audio: modularize

Add registry for audio drivers, using the existing audio_driver struct. Make all drivers register themself. The old list of audio_driver struct pointers is now a list of audio driver names, specifying the priority (aka probe order) in case no driver is explicitly asked for.

Signed-off-by Gerd Hoffmann <[email protected]>

---
 audio/audio_int.h     | 14 ++++--------
 audio/alsaaudio.c     |  8 ++++++-
 audio/audio.c         | 63 ++++++++++++++++++++++++++++++---------------------
 audio/coreaudio.c     |  8 ++++++-
 audio/dsoundaudio.c   |  8 ++++++-
 audio/noaudio.c       |  8 ++++++-
 audio/ossaudio.c      |  8 ++++++-
 audio/paaudio.c       |  8 ++++++-
 audio/sdlaudio.c      |  8 ++++++-
 audio/spiceaudio.c    |  8 ++++++-
 audio/wavaudio.c      |  8 ++++++-
 scripts/create_config |  2 +-
 12 files changed, 106 insertions(+), 45 deletions(-)

audio/audio_int.h +5 -9

index 700bd43143..244b454012 100644
@@ -141,6 +141,7 @@ struct SWVoiceIn {
     QLIST_ENTRY (SWVoiceIn) entries;
 };
 
+typedef struct audio_driver audio_driver;
 struct audio_driver {
     const char *name;
     const char *descr;

@@ -154,6 +155,7 @@ struct audio_driver {
     int voice_size_out;
     int voice_size_in;
     int ctl_caps;
+    QLIST_ENTRY(audio_driver) next;
 };
 
 struct audio_pcm_ops {

@@ -203,17 +205,11 @@ struct AudioState {
     int vm_running;
 };
 
-extern struct audio_driver no_audio_driver;
-extern struct audio_driver oss_audio_driver;
-extern struct audio_driver sdl_audio_driver;
-extern struct audio_driver wav_audio_driver;
-extern struct audio_driver alsa_audio_driver;
-extern struct audio_driver coreaudio_audio_driver;
-extern struct audio_driver dsound_audio_driver;
-extern struct audio_driver pa_audio_driver;
-extern struct audio_driver spice_audio_driver;
 extern const struct mixeng_volume nominal_volume;
 
+void audio_driver_register(audio_driver *drv);
+audio_driver *audio_driver_lookup(const char *name);
+
 void audio_pcm_init_info (struct audio_pcm_info *info, struct audsettings *as);
 void audio_pcm_info_clear_buf (struct audio_pcm_info *info, void *buf, int len);
 

audio/alsaaudio.c +7 -1

index 92a96f8b2b..362a2276fd 100644
@@ -1213,7 +1213,7 @@ static struct audio_pcm_ops alsa_pcm_ops = {
     .ctl_in   = alsa_ctl_in,
 };
 
-struct audio_driver alsa_audio_driver = {
+static struct audio_driver alsa_audio_driver = {
     .name           = "alsa",
     .descr          = "ALSA http://www.alsa-project.org",
     .options        = alsa_options,

@@ -1226,3 +1226,9 @@ struct audio_driver alsa_audio_driver = {
     .voice_size_out = sizeof (ALSAVoiceOut),
     .voice_size_in  = sizeof (ALSAVoiceIn)
 };
+
+static void register_audio_alsa(void)
+{
+    audio_driver_register(&alsa_audio_driver);
+}
+type_init(register_audio_alsa);

audio/audio.c +37 -26

index 7658d2af66..2384612b87 100644
@@ -45,15 +45,32 @@
    The 1st one is the one used by default, that is the reason
     that we generate the list.
 */
-static struct audio_driver *drvtab[] = {
-#ifdef CONFIG_SPICE
-    &spice_audio_driver,
-#endif
+static const char *audio_prio_list[] = {
+    "spice",
     CONFIG_AUDIO_DRIVERS
-    &no_audio_driver,
-    &wav_audio_driver
+    "none",
+    "wav",
 };
 
+static QLIST_HEAD(, audio_driver) audio_drivers;
+
+void audio_driver_register(audio_driver *drv)
+{
+    QLIST_INSERT_HEAD(&audio_drivers, drv, next);
+}
+
+audio_driver *audio_driver_lookup(const char *name)
+{
+    struct audio_driver *d;
+
+    QLIST_FOREACH(d, &audio_drivers, next) {
+        if (strcmp(name, d->name) == 0) {
+            return d;
+        }
+    }
+    return NULL;
+}
+
 struct fixed_settings {
     int enabled;
     int nb_voices;

@@ -1656,11 +1673,10 @@ static void audio_pp_nb_voices (const char *typ, int nb)
 
 void AUD_help (void)
 {
-    size_t i;
+    struct audio_driver *d;
 
     audio_process_options ("AUDIO", audio_options);
-    for (i = 0; i < ARRAY_SIZE (drvtab); i++) {
-        struct audio_driver *d = drvtab[i];
+    QLIST_FOREACH(d, &audio_drivers, next) {
         if (d->options) {
             audio_process_options (d->name, d->options);
         }

@@ -1672,8 +1688,7 @@ void AUD_help (void)
 
     printf ("Available drivers:\n");
 
-    for (i = 0; i < ARRAY_SIZE (drvtab); i++) {
-        struct audio_driver *d = drvtab[i];
+    QLIST_FOREACH(d, &audio_drivers, next) {
 
         printf ("Name: %s\n", d->name);
         printf ("Description: %s\n", d->descr);

@@ -1807,6 +1822,7 @@ static void audio_init (void)
     const char *drvname;
     VMChangeStateEntry *e;
     AudioState *s = &glob_audio_state;
+    struct audio_driver *driver;
 
     if (s->drv) {
         return;

@@ -1842,32 +1858,27 @@ static void audio_init (void)
     }
 
     if (drvname) {
-        int found = 0;
-
-        for (i = 0; i < ARRAY_SIZE (drvtab); i++) {
-            if (!strcmp (drvname, drvtab[i]->name)) {
-                done = !audio_driver_init (s, drvtab[i]);
-                found = 1;
-                break;
-            }
-        }
-
-        if (!found) {
+        driver = audio_driver_lookup(drvname);
+        if (driver) {
+            done = !audio_driver_init(s, driver);
+        } else {
             dolog ("Unknown audio driver `%s'\n", drvname);
             dolog ("Run with -audio-help to list available drivers\n");
         }
     }
 
     if (!done) {
-        for (i = 0; !done && i < ARRAY_SIZE (drvtab); i++) {
-            if (drvtab[i]->can_be_default) {
-                done = !audio_driver_init (s, drvtab[i]);
+        for (i = 0; !done && i < ARRAY_SIZE(audio_prio_list); i++) {
+            driver = audio_driver_lookup(audio_prio_list[i]);
+            if (driver && driver->can_be_default) {
+                done = !audio_driver_init(s, driver);
             }
         }
     }
 
     if (!done) {
-        done = !audio_driver_init (s, &no_audio_driver);
+        driver = audio_driver_lookup("none");
+        done = !audio_driver_init(s, driver);
         assert(done);
         dolog("warning: Using timer based audio emulation\n");
     }

audio/coreaudio.c +7 -1

index c75142084f..638c60b300 100644
@@ -722,7 +722,7 @@ static struct audio_pcm_ops coreaudio_pcm_ops = {
     .ctl_out  = coreaudio_ctl_out
 };
 
-struct audio_driver coreaudio_audio_driver = {
+static struct audio_driver coreaudio_audio_driver = {
     .name           = "coreaudio",
     .descr          = "CoreAudio http://developer.apple.com/audio/coreaudio.html",
     .options        = coreaudio_options,

@@ -735,3 +735,9 @@ struct audio_driver coreaudio_audio_driver = {
     .voice_size_out = sizeof (coreaudioVoiceOut),
     .voice_size_in  = 0
 };
+
+static void register_audio_coreaudio(void)
+{
+    audio_driver_register(&coreaudio_audio_driver);
+}
+type_init(register_audio_coreaudio);

audio/dsoundaudio.c +7 -1

index bc39cb9b4d..3ed73a30d1 100644
@@ -890,7 +890,7 @@ static struct audio_pcm_ops dsound_pcm_ops = {
     .ctl_in   = dsound_ctl_in
 };
 
-struct audio_driver dsound_audio_driver = {
+static struct audio_driver dsound_audio_driver = {
     .name           = "dsound",
     .descr          = "DirectSound http://wikipedia.org/wiki/DirectSound",
     .options        = dsound_options,

@@ -903,3 +903,9 @@ struct audio_driver dsound_audio_driver = {
     .voice_size_out = sizeof (DSoundVoiceOut),
     .voice_size_in  = sizeof (DSoundVoiceIn)
 };
+
+static void register_audio_dsound(void)
+{
+    audio_driver_register(&dsound_audio_driver);
+}
+type_init(register_audio_dsound);

audio/noaudio.c +7 -1

index 9ca9eaf01f..1bfebeca7d 100644
@@ -160,7 +160,7 @@ static struct audio_pcm_ops no_pcm_ops = {
     .ctl_in   = no_ctl_in
 };
 
-struct audio_driver no_audio_driver = {
+static struct audio_driver no_audio_driver = {
     .name           = "none",
     .descr          = "Timer based audio emulation",
     .options        = NULL,

@@ -173,3 +173,9 @@ struct audio_driver no_audio_driver = {
     .voice_size_out = sizeof (NoVoiceOut),
     .voice_size_in  = sizeof (NoVoiceIn)
 };
+
+static void register_audio_none(void)
+{
+    audio_driver_register(&no_audio_driver);
+}
+type_init(register_audio_none);

audio/ossaudio.c +7 -1

index a0428881c2..6c69622b4c 100644
@@ -922,7 +922,7 @@ static struct audio_pcm_ops oss_pcm_ops = {
     .ctl_in   = oss_ctl_in
 };
 
-struct audio_driver oss_audio_driver = {
+static struct audio_driver oss_audio_driver = {
     .name           = "oss",
     .descr          = "OSS http://www.opensound.com",
     .options        = oss_options,

@@ -935,3 +935,9 @@ struct audio_driver oss_audio_driver = {
     .voice_size_out = sizeof (OSSVoiceOut),
     .voice_size_in  = sizeof (OSSVoiceIn)
 };
+
+static void register_audio_oss(void)
+{
+    audio_driver_register(&oss_audio_driver);
+}
+type_init(register_audio_oss);

audio/paaudio.c +7 -1

index aa0a7477d3..949769774d 100644
@@ -937,7 +937,7 @@ static struct audio_pcm_ops qpa_pcm_ops = {
     .ctl_in   = qpa_ctl_in
 };
 
-struct audio_driver pa_audio_driver = {
+static struct audio_driver pa_audio_driver = {
     .name           = "pa",
     .descr          = "http://www.pulseaudio.org/",
     .options        = qpa_options,

@@ -951,3 +951,9 @@ struct audio_driver pa_audio_driver = {
     .voice_size_in  = sizeof (PAVoiceIn),
     .ctl_caps       = VOICE_VOLUME_CAP
 };
+
+static void register_audio_pa(void)
+{
+    audio_driver_register(&pa_audio_driver);
+}
+type_init(register_audio_pa);

audio/sdlaudio.c +7 -1

index e92135bd2f..9db5ac92bc 100644
@@ -500,7 +500,7 @@ static struct audio_pcm_ops sdl_pcm_ops = {
     .ctl_out  = sdl_ctl_out,
 };
 
-struct audio_driver sdl_audio_driver = {
+static struct audio_driver sdl_audio_driver = {
     .name           = "sdl",
     .descr          = "SDL http://www.libsdl.org",
     .options        = sdl_options,

@@ -513,3 +513,9 @@ struct audio_driver sdl_audio_driver = {
     .voice_size_out = sizeof (SDLVoiceOut),
     .voice_size_in  = 0
 };
+
+static void register_audio_sdl(void)
+{
+    audio_driver_register(&sdl_audio_driver);
+}
+type_init(register_audio_sdl);

audio/spiceaudio.c +7 -1

index 5580e76307..6ad0eafbc6 100644
@@ -391,7 +391,7 @@ static struct audio_pcm_ops audio_callbacks = {
     .ctl_in   = line_in_ctl,
 };
 
-struct audio_driver spice_audio_driver = {
+static struct audio_driver spice_audio_driver = {
     .name           = "spice",
     .descr          = "spice audio driver",
     .options        = audio_options,

@@ -411,3 +411,9 @@ void qemu_spice_audio_init (void)
 {
     spice_audio_driver.can_be_default = 1;
 }
+
+static void register_audio_spice(void)
+{
+    audio_driver_register(&spice_audio_driver);
+}
+type_init(register_audio_spice);

audio/wavaudio.c +7 -1

index 068a595732..40adfa30c3 100644
@@ -278,7 +278,7 @@ static struct audio_pcm_ops wav_pcm_ops = {
     .ctl_out  = wav_ctl_out,
 };
 
-struct audio_driver wav_audio_driver = {
+static struct audio_driver wav_audio_driver = {
     .name           = "wav",
     .descr          = "WAV renderer http://wikipedia.org/wiki/WAV",
     .options        = wav_options,

@@ -291,3 +291,9 @@ struct audio_driver wav_audio_driver = {
     .voice_size_out = sizeof (WAVVoiceOut),
     .voice_size_in  = 0
 };
+
+static void register_audio_wav(void)
+{
+    audio_driver_register(&wav_audio_driver);
+}
+type_init(register_audio_wav);

scripts/create_config +1 -2

index 603b826886..d727e5e36e 100755
@@ -36,7 +36,7 @@ case $line in
     drivers=${line#*=}
     echo "#define CONFIG_AUDIO_DRIVERS \\"
     for drv in $drivers; do
-      echo "    &${drv}_audio_driver,\\"
+      echo "    \"${drv}\",\\"
     done
     echo ""
     ;;
--

2.9.3

Make audio_driver_lookup() try load the module in case it doesn't find the driver in the registry. Also load all modules for -audio-help, so the help output includes the help text for modular audio drivers.

Signed-off-by Gerd Hoffmann <[email protected]>

---
 include/qemu/module.h |  1 +
 audio/audio.c         | 20 ++++++++++++++++++++
 2 files changed, 21 insertions(+)

include/qemu/module.h +1 -0

index 9fea75aaeb..54300ab6e5 100644
@@ -54,6 +54,7 @@ typedef enum {
 
 #define block_module_load_one(lib) module_load_one("block-", lib)
 #define ui_module_load_one(lib) module_load_one("ui-", lib)
+#define audio_module_load_one(lib) module_load_one("audio-", lib)
 
 void register_module_init(void (*fn)(void), module_init_type type);
 void register_dso_module_init(void (*fn)(void), module_init_type type);

audio/audio.c +20 -1

index 2384612b87..6eccdb17ee 100644
@@ -68,9 +68,26 @@ audio_driver *audio_driver_lookup(const char *name)
             return d;
         }
     }
+
+    audio_module_load_one(name);
+    QLIST_FOREACH(d, &audio_drivers, next) {
+        if (strcmp(name, d->name) == 0) {
+            return d;
+        }
+    }
+
     return NULL;
 }
 
+static void audio_module_load_all(void)
+{
+    int i;
+
+    for (i = 0; i < ARRAY_SIZE(audio_prio_list); i++) {
+        audio_driver_lookup(audio_prio_list[i]);
+    }
+}
+
 struct fixed_settings {
     int enabled;
     int nb_voices;

@@ -1675,6 +1692,9 @@ void AUD_help (void)
 {
     struct audio_driver *d;
 
+    /* make sure we print the help text for modular drivers too */
+    audio_module_load_all();
+
     audio_process_options ("AUDIO", audio_options);
     QLIST_FOREACH(d, &audio_drivers, next) {
         if (d->options) {
--

2.9.3

Add audio driver (host backend) registry. Add audio module support. Enable module builds for alsa, oss, pulse and sdl.

Gerd Hoffmann (7):
audio: add driver registry
audio: add module loading support
build: enable audio modules
audio/alsa: build as module
audio/oss: build as module
audio/pulseaudio: build as module
audio/sdl: build as module

 configure             |  7 ++++-
 Makefile              |  4 +++
 Makefile.objs         |  1 +
 audio/audio_int.h     | 14 ++++-----
 include/qemu/module.h |  1 +
 audio/alsaaudio.c     |  8 ++++-
 audio/audio.c         | 83 +++++++++++++++++++++++++++++++++++----------------
 audio/coreaudio.c     |  8 ++++-
 audio/dsoundaudio.c   |  8 ++++-
 audio/noaudio.c       |  8 ++++-
 audio/ossaudio.c      |  8 ++++-
 audio/paaudio.c       |  8 ++++-
 audio/sdlaudio.c      |  8 ++++-
 audio/spiceaudio.c    |  8 ++++-
 audio/wavaudio.c      |  8 ++++-
 audio/Makefile.objs   | 30 +++++++++++++------
 scripts/create_config |  2 +-
 17 files changed, 159 insertions(+), 55 deletions(-)

--
2.9.3

Hi

Quoted 12 lines · Gerd Hoffmann

Add audio driver (host backend) registry. Add audio module support. Enable module builds for alsa, oss, pulse and sdl.

Gerd Hoffmann (7):
audio: add driver registry
audio: add module loading support
build: enable audio modules
audio/alsa: build as module
audio/oss: build as module
audio/pulseaudio: build as module
audio/sdl: build as module

Is this a problem on my side? (configure '--audio-drv-list=oss,alsa,pa,sdl' '--enable-modules')

elmarco@boraha:~/src/qemu/build (master %)$ x86_64-softmmu/qemu-system-x86_64 -audio-help
Failed to open module:
/home/elmarco/src/qemu/build/x86_64-softmmu/../audio-oss.so: undefined
symbol: _TRACE_OSS_INVALID_AVAILABLE_SIZE_DSTATE
Failed to open module:
/home/elmarco/src/qemu/build/x86_64-softmmu/../audio-alsa.so:
undefined symbol: _TRACE_ALSA_XRUN_OUT_DSTATE
Failed to open module:
/home/elmarco/src/qemu/build/x86_64-softmmu/../audio-pa.so: undefined
symbol: audio_pt_unlock_and_signal
Failed to open module:
/home/elmarco/src/qemu/build/x86_64-softmmu/../audio-sdl.so: undefined
symbol: audio_pcm_sw_write

Quoted 19 lines · Marc-André Lureau

Hi

Quoted 12 lines · Gerd Hoffmann

Add audio driver (host backend) registry. Add audio module support. Enable module builds for alsa, oss, pulse and sdl.

Gerd Hoffmann (7):
audio: add driver registry
audio: add module loading support
build: enable audio modules
audio/alsa: build as module
audio/oss: build as module
audio/pulseaudio: build as module
audio/sdl: build as module

Is this a problem on my side? (configure '--audio-drv-list=oss,alsa,pa,sdl' '--enable-modules')

Quoted 14 lines

elmarco@boraha:~/src/qemu/build (master %)$ x86_64-softmmu/qemu-system-x86_64 -audio-help
Failed to open module:
/home/elmarco/src/qemu/build/x86_64-softmmu/../audio-oss.so: undefined
symbol: _TRACE_OSS_INVALID_AVAILABLE_SIZE_DSTATE
Failed to open module:
/home/elmarco/src/qemu/build/x86_64-softmmu/../audio-alsa.so:
undefined symbol: _TRACE_ALSA_XRUN_OUT_DSTATE
Failed to open module:
/home/elmarco/src/qemu/build/x86_64-softmmu/../audio-pa.so: undefined
symbol: audio_pt_unlock_and_signal
Failed to open module:
/home/elmarco/src/qemu/build/x86_64-softmmu/../audio-sdl.so: undefined
symbol: audio_pcm_sw_write

Works fine here. Tried "make clean && make"?

Qemu build system seems to not rebuild object files when the compiler flags change. So you can't switch between --enable-modules and --disable-modules without "make clean" inbetween. Same issue when patches switch code from compiled-in to modular and you try an incremental build.

I've seen only build failues due to this, not module load errors. But possibly only because I stopped doing incremental builds when working on module patches ...

cheers,
Gerd

Quoted 2 lines

Quoted 2 lines

/home/elmarco/src/qemu/build/x86_64-softmmu/../audio-pa.so: undefined
symbol: audio_pt_unlock_and_signal

Fresh directory, cleaned ccache. That didn't help. fwiw, I am compiling on f27, gcc (GCC) 7.3.1 20180130. I'll investigate further if you can't reproduce.

Quoted 6 lines

Quoted 2 lines

Quoted 2 lines

/home/elmarco/src/qemu/build/x86_64-softmmu/../audio-pa.so: undefined
symbol: audio_pt_unlock_and_signal

Fresh directory, cleaned ccache. That didn't help. fwiw, I am compiling on f27, gcc (GCC) 7.3.1 20180130. I'll investigate further if you can't reproduce.

Hmm, working fine here (both rhel-7 and fedora-27 testbuild container, default build flags).

The symbol in question should be provided by qemu:

kraxel@fedora-64bit ~/projects/qemu/build/fedora# objdump -x audio-pa.so | grep audio_pt_unlock_and_signal
0000000000000000 *UND* 0000000000000000 audio_pt_unlock_and_signal
kraxel@fedora-64bit ~/projects/qemu/build/fedora# objdump -x x86_64-softmmu/qemu-system-x86_64 | grep audio_pt_unlock_and_signal
00000000004735f0 g F .text 0000000000000067 audio_pt_unlock_and_signal

Possibly your linker throws it away, thinking there is no user because of the modular drivers?