Merge tag 'qemu-macppc-20230206' of https://github.com/mcayland/qemu into staging
[qemu.git] / util / main-loop.c
blob58f776a8c9c8e29188e53dac13ff53721b3544e3
1 /*
2 * QEMU System Emulator
4 * Copyright (c) 2003-2008 Fabrice Bellard
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
25 #include "qemu/osdep.h"
26 #include "qapi/error.h"
27 #include "qemu/cutils.h"
28 #include "qemu/timer.h"
29 #include "sysemu/cpu-timers.h"
30 #include "sysemu/replay.h"
31 #include "qemu/main-loop.h"
32 #include "block/aio.h"
33 #include "block/thread-pool.h"
34 #include "qemu/error-report.h"
35 #include "qemu/queue.h"
36 #include "qemu/compiler.h"
37 #include "qom/object.h"
39 #ifndef _WIN32
40 #include <sys/wait.h>
41 #endif
43 #ifndef _WIN32
45 /* If we have signalfd, we mask out the signals we want to handle and then
46 * use signalfd to listen for them. We rely on whatever the current signal
47 * handler is to dispatch the signals when we receive them.
50 * Disable CFI checks.
51 * We are going to call a signal hander directly. Such handler may or may not
52 * have been defined in our binary, so there's no guarantee that the pointer
53 * used to set the handler is a cfi-valid pointer. Since the handlers are
54 * stored in kernel memory, changing the handler to an attacker-defined
55 * function requires being able to call a sigaction() syscall,
56 * which is not as easy as overwriting a pointer in memory.
58 QEMU_DISABLE_CFI
59 static void sigfd_handler(void *opaque)
61 int fd = (intptr_t)opaque;
62 struct qemu_signalfd_siginfo info;
63 struct sigaction action;
64 ssize_t len;
66 while (1) {
67 len = RETRY_ON_EINTR(read(fd, &info, sizeof(info)));
69 if (len == -1 && errno == EAGAIN) {
70 break;
73 if (len != sizeof(info)) {
74 error_report("read from sigfd returned %zd: %s", len,
75 g_strerror(errno));
76 return;
79 sigaction(info.ssi_signo, NULL, &action);
80 if ((action.sa_flags & SA_SIGINFO) && action.sa_sigaction) {
81 sigaction_invoke(&action, &info);
82 } else if (action.sa_handler) {
83 action.sa_handler(info.ssi_signo);
88 static int qemu_signal_init(Error **errp)
90 int sigfd;
91 sigset_t set;
94 * SIG_IPI must be blocked in the main thread and must not be caught
95 * by sigwait() in the signal thread. Otherwise, the cpu thread will
96 * not catch it reliably.
98 sigemptyset(&set);
99 sigaddset(&set, SIG_IPI);
100 sigaddset(&set, SIGIO);
101 sigaddset(&set, SIGALRM);
102 sigaddset(&set, SIGBUS);
103 /* SIGINT cannot be handled via signalfd, so that ^C can be used
104 * to interrupt QEMU when it is being run under gdb. SIGHUP and
105 * SIGTERM are also handled asynchronously, even though it is not
106 * strictly necessary, because they use the same handler as SIGINT.
108 pthread_sigmask(SIG_BLOCK, &set, NULL);
110 sigdelset(&set, SIG_IPI);
111 sigfd = qemu_signalfd(&set);
112 if (sigfd == -1) {
113 error_setg_errno(errp, errno, "failed to create signalfd");
114 return -errno;
117 g_unix_set_fd_nonblocking(sigfd, true, NULL);
119 qemu_set_fd_handler(sigfd, sigfd_handler, NULL, (void *)(intptr_t)sigfd);
121 return 0;
124 #else /* _WIN32 */
126 static int qemu_signal_init(Error **errp)
128 return 0;
130 #endif
132 static AioContext *qemu_aio_context;
133 static QEMUBH *qemu_notify_bh;
135 static void notify_event_cb(void *opaque)
137 /* No need to do anything; this bottom half is only used to
138 * kick the kernel out of ppoll/poll/WaitForMultipleObjects.
142 AioContext *qemu_get_aio_context(void)
144 return qemu_aio_context;
147 void qemu_notify_event(void)
149 if (!qemu_aio_context) {
150 return;
152 qemu_bh_schedule(qemu_notify_bh);
155 static GArray *gpollfds;
157 int qemu_init_main_loop(Error **errp)
159 int ret;
160 GSource *src;
162 init_clocks(qemu_timer_notify_cb);
164 ret = qemu_signal_init(errp);
165 if (ret) {
166 return ret;
169 qemu_aio_context = aio_context_new(errp);
170 if (!qemu_aio_context) {
171 return -EMFILE;
173 qemu_set_current_aio_context(qemu_aio_context);
174 qemu_notify_bh = qemu_bh_new(notify_event_cb, NULL);
175 gpollfds = g_array_new(FALSE, FALSE, sizeof(GPollFD));
176 src = aio_get_g_source(qemu_aio_context);
177 g_source_set_name(src, "aio-context");
178 g_source_attach(src, NULL);
179 g_source_unref(src);
180 src = iohandler_get_g_source();
181 g_source_set_name(src, "io-handler");
182 g_source_attach(src, NULL);
183 g_source_unref(src);
184 return 0;
187 static void main_loop_update_params(EventLoopBase *base, Error **errp)
189 ERRP_GUARD();
191 if (!qemu_aio_context) {
192 error_setg(errp, "qemu aio context not ready");
193 return;
196 aio_context_set_aio_params(qemu_aio_context, base->aio_max_batch, errp);
197 if (*errp) {
198 return;
201 aio_context_set_thread_pool_params(qemu_aio_context, base->thread_pool_min,
202 base->thread_pool_max, errp);
205 MainLoop *mloop;
207 static void main_loop_init(EventLoopBase *base, Error **errp)
209 MainLoop *m = MAIN_LOOP(base);
211 if (mloop) {
212 error_setg(errp, "only one main-loop instance allowed");
213 return;
216 main_loop_update_params(base, errp);
218 mloop = m;
219 return;
222 static bool main_loop_can_be_deleted(EventLoopBase *base)
224 return false;
227 static void main_loop_class_init(ObjectClass *oc, void *class_data)
229 EventLoopBaseClass *bc = EVENT_LOOP_BASE_CLASS(oc);
231 bc->init = main_loop_init;
232 bc->update_params = main_loop_update_params;
233 bc->can_be_deleted = main_loop_can_be_deleted;
236 static const TypeInfo main_loop_info = {
237 .name = TYPE_MAIN_LOOP,
238 .parent = TYPE_EVENT_LOOP_BASE,
239 .class_init = main_loop_class_init,
240 .instance_size = sizeof(MainLoop),
243 static void main_loop_register_types(void)
245 type_register_static(&main_loop_info);
248 type_init(main_loop_register_types)
250 static int max_priority;
252 #ifndef _WIN32
253 static int glib_pollfds_idx;
254 static int glib_n_poll_fds;
256 void qemu_fd_register(int fd)
260 static void glib_pollfds_fill(int64_t *cur_timeout)
262 GMainContext *context = g_main_context_default();
263 int timeout = 0;
264 int64_t timeout_ns;
265 int n;
267 g_main_context_prepare(context, &max_priority);
269 glib_pollfds_idx = gpollfds->len;
270 n = glib_n_poll_fds;
271 do {
272 GPollFD *pfds;
273 glib_n_poll_fds = n;
274 g_array_set_size(gpollfds, glib_pollfds_idx + glib_n_poll_fds);
275 pfds = &g_array_index(gpollfds, GPollFD, glib_pollfds_idx);
276 n = g_main_context_query(context, max_priority, &timeout, pfds,
277 glib_n_poll_fds);
278 } while (n != glib_n_poll_fds);
280 if (timeout < 0) {
281 timeout_ns = -1;
282 } else {
283 timeout_ns = (int64_t)timeout * (int64_t)SCALE_MS;
286 *cur_timeout = qemu_soonest_timeout(timeout_ns, *cur_timeout);
289 static void glib_pollfds_poll(void)
291 GMainContext *context = g_main_context_default();
292 GPollFD *pfds = &g_array_index(gpollfds, GPollFD, glib_pollfds_idx);
294 if (g_main_context_check(context, max_priority, pfds, glib_n_poll_fds)) {
295 g_main_context_dispatch(context);
299 #define MAX_MAIN_LOOP_SPIN (1000)
301 static int os_host_main_loop_wait(int64_t timeout)
303 GMainContext *context = g_main_context_default();
304 int ret;
306 g_main_context_acquire(context);
308 glib_pollfds_fill(&timeout);
310 qemu_mutex_unlock_iothread();
311 replay_mutex_unlock();
313 ret = qemu_poll_ns((GPollFD *)gpollfds->data, gpollfds->len, timeout);
315 replay_mutex_lock();
316 qemu_mutex_lock_iothread();
318 glib_pollfds_poll();
320 g_main_context_release(context);
322 return ret;
324 #else
325 /***********************************************************/
326 /* Polling handling */
328 typedef struct PollingEntry {
329 PollingFunc *func;
330 void *opaque;
331 struct PollingEntry *next;
332 } PollingEntry;
334 static PollingEntry *first_polling_entry;
336 int qemu_add_polling_cb(PollingFunc *func, void *opaque)
338 PollingEntry **ppe, *pe;
339 pe = g_new0(PollingEntry, 1);
340 pe->func = func;
341 pe->opaque = opaque;
342 for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next);
343 *ppe = pe;
344 return 0;
347 void qemu_del_polling_cb(PollingFunc *func, void *opaque)
349 PollingEntry **ppe, *pe;
350 for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next) {
351 pe = *ppe;
352 if (pe->func == func && pe->opaque == opaque) {
353 *ppe = pe->next;
354 g_free(pe);
355 break;
360 /***********************************************************/
361 /* Wait objects support */
362 typedef struct WaitObjects {
363 int num;
364 int revents[MAXIMUM_WAIT_OBJECTS];
365 HANDLE events[MAXIMUM_WAIT_OBJECTS];
366 WaitObjectFunc *func[MAXIMUM_WAIT_OBJECTS];
367 void *opaque[MAXIMUM_WAIT_OBJECTS];
368 } WaitObjects;
370 static WaitObjects wait_objects = {0};
372 int qemu_add_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
374 int i;
375 WaitObjects *w = &wait_objects;
377 if (w->num >= MAXIMUM_WAIT_OBJECTS) {
378 return -1;
381 for (i = 0; i < w->num; i++) {
382 /* check if the same handle is added twice */
383 if (w->events[i] == handle) {
384 return -1;
388 w->events[w->num] = handle;
389 w->func[w->num] = func;
390 w->opaque[w->num] = opaque;
391 w->revents[w->num] = 0;
392 w->num++;
393 return 0;
396 void qemu_del_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
398 int i, found;
399 WaitObjects *w = &wait_objects;
401 found = 0;
402 for (i = 0; i < w->num; i++) {
403 if (w->events[i] == handle) {
404 found = 1;
406 if (found && i < (MAXIMUM_WAIT_OBJECTS - 1)) {
407 w->events[i] = w->events[i + 1];
408 w->func[i] = w->func[i + 1];
409 w->opaque[i] = w->opaque[i + 1];
410 w->revents[i] = w->revents[i + 1];
413 if (found) {
414 w->num--;
418 void qemu_fd_register(int fd)
420 WSAEventSelect(fd, event_notifier_get_handle(&qemu_aio_context->notifier),
421 FD_READ | FD_ACCEPT | FD_CLOSE |
422 FD_CONNECT | FD_WRITE | FD_OOB);
425 static int pollfds_fill(GArray *pollfds, fd_set *rfds, fd_set *wfds,
426 fd_set *xfds)
428 int nfds = -1;
429 int i;
431 for (i = 0; i < pollfds->len; i++) {
432 GPollFD *pfd = &g_array_index(pollfds, GPollFD, i);
433 int fd = pfd->fd;
434 int events = pfd->events;
435 if (events & G_IO_IN) {
436 FD_SET(fd, rfds);
437 nfds = MAX(nfds, fd);
439 if (events & G_IO_OUT) {
440 FD_SET(fd, wfds);
441 nfds = MAX(nfds, fd);
443 if (events & G_IO_PRI) {
444 FD_SET(fd, xfds);
445 nfds = MAX(nfds, fd);
448 return nfds;
451 static void pollfds_poll(GArray *pollfds, int nfds, fd_set *rfds,
452 fd_set *wfds, fd_set *xfds)
454 int i;
456 for (i = 0; i < pollfds->len; i++) {
457 GPollFD *pfd = &g_array_index(pollfds, GPollFD, i);
458 int fd = pfd->fd;
459 int revents = 0;
461 if (FD_ISSET(fd, rfds)) {
462 revents |= G_IO_IN;
464 if (FD_ISSET(fd, wfds)) {
465 revents |= G_IO_OUT;
467 if (FD_ISSET(fd, xfds)) {
468 revents |= G_IO_PRI;
470 pfd->revents = revents & pfd->events;
474 static int os_host_main_loop_wait(int64_t timeout)
476 GMainContext *context = g_main_context_default();
477 GPollFD poll_fds[1024 * 2]; /* this is probably overkill */
478 int select_ret = 0;
479 int g_poll_ret, ret, i, n_poll_fds;
480 PollingEntry *pe;
481 WaitObjects *w = &wait_objects;
482 gint poll_timeout;
483 int64_t poll_timeout_ns;
484 static struct timeval tv0;
485 fd_set rfds, wfds, xfds;
486 int nfds;
488 g_main_context_acquire(context);
490 /* XXX: need to suppress polling by better using win32 events */
491 ret = 0;
492 for (pe = first_polling_entry; pe != NULL; pe = pe->next) {
493 ret |= pe->func(pe->opaque);
495 if (ret != 0) {
496 g_main_context_release(context);
497 return ret;
500 FD_ZERO(&rfds);
501 FD_ZERO(&wfds);
502 FD_ZERO(&xfds);
503 nfds = pollfds_fill(gpollfds, &rfds, &wfds, &xfds);
504 if (nfds >= 0) {
505 select_ret = select(nfds + 1, &rfds, &wfds, &xfds, &tv0);
506 if (select_ret != 0) {
507 timeout = 0;
509 if (select_ret > 0) {
510 pollfds_poll(gpollfds, nfds, &rfds, &wfds, &xfds);
514 g_main_context_prepare(context, &max_priority);
515 n_poll_fds = g_main_context_query(context, max_priority, &poll_timeout,
516 poll_fds, ARRAY_SIZE(poll_fds));
517 g_assert(n_poll_fds + w->num <= ARRAY_SIZE(poll_fds));
519 for (i = 0; i < w->num; i++) {
520 poll_fds[n_poll_fds + i].fd = (DWORD_PTR)w->events[i];
521 poll_fds[n_poll_fds + i].events = G_IO_IN;
524 if (poll_timeout < 0) {
525 poll_timeout_ns = -1;
526 } else {
527 poll_timeout_ns = (int64_t)poll_timeout * (int64_t)SCALE_MS;
530 poll_timeout_ns = qemu_soonest_timeout(poll_timeout_ns, timeout);
532 qemu_mutex_unlock_iothread();
534 replay_mutex_unlock();
536 g_poll_ret = qemu_poll_ns(poll_fds, n_poll_fds + w->num, poll_timeout_ns);
538 replay_mutex_lock();
540 qemu_mutex_lock_iothread();
541 if (g_poll_ret > 0) {
542 for (i = 0; i < w->num; i++) {
543 w->revents[i] = poll_fds[n_poll_fds + i].revents;
545 for (i = 0; i < w->num; i++) {
546 if (w->revents[i] && w->func[i]) {
547 w->func[i](w->opaque[i]);
552 if (g_main_context_check(context, max_priority, poll_fds, n_poll_fds)) {
553 g_main_context_dispatch(context);
556 g_main_context_release(context);
558 return select_ret || g_poll_ret;
560 #endif
562 static NotifierList main_loop_poll_notifiers =
563 NOTIFIER_LIST_INITIALIZER(main_loop_poll_notifiers);
565 void main_loop_poll_add_notifier(Notifier *notify)
567 notifier_list_add(&main_loop_poll_notifiers, notify);
570 void main_loop_poll_remove_notifier(Notifier *notify)
572 notifier_remove(notify);
575 void main_loop_wait(int nonblocking)
577 MainLoopPoll mlpoll = {
578 .state = MAIN_LOOP_POLL_FILL,
579 .timeout = UINT32_MAX,
580 .pollfds = gpollfds,
582 int ret;
583 int64_t timeout_ns;
585 if (nonblocking) {
586 mlpoll.timeout = 0;
589 /* poll any events */
590 g_array_set_size(gpollfds, 0); /* reset for new iteration */
591 /* XXX: separate device handlers from system ones */
592 notifier_list_notify(&main_loop_poll_notifiers, &mlpoll);
594 if (mlpoll.timeout == UINT32_MAX) {
595 timeout_ns = -1;
596 } else {
597 timeout_ns = (uint64_t)mlpoll.timeout * (int64_t)(SCALE_MS);
600 timeout_ns = qemu_soonest_timeout(timeout_ns,
601 timerlistgroup_deadline_ns(
602 &main_loop_tlg));
604 ret = os_host_main_loop_wait(timeout_ns);
605 mlpoll.state = ret < 0 ? MAIN_LOOP_POLL_ERR : MAIN_LOOP_POLL_OK;
606 notifier_list_notify(&main_loop_poll_notifiers, &mlpoll);
608 if (icount_enabled()) {
610 * CPU thread can infinitely wait for event after
611 * missing the warp
613 icount_start_warp_timer();
615 qemu_clock_run_all_timers();
618 /* Functions to operate on the main QEMU AioContext. */
620 QEMUBH *qemu_bh_new_full(QEMUBHFunc *cb, void *opaque, const char *name)
622 return aio_bh_new_full(qemu_aio_context, cb, opaque, name);
626 * Functions to operate on the I/O handler AioContext.
627 * This context runs on top of main loop. We can't reuse qemu_aio_context
628 * because iohandlers mustn't be polled by aio_poll(qemu_aio_context).
630 static AioContext *iohandler_ctx;
632 static void iohandler_init(void)
634 if (!iohandler_ctx) {
635 iohandler_ctx = aio_context_new(&error_abort);
639 AioContext *iohandler_get_aio_context(void)
641 iohandler_init();
642 return iohandler_ctx;
645 GSource *iohandler_get_g_source(void)
647 iohandler_init();
648 return aio_get_g_source(iohandler_ctx);
651 void qemu_set_fd_handler(int fd,
652 IOHandler *fd_read,
653 IOHandler *fd_write,
654 void *opaque)
656 iohandler_init();
657 aio_set_fd_handler(iohandler_ctx, fd, false,
658 fd_read, fd_write, NULL, NULL, opaque);
661 void event_notifier_set_handler(EventNotifier *e,
662 EventNotifierHandler *handler)
664 iohandler_init();
665 aio_set_event_notifier(iohandler_ctx, e, false,
666 handler, NULL, NULL);