From: Marc-André Lureau <marcandre.lureau@redhat.com>

Now "audio_driver" is a detail implementation of AudioMixengBackend and
not required to implement an AudioBackend.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 include/qemu/audio.h |  1 +
 audio/audio.c        | 40 ++++++++++++++++++++++++++--------------
 2 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/include/qemu/audio.h b/include/qemu/audio.h
index 474d761f0be..1eeead2a722 100644
--- a/include/qemu/audio.h
+++ b/include/qemu/audio.h
@@ -51,6 +51,7 @@ typedef struct AudioBackend {
 typedef struct AudioBackendClass {
     ObjectClass parent_class;
 
+    bool (*realize)(AudioBackend *be, Audiodev *dev, Error **errp);
     const char *(*get_id)(AudioBackend *be);
 #ifdef CONFIG_GIO
     bool (*set_dbus_server)(AudioBackend *be,
diff --git a/audio/audio.c b/audio/audio.c
index 7e23a63d401..f6896229cfb 100644
--- a/audio/audio.c
+++ b/audio/audio.c
@@ -1561,24 +1561,16 @@ size_t audio_generic_read(HWVoiceIn *hw, void *buf, size_t size)
     return total;
 }
 
-static AudioBackend *audio_be_new(Audiodev *dev, Error **errp)
+static bool audio_mixeng_backend_realize(AudioBackend *abe,
+                                         Audiodev *dev, Error **errp)
 {
-    const char *drvname = AudiodevDriver_str(dev->driver);
-    struct audio_driver *drv = audio_driver_lookup(drvname);
+    AudioMixengBackend *be = AUDIO_MIXENG_BACKEND(abe);
+    audio_driver *drv = AUDIO_MIXENG_BACKEND_GET_CLASS(be)->driver;
 
-    if (!drv) {
-        error_setg(errp, "Unknown audio driver `%s'", drvname);
-        qapi_free_Audiodev(dev);
-        return NULL;
-    }
-
-    AudioMixengBackend *be = AUDIO_MIXENG_BACKEND(object_new(TYPE_AUDIO_MIXENG_BACKEND));
     be->dev = dev;
-
     be->drv_opaque = drv->init(be->dev, errp);
     if (!be->drv_opaque) {
-        object_unref(OBJECT(be));
-        return NULL;
+        return false;
     }
 
     if (!drv->pcm_ops->get_buffer_in) {
@@ -1600,7 +1592,26 @@ static AudioBackend *audio_be_new(Audiodev *dev, Error **errp)
         be->period_ticks = be->dev->timer_period * (int64_t)SCALE_US;
     }
 
-    return AUDIO_BACKEND(be);
+    return true;
+}
+
+static AudioBackend *audio_be_new(Audiodev *dev, Error **errp)
+{
+    const char *drvname = AudiodevDriver_str(dev->driver);
+    g_autofree char *type = g_strconcat("audio-", drvname, NULL);
+    AudioBackend *be = AUDIO_BACKEND(object_new(type));
+
+    if (!be) {
+        error_setg(errp, "Unknown audio driver `%s'", drvname);
+        return NULL;
+    }
+
+    if (!AUDIO_BACKEND_GET_CLASS(be)->realize(be, dev, errp)) {
+        object_unref(OBJECT(be));
+        return NULL;
+    }
+
+    return be;
 }
 
 static void audio_vm_change_state_handler (void *opaque, bool running,
@@ -1643,6 +1654,7 @@ static void audio_mixeng_backend_class_init(ObjectClass *klass, const void *data
 {
     AudioBackendClass *be = AUDIO_BACKEND_CLASS(klass);
 
+    be->realize = audio_mixeng_backend_realize;
     be->get_id = audio_mixeng_backend_get_id;
 }
 
-- 
2.52.0