Merge remote-tracking branch 'remotes/kraxel/tags/ui-20180305-pull-request' into staging

ui: build curses, gtk and sdl as modules.

# gpg: Signature made Mon 05 Mar 2018 08:48:24 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/ui-20180305-pull-request:
  ui/sdl: build as module
  audio: rename CONFIG_* to CONFIG_AUDIO_*
  ui/curses: build as module
  ui/gtk: build as module
  configure: opengl doesn't depend on x11
  configure: add X11 vars to config-host.mak
  console: add ui module loading support
  console: add and use qemu_display_find_default
  egl-headless: switch over to new display registry
  curses: switch over to new display registry
  cocoa: switch over to new display registry
  sdl: switch over to new display registry
  console: add qemu display registry, add gtk

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

16 files changed, 220 insertions, 176 deletions

diff --git a/Makefile.objs b/Makefile.objs
index d741134cc7..69413d33b1 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -109,6 +109,7 @@ common-obj-y += hw/
 common-obj-y += replay/
 
 common-obj-y += ui/
+common-obj-m += ui/
 common-obj-y += bt-host.o bt-vhci.o
 bt-host.o-cflags := $(BLUEZ_CFLAGS)
 
diff --git a/audio/Makefile.objs b/audio/Makefile.objs
index 8a5ede6e2b..f6ce5c6744 100644
--- a/audio/Makefile.objs
+++ b/audio/Makefile.objs
@@ -1,11 +1,11 @@
 common-obj-y = audio.o noaudio.o wavaudio.o mixeng.o
-common-obj-$(CONFIG_SDL) += sdlaudio.o
-common-obj-$(CONFIG_OSS) += ossaudio.o
+common-obj-$(CONFIG_AUDIO_SDL) += sdlaudio.o
+common-obj-$(CONFIG_AUDIO_OSS) += ossaudio.o
 common-obj-$(CONFIG_SPICE) += spiceaudio.o
-common-obj-$(CONFIG_COREAUDIO) += coreaudio.o
-common-obj-$(CONFIG_ALSA) += alsaaudio.o
-common-obj-$(CONFIG_DSOUND) += dsoundaudio.o
-common-obj-$(CONFIG_PA) += paaudio.o
+common-obj-$(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
diff --git a/audio/audio_int.h b/audio/audio_int.h
index 5b25da0a37..700bd43143 100644
--- a/audio/audio_int.h
+++ b/audio/audio_int.h
@@ -25,7 +25,7 @@
 #ifndef QEMU_AUDIO_INT_H
 #define QEMU_AUDIO_INT_H
 
-#ifdef CONFIG_COREAUDIO
+#ifdef CONFIG_AUDIO_COREAUDIO
 #define FLOAT_MIXENG
 /* #define RECIPROCAL */
 #endif
diff --git a/configure b/configure
index 2c1cb58520..27d3f66bd5 100755
--- a/configure
+++ b/configure
@@ -2520,9 +2520,8 @@ fi
 
 ##########################################
 # X11 probe
-x11_cflags=
-x11_libs=-lX11
 if $pkg_config --exists "x11"; then
+    have_x11=yes
     x11_cflags=$($pkg_config --cflags x11)
     x11_libs=$($pkg_config --libs x11)
 fi
@@ -2555,10 +2554,10 @@ if test "$gtk" != "no"; then
         gtk_libs=$($pkg_config --libs $gtkpackage)
         gtk_version=$($pkg_config --modversion $gtkpackage)
         if $pkg_config --exists "$gtkx11package >= $gtkversion"; then
+            need_x11=yes
             gtk_cflags="$gtk_cflags $x11_cflags"
             gtk_libs="$gtk_libs $x11_libs"
         fi
-        libs_softmmu="$gtk_libs $libs_softmmu"
         gtk="yes"
     elif test "$gtk" = "yes"; then
         feature_not_found "gtk" "Install gtk3-devel"
@@ -2808,7 +2807,6 @@ if test "$vte" != "no"; then
         vte_cflags=$($pkg_config --cflags $vtepackage)
         vte_libs=$($pkg_config --libs $vtepackage)
         vteversion=$($pkg_config --modversion $vtepackage)
-        libs_softmmu="$vte_libs $libs_softmmu"
         vte="yes"
     elif test "$vte" = "yes"; then
         if test "$gtkabi" = "3.0"; then
@@ -2923,6 +2921,7 @@ if test "$sdl" = "yes" ; then
 int main(void) { return 0; }
 EOF
   if compile_prog "$sdl_cflags $x11_cflags" "$sdl_libs $x11_libs" ; then
+    need_x11=yes
     sdl_cflags="$sdl_cflags $x11_cflags"
     sdl_libs="$sdl_libs $x11_libs"
   fi
@@ -3281,8 +3280,6 @@ EOF
       unset IFS
       if compile_prog "$curses_inc" "$curses_lib" ; then
         curses_found=yes
-        QEMU_CFLAGS="$curses_inc $QEMU_CFLAGS"
-        libs_softmmu="$curses_lib $libs_softmmu"
         break
       fi
     done
@@ -3778,9 +3775,9 @@ libs_softmmu="$libs_softmmu $fdt_libs"
 
 if test "$opengl" != "no" ; then
   opengl_pkgs="epoxy libdrm gbm"
-  if $pkg_config $opengl_pkgs x11; then
-    opengl_cflags="$($pkg_config --cflags $opengl_pkgs) $x11_cflags"
-    opengl_libs="$($pkg_config --libs $opengl_pkgs) $x11_libs"
+  if $pkg_config $opengl_pkgs; then
+    opengl_cflags="$($pkg_config --cflags $opengl_pkgs)"
+    opengl_libs="$($pkg_config --libs $opengl_pkgs)"
     opengl=yes
     if test "$gtk" = "yes" && $pkg_config --exists "$gtkpackage >= 3.16"; then
         gtk_gl="yes"
@@ -5984,7 +5981,7 @@ if test "$cap_ng" = "yes" ; then
 fi
 echo "CONFIG_AUDIO_DRIVERS=$audio_drv_list" >> $config_host_mak
 for drv in $audio_drv_list; do
-    def=CONFIG_$(echo $drv | LC_ALL=C tr '[a-z]' '[A-Z]')
+    def=CONFIG_AUDIO_$(echo $drv | LC_ALL=C tr '[a-z]' '[A-Z]')
     echo "$def=y" >> $config_host_mak
 done
 echo "ALSA_LIBS=$alsa_libs" >> $config_host_mak
@@ -6036,8 +6033,13 @@ if test "$modules" = "yes"; then
   echo "CONFIG_STAMP=_$( (echo $qemu_version; echo $pkgversion; cat $0) | $shacmd - | cut -f1 -d\ )" >> $config_host_mak
   echo "CONFIG_MODULES=y" >> $config_host_mak
 fi
+if test "$have_x11" = "yes" -a "$need_x11" = "yes"; then
+  echo "CONFIG_X11=y" >> $config_host_mak
+  echo "X11_CFLAGS=$x11_cflags" >> $config_host_mak
+  echo "X11_LIBS=$x11_libs" >> $config_host_mak
+fi
 if test "$sdl" = "yes" ; then
-  echo "CONFIG_SDL=y" >> $config_host_mak
+  echo "CONFIG_SDL=m" >> $config_host_mak
   echo "CONFIG_SDLABI=$sdlabi" >> $config_host_mak
   echo "SDL_CFLAGS=$sdl_cflags" >> $config_host_mak
   echo "SDL_LIBS=$sdl_libs" >> $config_host_mak
@@ -6046,7 +6048,9 @@ if test "$cocoa" = "yes" ; then
   echo "CONFIG_COCOA=y" >> $config_host_mak
 fi
 if test "$curses" = "yes" ; then
-  echo "CONFIG_CURSES=y" >> $config_host_mak
+  echo "CONFIG_CURSES=m" >> $config_host_mak
+  echo "CURSES_CFLAGS=$curses_inc" >> $config_host_mak
+  echo "CURSES_LIBS=$curses_lib" >> $config_host_mak
 fi
 if test "$pipe2" = "yes" ; then
   echo "CONFIG_PIPE2=y" >> $config_host_mak
@@ -6143,7 +6147,7 @@ if test "$glib_subprocess" = "yes" ; then
   echo "CONFIG_HAS_GLIB_SUBPROCESS_TESTS=y" >> $config_host_mak
 fi
 if test "$gtk" = "yes" ; then
-  echo "CONFIG_GTK=y" >> $config_host_mak
+  echo "CONFIG_GTK=m" >> $config_host_mak
   echo "CONFIG_GTKABI=$gtkabi" >> $config_host_mak
   echo "GTK_CFLAGS=$gtk_cflags" >> $config_host_mak
   echo "GTK_LIBS=$gtk_libs" >> $config_host_mak
@@ -6194,6 +6198,7 @@ fi
 if test "$vte" = "yes" ; then
   echo "CONFIG_VTE=y" >> $config_host_mak
   echo "VTE_CFLAGS=$vte_cflags" >> $config_host_mak
+  echo "VTE_LIBS=$vte_libs" >> $config_host_mak
 fi
 if test "$virglrenderer" = "yes" ; then
   echo "CONFIG_VIRGL=y" >> $config_host_mak
diff --git a/include/qemu/module.h b/include/qemu/module.h
index 56dd218205..9fea75aaeb 100644
--- a/include/qemu/module.h
+++ b/include/qemu/module.h
@@ -53,6 +53,7 @@ typedef enum {
 #define trace_init(function) module_init(function, MODULE_INIT_TRACE)
 
 #define block_module_load_one(lib) module_load_one("block-", lib)
+#define ui_module_load_one(lib) module_load_one("ui-", lib)
 
 void register_module_init(void (*fn)(void), module_init_type type);
 void register_dso_module_init(void (*fn)(void), module_init_type type);
diff --git a/include/ui/console.h b/include/ui/console.h
index e0d81f1144..aae9e44cb3 100644
--- a/include/ui/console.h
+++ b/include/ui/console.h
@@ -433,36 +433,18 @@ void surface_gl_setup_viewport(QemuGLShader *gls,
                                int ww, int wh);
 #endif
 
-/* sdl.c */
-#ifdef CONFIG_SDL
-void sdl_display_early_init(DisplayOptions *opts);
-void sdl_display_init(DisplayState *ds, DisplayOptions *opts);
-#else
-static inline void sdl_display_early_init(DisplayOptions *opts)
-{
-    /* This must never be called if CONFIG_SDL is disabled */
-    error_report("SDL support is disabled");
-    abort();
-}
-static inline void sdl_display_init(DisplayState *ds, DisplayOptions *opts)
-{
-    /* This must never be called if CONFIG_SDL is disabled */
-    error_report("SDL support is disabled");
-    abort();
-}
-#endif
+typedef struct QemuDisplay QemuDisplay;
 
-/* cocoa.m */
-#ifdef CONFIG_COCOA
-void cocoa_display_init(DisplayState *ds, DisplayOptions *opts);
-#else
-static inline void cocoa_display_init(DisplayState *ds, DisplayOptions *opts)
-{
-    /* This must never be called if CONFIG_COCOA is disabled */
-    error_report("Cocoa support is disabled");
-    abort();
-}
-#endif
+struct QemuDisplay {
+    DisplayType type;
+    void (*early_init)(DisplayOptions *opts);
+    void (*init)(DisplayState *ds, DisplayOptions *opts);
+};
+
+void qemu_display_register(QemuDisplay *ui);
+bool qemu_display_find_default(DisplayOptions *opts);
+void qemu_display_early_init(DisplayOptions *opts);
+void qemu_display_init(DisplayState *ds, DisplayOptions *opts);
 
 /* vnc.c */
 void vnc_display_init(const char *id);
@@ -473,42 +455,7 @@ int vnc_display_pw_expire(const char *id, time_t expires);
 QemuOpts *vnc_parse(const char *str, Error **errp);
 int vnc_init_func(void *opaque, QemuOpts *opts, Error **errp);
 
-/* curses.c */
-#ifdef CONFIG_CURSES
-void curses_display_init(DisplayState *ds, DisplayOptions *opts);
-#else
-static inline void curses_display_init(DisplayState *ds, DisplayOptions *opts)
-{
-    /* This must never be called if CONFIG_CURSES is disabled */
-    error_report("curses support is disabled");
-    abort();
-}
-#endif
-
 /* input.c */
 int index_from_key(const char *key, size_t key_length);
 
-/* gtk.c */
-#ifdef CONFIG_GTK
-void early_gtk_display_init(DisplayOptions *opts);
-void gtk_display_init(DisplayState *ds, DisplayOptions *opts);
-#else
-static inline void gtk_display_init(DisplayState *ds, DisplayOptions *opts)
-{
-    /* This must never be called if CONFIG_GTK is disabled */
-    error_report("GTK support is disabled");
-    abort();
-}
-
-static inline void early_gtk_display_init(DisplayOptions *opts)
-{
-    /* This must never be called if CONFIG_GTK is disabled */
-    error_report("GTK support is disabled");
-    abort();
-}
-#endif
-
-/* egl-headless.c */
-void egl_headless_init(DisplayOptions *opts);
-
 #endif
diff --git a/target/unicore32/Makefile.objs b/target/unicore32/Makefile.objs
index 6b41b1e9ef..35d8bf530d 100644
--- a/target/unicore32/Makefile.objs
+++ b/target/unicore32/Makefile.objs
@@ -2,3 +2,7 @@ obj-y += translate.o op_helper.o helper.o cpu.o
 obj-y += ucf64_helper.o
 
 obj-$(CONFIG_SOFTMMU) += softmmu.o
+
+# Huh? Uses curses directly instead of using ui/console.h interfaces ...
+helper.o-cflags := $(CURSES_CFLAGS)
+helper.o-libs := $(CURSES_LIBS)
diff --git a/ui/Makefile.objs b/ui/Makefile.objs
index ced7d91a63..dcd54a5287 100644
--- a/ui/Makefile.objs
+++ b/ui/Makefile.objs
@@ -11,14 +11,16 @@ common-obj-y += keymaps.o console.o cursor.o qemu-pixman.o
 common-obj-y += input.o input-keymap.o input-legacy.o
 common-obj-$(CONFIG_LINUX) += input-linux.o
 common-obj-$(CONFIG_SPICE) += spice-core.o spice-input.o spice-display.o
-common-obj-$(CONFIG_SDL) += sdl.mo
 common-obj-$(CONFIG_COCOA) += cocoa.o
-common-obj-$(CONFIG_CURSES) += curses.o
 common-obj-$(CONFIG_VNC) += $(vnc-obj-y)
 common-obj-$(call lnot,$(CONFIG_VNC)) += vnc-stubs.o
-common-obj-$(CONFIG_GTK) += gtk.o
-common-obj-$(if $(CONFIG_WIN32),n,$(if $(CONFIG_SDL),y,$(CONFIG_GTK))) += x_keymap.o
 
+common-obj-$(CONFIG_X11) += x_keymap.o
+x_keymap.o-cflags := $(X11_CFLAGS)
+x_keymap.o-libs := $(X11_LIBS)
+
+# ui-sdl module
+common-obj-$(CONFIG_SDL) += sdl.mo
 ifeq ($(CONFIG_SDLABI),1.2)
 sdl.mo-objs := sdl.o sdl_zoom.o
 endif
@@ -31,6 +33,17 @@ endif
 sdl.mo-cflags := $(SDL_CFLAGS)
 sdl.mo-libs := $(SDL_LIBS)
 
+# ui-gtk module
+common-obj-$(CONFIG_GTK) += gtk.mo
+gtk.mo-objs := gtk.o
+gtk.mo-cflags := $(GTK_CFLAGS) $(VTE_CFLAGS)
+gtk.mo-libs := $(GTK_LIBS) $(VTE_LIBS)
+
+common-obj-$(CONFIG_CURSES) += curses.mo
+curses.mo-objs := curses.o
+curses.mo-cflags := $(CURSES_CFLAGS)
+curses.mo-libs := $(CURSES_LIBS)
+
 ifeq ($(CONFIG_OPENGL),y)
 common-obj-y += shader.o
 common-obj-y += console-gl.o
@@ -38,17 +51,13 @@ common-obj-y += egl-helpers.o
 common-obj-y += egl-context.o
 common-obj-$(CONFIG_OPENGL_DMABUF) += egl-headless.o
 ifeq ($(CONFIG_GTK_GL),y)
-common-obj-$(CONFIG_GTK) += gtk-gl-area.o
+gtk.mo-objs += gtk-gl-area.o
 else
-common-obj-$(CONFIG_GTK) += gtk-egl.o
+gtk.mo-objs += gtk-egl.o
+gtk.mo-libs += $(OPENGL_LIBS)
 endif
 endif
 
-gtk.o-cflags := $(GTK_CFLAGS) $(VTE_CFLAGS)
-gtk-egl.o-cflags := $(GTK_CFLAGS) $(VTE_CFLAGS)
-gtk-gl-area.o-cflags := $(GTK_CFLAGS) $(VTE_CFLAGS)
-
-gtk-egl.o-libs += $(OPENGL_LIBS)
 shader.o-libs += $(OPENGL_LIBS)
 console-gl.o-libs += $(OPENGL_LIBS)
 egl-helpers.o-libs += $(OPENGL_LIBS)
diff --git a/ui/cocoa.m b/ui/cocoa.m
index 30888ca8fd..18de0bb3ea 100644
--- a/ui/cocoa.m
+++ b/ui/cocoa.m
@@ -1683,7 +1683,7 @@ static void addRemovableDevicesMenuItems(void)
     qapi_free_BlockInfoList(pointerToFree);
 }
 
-void cocoa_display_init(DisplayState *ds, DisplayOptions *opts)
+static void cocoa_display_init(DisplayState *ds, DisplayOptions *opts)
 {
     COCOA_DEBUG("qemu_cocoa: cocoa_display_init\n");
 
@@ -1713,3 +1713,15 @@ void cocoa_display_init(DisplayState *ds, DisplayOptions *opts)
      */
     addRemovableDevicesMenuItems();
 }
+
+static QemuDisplay qemu_display_cocoa = {
+    .type       = DISPLAY_TYPE_COCOA,
+    .init       = cocoa_display_init,
+};
+
+static void register_cocoa(void)
+{
+    qemu_display_register(&qemu_display_cocoa);
+}
+
+type_init(register_cocoa);
diff --git a/ui/console.c b/ui/console.c
index 6a1f49916e..6ab4ff3baf 100644
--- a/ui/console.c
+++ b/ui/console.c
@@ -2180,6 +2180,65 @@ PixelFormat qemu_default_pixelformat(int bpp)
     return pf;
 }
 
+static QemuDisplay *dpys[DISPLAY_TYPE__MAX];
+
+void qemu_display_register(QemuDisplay *ui)
+{
+    assert(ui->type < DISPLAY_TYPE__MAX);
+    dpys[ui->type] = ui;
+}
+
+bool qemu_display_find_default(DisplayOptions *opts)
+{
+    static DisplayType prio[] = {
+        DISPLAY_TYPE_GTK,
+        DISPLAY_TYPE_SDL,
+        DISPLAY_TYPE_COCOA
+    };
+    int i;
+
+    for (i = 0; i < ARRAY_SIZE(prio); i++) {
+        if (dpys[prio[i]] == NULL) {
+            ui_module_load_one(DisplayType_lookup.array[prio[i]]);
+        }
+        if (dpys[prio[i]] == NULL) {
+            continue;
+        }
+        opts->type = prio[i];
+        return true;
+    }
+    return false;
+}
+
+void qemu_display_early_init(DisplayOptions *opts)
+{
+    assert(opts->type < DISPLAY_TYPE__MAX);
+    if (opts->type == DISPLAY_TYPE_NONE) {
+        return;
+    }
+    if (dpys[opts->type] == NULL) {
+        ui_module_load_one(DisplayType_lookup.array[opts->type]);
+    }
+    if (dpys[opts->type] == NULL) {
+        error_report("Display '%s' is not available.",
+                     DisplayType_lookup.array[opts->type]);
+        exit(1);
+    }
+    if (dpys[opts->type]->early_init) {
+        dpys[opts->type]->early_init(opts);
+    }
+}
+
+void qemu_display_init(DisplayState *ds, DisplayOptions *opts)
+{
+    assert(opts->type < DISPLAY_TYPE__MAX);
+    if (opts->type == DISPLAY_TYPE_NONE) {
+        return;
+    }
+    assert(dpys[opts->type] != NULL);
+    dpys[opts->type]->init(ds, opts);
+}
+
 void qemu_chr_parse_vc(QemuOpts *opts, ChardevBackend *backend, Error **errp)
 {
     int val;
diff --git a/ui/curses.c b/ui/curses.c
index 597e47fd4a..59d819fd4d 100644
--- a/ui/curses.c
+++ b/ui/curses.c
@@ -435,7 +435,7 @@ static const DisplayChangeListenerOps dcl_ops = {
     .dpy_text_cursor = curses_cursor_position,
 };
 
-void curses_display_init(DisplayState *ds, DisplayOptions *opts)
+static void curses_display_init(DisplayState *ds, DisplayOptions *opts)
 {
 #ifndef _WIN32
     if (!isatty(1)) {
@@ -456,3 +456,15 @@ void curses_display_init(DisplayState *ds, DisplayOptions *opts)
 
     invalidate = 1;
 }
+
+static QemuDisplay qemu_display_curses = {
+    .type       = DISPLAY_TYPE_CURSES,
+    .init       = curses_display_init,
+};
+
+static void register_curses(void)
+{
+    qemu_display_register(&qemu_display_curses);
+}
+
+type_init(register_curses);
diff --git a/ui/egl-headless.c b/ui/egl-headless.c
index b33e0b21fd..7c877122d3 100644
--- a/ui/egl-headless.c
+++ b/ui/egl-headless.c
@@ -164,7 +164,12 @@ static const DisplayChangeListenerOps egl_ops = {
     .dpy_gl_update           = egl_scanout_flush,
 };
 
-void egl_headless_init(DisplayOptions *opts)
+static void early_egl_headless_init(DisplayOptions *opts)
+{
+    display_opengl = 1;
+}
+
+static void egl_headless_init(DisplayState *ds, DisplayOptions *opts)
 {
     QemuConsole *con;
     egl_dpy *edpy;
@@ -188,3 +193,16 @@ void egl_headless_init(DisplayOptions *opts)
         register_displaychangelistener(&edpy->dcl);
     }
 }
+
+static QemuDisplay qemu_display_egl = {
+    .type       = DISPLAY_TYPE_EGL_HEADLESS,
+    .early_init = early_egl_headless_init,
+    .init       = egl_headless_init,
+};
+
+static void register_egl(void)
+{
+    qemu_display_register(&qemu_display_egl);
+}
+
+type_init(register_egl);
diff --git a/ui/gtk.c b/ui/gtk.c
index 0750262ca8..563cff32b8 100644
--- a/ui/gtk.c
+++ b/ui/gtk.c
@@ -2297,7 +2297,7 @@ static void gd_create_menus(GtkDisplayState *s)
 
 static gboolean gtkinit;
 
-void gtk_display_init(DisplayState *ds, DisplayOptions *opts)
+static void gtk_display_init(DisplayState *ds, DisplayOptions *opts)
 {
     VirtualConsole *vc;
 
@@ -2407,7 +2407,7 @@ void gtk_display_init(DisplayState *ds, DisplayOptions *opts)
     }
 }
 
-void early_gtk_display_init(DisplayOptions *opts)
+static void early_gtk_display_init(DisplayOptions *opts)
 {
     /* The QEMU code relies on the assumption that it's always run in
      * the C locale. Therefore it is not prepared to deal with
@@ -2450,3 +2450,16 @@ void early_gtk_display_init(DisplayOptions *opts)
     type_register(&char_gd_vc_type_info);
 #endif
 }
+
+static QemuDisplay qemu_display_gtk = {
+    .type       = DISPLAY_TYPE_GTK,
+    .early_init = early_gtk_display_init,
+    .init       = gtk_display_init,
+};
+
+static void register_gtk(void)
+{
+    qemu_display_register(&qemu_display_gtk);
+}
+
+type_init(register_gtk);
diff --git a/ui/sdl.c b/ui/sdl.c
index c4ae7ab05d..a5fd503c25 100644
--- a/ui/sdl.c
+++ b/ui/sdl.c
@@ -901,17 +901,7 @@ static const DisplayChangeListenerOps dcl_ops = {
     .dpy_cursor_define    = sdl_mouse_define,
 };
 
-void sdl_display_early_init(DisplayOptions *opts)
-{
-    if (opts->has_gl && opts->gl) {
-        fprintf(stderr,
-                "SDL1 display code has no opengl support.\n"
-                "Please recompile qemu with SDL2, using\n"
-                "./configure --enable-sdl --with-sdlabi=2.0\n");
-    }
-}
-
-void sdl_display_init(DisplayState *ds, DisplayOptions *o)
+static void sdl1_display_init(DisplayState *ds, DisplayOptions *o)
 {
     int flags;
     uint8_t data = 0;
@@ -1023,3 +1013,15 @@ void sdl_display_init(DisplayState *ds, DisplayOptions *o)
 
     atexit(sdl_cleanup);
 }
+
+static QemuDisplay qemu_display_sdl1 = {
+    .type       = DISPLAY_TYPE_SDL,
+    .init       = sdl1_display_init,
+};
+
+static void register_sdl1(void)
+{
+    qemu_display_register(&qemu_display_sdl1);
+}
+
+type_init(register_sdl1);
diff --git a/ui/sdl2.c b/ui/sdl2.c
index b5a0fa1d13..83b917fa37 100644
--- a/ui/sdl2.c
+++ b/ui/sdl2.c
@@ -751,7 +751,7 @@ static const DisplayChangeListenerOps dcl_gl_ops = {
 };
 #endif
 
-void sdl_display_early_init(DisplayOptions *o)
+static void sdl2_display_early_init(DisplayOptions *o)
 {
     assert(o->type == DISPLAY_TYPE_SDL);
     if (o->has_gl && o->gl) {
@@ -761,7 +761,7 @@ void sdl_display_early_init(DisplayOptions *o)
     }
 }
 
-void sdl_display_init(DisplayState *ds, DisplayOptions *o)
+static void sdl2_display_init(DisplayState *ds, DisplayOptions *o)
 {
     int flags;
     uint8_t data = 0;
@@ -861,3 +861,16 @@ void sdl_display_init(DisplayState *ds, DisplayOptions *o)
 
     atexit(sdl_cleanup);
 }
+
+static QemuDisplay qemu_display_sdl2 = {
+    .type       = DISPLAY_TYPE_SDL,
+    .early_init = sdl2_display_early_init,
+    .init       = sdl2_display_init,
+};
+
+static void register_sdl1(void)
+{
+    qemu_display_register(&qemu_display_sdl2);
+}
+
+type_init(register_sdl1);
diff --git a/vl.c b/vl.c
index f98ec983e8..6120b889ed 100644
--- a/vl.c
+++ b/vl.c
@@ -2094,7 +2094,6 @@ static void parse_display(const char *p)
     const char *opts;
 
     if (strstart(p, "sdl", &opts)) {
-#ifdef CONFIG_SDL
         dpy.type = DISPLAY_TYPE_SDL;
         while (*opts) {
             const char *nextopt;
@@ -2155,10 +2154,6 @@ static void parse_display(const char *p)
             }
             opts = nextopt;
         }
-#else
-        error_report("SDL support is disabled");
-        exit(1);
-#endif
     } else if (strstart(p, "vnc", &opts)) {
         if (*opts == '=') {
             vnc_parse(opts + 1, &error_fatal);
@@ -2167,22 +2162,10 @@ static void parse_display(const char *p)
             exit(1);
         }
     } else if (strstart(p, "egl-headless", &opts)) {
-#ifdef CONFIG_OPENGL_DMABUF
-        display_opengl = 1;
         dpy.type = DISPLAY_TYPE_EGL_HEADLESS;
-#else
-        error_report("egl support is disabled");
-        exit(1);
-#endif
     } else if (strstart(p, "curses", &opts)) {
-#ifdef CONFIG_CURSES
         dpy.type = DISPLAY_TYPE_CURSES;
-#else
-        error_report("curses support is disabled");
-        exit(1);
-#endif
     } else if (strstart(p, "gtk", &opts)) {
-#ifdef CONFIG_GTK
         dpy.type = DISPLAY_TYPE_GTK;
         while (*opts) {
             const char *nextopt;
@@ -2214,10 +2197,6 @@ static void parse_display(const char *p)
             }
             opts = nextopt;
         }
-#else
-        error_report("GTK support is disabled");
-        exit(1);
-#endif
     } else if (strstart(p, "none", &opts)) {
         dpy.type = DISPLAY_TYPE_NONE;
     } else {
@@ -4328,17 +4307,15 @@ int main(int argc, char **argv, char **envp)
     }
 #endif
     if (dpy.type == DISPLAY_TYPE_DEFAULT && !display_remote) {
-#if defined(CONFIG_GTK)
-        dpy.type = DISPLAY_TYPE_GTK;
-#elif defined(CONFIG_SDL)
-        dpy.type = DISPLAY_TYPE_SDL;
-#elif defined(CONFIG_COCOA)
-        dpy.type = DISPLAY_TYPE_COCOA;
-#elif defined(CONFIG_VNC)
-        vnc_parse("localhost:0,to=99,id=default", &error_abort);
-#else
-        dpy.type = DISPLAY_TYPE_NONE;
+        if (!qemu_display_find_default(&dpy)) {
+            dpy.type = DISPLAY_TYPE_NONE;
+#if defined(CONFIG_VNC)
+            vnc_parse("localhost:0,to=99,id=default", &error_abort);
 #endif
+        }
+    }
+    if (dpy.type == DISPLAY_TYPE_DEFAULT) {
+        dpy.type = DISPLAY_TYPE_NONE;
     }
 
     if ((no_frame || alt_grab || ctrl_grab) && dpy.type != DISPLAY_TYPE_SDL) {
@@ -4351,14 +4328,7 @@ int main(int argc, char **argv, char **envp)
                      "ignoring option");
     }
 
-    if (dpy.type == DISPLAY_TYPE_GTK) {
-        early_gtk_display_init(&dpy);
-    }
-
-    if (dpy.type == DISPLAY_TYPE_SDL) {
-        sdl_display_early_init(&dpy);
-    }
-
+    qemu_display_early_init(&dpy);
     qemu_console_early_init();
 
     if (dpy.has_gl && dpy.gl && display_opengl == 0) {
@@ -4684,25 +4654,9 @@ int main(int argc, char **argv, char **envp)
         qemu_register_reset(restore_boot_order, g_strdup(boot_order));
     }
 
-    ds = init_displaystate();
-
     /* init local displays */
-    switch (dpy.type) {
-    case DISPLAY_TYPE_CURSES:
-        curses_display_init(ds, &dpy);
-        break;
-    case DISPLAY_TYPE_SDL:
-        sdl_display_init(ds, &dpy);
-        break;
-    case DISPLAY_TYPE_COCOA:
-        cocoa_display_init(ds, &dpy);
-        break;
-    case DISPLAY_TYPE_GTK:
-        gtk_display_init(ds, &dpy);
-        break;
-    default:
-        break;
-    }
+    ds = init_displaystate();
+    qemu_display_init(ds, &dpy);
 
     /* must be after terminal init, SDL library changes signal handlers */
     os_setup_signal_handling();
@@ -4717,12 +4671,6 @@ int main(int argc, char **argv, char **envp)
         qemu_spice_display_init();
     }
 
-#ifdef CONFIG_OPENGL_DMABUF
-    if (dpy.type == DISPLAY_TYPE_EGL_HEADLESS) {
-        egl_headless_init(&dpy);
-    }
-#endif
-
     if (foreach_device_config(DEV_GDB, gdbserver_start) < 0) {
         exit(1);
     }