xref: /openbmc/qemu/hw/audio/virtio-snd.c (revision effd60c8)
1 /*
2  * VIRTIO Sound Device conforming to
3  *
4  * "Virtual I/O Device (VIRTIO) Version 1.2
5  * Committee Specification Draft 01
6  * 09 May 2022"
7  *
8  * <https://docs.oasis-open.org/virtio/virtio/v1.2/csd01/virtio-v1.2-csd01.html#x1-52900014>
9  *
10  * Copyright (c) 2023 Emmanouil Pitsidianakis <manos.pitsidianakis@linaro.org>
11  * Copyright (C) 2019 OpenSynergy GmbH
12  *
13  * This work is licensed under the terms of the GNU GPL, version 2 or
14  * (at your option) any later version.  See the COPYING file in the
15  * top-level directory.
16  */
17 
18 #include "qemu/osdep.h"
19 #include "qemu/iov.h"
20 #include "qemu/log.h"
21 #include "qemu/error-report.h"
22 #include "include/qemu/lockable.h"
23 #include "sysemu/runstate.h"
24 #include "trace.h"
25 #include "qapi/error.h"
26 #include "hw/audio/virtio-snd.h"
27 #include "hw/core/cpu.h"
28 
29 #define VIRTIO_SOUND_VM_VERSION 1
30 #define VIRTIO_SOUND_JACK_DEFAULT 0
31 #define VIRTIO_SOUND_STREAM_DEFAULT 2
32 #define VIRTIO_SOUND_CHMAP_DEFAULT 0
33 #define VIRTIO_SOUND_HDA_FN_NID 0
34 
35 static void virtio_snd_pcm_out_cb(void *data, int available);
36 static void virtio_snd_process_cmdq(VirtIOSound *s);
37 static void virtio_snd_pcm_flush(VirtIOSoundPCMStream *stream);
38 static void virtio_snd_pcm_in_cb(void *data, int available);
39 static void virtio_snd_unrealize(DeviceState *dev);
40 
41 static uint32_t supported_formats = BIT(VIRTIO_SND_PCM_FMT_S8)
42                                   | BIT(VIRTIO_SND_PCM_FMT_U8)
43                                   | BIT(VIRTIO_SND_PCM_FMT_S16)
44                                   | BIT(VIRTIO_SND_PCM_FMT_U16)
45                                   | BIT(VIRTIO_SND_PCM_FMT_S32)
46                                   | BIT(VIRTIO_SND_PCM_FMT_U32)
47                                   | BIT(VIRTIO_SND_PCM_FMT_FLOAT);
48 
49 static uint32_t supported_rates = BIT(VIRTIO_SND_PCM_RATE_5512)
50                                 | BIT(VIRTIO_SND_PCM_RATE_8000)
51                                 | BIT(VIRTIO_SND_PCM_RATE_11025)
52                                 | BIT(VIRTIO_SND_PCM_RATE_16000)
53                                 | BIT(VIRTIO_SND_PCM_RATE_22050)
54                                 | BIT(VIRTIO_SND_PCM_RATE_32000)
55                                 | BIT(VIRTIO_SND_PCM_RATE_44100)
56                                 | BIT(VIRTIO_SND_PCM_RATE_48000)
57                                 | BIT(VIRTIO_SND_PCM_RATE_64000)
58                                 | BIT(VIRTIO_SND_PCM_RATE_88200)
59                                 | BIT(VIRTIO_SND_PCM_RATE_96000)
60                                 | BIT(VIRTIO_SND_PCM_RATE_176400)
61                                 | BIT(VIRTIO_SND_PCM_RATE_192000)
62                                 | BIT(VIRTIO_SND_PCM_RATE_384000);
63 
64 static const VMStateDescription vmstate_virtio_snd_device = {
65     .name = TYPE_VIRTIO_SND,
66     .version_id = VIRTIO_SOUND_VM_VERSION,
67     .minimum_version_id = VIRTIO_SOUND_VM_VERSION,
68 };
69 
70 static const VMStateDescription vmstate_virtio_snd = {
71     .name = TYPE_VIRTIO_SND,
72     .unmigratable = 1,
73     .minimum_version_id = VIRTIO_SOUND_VM_VERSION,
74     .version_id = VIRTIO_SOUND_VM_VERSION,
75     .fields = (const VMStateField[]) {
76         VMSTATE_VIRTIO_DEVICE,
77         VMSTATE_END_OF_LIST()
78     },
79 };
80 
81 static Property virtio_snd_properties[] = {
82     DEFINE_AUDIO_PROPERTIES(VirtIOSound, card),
83     DEFINE_PROP_UINT32("jacks", VirtIOSound, snd_conf.jacks,
84                        VIRTIO_SOUND_JACK_DEFAULT),
85     DEFINE_PROP_UINT32("streams", VirtIOSound, snd_conf.streams,
86                        VIRTIO_SOUND_STREAM_DEFAULT),
87     DEFINE_PROP_UINT32("chmaps", VirtIOSound, snd_conf.chmaps,
88                        VIRTIO_SOUND_CHMAP_DEFAULT),
89     DEFINE_PROP_END_OF_LIST(),
90 };
91 
92 static void
93 virtio_snd_get_config(VirtIODevice *vdev, uint8_t *config)
94 {
95     VirtIOSound *s = VIRTIO_SND(vdev);
96     virtio_snd_config *sndconfig =
97         (virtio_snd_config *)config;
98     trace_virtio_snd_get_config(vdev,
99                                 s->snd_conf.jacks,
100                                 s->snd_conf.streams,
101                                 s->snd_conf.chmaps);
102 
103     memcpy(sndconfig, &s->snd_conf, sizeof(s->snd_conf));
104     cpu_to_le32s(&sndconfig->jacks);
105     cpu_to_le32s(&sndconfig->streams);
106     cpu_to_le32s(&sndconfig->chmaps);
107 
108 }
109 
110 static void
111 virtio_snd_set_config(VirtIODevice *vdev, const uint8_t *config)
112 {
113     VirtIOSound *s = VIRTIO_SND(vdev);
114     const virtio_snd_config *sndconfig =
115         (const virtio_snd_config *)config;
116 
117 
118    trace_virtio_snd_set_config(vdev,
119                                s->snd_conf.jacks,
120                                sndconfig->jacks,
121                                s->snd_conf.streams,
122                                sndconfig->streams,
123                                s->snd_conf.chmaps,
124                                sndconfig->chmaps);
125 
126     memcpy(&s->snd_conf, sndconfig, sizeof(virtio_snd_config));
127     le32_to_cpus(&s->snd_conf.jacks);
128     le32_to_cpus(&s->snd_conf.streams);
129     le32_to_cpus(&s->snd_conf.chmaps);
130 
131 }
132 
133 static void
134 virtio_snd_pcm_buffer_free(VirtIOSoundPCMBuffer *buffer)
135 {
136     g_free(buffer->elem);
137     g_free(buffer);
138 }
139 
140 static void
141 virtio_snd_ctrl_cmd_free(virtio_snd_ctrl_command *cmd)
142 {
143     g_free(cmd->elem);
144     g_free(cmd);
145 }
146 
147 /*
148  * Get a specific stream from the virtio sound card device.
149  * Returns NULL if @stream_id is invalid or not allocated.
150  *
151  * @s: VirtIOSound device
152  * @stream_id: stream id
153  */
154 static VirtIOSoundPCMStream *virtio_snd_pcm_get_stream(VirtIOSound *s,
155                                                        uint32_t stream_id)
156 {
157     return stream_id >= s->snd_conf.streams ? NULL :
158         s->pcm->streams[stream_id];
159 }
160 
161 /*
162  * Get params for a specific stream.
163  *
164  * @s: VirtIOSound device
165  * @stream_id: stream id
166  */
167 static virtio_snd_pcm_set_params *virtio_snd_pcm_get_params(VirtIOSound *s,
168                                                             uint32_t stream_id)
169 {
170     return stream_id >= s->snd_conf.streams ? NULL
171         : &s->pcm->pcm_params[stream_id];
172 }
173 
174 /*
175  * Handle the VIRTIO_SND_R_PCM_INFO request.
176  * The function writes the info structs to the request element.
177  *
178  * @s: VirtIOSound device
179  * @cmd: The request command queue element from VirtIOSound cmdq field
180  */
181 static void virtio_snd_handle_pcm_info(VirtIOSound *s,
182                                        virtio_snd_ctrl_command *cmd)
183 {
184     uint32_t stream_id, start_id, count, size;
185     virtio_snd_pcm_info val;
186     virtio_snd_query_info req;
187     VirtIOSoundPCMStream *stream = NULL;
188     g_autofree virtio_snd_pcm_info *pcm_info = NULL;
189     size_t msg_sz = iov_to_buf(cmd->elem->out_sg,
190                                cmd->elem->out_num,
191                                0,
192                                &req,
193                                sizeof(virtio_snd_query_info));
194 
195     if (msg_sz != sizeof(virtio_snd_query_info)) {
196         /*
197          * TODO: do we need to set DEVICE_NEEDS_RESET?
198          */
199         qemu_log_mask(LOG_GUEST_ERROR,
200                 "%s: virtio-snd command size incorrect %zu vs \
201                 %zu\n", __func__, msg_sz, sizeof(virtio_snd_query_info));
202         cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
203         return;
204     }
205 
206     start_id = le32_to_cpu(req.start_id);
207     count = le32_to_cpu(req.count);
208     size = le32_to_cpu(req.size);
209 
210     if (iov_size(cmd->elem->in_sg, cmd->elem->in_num) <
211         sizeof(virtio_snd_hdr) + size * count) {
212         /*
213          * TODO: do we need to set DEVICE_NEEDS_RESET?
214          */
215         error_report("pcm info: buffer too small, got: %zu, needed: %zu",
216                 iov_size(cmd->elem->in_sg, cmd->elem->in_num),
217                 sizeof(virtio_snd_pcm_info));
218         cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
219         return;
220     }
221 
222     pcm_info = g_new0(virtio_snd_pcm_info, count);
223     for (uint32_t i = 0; i < count; i++) {
224         stream_id = i + start_id;
225         trace_virtio_snd_handle_pcm_info(stream_id);
226         stream = virtio_snd_pcm_get_stream(s, stream_id);
227         if (!stream) {
228             error_report("Invalid stream id: %"PRIu32, stream_id);
229             cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
230             return;
231         }
232         val = stream->info;
233         val.hdr.hda_fn_nid = cpu_to_le32(val.hdr.hda_fn_nid);
234         val.features = cpu_to_le32(val.features);
235         val.formats = cpu_to_le64(val.formats);
236         val.rates = cpu_to_le64(val.rates);
237         /*
238          * 5.14.6.6.2.1 Device Requirements: Stream Information The device MUST
239          * NOT set undefined feature, format, rate and direction values. The
240          * device MUST initialize the padding bytes to 0.
241          */
242         pcm_info[i] = val;
243         memset(&pcm_info[i].padding, 0, 5);
244     }
245 
246     cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_OK);
247     iov_from_buf(cmd->elem->in_sg,
248                  cmd->elem->in_num,
249                  sizeof(virtio_snd_hdr),
250                  pcm_info,
251                  sizeof(virtio_snd_pcm_info) * count);
252 }
253 
254 /*
255  * Set the given stream params.
256  * Called by both virtio_snd_handle_pcm_set_params and during device
257  * initialization.
258  * Returns the response status code. (VIRTIO_SND_S_*).
259  *
260  * @s: VirtIOSound device
261  * @params: The PCM params as defined in the virtio specification
262  */
263 static
264 uint32_t virtio_snd_set_pcm_params(VirtIOSound *s,
265                                    uint32_t stream_id,
266                                    virtio_snd_pcm_set_params *params)
267 {
268     virtio_snd_pcm_set_params *st_params;
269 
270     if (stream_id >= s->snd_conf.streams || s->pcm->pcm_params == NULL) {
271         /*
272          * TODO: do we need to set DEVICE_NEEDS_RESET?
273          */
274         virtio_error(VIRTIO_DEVICE(s), "Streams have not been initialized.\n");
275         return cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
276     }
277 
278     st_params = virtio_snd_pcm_get_params(s, stream_id);
279 
280     if (params->channels < 1 || params->channels > AUDIO_MAX_CHANNELS) {
281         error_report("Number of channels is not supported.");
282         return cpu_to_le32(VIRTIO_SND_S_NOT_SUPP);
283     }
284     if (!(supported_formats & BIT(params->format))) {
285         error_report("Stream format is not supported.");
286         return cpu_to_le32(VIRTIO_SND_S_NOT_SUPP);
287     }
288     if (!(supported_rates & BIT(params->rate))) {
289         error_report("Stream rate is not supported.");
290         return cpu_to_le32(VIRTIO_SND_S_NOT_SUPP);
291     }
292 
293     st_params->buffer_bytes = le32_to_cpu(params->buffer_bytes);
294     st_params->period_bytes = le32_to_cpu(params->period_bytes);
295     st_params->features = le32_to_cpu(params->features);
296     /* the following are uint8_t, so there's no need to bswap the values. */
297     st_params->channels = params->channels;
298     st_params->format = params->format;
299     st_params->rate = params->rate;
300 
301     return cpu_to_le32(VIRTIO_SND_S_OK);
302 }
303 
304 /*
305  * Handles the VIRTIO_SND_R_PCM_SET_PARAMS request.
306  *
307  * @s: VirtIOSound device
308  * @cmd: The request command queue element from VirtIOSound cmdq field
309  */
310 static void virtio_snd_handle_pcm_set_params(VirtIOSound *s,
311                                              virtio_snd_ctrl_command *cmd)
312 {
313     virtio_snd_pcm_set_params req = { 0 };
314     uint32_t stream_id;
315     size_t msg_sz = iov_to_buf(cmd->elem->out_sg,
316                                cmd->elem->out_num,
317                                0,
318                                &req,
319                                sizeof(virtio_snd_pcm_set_params));
320 
321     if (msg_sz != sizeof(virtio_snd_pcm_set_params)) {
322         /*
323          * TODO: do we need to set DEVICE_NEEDS_RESET?
324          */
325         qemu_log_mask(LOG_GUEST_ERROR,
326                 "%s: virtio-snd command size incorrect %zu vs \
327                 %zu\n", __func__, msg_sz, sizeof(virtio_snd_pcm_set_params));
328         cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
329         return;
330     }
331     stream_id = le32_to_cpu(req.hdr.stream_id);
332     trace_virtio_snd_handle_pcm_set_params(stream_id);
333     cmd->resp.code = virtio_snd_set_pcm_params(s, stream_id, &req);
334 }
335 
336 /*
337  * Get a QEMU Audiosystem compatible format value from a VIRTIO_SND_PCM_FMT_*
338  */
339 static AudioFormat virtio_snd_get_qemu_format(uint32_t format)
340 {
341     #define CASE(FMT)               \
342     case VIRTIO_SND_PCM_FMT_##FMT:  \
343         return AUDIO_FORMAT_##FMT;
344 
345     switch (format) {
346     CASE(U8)
347     CASE(S8)
348     CASE(U16)
349     CASE(S16)
350     CASE(U32)
351     CASE(S32)
352     case VIRTIO_SND_PCM_FMT_FLOAT:
353         return AUDIO_FORMAT_F32;
354     default:
355         g_assert_not_reached();
356     }
357 
358     #undef CASE
359 }
360 
361 /*
362  * Get a QEMU Audiosystem compatible frequency value from a
363  * VIRTIO_SND_PCM_RATE_*
364  */
365 static uint32_t virtio_snd_get_qemu_freq(uint32_t rate)
366 {
367     #define CASE(RATE)               \
368     case VIRTIO_SND_PCM_RATE_##RATE: \
369         return RATE;
370 
371     switch (rate) {
372     CASE(5512)
373     CASE(8000)
374     CASE(11025)
375     CASE(16000)
376     CASE(22050)
377     CASE(32000)
378     CASE(44100)
379     CASE(48000)
380     CASE(64000)
381     CASE(88200)
382     CASE(96000)
383     CASE(176400)
384     CASE(192000)
385     CASE(384000)
386     default:
387         g_assert_not_reached();
388     }
389 
390     #undef CASE
391 }
392 
393 /*
394  * Get QEMU Audiosystem compatible audsettings from virtio based pcm stream
395  * params.
396  */
397 static void virtio_snd_get_qemu_audsettings(audsettings *as,
398                                             virtio_snd_pcm_set_params *params)
399 {
400     as->nchannels = MIN(AUDIO_MAX_CHANNELS, params->channels);
401     as->fmt = virtio_snd_get_qemu_format(params->format);
402     as->freq = virtio_snd_get_qemu_freq(params->rate);
403     as->endianness = target_words_bigendian() ? 1 : 0;
404 }
405 
406 /*
407  * Close a stream and free all its resources.
408  *
409  * @stream: VirtIOSoundPCMStream *stream
410  */
411 static void virtio_snd_pcm_close(VirtIOSoundPCMStream *stream)
412 {
413     if (stream) {
414         virtio_snd_pcm_flush(stream);
415         if (stream->info.direction == VIRTIO_SND_D_OUTPUT) {
416             AUD_close_out(&stream->pcm->snd->card, stream->voice.out);
417             stream->voice.out = NULL;
418         } else if (stream->info.direction == VIRTIO_SND_D_INPUT) {
419             AUD_close_in(&stream->pcm->snd->card, stream->voice.in);
420             stream->voice.in = NULL;
421         }
422     }
423 }
424 
425 /*
426  * Prepares a VirtIOSound card stream.
427  * Returns the response status code. (VIRTIO_SND_S_*).
428  *
429  * @s: VirtIOSound device
430  * @stream_id: stream id
431  */
432 static uint32_t virtio_snd_pcm_prepare(VirtIOSound *s, uint32_t stream_id)
433 {
434     audsettings as;
435     virtio_snd_pcm_set_params *params;
436     VirtIOSoundPCMStream *stream;
437 
438     if (s->pcm->streams == NULL ||
439         s->pcm->pcm_params == NULL ||
440         stream_id >= s->snd_conf.streams) {
441         return cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
442     }
443 
444     params = virtio_snd_pcm_get_params(s, stream_id);
445     if (params == NULL) {
446         return cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
447     }
448 
449     stream = virtio_snd_pcm_get_stream(s, stream_id);
450     if (stream == NULL) {
451         stream = g_new0(VirtIOSoundPCMStream, 1);
452         stream->active = false;
453         stream->id = stream_id;
454         stream->pcm = s->pcm;
455         stream->s = s;
456         qemu_mutex_init(&stream->queue_mutex);
457         QSIMPLEQ_INIT(&stream->queue);
458         QSIMPLEQ_INIT(&stream->invalid);
459 
460         /*
461          * stream_id >= s->snd_conf.streams was checked before so this is
462          * in-bounds
463          */
464         s->pcm->streams[stream_id] = stream;
465     }
466 
467     virtio_snd_get_qemu_audsettings(&as, params);
468     stream->info.direction = stream_id < s->snd_conf.streams / 2 +
469         (s->snd_conf.streams & 1) ? VIRTIO_SND_D_OUTPUT : VIRTIO_SND_D_INPUT;
470     stream->info.hdr.hda_fn_nid = VIRTIO_SOUND_HDA_FN_NID;
471     stream->info.features = 0;
472     stream->info.channels_min = 1;
473     stream->info.channels_max = as.nchannels;
474     stream->info.formats = supported_formats;
475     stream->info.rates = supported_rates;
476     stream->params = *params;
477 
478     stream->positions[0] = VIRTIO_SND_CHMAP_FL;
479     stream->positions[1] = VIRTIO_SND_CHMAP_FR;
480     stream->as = as;
481 
482     if (stream->info.direction == VIRTIO_SND_D_OUTPUT) {
483         stream->voice.out = AUD_open_out(&s->card,
484                                          stream->voice.out,
485                                          "virtio-sound.out",
486                                          stream,
487                                          virtio_snd_pcm_out_cb,
488                                          &as);
489         AUD_set_volume_out(stream->voice.out, 0, 255, 255);
490     } else {
491         stream->voice.in = AUD_open_in(&s->card,
492                                         stream->voice.in,
493                                         "virtio-sound.in",
494                                         stream,
495                                         virtio_snd_pcm_in_cb,
496                                         &as);
497         AUD_set_volume_in(stream->voice.in, 0, 255, 255);
498     }
499 
500     return cpu_to_le32(VIRTIO_SND_S_OK);
501 }
502 
503 static const char *print_code(uint32_t code)
504 {
505     #define CASE(CODE)            \
506     case VIRTIO_SND_R_##CODE:     \
507         return "VIRTIO_SND_R_"#CODE
508 
509     switch (code) {
510     CASE(JACK_INFO);
511     CASE(JACK_REMAP);
512     CASE(PCM_INFO);
513     CASE(PCM_SET_PARAMS);
514     CASE(PCM_PREPARE);
515     CASE(PCM_RELEASE);
516     CASE(PCM_START);
517     CASE(PCM_STOP);
518     CASE(CHMAP_INFO);
519     default:
520         return "invalid code";
521     }
522 
523     #undef CASE
524 };
525 
526 /*
527  * Handles VIRTIO_SND_R_PCM_PREPARE.
528  *
529  * @s: VirtIOSound device
530  * @cmd: The request command queue element from VirtIOSound cmdq field
531  */
532 static void virtio_snd_handle_pcm_prepare(VirtIOSound *s,
533                                           virtio_snd_ctrl_command *cmd)
534 {
535     uint32_t stream_id;
536     size_t msg_sz = iov_to_buf(cmd->elem->out_sg,
537                                cmd->elem->out_num,
538                                sizeof(virtio_snd_hdr),
539                                &stream_id,
540                                sizeof(stream_id));
541 
542     stream_id = le32_to_cpu(stream_id);
543     cmd->resp.code = msg_sz == sizeof(stream_id)
544                    ? virtio_snd_pcm_prepare(s, stream_id)
545                    : cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
546 }
547 
548 /*
549  * Handles VIRTIO_SND_R_PCM_START.
550  *
551  * @s: VirtIOSound device
552  * @cmd: The request command queue element from VirtIOSound cmdq field
553  * @start: whether to start or stop the device
554  */
555 static void virtio_snd_handle_pcm_start_stop(VirtIOSound *s,
556                                              virtio_snd_ctrl_command *cmd,
557                                              bool start)
558 {
559     VirtIOSoundPCMStream *stream;
560     virtio_snd_pcm_hdr req;
561     uint32_t stream_id;
562     size_t msg_sz = iov_to_buf(cmd->elem->out_sg,
563                                cmd->elem->out_num,
564                                0,
565                                &req,
566                                sizeof(virtio_snd_pcm_hdr));
567 
568     if (msg_sz != sizeof(virtio_snd_pcm_hdr)) {
569         qemu_log_mask(LOG_GUEST_ERROR,
570                 "%s: virtio-snd command size incorrect %zu vs \
571                 %zu\n", __func__, msg_sz, sizeof(virtio_snd_pcm_hdr));
572         cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
573         return;
574     }
575 
576     stream_id = le32_to_cpu(req.stream_id);
577     cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_OK);
578     trace_virtio_snd_handle_pcm_start_stop(start ? "VIRTIO_SND_R_PCM_START" :
579             "VIRTIO_SND_R_PCM_STOP", stream_id);
580 
581     stream = virtio_snd_pcm_get_stream(s, stream_id);
582     if (stream) {
583         WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
584             stream->active = start;
585         }
586         if (stream->info.direction == VIRTIO_SND_D_OUTPUT) {
587             AUD_set_active_out(stream->voice.out, start);
588         } else {
589             AUD_set_active_in(stream->voice.in, start);
590         }
591     } else {
592         error_report("Invalid stream id: %"PRIu32, stream_id);
593         cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
594         return;
595     }
596     stream->active = start;
597 }
598 
599 /*
600  * Returns the number of I/O messages that are being processed.
601  *
602  * @stream: VirtIOSoundPCMStream
603  */
604 static size_t virtio_snd_pcm_get_io_msgs_count(VirtIOSoundPCMStream *stream)
605 {
606     VirtIOSoundPCMBuffer *buffer, *next;
607     size_t count = 0;
608 
609     WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
610         QSIMPLEQ_FOREACH_SAFE(buffer, &stream->queue, entry, next) {
611             count += 1;
612         }
613         QSIMPLEQ_FOREACH_SAFE(buffer, &stream->invalid, entry, next) {
614             count += 1;
615         }
616     }
617     return count;
618 }
619 
620 /*
621  * Handles VIRTIO_SND_R_PCM_RELEASE.
622  *
623  * @s: VirtIOSound device
624  * @cmd: The request command queue element from VirtIOSound cmdq field
625  */
626 static void virtio_snd_handle_pcm_release(VirtIOSound *s,
627                                           virtio_snd_ctrl_command *cmd)
628 {
629     uint32_t stream_id;
630     VirtIOSoundPCMStream *stream;
631     size_t msg_sz = iov_to_buf(cmd->elem->out_sg,
632                                cmd->elem->out_num,
633                                sizeof(virtio_snd_hdr),
634                                &stream_id,
635                                sizeof(stream_id));
636 
637     if (msg_sz != sizeof(stream_id)) {
638         /*
639          * TODO: do we need to set DEVICE_NEEDS_RESET?
640          */
641         qemu_log_mask(LOG_GUEST_ERROR,
642                 "%s: virtio-snd command size incorrect %zu vs \
643                 %zu\n", __func__, msg_sz, sizeof(stream_id));
644         cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
645         return;
646     }
647 
648     stream_id = le32_to_cpu(stream_id);
649     trace_virtio_snd_handle_pcm_release(stream_id);
650     stream = virtio_snd_pcm_get_stream(s, stream_id);
651     if (stream == NULL) {
652         /*
653          * TODO: do we need to set DEVICE_NEEDS_RESET?
654          */
655         error_report("already released stream %"PRIu32, stream_id);
656         virtio_error(VIRTIO_DEVICE(s),
657                      "already released stream %"PRIu32,
658                      stream_id);
659         cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
660         return;
661     }
662 
663     if (virtio_snd_pcm_get_io_msgs_count(stream)) {
664         /*
665          * virtio-v1.2-csd01, 5.14.6.6.5.1,
666          * Device Requirements: Stream Release
667          *
668          * - The device MUST complete all pending I/O messages for the
669          *   specified stream ID.
670          * - The device MUST NOT complete the control request while there
671          *   are pending I/O messages for the specified stream ID.
672          */
673         trace_virtio_snd_pcm_stream_flush(stream_id);
674         virtio_snd_pcm_flush(stream);
675     }
676 
677     cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_OK);
678 }
679 
680 /*
681  * The actual processing done in virtio_snd_process_cmdq().
682  *
683  * @s: VirtIOSound device
684  * @cmd: control command request
685  */
686 static inline void
687 process_cmd(VirtIOSound *s, virtio_snd_ctrl_command *cmd)
688 {
689     uint32_t code;
690     size_t msg_sz = iov_to_buf(cmd->elem->out_sg,
691                                cmd->elem->out_num,
692                                0,
693                                &cmd->ctrl,
694                                sizeof(virtio_snd_hdr));
695 
696     if (msg_sz != sizeof(virtio_snd_hdr)) {
697         /*
698          * TODO: do we need to set DEVICE_NEEDS_RESET?
699          */
700         qemu_log_mask(LOG_GUEST_ERROR,
701                 "%s: virtio-snd command size incorrect %zu vs \
702                 %zu\n", __func__, msg_sz, sizeof(virtio_snd_hdr));
703         return;
704     }
705 
706     code = le32_to_cpu(cmd->ctrl.code);
707 
708     trace_virtio_snd_handle_code(code, print_code(code));
709 
710     switch (code) {
711     case VIRTIO_SND_R_JACK_INFO:
712     case VIRTIO_SND_R_JACK_REMAP:
713         qemu_log_mask(LOG_UNIMP,
714                      "virtio_snd: jack functionality is unimplemented.\n");
715         cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_NOT_SUPP);
716         break;
717     case VIRTIO_SND_R_PCM_INFO:
718         virtio_snd_handle_pcm_info(s, cmd);
719         break;
720     case VIRTIO_SND_R_PCM_START:
721         virtio_snd_handle_pcm_start_stop(s, cmd, true);
722         break;
723     case VIRTIO_SND_R_PCM_STOP:
724         virtio_snd_handle_pcm_start_stop(s, cmd, false);
725         break;
726     case VIRTIO_SND_R_PCM_SET_PARAMS:
727         virtio_snd_handle_pcm_set_params(s, cmd);
728         break;
729     case VIRTIO_SND_R_PCM_PREPARE:
730         virtio_snd_handle_pcm_prepare(s, cmd);
731         break;
732     case VIRTIO_SND_R_PCM_RELEASE:
733         virtio_snd_handle_pcm_release(s, cmd);
734         break;
735     case VIRTIO_SND_R_CHMAP_INFO:
736         qemu_log_mask(LOG_UNIMP,
737                      "virtio_snd: chmap info functionality is unimplemented.\n");
738         trace_virtio_snd_handle_chmap_info();
739         cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_NOT_SUPP);
740         break;
741     default:
742         /* error */
743         error_report("virtio snd header not recognized: %"PRIu32, code);
744         cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
745     }
746 
747     iov_from_buf(cmd->elem->in_sg,
748                  cmd->elem->in_num,
749                  0,
750                  &cmd->resp,
751                  sizeof(virtio_snd_hdr));
752     virtqueue_push(cmd->vq, cmd->elem, sizeof(virtio_snd_hdr));
753     virtio_notify(VIRTIO_DEVICE(s), cmd->vq);
754 }
755 
756 /*
757  * Consume all elements in command queue.
758  *
759  * @s: VirtIOSound device
760  */
761 static void virtio_snd_process_cmdq(VirtIOSound *s)
762 {
763     virtio_snd_ctrl_command *cmd;
764 
765     if (unlikely(qatomic_read(&s->processing_cmdq))) {
766         return;
767     }
768 
769     WITH_QEMU_LOCK_GUARD(&s->cmdq_mutex) {
770         qatomic_set(&s->processing_cmdq, true);
771         while (!QTAILQ_EMPTY(&s->cmdq)) {
772             cmd = QTAILQ_FIRST(&s->cmdq);
773 
774             /* process command */
775             process_cmd(s, cmd);
776 
777             QTAILQ_REMOVE(&s->cmdq, cmd, next);
778 
779             virtio_snd_ctrl_cmd_free(cmd);
780         }
781         qatomic_set(&s->processing_cmdq, false);
782     }
783 }
784 
785 /*
786  * The control message handler. Pops an element from the control virtqueue,
787  * and stores them to VirtIOSound's cmdq queue and finally calls
788  * virtio_snd_process_cmdq() for processing.
789  *
790  * @vdev: VirtIOSound device
791  * @vq: Control virtqueue
792  */
793 static void virtio_snd_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
794 {
795     VirtIOSound *s = VIRTIO_SND(vdev);
796     VirtQueueElement *elem;
797     virtio_snd_ctrl_command *cmd;
798 
799     trace_virtio_snd_handle_ctrl(vdev, vq);
800 
801     if (!virtio_queue_ready(vq)) {
802         return;
803     }
804 
805     elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
806     while (elem) {
807         cmd = g_new0(virtio_snd_ctrl_command, 1);
808         cmd->elem = elem;
809         cmd->vq = vq;
810         cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_OK);
811         QTAILQ_INSERT_TAIL(&s->cmdq, cmd, next);
812         elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
813     }
814 
815     virtio_snd_process_cmdq(s);
816 }
817 
818 /*
819  * The event virtqueue handler.
820  * Not implemented yet.
821  *
822  * @vdev: VirtIOSound device
823  * @vq: event vq
824  */
825 static void virtio_snd_handle_event(VirtIODevice *vdev, VirtQueue *vq)
826 {
827     qemu_log_mask(LOG_UNIMP, "virtio_snd: event queue is unimplemented.\n");
828     trace_virtio_snd_handle_event();
829 }
830 
831 static inline void empty_invalid_queue(VirtIODevice *vdev, VirtQueue *vq)
832 {
833     VirtIOSoundPCMBuffer *buffer = NULL;
834     VirtIOSoundPCMStream *stream = NULL;
835     virtio_snd_pcm_status resp = { 0 };
836     VirtIOSound *vsnd = VIRTIO_SND(vdev);
837     bool any = false;
838 
839     for (uint32_t i = 0; i < vsnd->snd_conf.streams; i++) {
840         stream = vsnd->pcm->streams[i];
841         if (stream) {
842             any = false;
843             WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
844                 while (!QSIMPLEQ_EMPTY(&stream->invalid)) {
845                     buffer = QSIMPLEQ_FIRST(&stream->invalid);
846                     if (buffer->vq != vq) {
847                         break;
848                     }
849                     any = true;
850                     resp.status = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
851                     iov_from_buf(buffer->elem->in_sg,
852                                  buffer->elem->in_num,
853                                  0,
854                                  &resp,
855                                  sizeof(virtio_snd_pcm_status));
856                     virtqueue_push(vq,
857                                    buffer->elem,
858                                    sizeof(virtio_snd_pcm_status));
859                     QSIMPLEQ_REMOVE_HEAD(&stream->invalid, entry);
860                     virtio_snd_pcm_buffer_free(buffer);
861                 }
862                 if (any) {
863                     /*
864                      * Notify vq about virtio_snd_pcm_status responses.
865                      * Buffer responses must be notified separately later.
866                      */
867                     virtio_notify(vdev, vq);
868                 }
869             }
870         }
871     }
872 }
873 
874 /*
875  * The tx virtqueue handler. Makes the buffers available to their respective
876  * streams for consumption.
877  *
878  * @vdev: VirtIOSound device
879  * @vq: tx virtqueue
880  */
881 static void virtio_snd_handle_tx_xfer(VirtIODevice *vdev, VirtQueue *vq)
882 {
883     VirtIOSound *s = VIRTIO_SND(vdev);
884     VirtIOSoundPCMStream *stream = NULL;
885     VirtIOSoundPCMBuffer *buffer;
886     VirtQueueElement *elem;
887     size_t msg_sz, size;
888     virtio_snd_pcm_xfer hdr;
889     uint32_t stream_id;
890     /*
891      * If any of the I/O messages are invalid, put them in stream->invalid and
892      * return them after the for loop.
893      */
894     bool must_empty_invalid_queue = false;
895 
896     if (!virtio_queue_ready(vq)) {
897         return;
898     }
899     trace_virtio_snd_handle_tx_xfer();
900 
901     for (;;) {
902         elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
903         if (!elem) {
904             break;
905         }
906         /* get the message hdr object */
907         msg_sz = iov_to_buf(elem->out_sg,
908                             elem->out_num,
909                             0,
910                             &hdr,
911                             sizeof(virtio_snd_pcm_xfer));
912         if (msg_sz != sizeof(virtio_snd_pcm_xfer)) {
913             goto tx_err;
914         }
915         stream_id = le32_to_cpu(hdr.stream_id);
916 
917         if (stream_id >= s->snd_conf.streams
918             || s->pcm->streams[stream_id] == NULL) {
919             goto tx_err;
920         }
921 
922         stream = s->pcm->streams[stream_id];
923         if (stream->info.direction != VIRTIO_SND_D_OUTPUT) {
924             goto tx_err;
925         }
926 
927         WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
928             size = iov_size(elem->out_sg, elem->out_num) - msg_sz;
929 
930             buffer = g_malloc0(sizeof(VirtIOSoundPCMBuffer) + size);
931             buffer->elem = elem;
932             buffer->populated = false;
933             buffer->vq = vq;
934             buffer->size = size;
935             buffer->offset = 0;
936 
937             QSIMPLEQ_INSERT_TAIL(&stream->queue, buffer, entry);
938         }
939         continue;
940 
941 tx_err:
942         WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
943             must_empty_invalid_queue = true;
944             buffer = g_malloc0(sizeof(VirtIOSoundPCMBuffer));
945             buffer->elem = elem;
946             buffer->vq = vq;
947             QSIMPLEQ_INSERT_TAIL(&stream->invalid, buffer, entry);
948         }
949     }
950 
951     if (must_empty_invalid_queue) {
952         empty_invalid_queue(vdev, vq);
953     }
954 }
955 
956 /*
957  * The rx virtqueue handler. Makes the buffers available to their respective
958  * streams for consumption.
959  *
960  * @vdev: VirtIOSound device
961  * @vq: rx virtqueue
962  */
963 static void virtio_snd_handle_rx_xfer(VirtIODevice *vdev, VirtQueue *vq)
964 {
965     VirtIOSound *s = VIRTIO_SND(vdev);
966     VirtIOSoundPCMStream *stream = NULL;
967     VirtIOSoundPCMBuffer *buffer;
968     VirtQueueElement *elem;
969     size_t msg_sz, size;
970     virtio_snd_pcm_xfer hdr;
971     uint32_t stream_id;
972     /*
973      * if any of the I/O messages are invalid, put them in stream->invalid and
974      * return them after the for loop.
975      */
976     bool must_empty_invalid_queue = false;
977 
978     if (!virtio_queue_ready(vq)) {
979         return;
980     }
981     trace_virtio_snd_handle_rx_xfer();
982 
983     for (;;) {
984         elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
985         if (!elem) {
986             break;
987         }
988         /* get the message hdr object */
989         msg_sz = iov_to_buf(elem->out_sg,
990                             elem->out_num,
991                             0,
992                             &hdr,
993                             sizeof(virtio_snd_pcm_xfer));
994         if (msg_sz != sizeof(virtio_snd_pcm_xfer)) {
995             goto rx_err;
996         }
997         stream_id = le32_to_cpu(hdr.stream_id);
998 
999         if (stream_id >= s->snd_conf.streams
1000             || !s->pcm->streams[stream_id]) {
1001             goto rx_err;
1002         }
1003 
1004         stream = s->pcm->streams[stream_id];
1005         if (stream == NULL || stream->info.direction != VIRTIO_SND_D_INPUT) {
1006             goto rx_err;
1007         }
1008         WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
1009             size = iov_size(elem->in_sg, elem->in_num) -
1010                 sizeof(virtio_snd_pcm_status);
1011             buffer = g_malloc0(sizeof(VirtIOSoundPCMBuffer) + size);
1012             buffer->elem = elem;
1013             buffer->vq = vq;
1014             buffer->size = 0;
1015             buffer->offset = 0;
1016             QSIMPLEQ_INSERT_TAIL(&stream->queue, buffer, entry);
1017         }
1018         continue;
1019 
1020 rx_err:
1021         WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
1022             must_empty_invalid_queue = true;
1023             buffer = g_malloc0(sizeof(VirtIOSoundPCMBuffer));
1024             buffer->elem = elem;
1025             buffer->vq = vq;
1026             QSIMPLEQ_INSERT_TAIL(&stream->invalid, buffer, entry);
1027         }
1028     }
1029 
1030     if (must_empty_invalid_queue) {
1031         empty_invalid_queue(vdev, vq);
1032     }
1033 }
1034 
1035 static uint64_t get_features(VirtIODevice *vdev, uint64_t features,
1036                              Error **errp)
1037 {
1038     /*
1039      * virtio-v1.2-csd01, 5.14.3,
1040      * Feature Bits
1041      * None currently defined.
1042      */
1043     VirtIOSound *s = VIRTIO_SND(vdev);
1044     features |= s->features;
1045 
1046     trace_virtio_snd_get_features(vdev, features);
1047 
1048     return features;
1049 }
1050 
1051 static void
1052 virtio_snd_vm_state_change(void *opaque, bool running,
1053                                        RunState state)
1054 {
1055     if (running) {
1056         trace_virtio_snd_vm_state_running();
1057     } else {
1058         trace_virtio_snd_vm_state_stopped();
1059     }
1060 }
1061 
1062 static void virtio_snd_realize(DeviceState *dev, Error **errp)
1063 {
1064     ERRP_GUARD();
1065     VirtIOSound *vsnd = VIRTIO_SND(dev);
1066     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
1067     virtio_snd_pcm_set_params default_params = { 0 };
1068     uint32_t status;
1069 
1070     trace_virtio_snd_realize(vsnd);
1071 
1072     /* check number of jacks and streams */
1073     if (vsnd->snd_conf.jacks > 8) {
1074         error_setg(errp,
1075                    "Invalid number of jacks: %"PRIu32,
1076                    vsnd->snd_conf.jacks);
1077         return;
1078     }
1079     if (vsnd->snd_conf.streams < 1 || vsnd->snd_conf.streams > 10) {
1080         error_setg(errp,
1081                    "Invalid number of streams: %"PRIu32,
1082                     vsnd->snd_conf.streams);
1083         return;
1084     }
1085 
1086     if (vsnd->snd_conf.chmaps > VIRTIO_SND_CHMAP_MAX_SIZE) {
1087         error_setg(errp,
1088                    "Invalid number of channel maps: %"PRIu32,
1089                    vsnd->snd_conf.chmaps);
1090         return;
1091     }
1092 
1093     if (!AUD_register_card("virtio-sound", &vsnd->card, errp)) {
1094         return;
1095     }
1096 
1097     vsnd->vmstate =
1098         qemu_add_vm_change_state_handler(virtio_snd_vm_state_change, vsnd);
1099 
1100     vsnd->pcm = g_new0(VirtIOSoundPCM, 1);
1101     vsnd->pcm->snd = vsnd;
1102     vsnd->pcm->streams =
1103         g_new0(VirtIOSoundPCMStream *, vsnd->snd_conf.streams);
1104     vsnd->pcm->pcm_params =
1105         g_new0(virtio_snd_pcm_set_params, vsnd->snd_conf.streams);
1106 
1107     virtio_init(vdev, VIRTIO_ID_SOUND, sizeof(virtio_snd_config));
1108     virtio_add_feature(&vsnd->features, VIRTIO_F_VERSION_1);
1109 
1110     /* set default params for all streams */
1111     default_params.features = 0;
1112     default_params.buffer_bytes = cpu_to_le32(8192);
1113     default_params.period_bytes = cpu_to_le32(2048);
1114     default_params.channels = 2;
1115     default_params.format = VIRTIO_SND_PCM_FMT_S16;
1116     default_params.rate = VIRTIO_SND_PCM_RATE_48000;
1117     vsnd->queues[VIRTIO_SND_VQ_CONTROL] =
1118         virtio_add_queue(vdev, 64, virtio_snd_handle_ctrl);
1119     vsnd->queues[VIRTIO_SND_VQ_EVENT] =
1120         virtio_add_queue(vdev, 64, virtio_snd_handle_event);
1121     vsnd->queues[VIRTIO_SND_VQ_TX] =
1122         virtio_add_queue(vdev, 64, virtio_snd_handle_tx_xfer);
1123     vsnd->queues[VIRTIO_SND_VQ_RX] =
1124         virtio_add_queue(vdev, 64, virtio_snd_handle_rx_xfer);
1125     qemu_mutex_init(&vsnd->cmdq_mutex);
1126     QTAILQ_INIT(&vsnd->cmdq);
1127 
1128     for (uint32_t i = 0; i < vsnd->snd_conf.streams; i++) {
1129         status = virtio_snd_set_pcm_params(vsnd, i, &default_params);
1130         if (status != cpu_to_le32(VIRTIO_SND_S_OK)) {
1131             error_setg(errp,
1132                        "Can't initialize stream params, device responded with %s.",
1133                        print_code(status));
1134             goto error_cleanup;
1135         }
1136         status = virtio_snd_pcm_prepare(vsnd, i);
1137         if (status != cpu_to_le32(VIRTIO_SND_S_OK)) {
1138             error_setg(errp,
1139                        "Can't prepare streams, device responded with %s.",
1140                        print_code(status));
1141             goto error_cleanup;
1142         }
1143     }
1144 
1145     return;
1146 
1147 error_cleanup:
1148     virtio_snd_unrealize(dev);
1149 }
1150 
1151 static inline void return_tx_buffer(VirtIOSoundPCMStream *stream,
1152                                     VirtIOSoundPCMBuffer *buffer)
1153 {
1154     virtio_snd_pcm_status resp = { 0 };
1155     resp.status = cpu_to_le32(VIRTIO_SND_S_OK);
1156     resp.latency_bytes = cpu_to_le32((uint32_t)buffer->size);
1157     iov_from_buf(buffer->elem->in_sg,
1158                  buffer->elem->in_num,
1159                  0,
1160                  &resp,
1161                  sizeof(virtio_snd_pcm_status));
1162     virtqueue_push(buffer->vq,
1163                    buffer->elem,
1164                    sizeof(virtio_snd_pcm_status));
1165     virtio_notify(VIRTIO_DEVICE(stream->s), buffer->vq);
1166     QSIMPLEQ_REMOVE(&stream->queue,
1167                     buffer,
1168                     VirtIOSoundPCMBuffer,
1169                     entry);
1170     virtio_snd_pcm_buffer_free(buffer);
1171 }
1172 
1173 /*
1174  * AUD_* output callback.
1175  *
1176  * @data: VirtIOSoundPCMStream stream
1177  * @available: number of bytes that can be written with AUD_write()
1178  */
1179 static void virtio_snd_pcm_out_cb(void *data, int available)
1180 {
1181     VirtIOSoundPCMStream *stream = data;
1182     VirtIOSoundPCMBuffer *buffer;
1183     size_t size;
1184 
1185     WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
1186         while (!QSIMPLEQ_EMPTY(&stream->queue)) {
1187             buffer = QSIMPLEQ_FIRST(&stream->queue);
1188             if (!virtio_queue_ready(buffer->vq)) {
1189                 return;
1190             }
1191             if (!stream->active) {
1192                 /* Stream has stopped, so do not perform AUD_write. */
1193                 return_tx_buffer(stream, buffer);
1194                 continue;
1195             }
1196             if (!buffer->populated) {
1197                 iov_to_buf(buffer->elem->out_sg,
1198                            buffer->elem->out_num,
1199                            sizeof(virtio_snd_pcm_xfer),
1200                            buffer->data,
1201                            buffer->size);
1202                 buffer->populated = true;
1203             }
1204             for (;;) {
1205                 size = AUD_write(stream->voice.out,
1206                                  buffer->data + buffer->offset,
1207                                  MIN(buffer->size, available));
1208                 assert(size <= MIN(buffer->size, available));
1209                 if (size == 0) {
1210                     /* break out of both loops */
1211                     available = 0;
1212                     break;
1213                 }
1214                 buffer->size -= size;
1215                 buffer->offset += size;
1216                 available -= size;
1217                 if (buffer->size < 1) {
1218                     return_tx_buffer(stream, buffer);
1219                     break;
1220                 }
1221                 if (!available) {
1222                     break;
1223                 }
1224             }
1225             if (!available) {
1226                 break;
1227             }
1228         }
1229     }
1230 }
1231 
1232 /*
1233  * Flush all buffer data from this input stream's queue into the driver's
1234  * virtual queue.
1235  *
1236  * @stream: VirtIOSoundPCMStream *stream
1237  */
1238 static inline void return_rx_buffer(VirtIOSoundPCMStream *stream,
1239                                     VirtIOSoundPCMBuffer *buffer)
1240 {
1241     virtio_snd_pcm_status resp = { 0 };
1242     resp.status = cpu_to_le32(VIRTIO_SND_S_OK);
1243     resp.latency_bytes = 0;
1244     /* Copy data -if any- to guest */
1245     iov_from_buf(buffer->elem->in_sg,
1246                  buffer->elem->in_num,
1247                  0,
1248                  buffer->data,
1249                  buffer->size);
1250     iov_from_buf(buffer->elem->in_sg,
1251                  buffer->elem->in_num,
1252                  buffer->size,
1253                  &resp,
1254                  sizeof(virtio_snd_pcm_status));
1255     virtqueue_push(buffer->vq,
1256                    buffer->elem,
1257                    sizeof(virtio_snd_pcm_status) + buffer->size);
1258     virtio_notify(VIRTIO_DEVICE(stream->s), buffer->vq);
1259     QSIMPLEQ_REMOVE(&stream->queue,
1260                     buffer,
1261                     VirtIOSoundPCMBuffer,
1262                     entry);
1263     virtio_snd_pcm_buffer_free(buffer);
1264 }
1265 
1266 
1267 /*
1268  * AUD_* input callback.
1269  *
1270  * @data: VirtIOSoundPCMStream stream
1271  * @available: number of bytes that can be read with AUD_read()
1272  */
1273 static void virtio_snd_pcm_in_cb(void *data, int available)
1274 {
1275     VirtIOSoundPCMStream *stream = data;
1276     VirtIOSoundPCMBuffer *buffer;
1277     size_t size;
1278 
1279     WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
1280         while (!QSIMPLEQ_EMPTY(&stream->queue)) {
1281             buffer = QSIMPLEQ_FIRST(&stream->queue);
1282             if (!virtio_queue_ready(buffer->vq)) {
1283                 return;
1284             }
1285             if (!stream->active) {
1286                 /* Stream has stopped, so do not perform AUD_read. */
1287                 return_rx_buffer(stream, buffer);
1288                 continue;
1289             }
1290 
1291             for (;;) {
1292                 size = AUD_read(stream->voice.in,
1293                         buffer->data + buffer->size,
1294                         MIN(available, (stream->params.period_bytes -
1295                                         buffer->size)));
1296                 if (!size) {
1297                     available = 0;
1298                     break;
1299                 }
1300                 buffer->size += size;
1301                 available -= size;
1302                 if (buffer->size >= stream->params.period_bytes) {
1303                     return_rx_buffer(stream, buffer);
1304                     break;
1305                 }
1306                 if (!available) {
1307                     break;
1308                 }
1309             }
1310             if (!available) {
1311                 break;
1312             }
1313         }
1314     }
1315 }
1316 
1317 /*
1318  * Flush all buffer data from this output stream's queue into the driver's
1319  * virtual queue.
1320  *
1321  * @stream: VirtIOSoundPCMStream *stream
1322  */
1323 static inline void virtio_snd_pcm_flush(VirtIOSoundPCMStream *stream)
1324 {
1325     VirtIOSoundPCMBuffer *buffer;
1326     void (*cb)(VirtIOSoundPCMStream *, VirtIOSoundPCMBuffer *) =
1327         (stream->info.direction == VIRTIO_SND_D_OUTPUT) ? return_tx_buffer :
1328         return_rx_buffer;
1329 
1330     WITH_QEMU_LOCK_GUARD(&stream->queue_mutex) {
1331         while (!QSIMPLEQ_EMPTY(&stream->queue)) {
1332             buffer = QSIMPLEQ_FIRST(&stream->queue);
1333             cb(stream, buffer);
1334         }
1335     }
1336 }
1337 
1338 static void virtio_snd_unrealize(DeviceState *dev)
1339 {
1340     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
1341     VirtIOSound *vsnd = VIRTIO_SND(dev);
1342     VirtIOSoundPCMStream *stream;
1343 
1344     qemu_del_vm_change_state_handler(vsnd->vmstate);
1345     trace_virtio_snd_unrealize(vsnd);
1346 
1347     if (vsnd->pcm) {
1348         if (vsnd->pcm->streams) {
1349             for (uint32_t i = 0; i < vsnd->snd_conf.streams; i++) {
1350                 stream = vsnd->pcm->streams[i];
1351                 if (stream) {
1352                     virtio_snd_process_cmdq(stream->s);
1353                     virtio_snd_pcm_close(stream);
1354                     qemu_mutex_destroy(&stream->queue_mutex);
1355                     g_free(stream);
1356                 }
1357             }
1358             g_free(vsnd->pcm->streams);
1359         }
1360         g_free(vsnd->pcm->pcm_params);
1361         g_free(vsnd->pcm);
1362         vsnd->pcm = NULL;
1363     }
1364     AUD_remove_card(&vsnd->card);
1365     qemu_mutex_destroy(&vsnd->cmdq_mutex);
1366     virtio_delete_queue(vsnd->queues[VIRTIO_SND_VQ_CONTROL]);
1367     virtio_delete_queue(vsnd->queues[VIRTIO_SND_VQ_EVENT]);
1368     virtio_delete_queue(vsnd->queues[VIRTIO_SND_VQ_TX]);
1369     virtio_delete_queue(vsnd->queues[VIRTIO_SND_VQ_RX]);
1370     virtio_cleanup(vdev);
1371 }
1372 
1373 
1374 static void virtio_snd_reset(VirtIODevice *vdev)
1375 {
1376     VirtIOSound *s = VIRTIO_SND(vdev);
1377     virtio_snd_ctrl_command *cmd;
1378 
1379     WITH_QEMU_LOCK_GUARD(&s->cmdq_mutex) {
1380         while (!QTAILQ_EMPTY(&s->cmdq)) {
1381             cmd = QTAILQ_FIRST(&s->cmdq);
1382             QTAILQ_REMOVE(&s->cmdq, cmd, next);
1383             virtio_snd_ctrl_cmd_free(cmd);
1384         }
1385     }
1386 }
1387 
1388 static void virtio_snd_class_init(ObjectClass *klass, void *data)
1389 {
1390     DeviceClass *dc = DEVICE_CLASS(klass);
1391     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1392 
1393 
1394     set_bit(DEVICE_CATEGORY_SOUND, dc->categories);
1395     device_class_set_props(dc, virtio_snd_properties);
1396 
1397     dc->vmsd = &vmstate_virtio_snd;
1398     vdc->vmsd = &vmstate_virtio_snd_device;
1399     vdc->realize = virtio_snd_realize;
1400     vdc->unrealize = virtio_snd_unrealize;
1401     vdc->get_config = virtio_snd_get_config;
1402     vdc->set_config = virtio_snd_set_config;
1403     vdc->get_features = get_features;
1404     vdc->reset = virtio_snd_reset;
1405     vdc->legacy_features = 0;
1406 }
1407 
1408 static const TypeInfo virtio_snd_types[] = {
1409     {
1410       .name          = TYPE_VIRTIO_SND,
1411       .parent        = TYPE_VIRTIO_DEVICE,
1412       .instance_size = sizeof(VirtIOSound),
1413       .class_init    = virtio_snd_class_init,
1414     }
1415 };
1416 
1417 DEFINE_TYPES(virtio_snd_types)
1418