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CommitLineData
d3b12f5d
PB
1/*
2 * QEMU System Emulator
3 *
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 *
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:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
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.
23 */
d3b12f5d 24
0ec024f6 25#include "qemu-common.h"
1de7afc9 26#include "qemu/timer.h"
520b6dd4 27#include "qemu/sockets.h" // struct in_addr needed for libslirp.h
01c22f2c 28#include "sysemu/qtest.h"
520b6dd4 29#include "slirp/libslirp.h"
1de7afc9 30#include "qemu/main-loop.h"
737e150e 31#include "block/aio.h"
d3b12f5d
PB
32
33#ifndef _WIN32
34
1de7afc9 35#include "qemu/compatfd.h"
0ec024f6 36
d3b12f5d
PB
37/* If we have signalfd, we mask out the signals we want to handle and then
38 * use signalfd to listen for them. We rely on whatever the current signal
39 * handler is to dispatch the signals when we receive them.
40 */
41static void sigfd_handler(void *opaque)
42{
43 int fd = (intptr_t)opaque;
44 struct qemu_signalfd_siginfo info;
45 struct sigaction action;
46 ssize_t len;
47
48 while (1) {
49 do {
50 len = read(fd, &info, sizeof(info));
51 } while (len == -1 && errno == EINTR);
52
53 if (len == -1 && errno == EAGAIN) {
54 break;
55 }
56
57 if (len != sizeof(info)) {
58 printf("read from sigfd returned %zd: %m\n", len);
59 return;
60 }
61
62 sigaction(info.ssi_signo, NULL, &action);
63 if ((action.sa_flags & SA_SIGINFO) && action.sa_sigaction) {
64 action.sa_sigaction(info.ssi_signo,
65 (siginfo_t *)&info, NULL);
66 } else if (action.sa_handler) {
67 action.sa_handler(info.ssi_signo);
68 }
69 }
70}
71
72static int qemu_signal_init(void)
73{
74 int sigfd;
75 sigset_t set;
76
77 /*
78 * SIG_IPI must be blocked in the main thread and must not be caught
79 * by sigwait() in the signal thread. Otherwise, the cpu thread will
80 * not catch it reliably.
81 */
82 sigemptyset(&set);
83 sigaddset(&set, SIG_IPI);
d3b12f5d
PB
84 sigaddset(&set, SIGIO);
85 sigaddset(&set, SIGALRM);
86 sigaddset(&set, SIGBUS);
87 pthread_sigmask(SIG_BLOCK, &set, NULL);
88
4aa7534d 89 sigdelset(&set, SIG_IPI);
d3b12f5d
PB
90 sigfd = qemu_signalfd(&set);
91 if (sigfd == -1) {
92 fprintf(stderr, "failed to create signalfd\n");
93 return -errno;
94 }
95
96 fcntl_setfl(sigfd, O_NONBLOCK);
97
98 qemu_set_fd_handler2(sigfd, NULL, sigfd_handler, NULL,
99 (void *)(intptr_t)sigfd);
100
101 return 0;
102}
103
104#else /* _WIN32 */
105
4c8d0d27 106static int qemu_signal_init(void)
d3b12f5d 107{
d3b12f5d
PB
108 return 0;
109}
4c8d0d27
PB
110#endif
111
112static AioContext *qemu_aio_context;
d3b12f5d 113
5f3aa1ff
SH
114AioContext *qemu_get_aio_context(void)
115{
116 return qemu_aio_context;
117}
118
d3b12f5d
PB
119void qemu_notify_event(void)
120{
4c8d0d27 121 if (!qemu_aio_context) {
ee77dfb2
MR
122 return;
123 }
4c8d0d27 124 aio_notify(qemu_aio_context);
d3b12f5d
PB
125}
126
cbff4b34
SH
127static GArray *gpollfds;
128
172061a0 129int qemu_init_main_loop(void)
d3b12f5d
PB
130{
131 int ret;
82cbbdc6 132 GSource *src;
d3b12f5d 133
172061a0 134 init_clocks();
172061a0 135
d3b12f5d
PB
136 ret = qemu_signal_init();
137 if (ret) {
138 return ret;
139 }
140
cbff4b34 141 gpollfds = g_array_new(FALSE, FALSE, sizeof(GPollFD));
f627aab1 142 qemu_aio_context = aio_context_new();
82cbbdc6
PB
143 src = aio_get_g_source(qemu_aio_context);
144 g_source_attach(src, NULL);
145 g_source_unref(src);
d3b12f5d
PB
146 return 0;
147}
148
d3b12f5d
PB
149static int max_priority;
150
ea26ce76 151#ifndef _WIN32
48ce11ff
SH
152static int glib_pollfds_idx;
153static int glib_n_poll_fds;
154
7b595f35 155static void glib_pollfds_fill(int64_t *cur_timeout)
d3b12f5d
PB
156{
157 GMainContext *context = g_main_context_default();
4dae83ae 158 int timeout = 0;
7b595f35 159 int64_t timeout_ns;
48ce11ff 160 int n;
d3b12f5d
PB
161
162 g_main_context_prepare(context, &max_priority);
163
48ce11ff
SH
164 glib_pollfds_idx = gpollfds->len;
165 n = glib_n_poll_fds;
166 do {
167 GPollFD *pfds;
168 glib_n_poll_fds = n;
169 g_array_set_size(gpollfds, glib_pollfds_idx + glib_n_poll_fds);
170 pfds = &g_array_index(gpollfds, GPollFD, glib_pollfds_idx);
171 n = g_main_context_query(context, max_priority, &timeout, pfds,
172 glib_n_poll_fds);
173 } while (n != glib_n_poll_fds);
d3b12f5d 174
7b595f35
AB
175 if (timeout < 0) {
176 timeout_ns = -1;
177 } else {
178 timeout_ns = (int64_t)timeout * (int64_t)SCALE_MS;
d3b12f5d 179 }
7b595f35
AB
180
181 *cur_timeout = qemu_soonest_timeout(timeout_ns, *cur_timeout);
d3b12f5d
PB
182}
183
48ce11ff 184static void glib_pollfds_poll(void)
d3b12f5d
PB
185{
186 GMainContext *context = g_main_context_default();
48ce11ff 187 GPollFD *pfds = &g_array_index(gpollfds, GPollFD, glib_pollfds_idx);
d3b12f5d 188
48ce11ff 189 if (g_main_context_check(context, max_priority, pfds, glib_n_poll_fds)) {
d3b12f5d
PB
190 g_main_context_dispatch(context);
191 }
192}
193
893986fe
AL
194#define MAX_MAIN_LOOP_SPIN (1000)
195
7b595f35 196static int os_host_main_loop_wait(int64_t timeout)
15455536 197{
15455536 198 int ret;
893986fe 199 static int spin_counter;
15455536 200
48ce11ff 201 glib_pollfds_fill(&timeout);
15455536 202
893986fe
AL
203 /* If the I/O thread is very busy or we are incorrectly busy waiting in
204 * the I/O thread, this can lead to starvation of the BQL such that the
205 * VCPU threads never run. To make sure we can detect the later case,
206 * print a message to the screen. If we run into this condition, create
207 * a fake timeout in order to give the VCPU threads a chance to run.
208 */
7b595f35 209 if (!timeout && (spin_counter > MAX_MAIN_LOOP_SPIN)) {
893986fe
AL
210 static bool notified;
211
01c22f2c 212 if (!notified && !qtest_enabled()) {
893986fe
AL
213 fprintf(stderr,
214 "main-loop: WARNING: I/O thread spun for %d iterations\n",
215 MAX_MAIN_LOOP_SPIN);
216 notified = true;
217 }
218
7b595f35 219 timeout = SCALE_MS;
893986fe
AL
220 }
221
7b595f35 222 if (timeout) {
893986fe 223 spin_counter = 0;
15455536 224 qemu_mutex_unlock_iothread();
893986fe
AL
225 } else {
226 spin_counter++;
15455536
PB
227 }
228
7b595f35 229 ret = qemu_poll_ns((GPollFD *)gpollfds->data, gpollfds->len, timeout);
cbff4b34 230
7b595f35 231 if (timeout) {
15455536
PB
232 qemu_mutex_lock_iothread();
233 }
234
48ce11ff 235 glib_pollfds_poll();
15455536
PB
236 return ret;
237}
238#else
d3b12f5d
PB
239/***********************************************************/
240/* Polling handling */
241
242typedef struct PollingEntry {
243 PollingFunc *func;
244 void *opaque;
245 struct PollingEntry *next;
246} PollingEntry;
247
248static PollingEntry *first_polling_entry;
249
250int qemu_add_polling_cb(PollingFunc *func, void *opaque)
251{
252 PollingEntry **ppe, *pe;
253 pe = g_malloc0(sizeof(PollingEntry));
254 pe->func = func;
255 pe->opaque = opaque;
256 for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next);
257 *ppe = pe;
258 return 0;
259}
260
261void qemu_del_polling_cb(PollingFunc *func, void *opaque)
262{
263 PollingEntry **ppe, *pe;
264 for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next) {
265 pe = *ppe;
266 if (pe->func == func && pe->opaque == opaque) {
267 *ppe = pe->next;
268 g_free(pe);
269 break;
270 }
271 }
272}
273
274/***********************************************************/
275/* Wait objects support */
276typedef struct WaitObjects {
277 int num;
06ac7d49 278 int revents[MAXIMUM_WAIT_OBJECTS + 1];
d3b12f5d
PB
279 HANDLE events[MAXIMUM_WAIT_OBJECTS + 1];
280 WaitObjectFunc *func[MAXIMUM_WAIT_OBJECTS + 1];
281 void *opaque[MAXIMUM_WAIT_OBJECTS + 1];
282} WaitObjects;
283
284static WaitObjects wait_objects = {0};
285
286int qemu_add_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
287{
288 WaitObjects *w = &wait_objects;
289 if (w->num >= MAXIMUM_WAIT_OBJECTS) {
290 return -1;
291 }
292 w->events[w->num] = handle;
293 w->func[w->num] = func;
294 w->opaque[w->num] = opaque;
06ac7d49 295 w->revents[w->num] = 0;
d3b12f5d
PB
296 w->num++;
297 return 0;
298}
299
300void qemu_del_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
301{
302 int i, found;
303 WaitObjects *w = &wait_objects;
304
305 found = 0;
306 for (i = 0; i < w->num; i++) {
307 if (w->events[i] == handle) {
308 found = 1;
309 }
310 if (found) {
311 w->events[i] = w->events[i + 1];
312 w->func[i] = w->func[i + 1];
313 w->opaque[i] = w->opaque[i + 1];
06ac7d49 314 w->revents[i] = w->revents[i + 1];
d3b12f5d
PB
315 }
316 }
317 if (found) {
318 w->num--;
319 }
320}
321
d3385eb4
PB
322void qemu_fd_register(int fd)
323{
4c8d0d27
PB
324 WSAEventSelect(fd, event_notifier_get_handle(&qemu_aio_context->notifier),
325 FD_READ | FD_ACCEPT | FD_CLOSE |
d3385eb4
PB
326 FD_CONNECT | FD_WRITE | FD_OOB);
327}
328
cbff4b34
SH
329static int pollfds_fill(GArray *pollfds, fd_set *rfds, fd_set *wfds,
330 fd_set *xfds)
331{
332 int nfds = -1;
333 int i;
334
335 for (i = 0; i < pollfds->len; i++) {
336 GPollFD *pfd = &g_array_index(pollfds, GPollFD, i);
337 int fd = pfd->fd;
338 int events = pfd->events;
8db165b3 339 if (events & G_IO_IN) {
cbff4b34
SH
340 FD_SET(fd, rfds);
341 nfds = MAX(nfds, fd);
342 }
8db165b3 343 if (events & G_IO_OUT) {
cbff4b34
SH
344 FD_SET(fd, wfds);
345 nfds = MAX(nfds, fd);
346 }
347 if (events & G_IO_PRI) {
348 FD_SET(fd, xfds);
349 nfds = MAX(nfds, fd);
350 }
351 }
352 return nfds;
353}
354
355static void pollfds_poll(GArray *pollfds, int nfds, fd_set *rfds,
356 fd_set *wfds, fd_set *xfds)
357{
358 int i;
359
360 for (i = 0; i < pollfds->len; i++) {
361 GPollFD *pfd = &g_array_index(pollfds, GPollFD, i);
362 int fd = pfd->fd;
363 int revents = 0;
364
365 if (FD_ISSET(fd, rfds)) {
8db165b3 366 revents |= G_IO_IN;
cbff4b34
SH
367 }
368 if (FD_ISSET(fd, wfds)) {
8db165b3 369 revents |= G_IO_OUT;
cbff4b34
SH
370 }
371 if (FD_ISSET(fd, xfds)) {
372 revents |= G_IO_PRI;
373 }
374 pfd->revents = revents & pfd->events;
375 }
376}
377
7b595f35 378static int os_host_main_loop_wait(int64_t timeout)
d3b12f5d 379{
ea26ce76 380 GMainContext *context = g_main_context_default();
48ce11ff 381 GPollFD poll_fds[1024 * 2]; /* this is probably overkill */
134a03e0 382 int select_ret = 0;
48ce11ff 383 int g_poll_ret, ret, i, n_poll_fds;
d3b12f5d 384 PollingEntry *pe;
d3385eb4 385 WaitObjects *w = &wait_objects;
42fe1c24 386 gint poll_timeout;
7b595f35 387 int64_t poll_timeout_ns;
15455536 388 static struct timeval tv0;
9cbaacf9
SH
389 fd_set rfds, wfds, xfds;
390 int nfds;
d3b12f5d
PB
391
392 /* XXX: need to suppress polling by better using win32 events */
393 ret = 0;
394 for (pe = first_polling_entry; pe != NULL; pe = pe->next) {
395 ret |= pe->func(pe->opaque);
396 }
d3385eb4
PB
397 if (ret != 0) {
398 return ret;
399 }
d3b12f5d 400
3cb8c205
SH
401 FD_ZERO(&rfds);
402 FD_ZERO(&wfds);
403 FD_ZERO(&xfds);
404 nfds = pollfds_fill(gpollfds, &rfds, &wfds, &xfds);
405 if (nfds >= 0) {
406 select_ret = select(nfds + 1, &rfds, &wfds, &xfds, &tv0);
407 if (select_ret != 0) {
408 timeout = 0;
409 }
410 if (select_ret > 0) {
411 pollfds_poll(gpollfds, nfds, &rfds, &wfds, &xfds);
412 }
413 }
414
ea26ce76 415 g_main_context_prepare(context, &max_priority);
42fe1c24 416 n_poll_fds = g_main_context_query(context, max_priority, &poll_timeout,
ea26ce76
PB
417 poll_fds, ARRAY_SIZE(poll_fds));
418 g_assert(n_poll_fds <= ARRAY_SIZE(poll_fds));
419
06ac7d49 420 for (i = 0; i < w->num; i++) {
58b9630d 421 poll_fds[n_poll_fds + i].fd = (DWORD_PTR)w->events[i];
ea26ce76 422 poll_fds[n_poll_fds + i].events = G_IO_IN;
06ac7d49
PB
423 }
424
7b595f35
AB
425 if (poll_timeout < 0) {
426 poll_timeout_ns = -1;
427 } else {
428 poll_timeout_ns = (int64_t)poll_timeout * (int64_t)SCALE_MS;
3239ad04
SW
429 }
430
7b595f35
AB
431 poll_timeout_ns = qemu_soonest_timeout(poll_timeout_ns, timeout);
432
d3385eb4 433 qemu_mutex_unlock_iothread();
7b595f35
AB
434 g_poll_ret = qemu_poll_ns(poll_fds, n_poll_fds + w->num, poll_timeout_ns);
435
d3385eb4 436 qemu_mutex_lock_iothread();
5e3bc735 437 if (g_poll_ret > 0) {
06ac7d49 438 for (i = 0; i < w->num; i++) {
ea26ce76 439 w->revents[i] = poll_fds[n_poll_fds + i].revents;
d3385eb4 440 }
06ac7d49
PB
441 for (i = 0; i < w->num; i++) {
442 if (w->revents[i] && w->func[i]) {
443 w->func[i](w->opaque[i]);
d3b12f5d 444 }
d3b12f5d
PB
445 }
446 }
447
ea26ce76
PB
448 if (g_main_context_check(context, max_priority, poll_fds, n_poll_fds)) {
449 g_main_context_dispatch(context);
450 }
451
5e3bc735 452 return select_ret || g_poll_ret;
d3b12f5d
PB
453}
454#endif
455
456int main_loop_wait(int nonblocking)
457{
7c7db755
SS
458 int ret;
459 uint32_t timeout = UINT32_MAX;
7b595f35 460 int64_t timeout_ns;
d3b12f5d
PB
461
462 if (nonblocking) {
463 timeout = 0;
d3b12f5d
PB
464 }
465
d3b12f5d 466 /* poll any events */
cbff4b34 467 g_array_set_size(gpollfds, 0); /* reset for new iteration */
d3b12f5d 468 /* XXX: separate device handlers from system ones */
d3b12f5d 469#ifdef CONFIG_SLIRP
a42e9c41 470 slirp_pollfds_fill(gpollfds, &timeout);
d3b12f5d 471#endif
a3e4b4a8 472 qemu_iohandler_fill(gpollfds);
7b595f35
AB
473
474 if (timeout == UINT32_MAX) {
475 timeout_ns = -1;
476 } else {
477 timeout_ns = (uint64_t)timeout * (int64_t)(SCALE_MS);
478 }
479
480 timeout_ns = qemu_soonest_timeout(timeout_ns,
481 timerlistgroup_deadline_ns(
482 &main_loop_tlg));
483
484 ret = os_host_main_loop_wait(timeout_ns);
a3e4b4a8 485 qemu_iohandler_poll(gpollfds, ret);
d3b12f5d 486#ifdef CONFIG_SLIRP
8917c3bd 487 slirp_pollfds_poll(gpollfds, (ret < 0));
d3b12f5d
PB
488#endif
489
40daca54 490 qemu_clock_run_all_timers();
d3b12f5d 491
d3b12f5d
PB
492 return ret;
493}
f627aab1
PB
494
495/* Functions to operate on the main QEMU AioContext. */
496
497QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque)
498{
499 return aio_bh_new(qemu_aio_context, cb, opaque);
500}
501
a915f4bc
PB
502bool qemu_aio_wait(void)
503{
7c0628b2 504 return aio_poll(qemu_aio_context, true);
a915f4bc
PB
505}
506
f42b2207 507#ifdef CONFIG_POSIX
a915f4bc
PB
508void qemu_aio_set_fd_handler(int fd,
509 IOHandler *io_read,
510 IOHandler *io_write,
a915f4bc
PB
511 void *opaque)
512{
f2e5dca4 513 aio_set_fd_handler(qemu_aio_context, fd, io_read, io_write, opaque);
a915f4bc 514}
82cbbdc6 515#endif
a915f4bc 516
a915f4bc 517void qemu_aio_set_event_notifier(EventNotifier *notifier,
f2e5dca4 518 EventNotifierHandler *io_read)
a915f4bc 519{
f2e5dca4 520 aio_set_event_notifier(qemu_aio_context, notifier, io_read);
a915f4bc 521}