[PATCH 02/10] hw/audio/virtio-sound: allocate all streams in advance

["Volker Rümelin" <vr_qemu@t-online.de>]

It is much easier to migrate an array of structs than individual
structs that are accessed via a pointer to a pointer to an array
of pointers to struct, where some pointers can also be NULL.

For this reason, the audio streams are already allocated during
the realization phase and all stream variables that are constant
at runtime are initialised immediately after allocation. This is
a step towards being able to migrate the audio streams of the
virtio sound device after the next few patches.

Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
---
 hw/audio/virtio-snd.c         | 35 ++++++++++++++++++++++-------------
 include/hw/audio/virtio-snd.h |  1 +
 2 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/hw/audio/virtio-snd.c b/hw/audio/virtio-snd.c
index 8344f61c64..36b1bb502c 100644
--- a/hw/audio/virtio-snd.c
+++ b/hw/audio/virtio-snd.c
@@ -447,11 +447,9 @@ static uint32_t virtio_snd_pcm_prepare(VirtIOSound *s, uint32_t stream_id)
 
     stream = virtio_snd_pcm_get_stream(s, stream_id);
     if (stream == NULL) {
-        stream = g_new0(VirtIOSoundPCMStream, 1);
+        stream = &s->streams[stream_id];
         stream->active = false;
-        stream->id = stream_id;
         stream->pcm = s->pcm;
-        stream->s = s;
         QSIMPLEQ_INIT(&stream->queue);
         QSIMPLEQ_INIT(&stream->invalid);
 
@@ -463,14 +461,6 @@ static uint32_t virtio_snd_pcm_prepare(VirtIOSound *s, uint32_t stream_id)
     }
 
     virtio_snd_get_qemu_audsettings(&as, params);
-    stream->info.direction = stream_id < s->snd_conf.streams / 2 +
-        (s->snd_conf.streams & 1) ? VIRTIO_SND_D_OUTPUT : VIRTIO_SND_D_INPUT;
-    stream->info.hdr.hda_fn_nid = VIRTIO_SOUND_HDA_FN_NID;
-    stream->info.features = 0;
-    stream->info.channels_min = 1;
-    stream->info.channels_max = as.nchannels;
-    stream->info.formats = supported_formats;
-    stream->info.rates = supported_rates;
     stream->params = *params;
 
     stream->positions[0] = VIRTIO_SND_CHMAP_FL;
@@ -1074,6 +1064,24 @@ static void virtio_snd_realize(DeviceState *dev, Error **errp)
     vsnd->vmstate =
         qemu_add_vm_change_state_handler(virtio_snd_vm_state_change, vsnd);
 
+    vsnd->streams = g_new0(VirtIOSoundPCMStream, vsnd->snd_conf.streams);
+
+    for (uint32_t i = 0; i < vsnd->snd_conf.streams; i++) {
+        VirtIOSoundPCMStream *stream = &vsnd->streams[i];
+
+        stream->id = i;
+        stream->s = vsnd;
+        stream->info.hdr.hda_fn_nid = VIRTIO_SOUND_HDA_FN_NID;
+        stream->info.features = 0;
+        stream->info.formats = supported_formats;
+        stream->info.rates = supported_rates;
+        stream->info.direction =
+            i < vsnd->snd_conf.streams / 2 + (vsnd->snd_conf.streams & 1)
+            ? VIRTIO_SND_D_OUTPUT : VIRTIO_SND_D_INPUT;
+        stream->info.channels_min = 1;
+        stream->info.channels_max = 2;
+    }
+
     vsnd->pcm = g_new0(VirtIOSoundPCM, 1);
     vsnd->pcm->snd = vsnd;
     vsnd->pcm->streams =
@@ -1314,14 +1322,13 @@ static void virtio_snd_unrealize(DeviceState *dev)
     qemu_del_vm_change_state_handler(vsnd->vmstate);
     trace_virtio_snd_unrealize(vsnd);
 
-    if (vsnd->pcm) {
+    if (vsnd->streams) {
         if (vsnd->pcm->streams) {
             for (uint32_t i = 0; i < vsnd->snd_conf.streams; i++) {
                 stream = vsnd->pcm->streams[i];
                 if (stream) {
                     virtio_snd_process_cmdq(stream->s);
                     virtio_snd_pcm_close(stream);
-                    g_free(stream);
                 }
             }
             g_free(vsnd->pcm->streams);
@@ -1329,6 +1336,8 @@ static void virtio_snd_unrealize(DeviceState *dev)
         g_free(vsnd->pcm->pcm_params);
         g_free(vsnd->pcm);
         vsnd->pcm = NULL;
+        g_free(vsnd->streams);
+        vsnd->streams = NULL;
     }
     AUD_remove_card(&vsnd->card);
     virtio_delete_queue(vsnd->queues[VIRTIO_SND_VQ_CONTROL]);
diff --git a/include/hw/audio/virtio-snd.h b/include/hw/audio/virtio-snd.h
index ea6315f59b..05b4490488 100644
--- a/include/hw/audio/virtio-snd.h
+++ b/include/hw/audio/virtio-snd.h
@@ -216,6 +216,7 @@ struct VirtIOSound {
     VirtQueue *queues[VIRTIO_SND_VQ_MAX];
     uint64_t features;
     VirtIOSoundPCM *pcm;
+    VirtIOSoundPCMStream *streams;
     QEMUSoundCard card;
     VMChangeStateEntry *vmstate;
     virtio_snd_config snd_conf;
-- 
2.35.3