Re: [PATCH] audio: exit(1) if audio backend failed to be found or initialized

[Volker Rümelin]

From: Marc-André Lureau<marcandre.lur...@redhat.com>
If you specify a known backend but it isn't compiled in, or failed to
initialize, you get a simple warning and the "none" backend as a
fallback, and QEMU runs happily:

$ qemu-system-x86_64 -audiodev id=audio,driver=dsound
audio: Unknown audio driver `dsound'
audio: warning: Using timer based audio emulation
...

Instead, QEMU should fail to start:
$ qemu-system-x86_64 -audiodev id=audio,driver=dsound
audio: Unknown audio driver `dsound'
$

Resolves:
https://bugzilla.redhat.com/show_bug.cgi?id=1983493

Signed-off-by: Marc-André Lureau<marcandre.lur...@redhat.com>
---
  audio/audio.h |  2 +-
  audio/audio.c | 14 +++++++++++---
  softmmu/vl.c  |  4 +++-
  3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/audio/audio.h b/audio/audio.h
index b5e17cd218..27e67079a0 100644
--- a/audio/audio.h
+++ b/audio/audio.h
@@ -170,7 +170,7 @@ void audio_sample_from_uint64(void *samples, int pos,
  
  void audio_define(Audiodev *audio);
  void audio_parse_option(const char *opt);
-void audio_init_audiodevs(void);
+bool audio_init_audiodevs(void);
  void audio_legacy_help(void);
  
  AudioState *audio_state_by_name(const char *name);
diff --git a/audio/audio.c b/audio/audio.c
index a02f3ce5c6..76b8735b44 100644
--- a/audio/audio.c
+++ b/audio/audio.c
@@ -1743,7 +1743,6 @@ static AudioState *audio_init(Audiodev *dev, const char 
*name)
          atexit(audio_cleanup);
          atexit_registered = true;
      }
-    QTAILQ_INSERT_TAIL(&audio_states, s, list);
  
      s->ts = timer_new_ns(QEMU_CLOCK_VIRTUAL, audio_timer, s);
  
@@ -1769,6 +1768,10 @@ static AudioState *audio_init(Audiodev *dev, const char *name)
          } else {
              dolog ("Unknown audio driver `%s'\n", drvname);
          }
+        if (!done) {
+            free_audio_state(s);
+            return NULL;

Hi Marc-André,

I don't understand why you move the QTAILQ_INSERT_TAIL(&audio_states, s, 
list) macro down. Without this you don't need the additional 
free_audio_state() call. audio_cleanup() takes care to free the audio state.

The rest looks good. You can add my

Reviewed-by: Volker Rümelin <vr_q...@t-online.de>

even if you insist on keeping the patch as it is.

With best regards,
Volker

+        }
      } else {
          for (i = 0; audio_prio_list[i]; i++) {
              AudiodevListEntry *e = audiodev_find(&head, audio_prio_list[i]);
@@ -1806,6 +1809,7 @@ static AudioState *audio_init(Audiodev *dev, const char 
*name)
                 "(Audio can continue looping even after stopping the VM)\n");
      }
  
+    QTAILQ_INSERT_TAIL(&audio_states, s, list);
      QLIST_INIT (&s->card_head);
      vmstate_register (NULL, 0, &vmstate_audio, s);
      return s;
@@ -2119,13 +2123,17 @@ void audio_define(Audiodev *dev)
      QSIMPLEQ_INSERT_TAIL(&audiodevs, e, next);
  }
  
-void audio_init_audiodevs(void)
+bool audio_init_audiodevs(void)
  {
      AudiodevListEntry *e;
  
      QSIMPLEQ_FOREACH(e, &audiodevs, next) {
-        audio_init(e->dev, NULL);
+        if (!audio_init(e->dev, NULL)) {
+            return false;
+        }
      }
+
+    return true;
  }
  
  audsettings audiodev_to_audsettings(AudiodevPerDirectionOptions *pdo)
diff --git a/softmmu/vl.c b/softmmu/vl.c
index 706bd7cff7..dea4005e47 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -1885,7 +1885,9 @@ static void qemu_create_early_backends(void)
       * setting machine properties, so they can be referred to.
       */
      configure_blockdev(&bdo_queue, machine_class, snapshot);
-    audio_init_audiodevs();
+    if (!audio_init_audiodevs()) {
+        exit(1);
+    }
  }