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25#include "qemu/osdep.h"
26#include "qapi/error.h"
27#include "qemu/cutils.h"
28#include "qemu/timer.h"
29#include "qemu/sockets.h"
30#include "sysemu/qtest.h"
31#include "sysemu/cpus.h"
32#include "sysemu/replay.h"
33#include "slirp/libslirp.h"
34#include "qemu/main-loop.h"
35#include "block/aio.h"
36#include "qemu/error-report.h"
37
38#ifndef _WIN32
39
40
41
42
43
44static void sigfd_handler(void *opaque)
45{
46 int fd = (intptr_t)opaque;
47 struct qemu_signalfd_siginfo info;
48 struct sigaction action;
49 ssize_t len;
50
51 while (1) {
52 do {
53 len = read(fd, &info, sizeof(info));
54 } while (len == -1 && errno == EINTR);
55
56 if (len == -1 && errno == EAGAIN) {
57 break;
58 }
59
60 if (len != sizeof(info)) {
61 printf("read from sigfd returned %zd: %m\n", len);
62 return;
63 }
64
65 sigaction(info.ssi_signo, NULL, &action);
66 if ((action.sa_flags & SA_SIGINFO) && action.sa_sigaction) {
67 sigaction_invoke(&action, &info);
68 } else if (action.sa_handler) {
69 action.sa_handler(info.ssi_signo);
70 }
71 }
72}
73
74static int qemu_signal_init(void)
75{
76 int sigfd;
77 sigset_t set;
78
79
80
81
82
83
84 sigemptyset(&set);
85 sigaddset(&set, SIG_IPI);
86 sigaddset(&set, SIGIO);
87 sigaddset(&set, SIGALRM);
88 sigaddset(&set, SIGBUS);
89
90
91
92
93
94 pthread_sigmask(SIG_BLOCK, &set, NULL);
95
96 sigdelset(&set, SIG_IPI);
97 sigfd = qemu_signalfd(&set);
98 if (sigfd == -1) {
99 fprintf(stderr, "failed to create signalfd\n");
100 return -errno;
101 }
102
103 fcntl_setfl(sigfd, O_NONBLOCK);
104
105 qemu_set_fd_handler(sigfd, sigfd_handler, NULL, (void *)(intptr_t)sigfd);
106
107 return 0;
108}
109
110#else
111
112static int qemu_signal_init(void)
113{
114 return 0;
115}
116#endif
117
118static AioContext *qemu_aio_context;
119static QEMUBH *qemu_notify_bh;
120
121static void notify_event_cb(void *opaque)
122{
123
124
125
126}
127
128AioContext *qemu_get_aio_context(void)
129{
130 return qemu_aio_context;
131}
132
133void qemu_notify_event(void)
134{
135 if (!qemu_aio_context) {
136 return;
137 }
138 qemu_bh_schedule(qemu_notify_bh);
139}
140
141static GArray *gpollfds;
142
143int qemu_init_main_loop(Error **errp)
144{
145 int ret;
146 GSource *src;
147 Error *local_error = NULL;
148
149 init_clocks(qemu_timer_notify_cb);
150
151 ret = qemu_signal_init();
152 if (ret) {
153 return ret;
154 }
155
156 qemu_aio_context = aio_context_new(&local_error);
157 if (!qemu_aio_context) {
158 error_propagate(errp, local_error);
159 return -EMFILE;
160 }
161 qemu_notify_bh = qemu_bh_new(notify_event_cb, NULL);
162 gpollfds = g_array_new(FALSE, FALSE, sizeof(GPollFD));
163 src = aio_get_g_source(qemu_aio_context);
164 g_source_set_name(src, "aio-context");
165 g_source_attach(src, NULL);
166 g_source_unref(src);
167 src = iohandler_get_g_source();
168 g_source_set_name(src, "io-handler");
169 g_source_attach(src, NULL);
170 g_source_unref(src);
171 return 0;
172}
173
174static int max_priority;
175
176#ifndef _WIN32
177static int glib_pollfds_idx;
178static int glib_n_poll_fds;
179
180static void glib_pollfds_fill(int64_t *cur_timeout)
181{
182 GMainContext *context = g_main_context_default();
183 int timeout = 0;
184 int64_t timeout_ns;
185 int n;
186
187 g_main_context_prepare(context, &max_priority);
188
189 glib_pollfds_idx = gpollfds->len;
190 n = glib_n_poll_fds;
191 do {
192 GPollFD *pfds;
193 glib_n_poll_fds = n;
194 g_array_set_size(gpollfds, glib_pollfds_idx + glib_n_poll_fds);
195 pfds = &g_array_index(gpollfds, GPollFD, glib_pollfds_idx);
196 n = g_main_context_query(context, max_priority, &timeout, pfds,
197 glib_n_poll_fds);
198 } while (n != glib_n_poll_fds);
199
200 if (timeout < 0) {
201 timeout_ns = -1;
202 } else {
203 timeout_ns = (int64_t)timeout * (int64_t)SCALE_MS;
204 }
205
206 *cur_timeout = qemu_soonest_timeout(timeout_ns, *cur_timeout);
207}
208
209static void glib_pollfds_poll(void)
210{
211 GMainContext *context = g_main_context_default();
212 GPollFD *pfds = &g_array_index(gpollfds, GPollFD, glib_pollfds_idx);
213
214 if (g_main_context_check(context, max_priority, pfds, glib_n_poll_fds)) {
215 g_main_context_dispatch(context);
216 }
217}
218
219#define MAX_MAIN_LOOP_SPIN (1000)
220
221static int os_host_main_loop_wait(int64_t timeout)
222{
223 GMainContext *context = g_main_context_default();
224 int ret;
225 static int spin_counter;
226
227 g_main_context_acquire(context);
228
229 glib_pollfds_fill(&timeout);
230
231
232
233
234
235
236
237 if (!timeout && (spin_counter > MAX_MAIN_LOOP_SPIN)) {
238 static bool notified;
239
240 if (!notified && !qtest_enabled() && !qtest_driver()) {
241 warn_report("I/O thread spun for %d iterations",
242 MAX_MAIN_LOOP_SPIN);
243 notified = true;
244 }
245
246 timeout = SCALE_MS;
247 }
248
249
250 if (timeout) {
251 spin_counter = 0;
252 } else {
253 spin_counter++;
254 }
255 qemu_mutex_unlock_iothread();
256 replay_mutex_unlock();
257
258 ret = qemu_poll_ns((GPollFD *)gpollfds->data, gpollfds->len, timeout);
259
260 replay_mutex_lock();
261 qemu_mutex_lock_iothread();
262
263 glib_pollfds_poll();
264
265 g_main_context_release(context);
266
267 return ret;
268}
269#else
270
271
272
273typedef struct PollingEntry {
274 PollingFunc *func;
275 void *opaque;
276 struct PollingEntry *next;
277} PollingEntry;
278
279static PollingEntry *first_polling_entry;
280
281int qemu_add_polling_cb(PollingFunc *func, void *opaque)
282{
283 PollingEntry **ppe, *pe;
284 pe = g_malloc0(sizeof(PollingEntry));
285 pe->func = func;
286 pe->opaque = opaque;
287 for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next);
288 *ppe = pe;
289 return 0;
290}
291
292void qemu_del_polling_cb(PollingFunc *func, void *opaque)
293{
294 PollingEntry **ppe, *pe;
295 for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next) {
296 pe = *ppe;
297 if (pe->func == func && pe->opaque == opaque) {
298 *ppe = pe->next;
299 g_free(pe);
300 break;
301 }
302 }
303}
304
305
306
307typedef struct WaitObjects {
308 int num;
309 int revents[MAXIMUM_WAIT_OBJECTS + 1];
310 HANDLE events[MAXIMUM_WAIT_OBJECTS + 1];
311 WaitObjectFunc *func[MAXIMUM_WAIT_OBJECTS + 1];
312 void *opaque[MAXIMUM_WAIT_OBJECTS + 1];
313} WaitObjects;
314
315static WaitObjects wait_objects = {0};
316
317int qemu_add_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
318{
319 WaitObjects *w = &wait_objects;
320 if (w->num >= MAXIMUM_WAIT_OBJECTS) {
321 return -1;
322 }
323 w->events[w->num] = handle;
324 w->func[w->num] = func;
325 w->opaque[w->num] = opaque;
326 w->revents[w->num] = 0;
327 w->num++;
328 return 0;
329}
330
331void qemu_del_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
332{
333 int i, found;
334 WaitObjects *w = &wait_objects;
335
336 found = 0;
337 for (i = 0; i < w->num; i++) {
338 if (w->events[i] == handle) {
339 found = 1;
340 }
341 if (found) {
342 w->events[i] = w->events[i + 1];
343 w->func[i] = w->func[i + 1];
344 w->opaque[i] = w->opaque[i + 1];
345 w->revents[i] = w->revents[i + 1];
346 }
347 }
348 if (found) {
349 w->num--;
350 }
351}
352
353void qemu_fd_register(int fd)
354{
355 WSAEventSelect(fd, event_notifier_get_handle(&qemu_aio_context->notifier),
356 FD_READ | FD_ACCEPT | FD_CLOSE |
357 FD_CONNECT | FD_WRITE | FD_OOB);
358}
359
360static int pollfds_fill(GArray *pollfds, fd_set *rfds, fd_set *wfds,
361 fd_set *xfds)
362{
363 int nfds = -1;
364 int i;
365
366 for (i = 0; i < pollfds->len; i++) {
367 GPollFD *pfd = &g_array_index(pollfds, GPollFD, i);
368 int fd = pfd->fd;
369 int events = pfd->events;
370 if (events & G_IO_IN) {
371 FD_SET(fd, rfds);
372 nfds = MAX(nfds, fd);
373 }
374 if (events & G_IO_OUT) {
375 FD_SET(fd, wfds);
376 nfds = MAX(nfds, fd);
377 }
378 if (events & G_IO_PRI) {
379 FD_SET(fd, xfds);
380 nfds = MAX(nfds, fd);
381 }
382 }
383 return nfds;
384}
385
386static void pollfds_poll(GArray *pollfds, int nfds, fd_set *rfds,
387 fd_set *wfds, fd_set *xfds)
388{
389 int i;
390
391 for (i = 0; i < pollfds->len; i++) {
392 GPollFD *pfd = &g_array_index(pollfds, GPollFD, i);
393 int fd = pfd->fd;
394 int revents = 0;
395
396 if (FD_ISSET(fd, rfds)) {
397 revents |= G_IO_IN;
398 }
399 if (FD_ISSET(fd, wfds)) {
400 revents |= G_IO_OUT;
401 }
402 if (FD_ISSET(fd, xfds)) {
403 revents |= G_IO_PRI;
404 }
405 pfd->revents = revents & pfd->events;
406 }
407}
408
409static int os_host_main_loop_wait(int64_t timeout)
410{
411 GMainContext *context = g_main_context_default();
412 GPollFD poll_fds[1024 * 2];
413 int select_ret = 0;
414 int g_poll_ret, ret, i, n_poll_fds;
415 PollingEntry *pe;
416 WaitObjects *w = &wait_objects;
417 gint poll_timeout;
418 int64_t poll_timeout_ns;
419 static struct timeval tv0;
420 fd_set rfds, wfds, xfds;
421 int nfds;
422
423 g_main_context_acquire(context);
424
425
426 ret = 0;
427 for (pe = first_polling_entry; pe != NULL; pe = pe->next) {
428 ret |= pe->func(pe->opaque);
429 }
430 if (ret != 0) {
431 g_main_context_release(context);
432 return ret;
433 }
434
435 FD_ZERO(&rfds);
436 FD_ZERO(&wfds);
437 FD_ZERO(&xfds);
438 nfds = pollfds_fill(gpollfds, &rfds, &wfds, &xfds);
439 if (nfds >= 0) {
440 select_ret = select(nfds + 1, &rfds, &wfds, &xfds, &tv0);
441 if (select_ret != 0) {
442 timeout = 0;
443 }
444 if (select_ret > 0) {
445 pollfds_poll(gpollfds, nfds, &rfds, &wfds, &xfds);
446 }
447 }
448
449 g_main_context_prepare(context, &max_priority);
450 n_poll_fds = g_main_context_query(context, max_priority, &poll_timeout,
451 poll_fds, ARRAY_SIZE(poll_fds));
452 g_assert(n_poll_fds <= ARRAY_SIZE(poll_fds));
453
454 for (i = 0; i < w->num; i++) {
455 poll_fds[n_poll_fds + i].fd = (DWORD_PTR)w->events[i];
456 poll_fds[n_poll_fds + i].events = G_IO_IN;
457 }
458
459 if (poll_timeout < 0) {
460 poll_timeout_ns = -1;
461 } else {
462 poll_timeout_ns = (int64_t)poll_timeout * (int64_t)SCALE_MS;
463 }
464
465 poll_timeout_ns = qemu_soonest_timeout(poll_timeout_ns, timeout);
466
467 qemu_mutex_unlock_iothread();
468
469 replay_mutex_unlock();
470
471 g_poll_ret = qemu_poll_ns(poll_fds, n_poll_fds + w->num, poll_timeout_ns);
472
473 replay_mutex_lock();
474
475 qemu_mutex_lock_iothread();
476 if (g_poll_ret > 0) {
477 for (i = 0; i < w->num; i++) {
478 w->revents[i] = poll_fds[n_poll_fds + i].revents;
479 }
480 for (i = 0; i < w->num; i++) {
481 if (w->revents[i] && w->func[i]) {
482 w->func[i](w->opaque[i]);
483 }
484 }
485 }
486
487 if (g_main_context_check(context, max_priority, poll_fds, n_poll_fds)) {
488 g_main_context_dispatch(context);
489 }
490
491 g_main_context_release(context);
492
493 return select_ret || g_poll_ret;
494}
495#endif
496
497void main_loop_wait(int nonblocking)
498{
499 int ret;
500 uint32_t timeout = UINT32_MAX;
501 int64_t timeout_ns;
502
503 if (nonblocking) {
504 timeout = 0;
505 }
506
507
508 g_array_set_size(gpollfds, 0);
509
510 slirp_pollfds_fill(gpollfds, &timeout);
511
512 if (timeout == UINT32_MAX) {
513 timeout_ns = -1;
514 } else {
515 timeout_ns = (uint64_t)timeout * (int64_t)(SCALE_MS);
516 }
517
518 timeout_ns = qemu_soonest_timeout(timeout_ns,
519 timerlistgroup_deadline_ns(
520 &main_loop_tlg));
521
522 ret = os_host_main_loop_wait(timeout_ns);
523 slirp_pollfds_poll(gpollfds, (ret < 0));
524
525
526
527 qemu_start_warp_timer();
528 qemu_clock_run_all_timers();
529}
530
531
532
533QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque)
534{
535 return aio_bh_new(qemu_aio_context, cb, opaque);
536}
537