From bab6a301c58286229ca8fbc36728d1469f243260 Mon Sep 17 00:00:00 2001 From: Akihiko Odaki Date: Fri, 19 Aug 2022 22:27:54 +0900 Subject: [PATCH] ui/cocoa: Run qemu_init in the main thread This work is based on: https://patchew.org/QEMU/20220317125534.38706-1-philippe.mathieu.daude@gmail.com/ Simplify the initialization dance by running qemu_init() in the main thread before the Cocoa event loop starts. The secondary thread only runs only qemu_main_loop() and qemu_cleanup(). This fixes a case where addRemovableDevicesMenuItems() calls qmp_query_block() while expecting the main thread to still hold the BQL. Overriding the code after calling qemu_init() is done by dynamically replacing a function pointer variable, qemu_main when initializing ui/cocoa, which unifies the static implementation of main() for builds with ui/cocoa and ones without ui/cocoa. Signed-off-by: Akihiko Odaki Message-Id: <20220819132756.74641-2-akihiko.odaki@gmail.com> Signed-off-by: Gerd Hoffmann --- docs/devel/fuzzing.rst | 4 +- include/qemu-main.h | 3 +- include/sysemu/sysemu.h | 2 +- softmmu/main.c | 10 +-- softmmu/vl.c | 2 +- tests/qtest/fuzz/fuzz.c | 2 +- ui/cocoa.m | 144 ++++++++++++++-------------------------- 7 files changed, 62 insertions(+), 105 deletions(-) diff --git a/docs/devel/fuzzing.rst b/docs/devel/fuzzing.rst index 784ecb99e6..715330c856 100644 --- a/docs/devel/fuzzing.rst +++ b/docs/devel/fuzzing.rst @@ -287,8 +287,8 @@ select the fuzz target. Then, the qtest client is initialized. If the target requires qos, qgraph is set up and the QOM/LIBQOS modules are initialized. Then the QGraph is walked and the QEMU cmd_line is determined and saved. -After this, the ``vl.c:qemu_main`` is called to set up the guest. There are -target-specific hooks that can be called before and after qemu_main, for +After this, the ``vl.c:main`` is called to set up the guest. There are +target-specific hooks that can be called before and after main, for additional setup(e.g. PCI setup, or VM snapshotting). ``LLVMFuzzerTestOneInput``: Uses qtest/qos functions to act based on the fuzz diff --git a/include/qemu-main.h b/include/qemu-main.h index 6a3e90d0ad..940960a7db 100644 --- a/include/qemu-main.h +++ b/include/qemu-main.h @@ -5,6 +5,7 @@ #ifndef QEMU_MAIN_H #define QEMU_MAIN_H -int qemu_main(int argc, char **argv, char **envp); +int qemu_default_main(void); +extern int (*qemu_main)(void); #endif /* QEMU_MAIN_H */ diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h index 31aa45160b..6a7a31e64d 100644 --- a/include/sysemu/sysemu.h +++ b/include/sysemu/sysemu.h @@ -102,7 +102,7 @@ void qemu_boot_set(const char *boot_order, Error **errp); bool defaults_enabled(void); -void qemu_init(int argc, char **argv, char **envp); +void qemu_init(int argc, char **argv); int qemu_main_loop(void); void qemu_cleanup(void); diff --git a/softmmu/main.c b/softmmu/main.c index 1b675a8c03..694388bd7f 100644 --- a/softmmu/main.c +++ b/softmmu/main.c @@ -30,20 +30,20 @@ #include #endif -int qemu_main(int argc, char **argv, char **envp) +int qemu_default_main(void) { int status; - qemu_init(argc, argv, envp); status = qemu_main_loop(); qemu_cleanup(); return status; } -#ifndef CONFIG_COCOA +int (*qemu_main)(void) = qemu_default_main; + int main(int argc, char **argv) { - return qemu_main(argc, argv, NULL); + qemu_init(argc, argv); + return qemu_main(); } -#endif diff --git a/softmmu/vl.c b/softmmu/vl.c index e62b9cc35d..9abadcc150 100644 --- a/softmmu/vl.c +++ b/softmmu/vl.c @@ -2605,7 +2605,7 @@ void qmp_x_exit_preconfig(Error **errp) } } -void qemu_init(int argc, char **argv, char **envp) +void qemu_init(int argc, char **argv) { QemuOpts *opts; QemuOpts *icount_opts = NULL, *accel_opts = NULL; diff --git a/tests/qtest/fuzz/fuzz.c b/tests/qtest/fuzz/fuzz.c index 2b3bc1fb9d..eb7520544b 100644 --- a/tests/qtest/fuzz/fuzz.c +++ b/tests/qtest/fuzz/fuzz.c @@ -218,7 +218,7 @@ int LLVMFuzzerInitialize(int *argc, char ***argv, char ***envp) g_free(pretty_cmd_line); } - qemu_init(result.we_wordc, result.we_wordv, NULL); + qemu_init(result.we_wordc, result.we_wordv); /* re-enable the rcu atfork, which was previously disabled in qemu_init */ rcu_enable_atfork(); diff --git a/ui/cocoa.m b/ui/cocoa.m index 5a8bd5dd84..660d3e0935 100644 --- a/ui/cocoa.m +++ b/ui/cocoa.m @@ -100,13 +100,9 @@ static int cursor_hide = 1; static int left_command_key_enabled = 1; static bool swap_opt_cmd; -static int gArgc; -static char **gArgv; static bool stretch_video; static NSTextField *pauseLabel; -static QemuSemaphore display_init_sem; -static QemuSemaphore app_started_sem; static bool allow_events; static NSInteger cbchangecount = -1; @@ -597,7 +593,7 @@ static CGEventRef handleTapEvent(CGEventTapProxy proxy, CGEventType type, CGEven /* * Don't try to tell QEMU about UI information in the application * startup phase -- we haven't yet registered dcl with the QEMU UI - * layer, and also trying to take the iothread lock would deadlock. + * layer. * When cocoa_display_init() does register the dcl, the UI layer * will call cocoa_switch(), which will call updateUIInfo, so * we don't lose any information here. @@ -790,16 +786,6 @@ static CGEventRef handleTapEvent(CGEventTapProxy proxy, CGEventType type, CGEven - (bool) handleEvent:(NSEvent *)event { - if(!allow_events) { - /* - * Just let OSX have all events that arrive before - * applicationDidFinishLaunching. - * This avoids a deadlock on the iothread lock, which cocoa_display_init() - * will not drop until after the app_started_sem is posted. (In theory - * there should not be any such events, but OSX Catalina now emits some.) - */ - return false; - } return bool_with_iothread_lock(^{ return [self handleEventLocked:event]; }); @@ -1287,8 +1273,6 @@ static CGEventRef handleTapEvent(CGEventTapProxy proxy, CGEventType type, CGEven { COCOA_DEBUG("QemuCocoaAppController: applicationDidFinishLaunching\n"); allow_events = true; - /* Tell cocoa_display_init to proceed */ - qemu_sem_post(&app_started_sem); } - (void)applicationWillTerminate:(NSNotification *)aNotification @@ -1919,92 +1903,45 @@ static void cocoa_clipboard_request(QemuClipboardInfo *info, /* * The startup process for the OSX/Cocoa UI is complicated, because * OSX insists that the UI runs on the initial main thread, and so we - * need to start a second thread which runs the vl.c qemu_main(): - * - * Initial thread: 2nd thread: + * need to start a second thread which runs the qemu_default_main(): * in main(): - * create qemu-main thread - * wait on display_init semaphore - * call qemu_main() - * ... - * in cocoa_display_init(): - * post the display_init semaphore - * wait on app_started semaphore - * create application, menus, etc - * enter OSX run loop - * in applicationDidFinishLaunching: - * post app_started semaphore - * tell main thread to fullscreen if needed - * [...] - * run qemu main-loop - * - * We do this in two stages so that we don't do the creation of the - * GUI application menus and so on for command line options like --help - * where we want to just print text to stdout and exit immediately. + * in cocoa_display_init(): + * assign cocoa_main to qemu_main + * create application, menus, etc + * in cocoa_main(): + * create qemu-main thread + * enter OSX run loop */ static void *call_qemu_main(void *opaque) { int status; - COCOA_DEBUG("Second thread: calling qemu_main()\n"); - status = qemu_main(gArgc, gArgv, *_NSGetEnviron()); - COCOA_DEBUG("Second thread: qemu_main() returned, exiting\n"); + COCOA_DEBUG("Second thread: calling qemu_default_main()\n"); + qemu_mutex_lock_iothread(); + status = qemu_default_main(); + qemu_mutex_unlock_iothread(); + COCOA_DEBUG("Second thread: qemu_default_main() returned, exiting\n"); [cbowner release]; exit(status); } -int main (int argc, char **argv) { +static int cocoa_main() +{ QemuThread thread; - COCOA_DEBUG("Entered main()\n"); - gArgc = argc; - gArgv = argv; - - qemu_sem_init(&display_init_sem, 0); - qemu_sem_init(&app_started_sem, 0); + COCOA_DEBUG("Entered %s()\n", __func__); + qemu_mutex_unlock_iothread(); qemu_thread_create(&thread, "qemu_main", call_qemu_main, NULL, QEMU_THREAD_DETACHED); - COCOA_DEBUG("Main thread: waiting for display_init_sem\n"); - qemu_sem_wait(&display_init_sem); - COCOA_DEBUG("Main thread: initializing app\n"); - - NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; - - // Pull this console process up to being a fully-fledged graphical - // app with a menubar and Dock icon - ProcessSerialNumber psn = { 0, kCurrentProcess }; - TransformProcessType(&psn, kProcessTransformToForegroundApplication); - - [QemuApplication sharedApplication]; - - create_initial_menus(); - - /* - * Create the menu entries which depend on QEMU state (for consoles - * and removeable devices). These make calls back into QEMU functions, - * which is OK because at this point we know that the second thread - * holds the iothread lock and is synchronously waiting for us to - * finish. - */ - add_console_menu_entries(); - addRemovableDevicesMenuItems(); - - // Create an Application controller - QemuCocoaAppController *appController = [[QemuCocoaAppController alloc] init]; - [NSApp setDelegate:appController]; - // Start the main event loop COCOA_DEBUG("Main thread: entering OSX run loop\n"); [NSApp run]; - COCOA_DEBUG("Main thread: left OSX run loop, exiting\n"); + COCOA_DEBUG("Main thread: left OSX run loop, which should never happen\n"); - [appController release]; - [pool release]; - - return 0; + abort(); } @@ -2083,25 +2020,42 @@ static void cocoa_refresh(DisplayChangeListener *dcl) static void cocoa_display_init(DisplayState *ds, DisplayOptions *opts) { + NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; + COCOA_DEBUG("qemu_cocoa: cocoa_display_init\n"); - /* Tell main thread to go ahead and create the app and enter the run loop */ - qemu_sem_post(&display_init_sem); - qemu_sem_wait(&app_started_sem); - COCOA_DEBUG("cocoa_display_init: app start completed\n"); + qemu_main = cocoa_main; + + // Pull this console process up to being a fully-fledged graphical + // app with a menubar and Dock icon + ProcessSerialNumber psn = { 0, kCurrentProcess }; + TransformProcessType(&psn, kProcessTransformToForegroundApplication); + + [QemuApplication sharedApplication]; + + create_initial_menus(); + + /* + * Create the menu entries which depend on QEMU state (for consoles + * and removeable devices). These make calls back into QEMU functions, + * which is OK because at this point we know that the second thread + * holds the iothread lock and is synchronously waiting for us to + * finish. + */ + add_console_menu_entries(); + addRemovableDevicesMenuItems(); + + // Create an Application controller + QemuCocoaAppController *controller = [[QemuCocoaAppController alloc] init]; + [NSApp setDelegate:controller]; - QemuCocoaAppController *controller = (QemuCocoaAppController *)[[NSApplication sharedApplication] delegate]; /* if fullscreen mode is to be used */ if (opts->has_full_screen && opts->full_screen) { - dispatch_async(dispatch_get_main_queue(), ^{ - [NSApp activateIgnoringOtherApps: YES]; - [controller toggleFullScreen: nil]; - }); + [NSApp activateIgnoringOtherApps: YES]; + [controller toggleFullScreen: nil]; } if (opts->u.cocoa.has_full_grab && opts->u.cocoa.full_grab) { - dispatch_async(dispatch_get_main_queue(), ^{ - [controller setFullGrab: nil]; - }); + [controller setFullGrab: nil]; } if (opts->has_show_cursor && opts->show_cursor) { @@ -2121,6 +2075,8 @@ static void cocoa_display_init(DisplayState *ds, DisplayOptions *opts) qemu_event_init(&cbevent, false); cbowner = [[QemuCocoaPasteboardTypeOwner alloc] init]; qemu_clipboard_peer_register(&cbpeer); + + [pool release]; } static QemuDisplay qemu_display_cocoa = {