[PATCH v11 05/11] virtio-sound: handle VIRTIO_SND_R_PCM_{START,STOP}

[Manos Pitsidianakis <manos.pitsidianakis@linaro.org>]

From: Emmanouil Pitsidianakis <manos.pitsidianakis@linaro.org>

Handle the start and stop control messages for a stream_id. This request
does nothing at the moment except for replying to it. Audio playback
or capture will be started/stopped here in follow-up commits.

Based-on: https://github.com/OpenSynergy/qemu/commit/5a2f350eec5d157b90d9c7b40a8e603f4da92471
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>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
---
 hw/virtio/trace-events |  1 +
 hw/virtio/virtio-snd.c | 49 ++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index 88de2021c8..7044b110b7 100644
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -165,6 +165,7 @@ 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_pcm_info(uint32_t stream) "VIRTIO_SND_R_PCM_INFO called for stream %"PRIu32
+virtio_snd_handle_pcm_start_stop(const char *code, uint32_t stream) "%s called for stream %"PRIu32
 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 ec945d55a7..50b5a9d5df 100644
--- a/hw/virtio/virtio-snd.c
+++ b/hw/virtio/virtio-snd.c
@@ -426,29 +426,70 @@ static uint32_t virtio_snd_pcm_prepare(VirtIOSound *s, uint32_t stream_id)
 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
 };
 
+/*
+ * Handles VIRTIO_SND_R_PCM_START.
+ *
+ * @s: VirtIOSound device
+ * @cmd: The request command queue element from VirtIOSound cmdq field
+ * @start: whether to start or stop the device
+ */
+static void virtio_snd_handle_pcm_start_stop(VirtIOSound *s,
+                                             virtio_snd_ctrl_command *cmd,
+                                             bool start)
+{
+    VirtIOSoundPCMStream *stream;
+    virtio_snd_pcm_hdr req;
+    uint32_t stream_id;
+    size_t msg_sz = iov_to_buf(cmd->elem->out_sg,
+                               cmd->elem->out_num,
+                               0,
+                               &req,
+                               sizeof(virtio_snd_pcm_hdr));
+
+    if (msg_sz != sizeof(virtio_snd_pcm_hdr)) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                "%s: virtio-snd command size incorrect %zu vs \
+                %zu\n", __func__, msg_sz, sizeof(virtio_snd_pcm_hdr));
+        cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
+        return;
+    }
+
+    stream_id = le32_to_cpu(req.stream_id);
+    cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_OK);
+    trace_virtio_snd_handle_pcm_start_stop(start ? "VIRTIO_SND_R_PCM_START" :
+            "VIRTIO_SND_R_PCM_STOP", stream_id);
+    stream = virtio_snd_pcm_get_stream(s, stream_id);
+    if (stream == NULL) {
+        error_report("Invalid stream id: %"PRIu32, req.stream_id);
+        cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
+        return;
+    }
+    stream->active = start;
+}
+
 /*
  * The actual processing done in virtio_snd_process_cmdq().
  *
  * @s: VirtIOSound device
  * @cmd: control command request
  */
@@ -456,66 +497,70 @@ static inline void
 process_cmd(VirtIOSound *s, virtio_snd_ctrl_command *cmd)
 {
     uint32_t code;
     size_t msg_sz = iov_to_buf(cmd->elem->out_sg,
                                cmd->elem->out_num,
                                0,
                                &cmd->ctrl,
                                sizeof(virtio_snd_hdr));
 
     if (msg_sz != sizeof(virtio_snd_hdr)) {
         /*
          * TODO: do we need to set DEVICE_NEEDS_RESET?
          */
         qemu_log_mask(LOG_GUEST_ERROR,
                 "%s: virtio-snd command size incorrect %zu vs \
                 %zu\n", __func__, msg_sz, sizeof(virtio_snd_hdr));
         return;
     }
 
     code = le32_to_cpu(cmd->ctrl.code);
 
     trace_virtio_snd_handle_code(code, print_code(code));
 
     switch (code) {
     case VIRTIO_SND_R_JACK_INFO:
     case VIRTIO_SND_R_JACK_REMAP:
         qemu_log_mask(LOG_UNIMP,
                      "virtio_snd: jack functionality is unimplemented.\n");
         cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_NOT_SUPP);
         break;
     case VIRTIO_SND_R_PCM_INFO:
         virtio_snd_handle_pcm_info(s, cmd);
         break;
-    case VIRTIO_SND_R_PCM_SET_PARAMS:
-    case VIRTIO_SND_R_PCM_PREPARE:
     case VIRTIO_SND_R_PCM_START:
+        virtio_snd_handle_pcm_start_stop(s, cmd, true);
+        break;
     case VIRTIO_SND_R_PCM_STOP:
+        virtio_snd_handle_pcm_start_stop(s, cmd, false);
+        break;
+    case VIRTIO_SND_R_PCM_SET_PARAMS:
+    case VIRTIO_SND_R_PCM_PREPARE:
     case VIRTIO_SND_R_PCM_RELEASE:
         cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_NOT_SUPP);
         break;
     case VIRTIO_SND_R_CHMAP_INFO:
         qemu_log_mask(LOG_UNIMP,
                      "virtio_snd: chmap info functionality is unimplemented.\n");
         trace_virtio_snd_handle_chmap_info();
         cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_NOT_SUPP);
         break;
     default:
         /* error */
         error_report("virtio snd header not recognized: %"PRIu32, code);
         cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
     }
 
     iov_from_buf(cmd->elem->in_sg,
                  cmd->elem->in_num,
                  0,
                  &cmd->resp,
                  sizeof(virtio_snd_hdr));
     virtqueue_push(cmd->vq, cmd->elem, sizeof(virtio_snd_hdr));
     virtio_notify(VIRTIO_DEVICE(s), cmd->vq);
 }
 
 /*
  * Consume all elements in command queue.
  *
  * @s: VirtIOSound device
  */
-- 
2.39.2