diff mbox series

[v8,03/12] virtio-sound: handle control messages and streams

Message ID e3e57dd125611eeb5e563eb7fab8eb89194ed50e.1693252037.git.manos.pitsidianakis@linaro.org (mailing list archive)
State New, archived
Headers show
Series Add VIRTIO sound card | expand

Commit Message

Manos Pitsidianakis Aug. 28, 2023, 7:55 p.m. UTC
Receive guest requests in the control (CTRL) queue of the virtio sound
device and reply with a NOT SUPPORTED error to all control commands.

The receiving handler is virtio_snd_handle_ctrl(). It stores all control
messages in the queue in the device's command queue. Then it calls
virtio_snd_process_cmdq() to handle each message.

The handler is process_cmd() which replies with VIRTIO_SND_S_NOT_SUPP.

Based-on: https://github.com/OpenSynergy/qemu/commit/5a2f350eec5d157b90d9c7b40a8e603f4da92471
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Igor Skalkin <Igor.Skalkin@opensynergy.com>
Signed-off-by: Anton Yakovlev <Anton.Yakovlev@opensynergy.com>
Signed-off-by: Emmanouil Pitsidianakis <manos.pitsidianakis@linaro.org>
---
 hw/virtio/trace-events         |   4 +
 hw/virtio/virtio-snd.c         | 227 ++++++++++++++++++++++++++++++++-
 include/hw/virtio/virtio-snd.h |  70 +++++++++-
 3 files changed, 292 insertions(+), 9 deletions(-)

Comments

Philippe Mathieu-Daudé Sept. 4, 2023, 10:08 a.m. UTC | #1
Hi Emmanouil,

On 28/8/23 21:55, Emmanouil Pitsidianakis wrote:
> Receive guest requests in the control (CTRL) queue of the virtio sound
> device and reply with a NOT SUPPORTED error to all control commands.
> 
> The receiving handler is virtio_snd_handle_ctrl(). It stores all control
> messages in the queue in the device's command queue. Then it calls
> virtio_snd_process_cmdq() to handle each message.
> 
> The handler is process_cmd() which replies with VIRTIO_SND_S_NOT_SUPP.
> 
> Based-on: https://github.com/OpenSynergy/qemu/commit/5a2f350eec5d157b90d9c7b40a8e603f4da92471
> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: Igor Skalkin <Igor.Skalkin@opensynergy.com>
> Signed-off-by: Anton Yakovlev <Anton.Yakovlev@opensynergy.com>
> Signed-off-by: Emmanouil Pitsidianakis <manos.pitsidianakis@linaro.org>
> ---
>   hw/virtio/trace-events         |   4 +
>   hw/virtio/virtio-snd.c         | 227 ++++++++++++++++++++++++++++++++-
>   include/hw/virtio/virtio-snd.h |  70 +++++++++-
>   3 files changed, 292 insertions(+), 9 deletions(-)


>   /*
> - * Queue handler stub.
> + * The actual processing done in virtio_snd_process_cmdq().
> + *
> + * @s: VirtIOSound device
> + * @cmd: control command request
> + */
> +static inline void
> +process_cmd(VirtIOSound *s, virtio_snd_ctrl_command *cmd)
> +{
> +    size_t sz = iov_to_buf(cmd->elem->out_sg,
> +                           cmd->elem->out_num,
> +                           0,
> +                           &cmd->ctrl,
> +                           sizeof(cmd->ctrl));
> +    if (sz != sizeof(cmd->ctrl)) {
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                "%s: virtio-snd command size incorrect %zu vs \
> +                %zu\n", __func__, sz, sizeof(cmd->ctrl));
> +        return;
> +    }
> +
> +    trace_virtio_snd_handle_code(cmd->ctrl.code,
> +                                 print_code(cmd->ctrl.code));
> +
> +    switch (cmd->ctrl.code) {
> +    case VIRTIO_SND_R_JACK_INFO:
> +    case VIRTIO_SND_R_JACK_REMAP:
> +        qemu_log_mask(LOG_UNIMP,
> +                     "virtio_snd: jack functionality is unimplemented.");
> +        cmd->resp.code = VIRTIO_SND_S_NOT_SUPP;
> +        break;
> +    case VIRTIO_SND_R_PCM_INFO:
> +    case VIRTIO_SND_R_PCM_SET_PARAMS:
> +    case VIRTIO_SND_R_PCM_PREPARE:
> +    case VIRTIO_SND_R_PCM_START:
> +    case VIRTIO_SND_R_PCM_STOP:
> +    case VIRTIO_SND_R_PCM_RELEASE:
> +        cmd->resp.code = VIRTIO_SND_S_NOT_SUPP;
> +        break;
> +    case VIRTIO_SND_R_CHMAP_INFO:
> +        qemu_log_mask(LOG_UNIMP,
> +                     "virtio_snd: chmap info functionality is unimplemented.");
> +        trace_virtio_snd_handle_chmap_info();
> +        cmd->resp.code = VIRTIO_SND_S_NOT_SUPP;
> +        break;
> +    default:
> +        /* error */
> +        error_report("virtio snd header not recognized: %"PRIu32,
> +                     cmd->ctrl.code);
> +        cmd->resp.code = VIRTIO_SND_S_BAD_MSG;
> +    }
> +
> +    iov_from_buf(cmd->elem->in_sg,
> +                 cmd->elem->in_num,
> +                 0,
> +                 &cmd->resp,
> +                 sizeof(cmd->resp));
> +    virtqueue_push(cmd->vq, cmd->elem, sizeof(cmd->elem));
> +    virtio_notify(VIRTIO_DEVICE(s), cmd->vq);

I have very few understanding of virtio, but I'm wondering here,
since this function is called under cmdq_mutex(), could it be
useful to batch the queue by calling virtio_notify() only once
in the caller once the whole cmdq is processed ...

> +}
> +
> +/*
> + * Consume all elements in command queue.
> + *
> + * @s: VirtIOSound device
> + */
> +static void virtio_snd_process_cmdq(VirtIOSound *s)
> +{
> +    virtio_snd_ctrl_command *cmd;
> +
> +    if (unlikely(qatomic_read(&s->processing_cmdq))) {
> +        return;
> +    }
> +
> +    WITH_QEMU_LOCK_GUARD(&s->cmdq_mutex) {
> +        qatomic_set(&s->processing_cmdq, true);
> +        while (!QTAILQ_EMPTY(&s->cmdq)) {
> +            cmd = QTAILQ_FIRST(&s->cmdq);
> +
> +            /* process command */
> +            process_cmd(s, cmd);
> +
> +            QTAILQ_REMOVE(&s->cmdq, cmd, next);
> +
> +            g_free(cmd);
> +        }

... here?

> +        qatomic_set(&s->processing_cmdq, false);
> +    }
> +}
Manos Pitsidianakis Sept. 4, 2023, 10:18 a.m. UTC | #2
Good morning Philippe,

On Mon, 04 Sep 2023 13:08, Philippe Mathieu-Daudé <philmd@linaro.org> wrote:
>> +    iov_from_buf(cmd->elem->in_sg,
>> +                 cmd->elem->in_num,
>> +                 0,
>> +                 &cmd->resp,
>> +                 sizeof(cmd->resp));
>> +    virtqueue_push(cmd->vq, cmd->elem, sizeof(cmd->elem));
>> +    virtio_notify(VIRTIO_DEVICE(s), cmd->vq);
>
>I have very few understanding of virtio, but I'm wondering here,
>since this function is called under cmdq_mutex(), could it be
>useful to batch the queue by calling virtio_notify() only once
>in the caller once the whole cmdq is processed ...

In the linux driver (sound/virtio/virtio_ctl_msg.c), the guest has a 
timeout for receiving the message. I found that if I did not notify as 
fast as possible, I got timeout errors on the guest.
Philippe Mathieu-Daudé Sept. 4, 2023, 10:42 a.m. UTC | #3
On 4/9/23 12:18, Manos Pitsidianakis wrote:
> Good morning Philippe,
> 
> On Mon, 04 Sep 2023 13:08, Philippe Mathieu-Daudé <philmd@linaro.org> 
> wrote:
>>> +    iov_from_buf(cmd->elem->in_sg,
>>> +                 cmd->elem->in_num,
>>> +                 0,
>>> +                 &cmd->resp,
>>> +                 sizeof(cmd->resp));
>>> +    virtqueue_push(cmd->vq, cmd->elem, sizeof(cmd->elem));
>>> +    virtio_notify(VIRTIO_DEVICE(s), cmd->vq);
>>
>> I have very few understanding of virtio, but I'm wondering here,
>> since this function is called under cmdq_mutex(), could it be
>> useful to batch the queue by calling virtio_notify() only once
>> in the caller once the whole cmdq is processed ...
> 
> In the linux driver (sound/virtio/virtio_ctl_msg.c), the guest has a 
> timeout for receiving the message. I found that if I did not notify as 
> fast as possible, I got timeout errors on the guest.

Ah, I see, 1ms per default:

sound/virtio/virtio_card.c:14:u32 virtsnd_msg_timeout_ms = MSEC_PER_SEC;
Philippe Mathieu-Daudé Sept. 4, 2023, 10:46 a.m. UTC | #4
On 28/8/23 21:55, Emmanouil Pitsidianakis wrote:
> Receive guest requests in the control (CTRL) queue of the virtio sound
> device and reply with a NOT SUPPORTED error to all control commands.
> 
> The receiving handler is virtio_snd_handle_ctrl(). It stores all control
> messages in the queue in the device's command queue. Then it calls
> virtio_snd_process_cmdq() to handle each message.
> 
> The handler is process_cmd() which replies with VIRTIO_SND_S_NOT_SUPP.
> 
> Based-on: https://github.com/OpenSynergy/qemu/commit/5a2f350eec5d157b90d9c7b40a8e603f4da92471
> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: Igor Skalkin <Igor.Skalkin@opensynergy.com>
> Signed-off-by: Anton Yakovlev <Anton.Yakovlev@opensynergy.com>
> Signed-off-by: Emmanouil Pitsidianakis <manos.pitsidianakis@linaro.org>
> ---
>   hw/virtio/trace-events         |   4 +
>   hw/virtio/virtio-snd.c         | 227 ++++++++++++++++++++++++++++++++-
>   include/hw/virtio/virtio-snd.h |  70 +++++++++-
>   3 files changed, 292 insertions(+), 9 deletions(-)


>   /*
> - * Queue handler stub.
> + * The actual processing done in virtio_snd_process_cmdq().
> + *
> + * @s: VirtIOSound device
> + * @cmd: control command request
> + */
> +static inline void
> +process_cmd(VirtIOSound *s, virtio_snd_ctrl_command *cmd)
> +{
> +    size_t sz = iov_to_buf(cmd->elem->out_sg,
> +                           cmd->elem->out_num,
> +                           0,
> +                           &cmd->ctrl,
> +                           sizeof(cmd->ctrl));
> +    if (sz != sizeof(cmd->ctrl)) {
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                "%s: virtio-snd command size incorrect %zu vs \
> +                %zu\n", __func__, sz, sizeof(cmd->ctrl));
> +        return;
> +    }
> +
> +    trace_virtio_snd_handle_code(cmd->ctrl.code,

IIUC the spec, this structure is in little endian, is that right?
So shouldn't swap various fields in this series?

> +                                 print_code(cmd->ctrl.code));
> +
> +    switch (cmd->ctrl.code) {
> +    case VIRTIO_SND_R_JACK_INFO:
> +    case VIRTIO_SND_R_JACK_REMAP:
> +        qemu_log_mask(LOG_UNIMP,
> +                     "virtio_snd: jack functionality is unimplemented.");
> +        cmd->resp.code = VIRTIO_SND_S_NOT_SUPP;
> +        break;
> +    case VIRTIO_SND_R_PCM_INFO:
> +    case VIRTIO_SND_R_PCM_SET_PARAMS:
> +    case VIRTIO_SND_R_PCM_PREPARE:
> +    case VIRTIO_SND_R_PCM_START:
> +    case VIRTIO_SND_R_PCM_STOP:
> +    case VIRTIO_SND_R_PCM_RELEASE:
> +        cmd->resp.code = VIRTIO_SND_S_NOT_SUPP;
> +        break;
> +    case VIRTIO_SND_R_CHMAP_INFO:
> +        qemu_log_mask(LOG_UNIMP,
> +                     "virtio_snd: chmap info functionality is unimplemented.");
> +        trace_virtio_snd_handle_chmap_info();
> +        cmd->resp.code = VIRTIO_SND_S_NOT_SUPP;
> +        break;
> +    default:
> +        /* error */
> +        error_report("virtio snd header not recognized: %"PRIu32,
> +                     cmd->ctrl.code);
> +        cmd->resp.code = VIRTIO_SND_S_BAD_MSG;
> +    }
> +
> +    iov_from_buf(cmd->elem->in_sg,
> +                 cmd->elem->in_num,
> +                 0,
> +                 &cmd->resp,
> +                 sizeof(cmd->resp));
> +    virtqueue_push(cmd->vq, cmd->elem, sizeof(cmd->elem));
> +    virtio_notify(VIRTIO_DEVICE(s), cmd->vq);
> +}
Manos Pitsidianakis Sept. 4, 2023, 11 a.m. UTC | #5
On Mon, 04 Sep 2023 13:46, Philippe Mathieu-Daudé <philmd@linaro.org> wrote:
>> +    size_t sz = iov_to_buf(cmd->elem->out_sg,
>> +                           cmd->elem->out_num,
>> +                           0,
>> +                           &cmd->ctrl,
>> +                           sizeof(cmd->ctrl));
>> +    if (sz != sizeof(cmd->ctrl)) {
>> +        qemu_log_mask(LOG_GUEST_ERROR,
>> +                "%s: virtio-snd command size incorrect %zu vs \
>> +                %zu\n", __func__, sz, sizeof(cmd->ctrl));
>> +        return;
>> +    }
>> +
>> +    trace_virtio_snd_handle_code(cmd->ctrl.code,
>
>IIUC the spec, this structure is in little endian, is that right?
>So shouldn't swap various fields in this series?

Not sure about the answer to this. Need input from someone more 
knowledgeable in virtio.
Philippe Mathieu-Daudé Sept. 4, 2023, 11:30 a.m. UTC | #6
On 4/9/23 13:00, Manos Pitsidianakis wrote:
> On Mon, 04 Sep 2023 13:46, Philippe Mathieu-Daudé <philmd@linaro.org> 
> wrote:
>>> +    size_t sz = iov_to_buf(cmd->elem->out_sg,
>>> +                           cmd->elem->out_num,
>>> +                           0,
>>> +                           &cmd->ctrl,
>>> +                           sizeof(cmd->ctrl));
>>> +    if (sz != sizeof(cmd->ctrl)) {
>>> +        qemu_log_mask(LOG_GUEST_ERROR,
>>> +                "%s: virtio-snd command size incorrect %zu vs \
>>> +                %zu\n", __func__, sz, sizeof(cmd->ctrl));
>>> +        return;
>>> +    }
>>> +
>>> +    trace_virtio_snd_handle_code(cmd->ctrl.code,
>>
>> IIUC the spec, this structure is in little endian, is that right?
>> So shouldn't swap various fields in this series?
> 
> Not sure about the answer to this. Need input from someone more 
> knowledgeable in virtio.

You can test running a big-endian guest (m68k, s390x, sparc64) on your
little-endian host.
Manos Pitsidianakis Sept. 4, 2023, 11:46 a.m. UTC | #7
On Mon, 04 Sep 2023 14:30, Philippe Mathieu-Daudé <philmd@linaro.org> wrote:
>On 4/9/23 13:00, Manos Pitsidianakis wrote:
>> On Mon, 04 Sep 2023 13:46, Philippe Mathieu-Daudé <philmd@linaro.org> 
>> wrote:
>>>> +    size_t sz = iov_to_buf(cmd->elem->out_sg,
>>>> +                           cmd->elem->out_num,
>>>> +                           0,
>>>> +                           &cmd->ctrl,
>>>> +                           sizeof(cmd->ctrl));
>>>> +    if (sz != sizeof(cmd->ctrl)) {
>>>> +        qemu_log_mask(LOG_GUEST_ERROR,
>>>> +                "%s: virtio-snd command size incorrect %zu vs \
>>>> +                %zu\n", __func__, sz, sizeof(cmd->ctrl));
>>>> +        return;
>>>> +    }
>>>> +
>>>> +    trace_virtio_snd_handle_code(cmd->ctrl.code,
>>>
>>> IIUC the spec, this structure is in little endian, is that right?
>>> So shouldn't swap various fields in this series?
>> 
>> Not sure about the answer to this. Need input from someone more 
>> knowledgeable in virtio.
>
>You can test running a big-endian guest (m68k, s390x, sparc64) on your
>little-endian host.

The linux driver uses le{32,64}_to_cpu for reading fields, if there's 
any problem then it would be with the host?
Philippe Mathieu-Daudé Sept. 4, 2023, 12:17 p.m. UTC | #8
On 4/9/23 13:46, Manos Pitsidianakis wrote:
> On Mon, 04 Sep 2023 14:30, Philippe Mathieu-Daudé <philmd@linaro.org> 
> wrote:
>> On 4/9/23 13:00, Manos Pitsidianakis wrote:
>>> On Mon, 04 Sep 2023 13:46, Philippe Mathieu-Daudé <philmd@linaro.org> 
>>> wrote:
>>>>> +    size_t sz = iov_to_buf(cmd->elem->out_sg,
>>>>> +                           cmd->elem->out_num,
>>>>> +                           0,
>>>>> +                           &cmd->ctrl,
>>>>> +                           sizeof(cmd->ctrl));
>>>>> +    if (sz != sizeof(cmd->ctrl)) {
>>>>> +        qemu_log_mask(LOG_GUEST_ERROR,
>>>>> +                "%s: virtio-snd command size incorrect %zu vs \
>>>>> +                %zu\n", __func__, sz, sizeof(cmd->ctrl));
>>>>> +        return;
>>>>> +    }
>>>>> +
>>>>> +    trace_virtio_snd_handle_code(cmd->ctrl.code,
>>>>
>>>> IIUC the spec, this structure is in little endian, is that right?
>>>> So shouldn't swap various fields in this series?
>>>
>>> Not sure about the answer to this. Need input from someone more 
>>> knowledgeable in virtio.
>>
>> You can test running a big-endian guest (m68k, s390x, sparc64) on your
>> little-endian host.
> 
> The linux driver uses le{32,64}_to_cpu for reading fields, if there's 
> any problem then it would be with the host?

Ah right. Since using a BE guest is often simpler for most developers
than accessing a BE host -- in particular to test recent kernel -- I was
hoping this would be an easy enough suggestion.

Anyhow Linux swapping the fields confirms the virtio-sound model has to
do the same.
Mark Cave-Ayland Sept. 6, 2023, 9:29 a.m. UTC | #9
On 28/08/2023 20:55, Emmanouil Pitsidianakis wrote:

Hi Emmanouil,

> Receive guest requests in the control (CTRL) queue of the virtio sound
> device and reply with a NOT SUPPORTED error to all control commands.
> 
> The receiving handler is virtio_snd_handle_ctrl(). It stores all control
> messages in the queue in the device's command queue. Then it calls
> virtio_snd_process_cmdq() to handle each message.
> 
> The handler is process_cmd() which replies with VIRTIO_SND_S_NOT_SUPP.
> 
> Based-on: https://github.com/OpenSynergy/qemu/commit/5a2f350eec5d157b90d9c7b40a8e603f4da92471
> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: Igor Skalkin <Igor.Skalkin@opensynergy.com>
> Signed-off-by: Anton Yakovlev <Anton.Yakovlev@opensynergy.com>
> Signed-off-by: Emmanouil Pitsidianakis <manos.pitsidianakis@linaro.org>
> ---
>   hw/virtio/trace-events         |   4 +
>   hw/virtio/virtio-snd.c         | 227 ++++++++++++++++++++++++++++++++-
>   include/hw/virtio/virtio-snd.h |  70 +++++++++-
>   3 files changed, 292 insertions(+), 9 deletions(-)
> 
> diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
> index 3ed7da35f2..8a223e36e9 100644
> --- a/hw/virtio/trace-events
> +++ b/hw/virtio/trace-events
> @@ -163,3 +163,7 @@ virtio_snd_vm_state_running(void) "vm state running"
>   virtio_snd_vm_state_stopped(void) "vm state stopped"
>   virtio_snd_realize(void *snd) "snd %p: realize"
>   virtio_snd_unrealize(void *snd) "snd %p: unrealize"
> +virtio_snd_handle_ctrl(void *vdev, void *vq) "snd %p: handle ctrl event for queue %p"
> +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"
> diff --git a/hw/virtio/virtio-snd.c b/hw/virtio/virtio-snd.c
> index a056a7bcc6..b921903905 100644
> --- a/hw/virtio/virtio-snd.c
> +++ b/hw/virtio/virtio-snd.c
> @@ -31,6 +31,29 @@
>   #define VIRTIO_SOUND_CHMAP_DEFAULT 0
>   #define VIRTIO_SOUND_HDA_FN_NID 0
>   
> +static const char *print_code(uint32_t code)
> +{
> +    #define CASE(CODE)            \
> +    case VIRTIO_SND_R_##CODE:     \
> +        return "VIRTIO_SND_R_"#CODE
> +
> +    switch (code) {
> +    CASE(JACK_INFO);
> +    CASE(JACK_REMAP);
> +    CASE(PCM_INFO);
> +    CASE(PCM_SET_PARAMS);
> +    CASE(PCM_PREPARE);
> +    CASE(PCM_RELEASE);
> +    CASE(PCM_START);
> +    CASE(PCM_STOP);
> +    CASE(CHMAP_INFO);
> +    default:
> +        return "invalid code";
> +    }
> +
> +    #undef CASE
> +};
> +
>   static const VMStateDescription vmstate_virtio_snd_device = {
>       .name = TYPE_VIRTIO_SND,
>       .version_id = VIRTIO_SOUND_VM_VERSION,
> @@ -89,12 +112,148 @@ virtio_snd_set_config(VirtIODevice *vdev, const uint8_t *config)
>   }
>   
>   /*
> - * Queue handler stub.
> + * The actual processing done in virtio_snd_process_cmdq().
> + *
> + * @s: VirtIOSound device
> + * @cmd: control command request
> + */
> +static inline void
> +process_cmd(VirtIOSound *s, virtio_snd_ctrl_command *cmd)
> +{
> +    size_t sz = iov_to_buf(cmd->elem->out_sg,
> +                           cmd->elem->out_num,
> +                           0,
> +                           &cmd->ctrl,
> +                           sizeof(cmd->ctrl));
> +    if (sz != sizeof(cmd->ctrl)) {
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                "%s: virtio-snd command size incorrect %zu vs \
> +                %zu\n", __func__, sz, sizeof(cmd->ctrl));
> +        return;
> +    }
> +
> +    trace_virtio_snd_handle_code(cmd->ctrl.code,
> +                                 print_code(cmd->ctrl.code));
> +
> +    switch (cmd->ctrl.code) {
> +    case VIRTIO_SND_R_JACK_INFO:
> +    case VIRTIO_SND_R_JACK_REMAP:
> +        qemu_log_mask(LOG_UNIMP,
> +                     "virtio_snd: jack functionality is unimplemented.");
> +        cmd->resp.code = VIRTIO_SND_S_NOT_SUPP;
> +        break;
> +    case VIRTIO_SND_R_PCM_INFO:
> +    case VIRTIO_SND_R_PCM_SET_PARAMS:
> +    case VIRTIO_SND_R_PCM_PREPARE:
> +    case VIRTIO_SND_R_PCM_START:
> +    case VIRTIO_SND_R_PCM_STOP:
> +    case VIRTIO_SND_R_PCM_RELEASE:
> +        cmd->resp.code = VIRTIO_SND_S_NOT_SUPP;
> +        break;
> +    case VIRTIO_SND_R_CHMAP_INFO:
> +        qemu_log_mask(LOG_UNIMP,
> +                     "virtio_snd: chmap info functionality is unimplemented.");
> +        trace_virtio_snd_handle_chmap_info();
> +        cmd->resp.code = VIRTIO_SND_S_NOT_SUPP;
> +        break;
> +    default:
> +        /* error */
> +        error_report("virtio snd header not recognized: %"PRIu32,
> +                     cmd->ctrl.code);
> +        cmd->resp.code = VIRTIO_SND_S_BAD_MSG;
> +    }
> +
> +    iov_from_buf(cmd->elem->in_sg,
> +                 cmd->elem->in_num,
> +                 0,
> +                 &cmd->resp,
> +                 sizeof(cmd->resp));
> +    virtqueue_push(cmd->vq, cmd->elem, sizeof(cmd->elem));
> +    virtio_notify(VIRTIO_DEVICE(s), cmd->vq);
> +}
> +
> +/*
> + * Consume all elements in command queue.
> + *
> + * @s: VirtIOSound device
> + */
> +static void virtio_snd_process_cmdq(VirtIOSound *s)
> +{
> +    virtio_snd_ctrl_command *cmd;
> +
> +    if (unlikely(qatomic_read(&s->processing_cmdq))) {
> +        return;
> +    }
> +
> +    WITH_QEMU_LOCK_GUARD(&s->cmdq_mutex) {
> +        qatomic_set(&s->processing_cmdq, true);
> +        while (!QTAILQ_EMPTY(&s->cmdq)) {
> +            cmd = QTAILQ_FIRST(&s->cmdq);
> +
> +            /* process command */
> +            process_cmd(s, cmd);
> +
> +            QTAILQ_REMOVE(&s->cmdq, cmd, next);
> +
> +            g_free(cmd);
> +        }
> +        qatomic_set(&s->processing_cmdq, false);
> +    }
> +}
> +
> +/*
> + * The control message handler. Pops an element from the control virtqueue,
> + * and stores them to VirtIOSound's cmdq queue and finally calls
> + * virtio_snd_process_cmdq() for processing.
> + *
> + * @vdev: VirtIOSound device
> + * @vq: Control virtqueue
> + */
> +static void virtio_snd_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
> +{
> +    VirtIOSound *s = VIRTIO_SND(vdev);
> +    VirtQueueElement *elem;
> +    virtio_snd_ctrl_command *cmd;
> +
> +    trace_virtio_snd_handle_ctrl(vdev, vq);
> +
> +    if (!virtio_queue_ready(vq)) {
> +        return;
> +    }
> +
> +    elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
> +    while (elem) {
> +        cmd = g_new0(virtio_snd_ctrl_command, 1);
> +        cmd->elem = elem;
> +        cmd->vq = vq;
> +        cmd->resp.code = VIRTIO_SND_S_OK;
> +        QTAILQ_INSERT_TAIL(&s->cmdq, cmd, next);
> +        elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
> +    }
> +
> +    virtio_snd_process_cmdq(s);
> +}
> +
> +/*
> + * 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.");
> +    trace_virtio_snd_handle_event();
> +}
> +
> +/*
> + * Stub buffer virtqueue handler.
>    *
>    * @vdev: VirtIOSound device
>    * @vq: virtqueue
>    */
> -static void virtio_snd_handle_queue(VirtIODevice *vdev, VirtQueue *vq) {}
> +static void virtio_snd_handle_xfer(VirtIODevice *vdev, VirtQueue *vq) {}
>   
>   static uint64_t get_features(VirtIODevice *vdev, uint64_t features,
>                                Error **errp)
> @@ -123,17 +282,32 @@ virtio_snd_vm_state_change(void *opaque, bool running,
>       }
>   }
>   
> +static void virtio_snd_set_pcm(VirtIOSound *snd)
> +{
> +    VirtIOSoundPCM *pcm;
> +
> +    pcm = g_new0(VirtIOSoundPCM, 1);
> +    pcm->snd = snd;
> +    pcm->streams = g_new0(VirtIOSoundPCMStream *, snd->snd_conf.streams);
> +    pcm->pcm_params = g_new0(VirtIOSoundPCMParams, snd->snd_conf.streams);
> +
> +    snd->pcm = pcm;
> +}

This modelling seems a bit odd: I'll comment a bit further below.

>   static void virtio_snd_realize(DeviceState *dev, Error **errp)
>   {
>       ERRP_GUARD();
>       VirtIOSound *vsnd = VIRTIO_SND(dev);
>       VirtIODevice *vdev = VIRTIO_DEVICE(dev);
>   
> +    vsnd->pcm = NULL;
>       vsnd->vmstate =
>           qemu_add_vm_change_state_handler(virtio_snd_vm_state_change, vsnd);
>   
>       trace_virtio_snd_realize(vsnd);
>   
> +    virtio_snd_set_pcm(vsnd);
> +
>       virtio_init(vdev, VIRTIO_ID_SOUND, sizeof(virtio_snd_config));
>       virtio_add_feature(&vsnd->features, VIRTIO_F_VERSION_1);
>   
> @@ -161,31 +335,70 @@ static void virtio_snd_realize(DeviceState *dev, Error **errp)
>       AUD_register_card("virtio-sound", &vsnd->card);
>   
>       vsnd->queues[VIRTIO_SND_VQ_CONTROL] =
> -        virtio_add_queue(vdev, 64, virtio_snd_handle_queue);
> +        virtio_add_queue(vdev, 64, virtio_snd_handle_ctrl);
>       vsnd->queues[VIRTIO_SND_VQ_EVENT] =
> -        virtio_add_queue(vdev, 64, virtio_snd_handle_queue);
> +        virtio_add_queue(vdev, 64, virtio_snd_handle_event);
>       vsnd->queues[VIRTIO_SND_VQ_TX] =
> -        virtio_add_queue(vdev, 64, virtio_snd_handle_queue);
> +        virtio_add_queue(vdev, 64, virtio_snd_handle_xfer);
>       vsnd->queues[VIRTIO_SND_VQ_RX] =
> -        virtio_add_queue(vdev, 64, virtio_snd_handle_queue);
> +        virtio_add_queue(vdev, 64, virtio_snd_handle_xfer);
> +    qemu_mutex_init(&vsnd->cmdq_mutex);
> +    QTAILQ_INIT(&vsnd->cmdq);
> +}
> +
> +/*
> + * Close the stream and free its resources.
> + *
> + * @stream: VirtIOSoundPCMStream *stream
> + */
> +static void virtio_snd_pcm_close(VirtIOSoundPCMStream *stream)
> +{
>   }
>   
>   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);
>       virtio_del_queue(vdev, 0);
>   
>       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);
> +                    g_free(stream);
> +                }
> +            }
> +            g_free(vsnd->pcm->streams);
> +        }
> +        g_free(vsnd->pcm);
> +        vsnd->pcm = NULL;
> +    }
>       AUD_remove_card(&vsnd->card);
>       virtio_cleanup(vdev);
>   }
>   
>   
> -static void virtio_snd_reset(VirtIODevice *vdev) {}
> +static void virtio_snd_reset(VirtIODevice *vdev)
> +{
> +    VirtIOSound *s = VIRTIO_SND(vdev);
> +    virtio_snd_ctrl_command *cmd;
> +
> +    WITH_QEMU_LOCK_GUARD(&s->cmdq_mutex) {
> +        while (!QTAILQ_EMPTY(&s->cmdq)) {
> +            cmd = QTAILQ_FIRST(&s->cmdq);
> +            QTAILQ_REMOVE(&s->cmdq, cmd, next);
> +            g_free(cmd);
> +        }
> +    }
> +}
>   
>   static void virtio_snd_class_init(ObjectClass *klass, void *data)
>   {
> diff --git a/include/hw/virtio/virtio-snd.h b/include/hw/virtio/virtio-snd.h
> index b3c0e6f079..b7046418cf 100644
> --- a/include/hw/virtio/virtio-snd.h
> +++ b/include/hw/virtio/virtio-snd.h
> @@ -67,12 +67,78 @@ typedef struct virtio_snd_pcm_xfer virtio_snd_pcm_xfer;
>   /* I/O request status */
>   typedef struct virtio_snd_pcm_status virtio_snd_pcm_status;
>   
> -typedef struct VirtIOSound {
> +/* device structs */
> +
> +typedef struct VirtIOSound VirtIOSound;
> +
> +typedef struct VirtIOSoundPCMStream VirtIOSoundPCMStream;
> +
> +typedef struct virtio_snd_ctrl_command virtio_snd_ctrl_command;
> +
> +typedef struct VirtIOSoundPCMParams VirtIOSoundPCMParams;
> +
> +typedef struct VirtIOSoundPCM VirtIOSoundPCM;
> +
> +/* Stream params */
> +struct VirtIOSoundPCMParams {
> +    uint32_t features;
> +    uint32_t buffer_bytes;          /* size of hardware buffer in bytes */
> +    uint32_t period_bytes;          /* size of hardware period in bytes */
> +    uint8_t channels;
> +    uint8_t format;
> +    uint8_t rate;
> +};
> +
> +struct VirtIOSoundPCM {
> +    VirtIOSound *snd;
> +    VirtIOSoundPCMParams *pcm_params;
> +    VirtIOSoundPCMStream **streams;
> +};
> +

Both pcm_params and streams are set in virtio_snd_set_pcm() to match the number of 
available streams.

> +struct VirtIOSoundPCMStream {
> +    VirtIOSoundPCM *pcm;
> +    virtio_snd_pcm_info info;
> +    uint32_t id;
> +    uint32_t buffer_bytes;
> +    uint32_t period_bytes;
> +    /* channel position values (VIRTIO_SND_CHMAP_XXX) */
> +    uint8_t positions[VIRTIO_SND_CHMAP_MAX_SIZE];
> +    VirtIOSound *s;
> +    uint32_t features; /* 1 << VIRTIO_SND_PCM_F_XXX */
> +    uint64_t formats; /* 1 << VIRTIO_SND_PCM_FMT_XXX */
> +    uint64_t rates; /* 1 << VIRTIO_SND_PCM_RATE_XXX */
> +    uint8_t direction;
> +    uint8_t channels_min;
> +    uint8_t channels_max;
> +    bool flushing;
> +    audsettings as;
> +    audsettings desired_as;
> +    union {
> +        SWVoiceIn *in;
> +        SWVoiceOut *out;
> +    } voice;
> +    QemuMutex queue_mutex;
> +    QSIMPLEQ_HEAD(, VirtIOSoundPCMBlock) queue;
> +};
> +
> +struct VirtIOSound {
>       VirtIODevice parent_obj;

Missing newline here.

>       VirtQueue *queues[VIRTIO_SND_VQ_MAX];
>       uint64_t features;
> +    VirtIOSoundPCM *pcm;

See comment below.

>       QEMUSoundCard card;
>       VMChangeStateEntry *vmstate;
>       virtio_snd_config snd_conf;
> -} VirtIOSound;
> +    QemuMutex cmdq_mutex;
> +    QTAILQ_HEAD(, virtio_snd_ctrl_command) cmdq;
> +    bool processing_cmdq;
> +};
> +
> +struct virtio_snd_ctrl_command {
> +    VirtQueueElement *elem;
> +    VirtQueue *vq;
> +    virtio_snd_hdr ctrl;
> +    virtio_snd_hdr resp;
> +    QTAILQ_ENTRY(virtio_snd_ctrl_command) next;
> +};
>   #endif

On that basis it seems a reasonable idea to embed the config directly in the stream 
and drop VirtIOSoundPCM i.e.:

struct VirtIOSoundPCMStream {
     VirtIOSoundPCMParams pcm_param;
     virtio_snd_pcm_info info;
     uint32_t id;
     uint32_t buffer_bytes;
     uint32_t period_bytes;
     ...
     ...
};

You can then alter VirtIOSound to point to the streams directly i.e.

struct VirtIOSound {
      VirtIODevice parent_obj;

      VirtQueue *queues[VIRTIO_SND_VQ_MAX];
      uint64_t features;

      VirtIOSoundPCMStream **streams;

      QEMUSoundCard card;
      VMChangeStateEntry *vmstate;
      virtio_snd_config snd_conf;

      QemuMutex cmdq_mutex;
      QTAILQ_HEAD(, virtio_snd_ctrl_command) cmdq;
      bool processing_cmdq;
};

This should also save maintaining extra "back" pointers, and you can still obtain a 
reference to elements in the parent object via container_of().


ATB,

Mark.
diff mbox series

Patch

diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index 3ed7da35f2..8a223e36e9 100644
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -163,3 +163,7 @@  virtio_snd_vm_state_running(void) "vm state running"
 virtio_snd_vm_state_stopped(void) "vm state stopped"
 virtio_snd_realize(void *snd) "snd %p: realize"
 virtio_snd_unrealize(void *snd) "snd %p: unrealize"
+virtio_snd_handle_ctrl(void *vdev, void *vq) "snd %p: handle ctrl event for queue %p"
+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"
diff --git a/hw/virtio/virtio-snd.c b/hw/virtio/virtio-snd.c
index a056a7bcc6..b921903905 100644
--- a/hw/virtio/virtio-snd.c
+++ b/hw/virtio/virtio-snd.c
@@ -31,6 +31,29 @@ 
 #define VIRTIO_SOUND_CHMAP_DEFAULT 0
 #define VIRTIO_SOUND_HDA_FN_NID 0
 
+static const char *print_code(uint32_t code)
+{
+    #define CASE(CODE)            \
+    case VIRTIO_SND_R_##CODE:     \
+        return "VIRTIO_SND_R_"#CODE
+
+    switch (code) {
+    CASE(JACK_INFO);
+    CASE(JACK_REMAP);
+    CASE(PCM_INFO);
+    CASE(PCM_SET_PARAMS);
+    CASE(PCM_PREPARE);
+    CASE(PCM_RELEASE);
+    CASE(PCM_START);
+    CASE(PCM_STOP);
+    CASE(CHMAP_INFO);
+    default:
+        return "invalid code";
+    }
+
+    #undef CASE
+};
+
 static const VMStateDescription vmstate_virtio_snd_device = {
     .name = TYPE_VIRTIO_SND,
     .version_id = VIRTIO_SOUND_VM_VERSION,
@@ -89,12 +112,148 @@  virtio_snd_set_config(VirtIODevice *vdev, const uint8_t *config)
 }
 
 /*
- * Queue handler stub.
+ * The actual processing done in virtio_snd_process_cmdq().
+ *
+ * @s: VirtIOSound device
+ * @cmd: control command request
+ */
+static inline void
+process_cmd(VirtIOSound *s, virtio_snd_ctrl_command *cmd)
+{
+    size_t sz = iov_to_buf(cmd->elem->out_sg,
+                           cmd->elem->out_num,
+                           0,
+                           &cmd->ctrl,
+                           sizeof(cmd->ctrl));
+    if (sz != sizeof(cmd->ctrl)) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                "%s: virtio-snd command size incorrect %zu vs \
+                %zu\n", __func__, sz, sizeof(cmd->ctrl));
+        return;
+    }
+
+    trace_virtio_snd_handle_code(cmd->ctrl.code,
+                                 print_code(cmd->ctrl.code));
+
+    switch (cmd->ctrl.code) {
+    case VIRTIO_SND_R_JACK_INFO:
+    case VIRTIO_SND_R_JACK_REMAP:
+        qemu_log_mask(LOG_UNIMP,
+                     "virtio_snd: jack functionality is unimplemented.");
+        cmd->resp.code = VIRTIO_SND_S_NOT_SUPP;
+        break;
+    case VIRTIO_SND_R_PCM_INFO:
+    case VIRTIO_SND_R_PCM_SET_PARAMS:
+    case VIRTIO_SND_R_PCM_PREPARE:
+    case VIRTIO_SND_R_PCM_START:
+    case VIRTIO_SND_R_PCM_STOP:
+    case VIRTIO_SND_R_PCM_RELEASE:
+        cmd->resp.code = VIRTIO_SND_S_NOT_SUPP;
+        break;
+    case VIRTIO_SND_R_CHMAP_INFO:
+        qemu_log_mask(LOG_UNIMP,
+                     "virtio_snd: chmap info functionality is unimplemented.");
+        trace_virtio_snd_handle_chmap_info();
+        cmd->resp.code = VIRTIO_SND_S_NOT_SUPP;
+        break;
+    default:
+        /* error */
+        error_report("virtio snd header not recognized: %"PRIu32,
+                     cmd->ctrl.code);
+        cmd->resp.code = VIRTIO_SND_S_BAD_MSG;
+    }
+
+    iov_from_buf(cmd->elem->in_sg,
+                 cmd->elem->in_num,
+                 0,
+                 &cmd->resp,
+                 sizeof(cmd->resp));
+    virtqueue_push(cmd->vq, cmd->elem, sizeof(cmd->elem));
+    virtio_notify(VIRTIO_DEVICE(s), cmd->vq);
+}
+
+/*
+ * Consume all elements in command queue.
+ *
+ * @s: VirtIOSound device
+ */
+static void virtio_snd_process_cmdq(VirtIOSound *s)
+{
+    virtio_snd_ctrl_command *cmd;
+
+    if (unlikely(qatomic_read(&s->processing_cmdq))) {
+        return;
+    }
+
+    WITH_QEMU_LOCK_GUARD(&s->cmdq_mutex) {
+        qatomic_set(&s->processing_cmdq, true);
+        while (!QTAILQ_EMPTY(&s->cmdq)) {
+            cmd = QTAILQ_FIRST(&s->cmdq);
+
+            /* process command */
+            process_cmd(s, cmd);
+
+            QTAILQ_REMOVE(&s->cmdq, cmd, next);
+
+            g_free(cmd);
+        }
+        qatomic_set(&s->processing_cmdq, false);
+    }
+}
+
+/*
+ * The control message handler. Pops an element from the control virtqueue,
+ * and stores them to VirtIOSound's cmdq queue and finally calls
+ * virtio_snd_process_cmdq() for processing.
+ *
+ * @vdev: VirtIOSound device
+ * @vq: Control virtqueue
+ */
+static void virtio_snd_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
+{
+    VirtIOSound *s = VIRTIO_SND(vdev);
+    VirtQueueElement *elem;
+    virtio_snd_ctrl_command *cmd;
+
+    trace_virtio_snd_handle_ctrl(vdev, vq);
+
+    if (!virtio_queue_ready(vq)) {
+        return;
+    }
+
+    elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
+    while (elem) {
+        cmd = g_new0(virtio_snd_ctrl_command, 1);
+        cmd->elem = elem;
+        cmd->vq = vq;
+        cmd->resp.code = VIRTIO_SND_S_OK;
+        QTAILQ_INSERT_TAIL(&s->cmdq, cmd, next);
+        elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
+    }
+
+    virtio_snd_process_cmdq(s);
+}
+
+/*
+ * 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.");
+    trace_virtio_snd_handle_event();
+}
+
+/*
+ * Stub buffer virtqueue handler.
  *
  * @vdev: VirtIOSound device
  * @vq: virtqueue
  */
-static void virtio_snd_handle_queue(VirtIODevice *vdev, VirtQueue *vq) {}
+static void virtio_snd_handle_xfer(VirtIODevice *vdev, VirtQueue *vq) {}
 
 static uint64_t get_features(VirtIODevice *vdev, uint64_t features,
                              Error **errp)
@@ -123,17 +282,32 @@  virtio_snd_vm_state_change(void *opaque, bool running,
     }
 }
 
+static void virtio_snd_set_pcm(VirtIOSound *snd)
+{
+    VirtIOSoundPCM *pcm;
+
+    pcm = g_new0(VirtIOSoundPCM, 1);
+    pcm->snd = snd;
+    pcm->streams = g_new0(VirtIOSoundPCMStream *, snd->snd_conf.streams);
+    pcm->pcm_params = g_new0(VirtIOSoundPCMParams, snd->snd_conf.streams);
+
+    snd->pcm = pcm;
+}
+
 static void virtio_snd_realize(DeviceState *dev, Error **errp)
 {
     ERRP_GUARD();
     VirtIOSound *vsnd = VIRTIO_SND(dev);
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 
+    vsnd->pcm = NULL;
     vsnd->vmstate =
         qemu_add_vm_change_state_handler(virtio_snd_vm_state_change, vsnd);
 
     trace_virtio_snd_realize(vsnd);
 
+    virtio_snd_set_pcm(vsnd);
+
     virtio_init(vdev, VIRTIO_ID_SOUND, sizeof(virtio_snd_config));
     virtio_add_feature(&vsnd->features, VIRTIO_F_VERSION_1);
 
@@ -161,31 +335,70 @@  static void virtio_snd_realize(DeviceState *dev, Error **errp)
     AUD_register_card("virtio-sound", &vsnd->card);
 
     vsnd->queues[VIRTIO_SND_VQ_CONTROL] =
-        virtio_add_queue(vdev, 64, virtio_snd_handle_queue);
+        virtio_add_queue(vdev, 64, virtio_snd_handle_ctrl);
     vsnd->queues[VIRTIO_SND_VQ_EVENT] =
-        virtio_add_queue(vdev, 64, virtio_snd_handle_queue);
+        virtio_add_queue(vdev, 64, virtio_snd_handle_event);
     vsnd->queues[VIRTIO_SND_VQ_TX] =
-        virtio_add_queue(vdev, 64, virtio_snd_handle_queue);
+        virtio_add_queue(vdev, 64, virtio_snd_handle_xfer);
     vsnd->queues[VIRTIO_SND_VQ_RX] =
-        virtio_add_queue(vdev, 64, virtio_snd_handle_queue);
+        virtio_add_queue(vdev, 64, virtio_snd_handle_xfer);
+    qemu_mutex_init(&vsnd->cmdq_mutex);
+    QTAILQ_INIT(&vsnd->cmdq);
+}
+
+/*
+ * Close the stream and free its resources.
+ *
+ * @stream: VirtIOSoundPCMStream *stream
+ */
+static void virtio_snd_pcm_close(VirtIOSoundPCMStream *stream)
+{
 }
 
 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);
     virtio_del_queue(vdev, 0);
 
     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);
+                    g_free(stream);
+                }
+            }
+            g_free(vsnd->pcm->streams);
+        }
+        g_free(vsnd->pcm);
+        vsnd->pcm = NULL;
+    }
     AUD_remove_card(&vsnd->card);
     virtio_cleanup(vdev);
 }
 
 
-static void virtio_snd_reset(VirtIODevice *vdev) {}
+static void virtio_snd_reset(VirtIODevice *vdev)
+{
+    VirtIOSound *s = VIRTIO_SND(vdev);
+    virtio_snd_ctrl_command *cmd;
+
+    WITH_QEMU_LOCK_GUARD(&s->cmdq_mutex) {
+        while (!QTAILQ_EMPTY(&s->cmdq)) {
+            cmd = QTAILQ_FIRST(&s->cmdq);
+            QTAILQ_REMOVE(&s->cmdq, cmd, next);
+            g_free(cmd);
+        }
+    }
+}
 
 static void virtio_snd_class_init(ObjectClass *klass, void *data)
 {
diff --git a/include/hw/virtio/virtio-snd.h b/include/hw/virtio/virtio-snd.h
index b3c0e6f079..b7046418cf 100644
--- a/include/hw/virtio/virtio-snd.h
+++ b/include/hw/virtio/virtio-snd.h
@@ -67,12 +67,78 @@  typedef struct virtio_snd_pcm_xfer virtio_snd_pcm_xfer;
 /* I/O request status */
 typedef struct virtio_snd_pcm_status virtio_snd_pcm_status;
 
-typedef struct VirtIOSound {
+/* device structs */
+
+typedef struct VirtIOSound VirtIOSound;
+
+typedef struct VirtIOSoundPCMStream VirtIOSoundPCMStream;
+
+typedef struct virtio_snd_ctrl_command virtio_snd_ctrl_command;
+
+typedef struct VirtIOSoundPCMParams VirtIOSoundPCMParams;
+
+typedef struct VirtIOSoundPCM VirtIOSoundPCM;
+
+/* Stream params */
+struct VirtIOSoundPCMParams {
+    uint32_t features;
+    uint32_t buffer_bytes;          /* size of hardware buffer in bytes */
+    uint32_t period_bytes;          /* size of hardware period in bytes */
+    uint8_t channels;
+    uint8_t format;
+    uint8_t rate;
+};
+
+struct VirtIOSoundPCM {
+    VirtIOSound *snd;
+    VirtIOSoundPCMParams *pcm_params;
+    VirtIOSoundPCMStream **streams;
+};
+
+struct VirtIOSoundPCMStream {
+    VirtIOSoundPCM *pcm;
+    virtio_snd_pcm_info info;
+    uint32_t id;
+    uint32_t buffer_bytes;
+    uint32_t period_bytes;
+    /* channel position values (VIRTIO_SND_CHMAP_XXX) */
+    uint8_t positions[VIRTIO_SND_CHMAP_MAX_SIZE];
+    VirtIOSound *s;
+    uint32_t features; /* 1 << VIRTIO_SND_PCM_F_XXX */
+    uint64_t formats; /* 1 << VIRTIO_SND_PCM_FMT_XXX */
+    uint64_t rates; /* 1 << VIRTIO_SND_PCM_RATE_XXX */
+    uint8_t direction;
+    uint8_t channels_min;
+    uint8_t channels_max;
+    bool flushing;
+    audsettings as;
+    audsettings desired_as;
+    union {
+        SWVoiceIn *in;
+        SWVoiceOut *out;
+    } voice;
+    QemuMutex queue_mutex;
+    QSIMPLEQ_HEAD(, VirtIOSoundPCMBlock) queue;
+};
+
+struct VirtIOSound {
     VirtIODevice parent_obj;
     VirtQueue *queues[VIRTIO_SND_VQ_MAX];
     uint64_t features;
+    VirtIOSoundPCM *pcm;
     QEMUSoundCard card;
     VMChangeStateEntry *vmstate;
     virtio_snd_config snd_conf;
-} VirtIOSound;
+    QemuMutex cmdq_mutex;
+    QTAILQ_HEAD(, virtio_snd_ctrl_command) cmdq;
+    bool processing_cmdq;
+};
+
+struct virtio_snd_ctrl_command {
+    VirtQueueElement *elem;
+    VirtQueue *vq;
+    virtio_snd_hdr ctrl;
+    virtio_snd_hdr resp;
+    QTAILQ_ENTRY(virtio_snd_ctrl_command) next;
+};
 #endif