linux-user: arm: Remove ARM_cpsr and similar #defines
[qemu.git] / main-loop.c
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 */
24
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" // struct in_addr needed for libslirp.h
30 #include "sysemu/qtest.h"
31 #include "slirp/libslirp.h"
32 #include "qemu/main-loop.h"
33 #include "block/aio.h"
34
35 #ifndef _WIN32
36
37 #include "qemu/compatfd.h"
38
39 /* If we have signalfd, we mask out the signals we want to handle and then
40 * use signalfd to listen for them. We rely on whatever the current signal
41 * handler is to dispatch the signals when we receive them.
42 */
43 static void sigfd_handler(void *opaque)
44 {
45 int fd = (intptr_t)opaque;
46 struct qemu_signalfd_siginfo info;
47 struct sigaction action;
48 ssize_t len;
49
50 while (1) {
51 do {
52 len = read(fd, &info, sizeof(info));
53 } while (len == -1 && errno == EINTR);
54
55 if (len == -1 && errno == EAGAIN) {
56 break;
57 }
58
59 if (len != sizeof(info)) {
60 printf("read from sigfd returned %zd: %m\n", len);
61 return;
62 }
63
64 sigaction(info.ssi_signo, NULL, &action);
65 if ((action.sa_flags & SA_SIGINFO) && action.sa_sigaction) {
66 action.sa_sigaction(info.ssi_signo,
67 (siginfo_t *)&info, NULL);
68 } else if (action.sa_handler) {
69 action.sa_handler(info.ssi_signo);
70 }
71 }
72 }
73
74 static int qemu_signal_init(void)
75 {
76 int sigfd;
77 sigset_t set;
78
79 /*
80 * SIG_IPI must be blocked in the main thread and must not be caught
81 * by sigwait() in the signal thread. Otherwise, the cpu thread will
82 * not catch it reliably.
83 */
84 sigemptyset(&set);
85 sigaddset(&set, SIG_IPI);
86 sigaddset(&set, SIGIO);
87 sigaddset(&set, SIGALRM);
88 sigaddset(&set, SIGBUS);
89 /* SIGINT cannot be handled via signalfd, so that ^C can be used
90 * to interrupt QEMU when it is being run under gdb. SIGHUP and
91 * SIGTERM are also handled asynchronously, even though it is not
92 * strictly necessary, because they use the same handler as SIGINT.
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 /* _WIN32 */
111
112 static int qemu_signal_init(void)
113 {
114 return 0;
115 }
116 #endif
117
118 static AioContext *qemu_aio_context;
119 static QEMUBH *qemu_notify_bh;
120
121 static void notify_event_cb(void *opaque)
122 {
123 /* No need to do anything; this bottom half is only used to
124 * kick the kernel out of ppoll/poll/WaitForMultipleObjects.
125 */
126 }
127
128 AioContext *qemu_get_aio_context(void)
129 {
130 return qemu_aio_context;
131 }
132
133 void qemu_notify_event(void)
134 {
135 if (!qemu_aio_context) {
136 return;
137 }
138 qemu_bh_schedule(qemu_notify_bh);
139 }
140
141 static GArray *gpollfds;
142
143 int qemu_init_main_loop(Error **errp)
144 {
145 int ret;
146 GSource *src;
147 Error *local_error = NULL;
148
149 init_clocks();
150
151 ret = qemu_signal_init();
152 if (ret) {
153 return ret;
154 }
155
156 qemu_aio_context = aio_context_new(&local_error);
157 qemu_notify_bh = qemu_bh_new(notify_event_cb, NULL);
158 if (!qemu_aio_context) {
159 error_propagate(errp, local_error);
160 return -EMFILE;
161 }
162 gpollfds = g_array_new(FALSE, FALSE, sizeof(GPollFD));
163 src = aio_get_g_source(qemu_aio_context);
164 g_source_attach(src, NULL);
165 g_source_unref(src);
166 src = iohandler_get_g_source();
167 g_source_attach(src, NULL);
168 g_source_unref(src);
169 return 0;
170 }
171
172 static int max_priority;
173
174 #ifndef _WIN32
175 static int glib_pollfds_idx;
176 static int glib_n_poll_fds;
177
178 static void glib_pollfds_fill(int64_t *cur_timeout)
179 {
180 GMainContext *context = g_main_context_default();
181 int timeout = 0;
182 int64_t timeout_ns;
183 int n;
184
185 g_main_context_prepare(context, &max_priority);
186
187 glib_pollfds_idx = gpollfds->len;
188 n = glib_n_poll_fds;
189 do {
190 GPollFD *pfds;
191 glib_n_poll_fds = n;
192 g_array_set_size(gpollfds, glib_pollfds_idx + glib_n_poll_fds);
193 pfds = &g_array_index(gpollfds, GPollFD, glib_pollfds_idx);
194 n = g_main_context_query(context, max_priority, &timeout, pfds,
195 glib_n_poll_fds);
196 } while (n != glib_n_poll_fds);
197
198 if (timeout < 0) {
199 timeout_ns = -1;
200 } else {
201 timeout_ns = (int64_t)timeout * (int64_t)SCALE_MS;
202 }
203
204 *cur_timeout = qemu_soonest_timeout(timeout_ns, *cur_timeout);
205 }
206
207 static void glib_pollfds_poll(void)
208 {
209 GMainContext *context = g_main_context_default();
210 GPollFD *pfds = &g_array_index(gpollfds, GPollFD, glib_pollfds_idx);
211
212 if (g_main_context_check(context, max_priority, pfds, glib_n_poll_fds)) {
213 g_main_context_dispatch(context);
214 }
215 }
216
217 #define MAX_MAIN_LOOP_SPIN (1000)
218
219 static int os_host_main_loop_wait(int64_t timeout)
220 {
221 int ret;
222 static int spin_counter;
223
224 glib_pollfds_fill(&timeout);
225
226 /* If the I/O thread is very busy or we are incorrectly busy waiting in
227 * the I/O thread, this can lead to starvation of the BQL such that the
228 * VCPU threads never run. To make sure we can detect the later case,
229 * print a message to the screen. If we run into this condition, create
230 * a fake timeout in order to give the VCPU threads a chance to run.
231 */
232 if (!timeout && (spin_counter > MAX_MAIN_LOOP_SPIN)) {
233 static bool notified;
234
235 if (!notified && !qtest_driver()) {
236 fprintf(stderr,
237 "main-loop: WARNING: I/O thread spun for %d iterations\n",
238 MAX_MAIN_LOOP_SPIN);
239 notified = true;
240 }
241
242 timeout = SCALE_MS;
243 }
244
245 if (timeout) {
246 spin_counter = 0;
247 qemu_mutex_unlock_iothread();
248 } else {
249 spin_counter++;
250 }
251
252 ret = qemu_poll_ns((GPollFD *)gpollfds->data, gpollfds->len, timeout);
253
254 if (timeout) {
255 qemu_mutex_lock_iothread();
256 }
257
258 glib_pollfds_poll();
259 return ret;
260 }
261 #else
262 /***********************************************************/
263 /* Polling handling */
264
265 typedef struct PollingEntry {
266 PollingFunc *func;
267 void *opaque;
268 struct PollingEntry *next;
269 } PollingEntry;
270
271 static PollingEntry *first_polling_entry;
272
273 int qemu_add_polling_cb(PollingFunc *func, void *opaque)
274 {
275 PollingEntry **ppe, *pe;
276 pe = g_malloc0(sizeof(PollingEntry));
277 pe->func = func;
278 pe->opaque = opaque;
279 for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next);
280 *ppe = pe;
281 return 0;
282 }
283
284 void qemu_del_polling_cb(PollingFunc *func, void *opaque)
285 {
286 PollingEntry **ppe, *pe;
287 for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next) {
288 pe = *ppe;
289 if (pe->func == func && pe->opaque == opaque) {
290 *ppe = pe->next;
291 g_free(pe);
292 break;
293 }
294 }
295 }
296
297 /***********************************************************/
298 /* Wait objects support */
299 typedef struct WaitObjects {
300 int num;
301 int revents[MAXIMUM_WAIT_OBJECTS + 1];
302 HANDLE events[MAXIMUM_WAIT_OBJECTS + 1];
303 WaitObjectFunc *func[MAXIMUM_WAIT_OBJECTS + 1];
304 void *opaque[MAXIMUM_WAIT_OBJECTS + 1];
305 } WaitObjects;
306
307 static WaitObjects wait_objects = {0};
308
309 int qemu_add_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
310 {
311 WaitObjects *w = &wait_objects;
312 if (w->num >= MAXIMUM_WAIT_OBJECTS) {
313 return -1;
314 }
315 w->events[w->num] = handle;
316 w->func[w->num] = func;
317 w->opaque[w->num] = opaque;
318 w->revents[w->num] = 0;
319 w->num++;
320 return 0;
321 }
322
323 void qemu_del_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
324 {
325 int i, found;
326 WaitObjects *w = &wait_objects;
327
328 found = 0;
329 for (i = 0; i < w->num; i++) {
330 if (w->events[i] == handle) {
331 found = 1;
332 }
333 if (found) {
334 w->events[i] = w->events[i + 1];
335 w->func[i] = w->func[i + 1];
336 w->opaque[i] = w->opaque[i + 1];
337 w->revents[i] = w->revents[i + 1];
338 }
339 }
340 if (found) {
341 w->num--;
342 }
343 }
344
345 void qemu_fd_register(int fd)
346 {
347 WSAEventSelect(fd, event_notifier_get_handle(&qemu_aio_context->notifier),
348 FD_READ | FD_ACCEPT | FD_CLOSE |
349 FD_CONNECT | FD_WRITE | FD_OOB);
350 }
351
352 static int pollfds_fill(GArray *pollfds, fd_set *rfds, fd_set *wfds,
353 fd_set *xfds)
354 {
355 int nfds = -1;
356 int i;
357
358 for (i = 0; i < pollfds->len; i++) {
359 GPollFD *pfd = &g_array_index(pollfds, GPollFD, i);
360 int fd = pfd->fd;
361 int events = pfd->events;
362 if (events & G_IO_IN) {
363 FD_SET(fd, rfds);
364 nfds = MAX(nfds, fd);
365 }
366 if (events & G_IO_OUT) {
367 FD_SET(fd, wfds);
368 nfds = MAX(nfds, fd);
369 }
370 if (events & G_IO_PRI) {
371 FD_SET(fd, xfds);
372 nfds = MAX(nfds, fd);
373 }
374 }
375 return nfds;
376 }
377
378 static void pollfds_poll(GArray *pollfds, int nfds, fd_set *rfds,
379 fd_set *wfds, fd_set *xfds)
380 {
381 int i;
382
383 for (i = 0; i < pollfds->len; i++) {
384 GPollFD *pfd = &g_array_index(pollfds, GPollFD, i);
385 int fd = pfd->fd;
386 int revents = 0;
387
388 if (FD_ISSET(fd, rfds)) {
389 revents |= G_IO_IN;
390 }
391 if (FD_ISSET(fd, wfds)) {
392 revents |= G_IO_OUT;
393 }
394 if (FD_ISSET(fd, xfds)) {
395 revents |= G_IO_PRI;
396 }
397 pfd->revents = revents & pfd->events;
398 }
399 }
400
401 static int os_host_main_loop_wait(int64_t timeout)
402 {
403 GMainContext *context = g_main_context_default();
404 GPollFD poll_fds[1024 * 2]; /* this is probably overkill */
405 int select_ret = 0;
406 int g_poll_ret, ret, i, n_poll_fds;
407 PollingEntry *pe;
408 WaitObjects *w = &wait_objects;
409 gint poll_timeout;
410 int64_t poll_timeout_ns;
411 static struct timeval tv0;
412 fd_set rfds, wfds, xfds;
413 int nfds;
414
415 /* XXX: need to suppress polling by better using win32 events */
416 ret = 0;
417 for (pe = first_polling_entry; pe != NULL; pe = pe->next) {
418 ret |= pe->func(pe->opaque);
419 }
420 if (ret != 0) {
421 return ret;
422 }
423
424 FD_ZERO(&rfds);
425 FD_ZERO(&wfds);
426 FD_ZERO(&xfds);
427 nfds = pollfds_fill(gpollfds, &rfds, &wfds, &xfds);
428 if (nfds >= 0) {
429 select_ret = select(nfds + 1, &rfds, &wfds, &xfds, &tv0);
430 if (select_ret != 0) {
431 timeout = 0;
432 }
433 if (select_ret > 0) {
434 pollfds_poll(gpollfds, nfds, &rfds, &wfds, &xfds);
435 }
436 }
437
438 g_main_context_prepare(context, &max_priority);
439 n_poll_fds = g_main_context_query(context, max_priority, &poll_timeout,
440 poll_fds, ARRAY_SIZE(poll_fds));
441 g_assert(n_poll_fds <= ARRAY_SIZE(poll_fds));
442
443 for (i = 0; i < w->num; i++) {
444 poll_fds[n_poll_fds + i].fd = (DWORD_PTR)w->events[i];
445 poll_fds[n_poll_fds + i].events = G_IO_IN;
446 }
447
448 if (poll_timeout < 0) {
449 poll_timeout_ns = -1;
450 } else {
451 poll_timeout_ns = (int64_t)poll_timeout * (int64_t)SCALE_MS;
452 }
453
454 poll_timeout_ns = qemu_soonest_timeout(poll_timeout_ns, timeout);
455
456 qemu_mutex_unlock_iothread();
457 g_poll_ret = qemu_poll_ns(poll_fds, n_poll_fds + w->num, poll_timeout_ns);
458
459 qemu_mutex_lock_iothread();
460 if (g_poll_ret > 0) {
461 for (i = 0; i < w->num; i++) {
462 w->revents[i] = poll_fds[n_poll_fds + i].revents;
463 }
464 for (i = 0; i < w->num; i++) {
465 if (w->revents[i] && w->func[i]) {
466 w->func[i](w->opaque[i]);
467 }
468 }
469 }
470
471 if (g_main_context_check(context, max_priority, poll_fds, n_poll_fds)) {
472 g_main_context_dispatch(context);
473 }
474
475 return select_ret || g_poll_ret;
476 }
477 #endif
478
479 int main_loop_wait(int nonblocking)
480 {
481 int ret;
482 uint32_t timeout = UINT32_MAX;
483 int64_t timeout_ns;
484
485 if (nonblocking) {
486 timeout = 0;
487 }
488
489 /* poll any events */
490 g_array_set_size(gpollfds, 0); /* reset for new iteration */
491 /* XXX: separate device handlers from system ones */
492 #ifdef CONFIG_SLIRP
493 slirp_pollfds_fill(gpollfds, &timeout);
494 #endif
495
496 if (timeout == UINT32_MAX) {
497 timeout_ns = -1;
498 } else {
499 timeout_ns = (uint64_t)timeout * (int64_t)(SCALE_MS);
500 }
501
502 timeout_ns = qemu_soonest_timeout(timeout_ns,
503 timerlistgroup_deadline_ns(
504 &main_loop_tlg));
505
506 ret = os_host_main_loop_wait(timeout_ns);
507 #ifdef CONFIG_SLIRP
508 slirp_pollfds_poll(gpollfds, (ret < 0));
509 #endif
510
511 /* CPU thread can infinitely wait for event after
512 missing the warp */
513 qemu_start_warp_timer();
514 qemu_clock_run_all_timers();
515
516 return ret;
517 }
518
519 /* Functions to operate on the main QEMU AioContext. */
520
521 QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque)
522 {
523 return aio_bh_new(qemu_aio_context, cb, opaque);
524 }