[PATCH v10 04/11] 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>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
---
 hw/virtio/trace-events |  1 +
 hw/virtio/virtio-snd.c | 82 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 83 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 96dbe2be65..823aa3b5dc 100644
--- a/hw/virtio/virtio-snd.c
+++ b/hw/virtio/virtio-snd.c
@@ -157,6 +157,86 @@ 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_pcm_info val;
+    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(virtio_snd_query_info));
+
+    if (msg_sz != sizeof(virtio_snd_query_info)) {
+        /*
+         * 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_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) {
+        /*
+         * TODO: do we need to set DEVICE_NEEDS_RESET?
+         */
+        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;
+        }
+        val = stream->info;
+        val.hdr.hda_fn_nid = cpu_to_le32(val.hdr.hda_fn_nid);
+        val.features = cpu_to_le32(val.features);
+        val.formats = cpu_to_le64(val.formats);
+        val.rates = cpu_to_le64(val.rates);
+        /*
+         * 5.14.6.6.2.1 Device Requirements: Stream Information The device MUST
+         * NOT set undefined feature, format, rate and direction values. The
+         * device MUST initialize the padding bytes to 0.
+         */
+        pcm_info[i] = val;
+        memset(&pcm_info[i].padding, 0, 5);
+    }
+
+    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
@@ -404,6 +484,8 @@ 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