Re: [PATCH v3 4/9] hw/audio/virtio-sound: split out virtio_snd_pcm_start_stop()

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

On Fri, 26 Jun 2026 15:35, Alexander Mikhalitsyn <alexander@mihalicyn.com> wrote:
>From: Volker Rümelin <vr_qemu@t-online.de>
>
>Split out virtio_snd_pcm_start_stop(). This is a preparation
>for the next patch so that it doesn't become too big.
>
>Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
>[AM: there were too many conflicts, I did `git checkout --ours -- <.>`
>     and then reimplemented the patch idea
>/AM]
>Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@futurfusion.io>
>Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
>---
>v3:
>	- resurrected error_report(..) as suggested by Marc-André Lureau
>---
> hw/audio/trace-events |  3 ++-
> hw/audio/virtio-snd.c | 59 ++++++++++++++++++++++++++++---------------
> 2 files changed, 41 insertions(+), 21 deletions(-)
>
>diff --git a/hw/audio/trace-events b/hw/audio/trace-events
>index 30f59215453..75d1fb37bd9 100644
>--- a/hw/audio/trace-events
>+++ b/hw/audio/trace-events
>@@ -53,7 +53,8 @@ virtio_snd_unrealize(void *snd) "snd %p: unrealize"
> virtio_snd_handle_pcm_set_params(uint32_t stream) "VIRTIO_SND_PCM_SET_PARAMS called for stream %"PRIu32
> 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_pcm_start(uint32_t stream) "VIRTIO_SND_R_PCM_START called for stream %"PRIu32
>+virtio_snd_handle_pcm_stop(uint32_t stream) "VIRTIO_SND_R_PCM_STOP called for stream %"PRIu32
> virtio_snd_handle_pcm_release(uint32_t stream) "VIRTIO_SND_PCM_RELEASE 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"
>diff --git a/hw/audio/virtio-snd.c b/hw/audio/virtio-snd.c
>index 8f4421ba844..300ba13ffeb 100644
>--- a/hw/audio/virtio-snd.c
>+++ b/hw/audio/virtio-snd.c
>@@ -521,7 +521,44 @@ static void virtio_snd_handle_pcm_prepare(VirtIOSound *s,
> }
> 
> /*
>- * Handles VIRTIO_SND_R_PCM_START.
>+ * Starts/Stops a VirtIOSound card stream.
>+ * Returns the response status code. (VIRTIO_SND_S_*).
>+ *
>+ * @s: VirtIOSound device
>+ * @stream_id: stream id
>+ * @start: whether to start or stop the stream
>+ */
>+static uint32_t virtio_snd_pcm_start_stop(VirtIOSound *s,
>+                                          uint32_t stream_id,
>+                                          bool start)
>+{
>+    VirtIOSoundPCMStream *stream;
>+
>+    stream = virtio_snd_pcm_get_stream(s, stream_id);
>+    if (!stream) {
>+        qemu_log_mask(LOG_GUEST_ERROR,
>+            "%s: Invalid stream id: %"PRIu32 "\n", __func__, stream_id);

Minor formatting nit:

+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: Invalid stream id: %"PRIu32 "\n",
+                      __func__, stream_id);

>+        return cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
>+    }
>+
>+    if (start) {
>+        trace_virtio_snd_handle_pcm_start(stream_id);
>+    } else {
>+        trace_virtio_snd_handle_pcm_stop(stream_id);
>+    }

Let's move the trace_*() calls at the start of the function, before the 
error checking, like it used to be.

>+
>+    stream->active = start;
>+    if (stream->info.direction == VIRTIO_SND_D_OUTPUT) {
>+        audio_be_set_active_out(s->audio_be, stream->voice.out, start);
>+    } else {
>+        audio_be_set_active_in(s->audio_be, stream->voice.in, start);
>+    }
>+
>+    return cpu_to_le32(VIRTIO_SND_S_OK);
>+}
>+
>+/*
>+ * Handles VIRTIO_SND_R_PCM_START and VIRTIO_SND_R_PCM_STOP.
>  *
>  * @s: VirtIOSound device
>  * @cmd: The request command queue element from VirtIOSound cmdq field
>@@ -531,7 +568,6 @@ 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,
>@@ -549,24 +585,7 @@ static void virtio_snd_handle_pcm_start_stop(VirtIOSound *s,
>     }
> 
>     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) {
>-        stream->active = start;
>-        if (stream->info.direction == VIRTIO_SND_D_OUTPUT) {
>-            audio_be_set_active_out(s->audio_be, stream->voice.out, start);
>-        } else {
>-            audio_be_set_active_in(s->audio_be, stream->voice.in, start);
>-        }
>-    } else {
>-        error_report("Invalid stream id: %"PRIu32, stream_id);
>-        cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
>-        return;
>-    }
>-    stream->active = start;
>+    cmd->resp.code = virtio_snd_pcm_start_stop(s, stream_id, start);
> }
> 
> /*
>-- 
>2.47.3
>