[PATCH v9 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.

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>
---
 hw/virtio/trace-events |  1 +
 hw/virtio/virtio-snd.c | 76 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 77 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 dea4ce6305..fd7c3ff000 100644
--- a/hw/virtio/virtio-snd.c
+++ b/hw/virtio/virtio-snd.c
@@ -32,6 +32,21 @@
 #define VIRTIO_SOUND_CHMAP_DEFAULT 0
 #define VIRTIO_SOUND_HDA_FN_NID 0
 
+static struct virtio_snd_info info_to_le32(struct virtio_snd_info val) {
+    val.hda_fn_nid = cpu_to_le32(val.hda_fn_nid);
+
+    return val;
+}
+
+static virtio_snd_pcm_info pcm_info_to_le32(virtio_snd_pcm_info val) {
+    val.hdr = info_to_le32(val.hdr);
+    val.features = cpu_to_le32(val.features);
+    val.formats = cpu_to_le64(val.formats);
+    val.rates = cpu_to_le64(val.rates);
+
+    return val;
+}
+
 static uint32_t supported_formats = BIT(VIRTIO_SND_PCM_FMT_S8)
                                   | BIT(VIRTIO_SND_PCM_FMT_U8)
                                   | BIT(VIRTIO_SND_PCM_FMT_S16)
@@ -147,6 +162,65 @@ static virtio_snd_pcm_set_params 
*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)
+{
+    uint32_t stream_id, start_id, count, size;
+    virtio_snd_query_info req;
+    VirtIOSoundPCMStream *stream = NULL;
+    g_autofree virtio_snd_pcm_info *pcm_info = NULL;
+    size_t msg_sz = iov_to_buf(cmd->elem->out_sg,
+                               cmd->elem->out_num,
+                               0,
+                               &req,
+                               sizeof(req));
+
+    if (msg_sz != sizeof(virtio_snd_query_info)) {
+        cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
+        return;
+    }
+
+    start_id = le32_to_cpu(req.start_id);
+    count = le32_to_cpu(req.count);
+    size = le32_to_cpu(req.size);
+
+    if (iov_size(cmd->elem->in_sg, cmd->elem->in_num) <
+        sizeof(virtio_snd_hdr) + size * 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 = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
+        return;
+    }
+
+    pcm_info = g_new0(virtio_snd_pcm_info, count);
+    for (uint32_t i = 0; i < count; i++) {
+        stream_id = i + start_id;
+        trace_virtio_snd_handle_pcm_info(stream_id);
+        stream = virtio_snd_pcm_get_stream(s, stream_id);
+        if (!stream) {
+            error_report("Invalid stream id: %"PRIu32, stream_id);
+            cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_BAD_MSG);
+            return;
+        }
+        pcm_info[i] = pcm_info_to_le32(stream->info);
+    }
+
+    cmd->resp.code = cpu_to_le32(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) * count);
+}
+
 /*
  * Set the given stream params.
  * Called by both virtio_snd_handle_pcm_set_params and during device
@@ -387,6 +461,8 @@ process_cmd(VirtIOSound *s, virtio_snd_ctrl_command *cmd)
         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:
-- 
2.39.2