modules: use gmodule-export.

audio: add driver registry, enable module builds.
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Merge remote-tracking branch 'remotes/kraxel/tags/audio-20180312-pull-request' into staging

modules: use gmodule-export.
audio: add driver registry, enable module builds.

# gpg: Signature made Mon 12 Mar 2018 10:42:19 GMT
# gpg:                using RSA key 4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>"
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/audio-20180312-pull-request:
  audio/sdl: build as module
  audio/pulseaudio: build as module
  audio/oss: build as module
  audio/alsa: build as module
  build: enable audio modules
  audio: add module loading support
  audio: add driver registry
  modules: use gmodule-export

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Makefile

@@ -425,6 +425,10 @@ dummy := $(call unnest-vars,, \
                 io-obj-y \
                 common-obj-y \
                 common-obj-m \
+                ui-obj-y \
+                ui-obj-m \
+                audio-obj-y \
+                audio-obj-m \
                 trace-obj-y)
 
 include $(SRC_PATH)/tests/Makefile.include

Makefile.objs

@@ -104,6 +104,7 @@ common-obj-$(CONFIG_LINUX) += fsdev/
 common-obj-y += migration/
 
 common-obj-y += audio/
+common-obj-m += audio/
 common-obj-y += hw/
 
 common-obj-y += replay/

audio/Makefile.objs

@@ -1,19 +1,31 @@
 common-obj-y = audio.o noaudio.o wavaudio.o mixeng.o
-common-obj-$(CONFIG_AUDIO_SDL) += sdlaudio.o
-common-obj-$(CONFIG_AUDIO_OSS) += ossaudio.o
 common-obj-$(CONFIG_SPICE) += spiceaudio.o
 common-obj-$(CONFIG_AUDIO_COREAUDIO) += coreaudio.o
-common-obj-$(CONFIG_AUDIO_ALSA) += alsaaudio.o
 common-obj-$(CONFIG_AUDIO_DSOUND) += dsoundaudio.o
-common-obj-$(CONFIG_AUDIO_PA) += paaudio.o
 common-obj-$(CONFIG_AUDIO_PT_INT) += audio_pt_int.o
 common-obj-$(CONFIG_AUDIO_WIN_INT) += audio_win_int.o
 common-obj-y += wavcapture.o
 
-sdlaudio.o-cflags := $(SDL_CFLAGS)
-sdlaudio.o-libs := $(SDL_LIBS)
-alsaaudio.o-libs := $(ALSA_LIBS)
-paaudio.o-libs := $(PULSE_LIBS)
 coreaudio.o-libs := $(COREAUDIO_LIBS)
 dsoundaudio.o-libs := $(DSOUND_LIBS)
-ossaudio.o-libs := $(OSS_LIBS)
+
+# alsa module
+common-obj-$(CONFIG_AUDIO_ALSA) += alsa.mo
+alsa.mo-objs = alsaaudio.o
+alsa.mo-libs := $(ALSA_LIBS)
+
+# oss module
+common-obj-$(CONFIG_AUDIO_OSS) += oss.mo
+oss.mo-objs = ossaudio.o
+oss.mo-libs := $(OSS_LIBS)
+
+# pulseaudio module
+common-obj-$(CONFIG_AUDIO_PA) += pa.mo
+pa.mo-objs = paaudio.o
+pa.mo-libs := $(PULSE_LIBS)
+
+# sdl module
+common-obj-$(CONFIG_AUDIO_SDL) += sdl.mo
+sdl.mo-objs = sdlaudio.o
+sdl.mo-cflags := $(SDL_CFLAGS)
+sdl.mo-libs := $(SDL_LIBS)

audio/alsaaudio.c

@@ -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

@@ -45,15 +45,49 @@
    The 1st one is the one used by default, that is the reason
     that we generate the list.
 */
-static struct audio_driver *drvtab[] = {
+static const char *audio_prio_list[] = {
-#ifdef CONFIG_SPICE
+    "spice",
-    &spice_audio_driver,
-#endif
     CONFIG_AUDIO_DRIVERS
-    &no_audio_driver,
+    "none",
-    &wav_audio_driver
+    "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;
+        }
+    }
+
+    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;
@@ -1656,11 +1690,13 @@ static void audio_pp_nb_voices (const char *typ, int nb)
 
 void AUD_help (void)
 {
-    size_t i;
+    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);
-    for (i = 0; i < ARRAY_SIZE (drvtab); i++) {
+    QLIST_FOREACH(d, &audio_drivers, next) {
-        struct audio_driver *d = drvtab[i];
         if (d->options) {
             audio_process_options (d->name, d->options);
         }
@@ -1672,8 +1708,7 @@ void AUD_help (void)
 
     printf ("Available drivers:\n");
 
-    for (i = 0; i < ARRAY_SIZE (drvtab); i++) {
+    QLIST_FOREACH(d, &audio_drivers, next) {
-        struct audio_driver *d = drvtab[i];
 
         printf ("Name: %s\n", d->name);
         printf ("Description: %s\n", d->descr);
@@ -1807,6 +1842,7 @@ 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 +1878,27 @@ static void audio_init (void)
     }
 
     if (drvname) {
-        int found = 0;
+        driver = audio_driver_lookup(drvname);
-
+        if (driver) {
-        for (i = 0; i < ARRAY_SIZE (drvtab); i++) {
+            done = !audio_driver_init(s, driver);
-            if (!strcmp (drvname, drvtab[i]->name)) {
+        } else {
-                done = !audio_driver_init (s, drvtab[i]);
-                found = 1;
-                break;
-            }
-        }
-
-        if (!found) {
             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++) {
+        for (i = 0; !done && i < ARRAY_SIZE(audio_prio_list); i++) {
-            if (drvtab[i]->can_be_default) {
+            driver = audio_driver_lookup(audio_prio_list[i]);
-                done = !audio_driver_init (s, drvtab[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/audio_int.h

@@ -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/coreaudio.c

@@ -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

@@ -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

@@ -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

@@ -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

@@ -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

@@ -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

@@ -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

@@ -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);

configure

@@ -3354,7 +3354,7 @@ else
 fi
 glib_modules=gthread-2.0
 if test "$modules" = yes; then
-    glib_modules="$glib_modules gmodule-2.0"
+    glib_modules="$glib_modules gmodule-export-2.0"
 fi
 
 # This workaround is required due to a bug in pkg-config file for glib as it
@@ -5974,7 +5974,12 @@ fi
 echo "CONFIG_AUDIO_DRIVERS=$audio_drv_list" >> $config_host_mak
 for drv in $audio_drv_list; do
     def=CONFIG_AUDIO_$(echo $drv | LC_ALL=C tr '[a-z]' '[A-Z]')
-    echo "$def=y" >> $config_host_mak
+    case "$drv" in
+	alsa | oss | pa | sdl)
+	    echo "$def=m" >> $config_host_mak ;;
+	*)
+	    echo "$def=y" >> $config_host_mak ;;
+    esac
 done
 echo "ALSA_LIBS=$alsa_libs" >> $config_host_mak
 echo "PULSE_LIBS=$pulse_libs" >> $config_host_mak

include/qemu/module.h

@@ -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);

scripts/create_config

@@ -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 ""
     ;;