[PATCH v6 05/12] virtio-sound: handle VIRTIO_SND_R_PCM_INFO request

[Emmanouil Pitsidianakis]

Respond to the VIRTIO_SND_R_PCM_INFO control request with the parameters
of each requested PCM stream.

Signed-off-by: Emmanouil Pitsidianakis <manos.pitsidianakis@linaro.org>
---
 hw/virtio/trace-events |  1 +
 hw/virtio/virtio-snd.c | 78 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 79 insertions(+)

diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index 8a223e36e9..3e619f778b 100644
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -164,6 +164,7 @@ 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_pcm_info(uint32_t stream) "VIRTIO_SND_R_PCM_INFO 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 2be656d64b..c75014233e 100644
--- a/hw/virtio/virtio-snd.c
+++ b/hw/virtio/virtio-snd.c
@@ -134,6 +134,19 @@ virtio_snd_set_config(VirtIODevice *vdev, const uint8_t 
*config)
     memcpy(&s->snd_conf, sndconfig, sizeof(s->snd_conf));
 }
 
+/*
+ * Get a specific stream from the virtio sound card device.
+ * Returns NULL if @stream_id is invalid or not allocated.
+ *
+ * @s: VirtIOSound device
+ * @stream_id: stream id
+ */
+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];
+}
+
 /*
  * Get params for a specific stream.
  *
@@ -147,6 +160,69 @@ static VirtIOSoundPCMParams 
*virtio_snd_pcm_get_params(VirtIOSound *s,
         : s->pcm->pcm_params[stream_id];
 }
 
+/*
+ * Handle the VIRTIO_SND_R_PCM_INFO request.
+ * The function writes the info structs to the request element.
+ *
+ * @s: VirtIOSound device
+ * @cmd: The request command queue element from VirtIOSound cmdq field
+ */
+static void virtio_snd_handle_pcm_info(VirtIOSound *s,
+                                       virtio_snd_ctrl_command *cmd)
+{
+    virtio_snd_query_info req;
+    VirtIOSoundPCMStream *stream = NULL;
+    g_autofree virtio_snd_pcm_info *pcm_info = NULL;
+    size_t sz = iov_to_buf(cmd->elem->out_sg,
+                           cmd->elem->out_num,
+                           0,
+                           &req,
+                           sizeof(req));
+    if (sz != sizeof(virtio_snd_query_info)) {
+        cmd->resp.code = VIRTIO_SND_S_BAD_MSG;
+        return;
+    }
+
+    if (iov_size(cmd->elem->in_sg, cmd->elem->in_num) <
+        sizeof(virtio_snd_hdr) + req.size * req.count) {
+        error_report("pcm info: buffer too small, got: %zu, needed: %zu",
+                iov_size(cmd->elem->in_sg, cmd->elem->in_num),
+                sizeof(virtio_snd_pcm_info));
+        cmd->resp.code = VIRTIO_SND_S_BAD_MSG;
+        return;
+    }
+
+    pcm_info = g_new0(virtio_snd_pcm_info, req.count);
+    for (uint32_t i = req.start_id; i < req.start_id + req.count; i++) {
+        trace_virtio_snd_handle_pcm_info(i);
+        stream = virtio_snd_pcm_get_stream(s, i);
+
+        if (!stream) {
+            error_report("Invalid stream id: %"PRIu32, i);
+            cmd->resp.code = VIRTIO_SND_S_BAD_MSG;
+            return;
+        }
+
+        pcm_info[i - req.start_id].hdr.hda_fn_nid = 
stream->info.hdr.hda_fn_nid;
+        pcm_info[i - req.start_id].features = stream->features;
+        pcm_info[i - req.start_id].formats = stream->formats;
+        pcm_info[i - req.start_id].rates = stream->rates;
+        pcm_info[i - req.start_id].direction = stream->direction;
+        pcm_info[i - req.start_id].channels_min = stream->channels_min;
+        pcm_info[i - req.start_id].channels_max = stream->channels_max;
+
+        memset(&pcm_info[i].padding, 0, sizeof(pcm_info[i].padding));
+    }
+
+    cmd->resp.code = VIRTIO_SND_S_OK;
+
+    iov_from_buf(cmd->elem->in_sg,
+                 cmd->elem->in_num,
+                 sizeof(virtio_snd_hdr),
+                 pcm_info,
+                 sizeof(virtio_snd_pcm_info) * req.count);
+}
+
 /*
  * Set the given stream params.
  * Called by both virtio_snd_handle_pcm_set_params and during device
@@ -373,6 +449,8 @@ process_cmd(VirtIOSound *s, virtio_snd_ctrl_command *cmd)
         cmd->resp.code = 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:
-- 
2.39.2