
}
if (vsnd->snd_conf.chmaps > VIRTIO_SND_CHMAP_MAX_SIZE) {
error_setg(errp,
"Invalid number of channel maps: %"PRIu32,
vsnd->snd_conf.chmaps);
return;
}
AUD_register_card("virtio-sound", &vsnd->card, errp);
/* set default params for all streams */
default_params.features = 0;
default_params.buffer_bytes = cpu_to_le32(8192);
default_params.period_bytes = cpu_to_le32(2048);
default_params.channels = 2;
default_params.format = VIRTIO_SND_PCM_FMT_S16;
default_params.rate = VIRTIO_SND_PCM_RATE_48000;
vsnd->queues[VIRTIO_SND_VQ_CONTROL] =
virtio_add_queue(vdev, 64, virtio_snd_handle_ctrl);
vsnd->queues[VIRTIO_SND_VQ_EVENT] =
virtio_add_queue(vdev, 64, virtio_snd_handle_event);
vsnd->queues[VIRTIO_SND_VQ_TX] =
- virtio_add_queue(vdev, 64, virtio_snd_handle_xfer);
+ virtio_add_queue(vdev, 64, virtio_snd_handle_tx);
vsnd->queues[VIRTIO_SND_VQ_RX] =
virtio_add_queue(vdev, 64, virtio_snd_handle_xfer);
qemu_mutex_init(&vsnd->cmdq_mutex);
QTAILQ_INIT(&vsnd->cmdq);
for (uint32_t i = 0; i < vsnd->snd_conf.streams; i++) {
status = virtio_snd_set_pcm_params(vsnd, i, &default_params);
if (status != cpu_to_le32(VIRTIO_SND_S_OK)) {
error_setg(errp,
"Can't initalize stream params, device responded with %s.",
print_code(status));
return;
}
status = virtio_snd_pcm_prepare(vsnd, i);
if (status != cpu_to_le32(VIRTIO_SND_S_OK)) {
error_setg(errp,
"Can't prepare streams, device responded with %s.",
print_code(status));
return;
}
}
}
+static inline void return_tx_buffer(VirtIOSoundPCMStream *stream,
+ VirtIOSoundPCMBuffer *buffer)
+{
+ virtio_snd_pcm_status resp = { 0 };
+ resp.status = cpu_to_le32(VIRTIO_SND_S_OK);
+ resp.latency_bytes = cpu_to_le32((uint32_t)buffer->size);
+ iov_from_buf(buffer->elem->in_sg,
+ buffer->elem->in_num,
+ 0,
+ &resp,
+ sizeof(virtio_snd_pcm_status));
+ virtqueue_push(buffer->vq,
+ buffer->elem,
+ sizeof(virtio_snd_pcm_status));
+ virtio_notify(VIRTIO_DEVICE(stream->s), buffer->vq);
+ QSIMPLEQ_REMOVE(&stream->queue,
+ buffer,
+ VirtIOSoundPCMBuffer,
+ entry);
+ virtio_snd_pcm_buffer_free(buffer);
+}
+
+/*
+ * AUD_* output callback.
+ *
+ * @data: VirtIOSoundPCMStream stream
+ * @available: number of bytes that can be written with AUD_write()
+ */
+static void virtio_snd_pcm_out_cb(void *data, int available)
+{
+ VirtIOSoundPCMStream *stream = data;
+ VirtIOSoundPCMBuffer *buffer;
+ size_t size;
+
+ WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
+ while (!QSIMPLEQ_EMPTY(&stream->queue)) {
+ buffer = QSIMPLEQ_FIRST(&stream->queue);
+ if (!virtio_queue_ready(buffer->vq)) {
+ return;
+ }
+ if (!stream->active) {
+ /* Stream has stopped, so do not perform AUD_write. */
+ return_tx_buffer(stream, buffer);
+ continue;
+ }
+ if (!buffer->populated) {
+ iov_to_buf(buffer->elem->out_sg,
+ buffer->elem->out_num,
+ sizeof(virtio_snd_pcm_xfer),
+ buffer->data,
+ buffer->size);
+ buffer->populated = true;
+ }
+ for (;;) {
+ size = AUD_write(stream->voice.out,
+ buffer->data + buffer->offset,
+ MIN(buffer->size, available));
+ assert(size <= MIN(buffer->size, available));
+ if (size == 0) {
+ /* break out of both loops */
+ available = 0;
+ break;
+ }
+ buffer->size -= size;
+ buffer->offset += size;
+ available -= size;
+ if (buffer->size < 1) {
+ return_tx_buffer(stream, buffer);
+ break;
+ }
+ if (!available) {
+ break;
+ }
+ }
+ if (!available) {
+ break;
+ }
+ }
+ }
+}
+
+/*
+ * Flush all buffer data from this stream's queue into the driver's virtual
+ * queue.
+ *
+ * @stream: VirtIOSoundPCMStream *stream
+ */
+static inline void virtio_snd_pcm_flush(VirtIOSoundPCMStream *stream)
+{
+ VirtIOSoundPCMBuffer *buffer;
+
+ WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
+ while (!QSIMPLEQ_EMPTY(&stream->queue)) {
+ buffer = QSIMPLEQ_FIRST(&stream->queue);
+ return_tx_buffer(stream, buffer);
+ }
+ }
+}
+
static void virtio_snd_unrealize(DeviceState *dev)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VirtIOSound *vsnd = VIRTIO_SND(dev);
VirtIOSoundPCMStream *stream;
qemu_del_vm_change_state_handler(vsnd->vmstate);
trace_virtio_snd_unrealize(vsnd);
if (vsnd->pcm) {
if (vsnd->pcm->streams) {
for (uint32_t i = 0; i < vsnd->snd_conf.streams; i++) {
stream = vsnd->pcm->streams[i];
if (stream) {
virtio_snd_process_cmdq(stream->s);
virtio_snd_pcm_close(stream);
+ qemu_mutex_destroy(&stream->queue_mutex);
g_free(stream);
}
}
g_free(vsnd->pcm->streams);
}
g_free(vsnd->pcm->pcm_params);
g_free(vsnd->pcm);
vsnd->pcm = NULL;
}
AUD_remove_card(&vsnd->card);
qemu_mutex_destroy(&vsnd->cmdq_mutex);
virtio_delete_queue(vsnd->queues[VIRTIO_SND_VQ_CONTROL]);
virtio_delete_queue(vsnd->queues[VIRTIO_SND_VQ_EVENT]);
virtio_delete_queue(vsnd->queues[VIRTIO_SND_VQ_TX]);
virtio_delete_queue(vsnd->queues[VIRTIO_SND_VQ_RX]);
virtio_cleanup(vdev);
}
@@ -77,6 +77,50 @@ typedef struct virtio_snd_ctrl_command virtio_snd_ctrl_command;
typedef struct VirtIOSoundPCM VirtIOSoundPCM;
+typedef struct VirtIOSoundPCMBuffer VirtIOSoundPCMBuffer;
+
+/*
+ * The VirtIO sound spec reuses layouts and values from the High Definition
+ * Audio spec (virtio/v1.2: 5.14 Sound Device). This struct handles each I/O
+ * message's buffer (virtio/v1.2: 5.14.6.8 PCM I/O Messages).
+ *
+ * In the case of TX (i.e. playback) buffers, we defer reading the raw PCM data
+ * from the virtqueue until QEMU's sound backsystem calls the output callback.
+ * This is tracked by the `bool populated;` field, which is set to true when
+ * data has been read into our own buffer for consumption.
+ *
+ * VirtIOSoundPCMBuffer has a dynamic size since it includes the raw PCM data
+ * in its allocation. It must be initialized and destroyed as follows:
+ *
+ * size_t size = [[derived from owned VQ element descriptor sizes]];
+ * buffer = g_malloc0(sizeof(VirtIOSoundPCMBuffer) + size);
+ * buffer->elem = [[owned VQ element]];
+ *
+ * [..]
+ *
+ * g_free(buffer->elem);
+ * g_free(buffer);
+ */
+struct VirtIOSoundPCMBuffer {
+ QSIMPLEQ_ENTRY(VirtIOSoundPCMBuffer) entry;
+ VirtQueueElement *elem;
+ VirtQueue *vq;
+ size_t size;
+ /*
+ * In TX / Plaback, `offset` represents the first unused position inside
+ * `data`. If `offset == size` then there are no unused data left.
+ */
+ uint64_t offset;
+ /* Used for the TX queue for lazy I/O copy from `elem` */
+ bool populated;
+ /*
+ * VirtIOSoundPCMBuffer is an unsized type because it ends with an array of
+ * bytes. The size of `data` is determined from the I/O message's read-only
+ * or write-only size when allocating VirtIOSoundPCMBuffer.
+ */
+ uint8_t data[];
+};
+
struct VirtIOSoundPCM {
VirtIOSound *snd;
/*
@@ -93,74 +137,77 @@ struct VirtIOSoundPCM {
struct VirtIOSoundPCMStream {
VirtIOSoundPCM *pcm;
virtio_snd_pcm_info info;
virtio_snd_pcm_set_params params;
uint32_t id;
/* channel position values (VIRTIO_SND_CHMAP_XXX) */
uint8_t positions[VIRTIO_SND_CHMAP_MAX_SIZE];
VirtIOSound *s;
bool flushing;
audsettings as;
union {
SWVoiceIn *in;
SWVoiceOut *out;
} voice;
+ QemuMutex queue_mutex;
bool active;
+ QSIMPLEQ_HEAD(, VirtIOSoundPCMBuffer) queue;
+ QSIMPLEQ_HEAD(, VirtIOSoundPCMBuffer) invalid;
};
/*
* PCM stream state machine.
* -------------------------
*
* 5.14.6.6.1 PCM Command Lifecycle
* ================================
*
* A PCM stream has the following command lifecycle:
* - `SET PARAMETERS`
* The driver negotiates the stream parameters (format, transport, etc) with
* the device.
* Possible valid transitions: `SET PARAMETERS`, `PREPARE`.
* - `PREPARE`
* The device prepares the stream (allocates resources, etc).
* Possible valid transitions: `SET PARAMETERS`, `PREPARE`, `START`,
* `RELEASE`. Output only: the driver transfers data for pre-buffing.
* - `START`
* The device starts the stream (unmute, putting into running state, etc).
* Possible valid transitions: `STOP`.
* The driver transfers data to/from the stream.
* - `STOP`
* The device stops the stream (mute, putting into non-running state, etc).
* Possible valid transitions: `START`, `RELEASE`.
* - `RELEASE`
* The device releases the stream (frees resources, etc).
* Possible valid transitions: `SET PARAMETERS`, `PREPARE`.
*
* +---------------+ +---------+ +---------+ +-------+ +-------+
* | SetParameters | | Prepare | | Release | | Start | | Stop |
* +---------------+ +---------+ +---------+ +-------+ +-------+
* |- | | | |
* || | | | |
* |< | | | |
* |------------->| | | |
* |<-------------| | | |
* | |- | | |
* | || | | |
* | |< | | |
* | |--------------------->| |
* | |---------->| | |
* | | | |-------->|
* | | | |<--------|
* | | |<-------------------|
* |<-------------------------| | |
* | |<----------| | |
*
* CTRL in the VirtIOSound device
* ==============================
*
* The control messages that affect the state of a stream arrive in the
* `virtio_snd_handle_ctrl()` queue callback and are of type `struct
* virtio_snd_ctrl_command`. They are stored in a queue field in the device
* type, `VirtIOSound`. This allows deferring the CTRL request completion if
* it's not immediately possible due to locking/state reasons.
*
* The CTRL message is finally handled in `process_cmd()`.
*/