[PATCH v13 05/11] virtio-sound: handle VIRTIO_SND_R_PCM_{START,STOP}

[Manos 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: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
---
 hw/audio/trace-events |  1 +
 hw/audio/virtio-snd.c | 49 +++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/hw/audio/trace-events b/hw/audio/trace-events
index 6def414f96..db48ff04fe 100644
--- a/hw/audio/trace-events
+++ b/hw/audio/trace-events
@@ -49,6 +49,7 @@ 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/audio/virtio-snd.c b/hw/audio/virtio-snd.c
index fd0c50de6e..e6791de6c6 100644
--- a/hw/audio/virtio-snd.c
+++ b/hw/audio/virtio-snd.c
@@ -446,6 +446,47 @@ static const char *print_code(uint32_t 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().
  *
@@ -486,10 +527,14 @@ process_cmd(VirtIOSound *s, virtio_snd_ctrl_command *cmd)
     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;
-- 
2.39.2