Re: [PATCH v2 07/11] hw/audio/virtio-sound: add stream state variable

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Feb 19, 2024 at 02:59:45PM +0200, Manos Pitsidianakis wrote:
> Hello Volker,
> 
> On Sun, 18 Feb 2024 at 10:34, Volker Rümelin <vr_qemu@t-online.de> wrote:
> >
> > So far, only rudimentary checks have been made to ensure that
> > the guest only performs state transitions permitted in
> > virtio-v1.2-csd01 5.14.6.6.1 PCM Command Lifecycle.
> 
> 5.14.6.6.1 is non-normative in virtio v1.2. You can even see it's not
> in device requirements. The state transitions were thus not checked on
> purpose.
> 
> There is nothing in the standard that describes error conditions
> pertaining to the "PCM lifecycle" state machine. It really should, but
> it doesn't, unfortunately.

Not too late to add it. It will have to be non-mandatory
(e.g. SHOULD) or depend on a feature bit, though.


> > Add a state
> > variable per audio stream and check all state transitions.
> >
> > Because only permitted state transitions are possible, only one
> > copy of the audio stream parameters is required and these do not
> > need to be initialised with default values.
> >
> > The state variable will also make it easier to restore the audio
> > stream after migration.
> 
> I suggest you instead add the state tracking but only use it for the
> post_load code for migration.
> 
> 
> 
> > Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
> > ---
> >  hw/audio/virtio-snd.c         | 213 ++++++++++++++++++----------------
> >  include/hw/audio/virtio-snd.h |  20 +---
> >  2 files changed, 111 insertions(+), 122 deletions(-)
> >
> > diff --git a/hw/audio/virtio-snd.c b/hw/audio/virtio-snd.c
> > index 435ce26430..bbbdd01aa9 100644
> > --- a/hw/audio/virtio-snd.c
> > +++ b/hw/audio/virtio-snd.c
> > @@ -31,11 +31,30 @@
> >  #define VIRTIO_SOUND_CHMAP_DEFAULT 0
> >  #define VIRTIO_SOUND_HDA_FN_NID 0
> >
> > +#define VSND_PCMSTREAM_STATE_F_PARAMS_SET  0x10000
> > +#define VSND_PCMSTREAM_STATE_F_PREPARED    0x20000
> > +#define VSND_PCMSTREAM_STATE_F_ACTIVE      0x40000
> > +
> > +#define VSND_PCMSTREAM_STATE_UNINITIALIZED 0
> > +#define VSND_PCMSTREAM_STATE_PARAMS_SET    (1 \
> > +                                           | VSND_PCMSTREAM_STATE_F_PARAMS_SET)
> > +#define VSND_PCMSTREAM_STATE_PREPARED      (2 \
> > +                                           | VSND_PCMSTREAM_STATE_F_PARAMS_SET \
> > +                                           | VSND_PCMSTREAM_STATE_F_PREPARED)
> > +#define VSND_PCMSTREAM_STATE_STARTED       (4 \
> > +                                           | VSND_PCMSTREAM_STATE_F_PARAMS_SET \
> > +                                           | VSND_PCMSTREAM_STATE_F_PREPARED \
> > +                                           | VSND_PCMSTREAM_STATE_F_ACTIVE)
> > +#define VSND_PCMSTREAM_STATE_STOPPED       (6 \
> > +                                           | VSND_PCMSTREAM_STATE_F_PARAMS_SET \
> > +                                           | VSND_PCMSTREAM_STATE_F_PREPARED)
> > +#define VSND_PCMSTREAM_STATE_RELEASED      (7 \
> > +                                           | VSND_PCMSTREAM_STATE_F_PARAMS_SET)
> > +
> >  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 void virtio_snd_pcm_in_cb(void *data, int available);
> > -static void virtio_snd_unrealize(DeviceState *dev);
> >
> >  static uint32_t supported_formats = BIT(VIRTIO_SND_PCM_FMT_S8)
> >                                    | BIT(VIRTIO_SND_PCM_FMT_U8)
> > @@ -153,8 +172,8 @@ virtio_snd_ctrl_cmd_free(virtio_snd_ctrl_command *cmd)
> >  static VirtIOSoundPCMStream *virtio_snd_pcm_get_stream(VirtIOSound *s,
> >                                                         uint32_t stream_id)
> >  {
> > -    return stream_id >= s->snd_conf.streams ? NULL :
> > -        s->pcm->streams[stream_id];
> > +    return stream_id >= s->snd_conf.streams ? NULL
> > +        : &s->streams[stream_id];
> >  }
> >
> >  /*
> > @@ -167,7 +186,7 @@ static virtio_snd_pcm_set_params *virtio_snd_pcm_get_params(VirtIOSound *s,
> >                                                              uint32_t stream_id)
> >  {
> >      return stream_id >= s->snd_conf.streams ? NULL
> > -        : &s->pcm->pcm_params[stream_id];
> > +        : &s->streams[stream_id].params;
> >  }
> >
> >  /*
> > @@ -253,11 +272,10 @@ static void virtio_snd_handle_pcm_info(VirtIOSound *s,
> >
> >  /*
> >   * Set the given stream params.
> > - * Called by both virtio_snd_handle_pcm_set_params and during device
> > - * initialization.
> >   * Returns the response status code. (VIRTIO_SND_S_*).
> >   *
> >   * @s: VirtIOSound device
> > + * @stream_id: stream id
> >   * @params: The PCM params as defined in the virtio specification
> >   */
> >  static
> > @@ -265,9 +283,10 @@ uint32_t virtio_snd_set_pcm_params(VirtIOSound *s,
> >                                     uint32_t stream_id,
> >                                     virtio_snd_pcm_set_params *params)
> >  {
> > +    VirtIOSoundPCMStream *stream;
> >      virtio_snd_pcm_set_params *st_params;
> >
> > -    if (stream_id >= s->snd_conf.streams || s->pcm->pcm_params == NULL) {
> > +    if (stream_id >= s->snd_conf.streams) {
> >          /*
> >           * TODO: do we need to set DEVICE_NEEDS_RESET?
> >           */
> > @@ -275,7 +294,17 @@ uint32_t virtio_snd_set_pcm_params(VirtIOSound *s,
> >          return cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
> >      }
> >
> > -    st_params = virtio_snd_pcm_get_params(s, stream_id);
> > +    stream = virtio_snd_pcm_get_stream(s, stream_id);
> > +
> > +    switch (stream->state) {
> > +    case VSND_PCMSTREAM_STATE_UNINITIALIZED:
> > +    case VSND_PCMSTREAM_STATE_PARAMS_SET:
> > +    case VSND_PCMSTREAM_STATE_PREPARED:
> > +    case VSND_PCMSTREAM_STATE_RELEASED:
> > +        break;
> > +    default:
> > +        return cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
> > +    }
> >
> >      if (params->channels < 1 || params->channels > AUDIO_MAX_CHANNELS) {
> >          error_report("Number of channels is not supported.");
> > @@ -290,6 +319,8 @@ uint32_t virtio_snd_set_pcm_params(VirtIOSound *s,
> >          return cpu_to_le32(VIRTIO_SND_S_NOT_SUPP);
> >      }
> >
> > +    st_params = virtio_snd_pcm_get_params(s, stream_id);
> > +
> >      st_params->buffer_bytes = le32_to_cpu(params->buffer_bytes);
> >      st_params->period_bytes = le32_to_cpu(params->period_bytes);
> >      st_params->features = le32_to_cpu(params->features);
> > @@ -298,6 +329,13 @@ uint32_t virtio_snd_set_pcm_params(VirtIOSound *s,
> >      st_params->format = params->format;
> >      st_params->rate = params->rate;
> >
> > +    if (stream->state & VSND_PCMSTREAM_STATE_F_PREPARED) {
> > +        /* implicit VIRTIO_SND_R_PCM_RELEASE */
> > +        virtio_snd_pcm_flush(stream);
> > +    }
> > +
> > +    stream->state = VSND_PCMSTREAM_STATE_PARAMS_SET;
> > +
> >      return cpu_to_le32(VIRTIO_SND_S_OK);
> >  }
> >
> > @@ -410,15 +448,12 @@ static void virtio_snd_get_qemu_audsettings(audsettings *as,
> >   */
> >  static void virtio_snd_pcm_close(VirtIOSoundPCMStream *stream)
> >  {
> > -    if (stream) {
> > -        virtio_snd_pcm_flush(stream);
> > -        if (stream->info.direction == VIRTIO_SND_D_OUTPUT) {
> > -            AUD_close_out(&stream->pcm->snd->card, stream->voice.out);
> > -            stream->voice.out = NULL;
> > -        } else if (stream->info.direction == VIRTIO_SND_D_INPUT) {
> > -            AUD_close_in(&stream->pcm->snd->card, stream->voice.in);
> > -            stream->voice.in = NULL;
> > -        }
> > +    if (stream->info.direction == VIRTIO_SND_D_OUTPUT) {
> > +        AUD_close_out(&stream->s->card, stream->voice.out);
> > +        stream->voice.out = NULL;
> > +    } else {
> > +        AUD_close_in(&stream->s->card, stream->voice.in);
> > +        stream->voice.in = NULL;
> >      }
> >  }
> >
> > @@ -435,33 +470,23 @@ static uint32_t virtio_snd_pcm_prepare(VirtIOSound *s, uint32_t stream_id)
> >      virtio_snd_pcm_set_params *params;
> >      VirtIOSoundPCMStream *stream;
> >
> > -    if (s->pcm->streams == NULL ||
> > -        s->pcm->pcm_params == NULL ||
> > -        stream_id >= s->snd_conf.streams) {
> > +    stream = virtio_snd_pcm_get_stream(s, stream_id);
> > +    if (!stream) {
> >          return cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
> >      }
> >
> > -    params = virtio_snd_pcm_get_params(s, stream_id);
> > -    if (params == NULL) {
> > +    switch (stream->state) {
> > +    case VSND_PCMSTREAM_STATE_PARAMS_SET:
> > +    case VSND_PCMSTREAM_STATE_PREPARED:
> > +    case VSND_PCMSTREAM_STATE_RELEASED:
> > +        break;
> > +    default:
> >          return cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
> >      }
> >
> > -    stream = virtio_snd_pcm_get_stream(s, stream_id);
> > -    if (stream == NULL) {
> > -        stream = &s->streams[stream_id];
> > -        stream->active = false;
> > -        stream->pcm = s->pcm;
> > -
> > -        /*
> > -         * stream_id >= s->snd_conf.streams was checked before so this is
> > -         * in-bounds
> > -         */
> > -        s->pcm->streams[stream_id] = stream;
> > -    }
> > +    params = virtio_snd_pcm_get_params(s, stream_id);
> >
> >      virtio_snd_get_qemu_audsettings(&as, params);
> > -    stream->params = *params;
> > -
> >      stream->positions[0] = VIRTIO_SND_CHMAP_FL;
> >      stream->positions[1] = VIRTIO_SND_CHMAP_FR;
> >      stream->as = as;
> > @@ -484,6 +509,8 @@ static uint32_t virtio_snd_pcm_prepare(VirtIOSound *s, uint32_t stream_id)
> >          AUD_set_volume_in(stream->voice.in, 0, 255, 255);
> >      }
> >
> > +    stream->state = VSND_PCMSTREAM_STATE_PREPARED;
> > +
> >      return cpu_to_le32(VIRTIO_SND_S_OK);
> >  }
> >
> > @@ -552,12 +579,28 @@ static uint32_t virtio_snd_pcm_start_stop(VirtIOSound *s,
> >      }
> >
> >      if (start) {
> > +        switch (stream->state) {
> > +        case VSND_PCMSTREAM_STATE_PREPARED:
> > +        case VSND_PCMSTREAM_STATE_STOPPED:
> > +            break;
> > +        default:
> > +            return cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
> > +        }
> > +
> >          trace_virtio_snd_handle_pcm_start(stream_id);
> > +        stream->state = VSND_PCMSTREAM_STATE_STARTED;
> >      } else {
> > +        switch (stream->state) {
> > +        case VSND_PCMSTREAM_STATE_STARTED:
> > +            break;
> > +        default:
> > +            return cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
> > +        }
> > +
> >          trace_virtio_snd_handle_pcm_stop(stream_id);
> > +        stream->state = VSND_PCMSTREAM_STATE_STOPPED;
> >      }
> >
> > -    stream->active = start;
> >      if (stream->info.direction == VIRTIO_SND_D_OUTPUT) {
> >          AUD_set_active_out(stream->voice.out, start);
> >      } else {
> > @@ -644,15 +687,18 @@ static void virtio_snd_handle_pcm_release(VirtIOSound *s,
> >
> >      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);
> > +    if (!stream) {
> > +        cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
> > +        return;
> > +    }
> > +
> > +    switch (stream->state) {
> > +    case VSND_PCMSTREAM_STATE_PREPARED:
> > +    case VSND_PCMSTREAM_STATE_STOPPED:
> > +        break;
> > +    default:
> >          cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
> >          return;
> >      }
> > @@ -671,6 +717,8 @@ static void virtio_snd_handle_pcm_release(VirtIOSound *s,
> >          virtio_snd_pcm_flush(stream);
> >      }
> >
> > +    stream->state = VSND_PCMSTREAM_STATE_RELEASED;
> > +
> >      cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_OK);
> >  }
> >
> > @@ -873,12 +921,11 @@ static void virtio_snd_handle_tx_xfer(VirtIODevice *vdev, VirtQueue *vq)
> >          }
> >          stream_id = le32_to_cpu(hdr.stream_id);
> >
> > -        if (stream_id >= s->snd_conf.streams
> > -            || s->pcm->streams[stream_id] == NULL) {
> > +        if (stream_id >= s->snd_conf.streams) {
> >              goto tx_err;
> >          }
> >
> > -        stream = s->pcm->streams[stream_id];
> > +        stream = &s->streams[stream_id];
> >          if (stream->info.direction != VIRTIO_SND_D_OUTPUT) {
> >              goto tx_err;
> >          }
> > @@ -948,13 +995,12 @@ static void virtio_snd_handle_rx_xfer(VirtIODevice *vdev, VirtQueue *vq)
> >          }
> >          stream_id = le32_to_cpu(hdr.stream_id);
> >
> > -        if (stream_id >= s->snd_conf.streams
> > -            || !s->pcm->streams[stream_id]) {
> > +        if (stream_id >= s->snd_conf.streams) {
> >              goto rx_err;
> >          }
> >
> > -        stream = s->pcm->streams[stream_id];
> > -        if (stream == NULL || stream->info.direction != VIRTIO_SND_D_INPUT) {
> > +        stream = &s->streams[stream_id];
> > +        if (stream->info.direction != VIRTIO_SND_D_INPUT) {
> >              goto rx_err;
> >          }
> >          size = iov_size(elem->in_sg, elem->in_num) -
> > @@ -1013,8 +1059,6 @@ 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;
> >
> >      trace_virtio_snd_realize(vsnd);
> >
> > @@ -1052,6 +1096,7 @@ static void virtio_snd_realize(DeviceState *dev, Error **errp)
> >          VirtIOSoundPCMStream *stream = &vsnd->streams[i];
> >
> >          stream->id = i;
> > +        stream->state = VSND_PCMSTREAM_STATE_UNINITIALIZED;
> >          stream->s = vsnd;
> >          QSIMPLEQ_INIT(&stream->queue);
> >          stream->info.hdr.hda_fn_nid = VIRTIO_SOUND_HDA_FN_NID;
> > @@ -1065,23 +1110,9 @@ static void virtio_snd_realize(DeviceState *dev, Error **errp)
> >          stream->info.channels_max = 2;
> >      }
> >
> > -    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 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] =
> > @@ -1091,28 +1122,6 @@ static void virtio_snd_realize(DeviceState *dev, Error **errp)
> >      vsnd->queues[VIRTIO_SND_VQ_RX] =
> >          virtio_add_queue(vdev, 64, virtio_snd_handle_rx_xfer);
> >      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 initialize stream params, device responded with %s.",
> > -                       print_code(status));
> > -            goto error_cleanup;
> > -        }
> > -        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));
> > -            goto error_cleanup;
> > -        }
> > -    }
> > -
> > -    return;
> > -
> > -error_cleanup:
> > -    virtio_snd_unrealize(dev);
> >  }
> >
> >  static inline void return_tx_buffer(VirtIOSoundPCMStream *stream,
> > @@ -1154,7 +1163,7 @@ static void virtio_snd_pcm_out_cb(void *data, int available)
> >          if (!virtio_queue_ready(buffer->vq)) {
> >              return;
> >          }
> > -        if (!stream->active) {
> > +        if (!(stream->state & VSND_PCMSTREAM_STATE_F_ACTIVE)) {
> >              /* Stream has stopped, so do not perform AUD_write. */
> >              return_tx_buffer(stream, buffer);
> >              continue;
> > @@ -1246,7 +1255,7 @@ static void virtio_snd_pcm_in_cb(void *data, int available)
> >          if (!virtio_queue_ready(buffer->vq)) {
> >              return;
> >          }
> > -        if (!stream->active) {
> > +        if (!(stream->state & VSND_PCMSTREAM_STATE_F_ACTIVE)) {
> >              /* Stream has stopped, so do not perform AUD_read. */
> >              return_rx_buffer(stream, buffer);
> >              continue;
> > @@ -1306,19 +1315,14 @@ static void virtio_snd_unrealize(DeviceState *dev)
> >      trace_virtio_snd_unrealize(vsnd);
> >
> >      if (vsnd->streams) {
> > -        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);
> > -                }
> > +        virtio_snd_process_cmdq(vsnd);
> > +        for (uint32_t i = 0; i < vsnd->snd_conf.streams; i++) {
> > +            stream = &vsnd->streams[i];
> > +            if (stream->state & VSND_PCMSTREAM_STATE_F_PREPARED) {
> > +                virtio_snd_pcm_flush(stream);
> >              }
> > -            g_free(vsnd->pcm->streams);
> > +            virtio_snd_pcm_close(stream);
> >          }
> > -        g_free(vsnd->pcm->pcm_params);
> > -        g_free(vsnd->pcm);
> > -        vsnd->pcm = NULL;
> >          g_free(vsnd->streams);
> >          vsnd->streams = NULL;
> >      }
> > @@ -1347,6 +1351,9 @@ static void virtio_snd_reset(VirtIODevice *vdev)
> >          VirtIOSoundPCMStream *stream = &s->streams[i];
> >          VirtIOSoundPCMBuffer *buffer;
> >
> > +        virtio_snd_pcm_close(stream);
> > +        stream->state = VSND_PCMSTREAM_STATE_UNINITIALIZED;
> > +
> >          while ((buffer = QSIMPLEQ_FIRST(&stream->queue))) {
> >              QSIMPLEQ_REMOVE_HEAD(&stream->queue, entry);
> >              virtio_snd_pcm_buffer_free(buffer);
> > diff --git a/include/hw/audio/virtio-snd.h b/include/hw/audio/virtio-snd.h
> > index 95aef8192a..65afa6c184 100644
> > --- a/include/hw/audio/virtio-snd.h
> > +++ b/include/hw/audio/virtio-snd.h
> > @@ -75,8 +75,6 @@ typedef struct VirtIOSoundPCMStream VirtIOSoundPCMStream;
> >
> >  typedef struct virtio_snd_ctrl_command virtio_snd_ctrl_command;
> >
> > -typedef struct VirtIOSoundPCM VirtIOSoundPCM;
> > -
> >  typedef struct VirtIOSoundPCMBuffer VirtIOSoundPCMBuffer;
> >
> >  /*
> > @@ -121,34 +119,19 @@ struct VirtIOSoundPCMBuffer {
> >      uint8_t data[];
> >  };
> >
> > -struct VirtIOSoundPCM {
> > -    VirtIOSound *snd;
> > -    /*
> > -     * PCM parameters are a separate field instead of a VirtIOSoundPCMStream
> > -     * field, because the operation of PCM control requests is first
> > -     * VIRTIO_SND_R_PCM_SET_PARAMS and then VIRTIO_SND_R_PCM_PREPARE; this
> > -     * means that some times we get parameters without having an allocated
> > -     * stream yet.
> > -     */
> > -    virtio_snd_pcm_set_params *pcm_params;
> > -    VirtIOSoundPCMStream **streams;
> > -};
> > -
> >  struct VirtIOSoundPCMStream {
> > -    VirtIOSoundPCM *pcm;
> >      virtio_snd_pcm_info info;
> >      virtio_snd_pcm_set_params params;
> >      uint32_t id;
> > +    uint32_t state;
> >      /* 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;
> > -    bool active;
> >      QSIMPLEQ_HEAD(, VirtIOSoundPCMBuffer) queue;
> >  };
> >
> > @@ -214,7 +197,6 @@ struct VirtIOSound {
> >
> >      VirtQueue *queues[VIRTIO_SND_VQ_MAX];
> >      uint64_t features;
> > -    VirtIOSoundPCM *pcm;
> >      VirtIOSoundPCMStream *streams;
> >      QEMUSoundCard card;
> >      VMChangeStateEntry *vmstate;
> > --
> > 2.35.3
> >