hw/net: fix mcf_fec driver receiver
[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-common.h"
26 #include "qemu/timer.h"
27 #include "qemu/sockets.h" // struct in_addr needed for libslirp.h
28 #include "sysemu/qtest.h"
29 #include "slirp/libslirp.h"
30 #include "qemu/main-loop.h"
31 #include "block/aio.h"
32
33 #ifndef _WIN32
34
35 #include "qemu/compatfd.h"
36
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 */
41 static 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
72 static 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);
84 sigaddset(&set, SIGIO);
85 sigaddset(&set, SIGALRM);
86 sigaddset(&set, SIGBUS);
87 /* SIGINT cannot be handled via signalfd, so that ^C can be used
88 * to interrupt QEMU when it is being run under gdb. SIGHUP and
89 * SIGTERM are also handled asynchronously, even though it is not
90 * strictly necessary, because they use the same handler as SIGINT.
91 */
92 pthread_sigmask(SIG_BLOCK, &set, NULL);
93
94 sigdelset(&set, SIG_IPI);
95 sigfd = qemu_signalfd(&set);
96 if (sigfd == -1) {
97 fprintf(stderr, "failed to create signalfd\n");
98 return -errno;
99 }
100
101 fcntl_setfl(sigfd, O_NONBLOCK);
102
103 qemu_set_fd_handler(sigfd, sigfd_handler, NULL, (void *)(intptr_t)sigfd);
104
105 return 0;
106 }
107
108 #else /* _WIN32 */
109
110 static int qemu_signal_init(void)
111 {
112 return 0;
113 }
114 #endif
115
116 static AioContext *qemu_aio_context;
117
118 AioContext *qemu_get_aio_context(void)
119 {
120 return qemu_aio_context;
121 }
122
123 void qemu_notify_event(void)
124 {
125 if (!qemu_aio_context) {
126 return;
127 }
128 aio_notify(qemu_aio_context);
129 }
130
131 static GArray *gpollfds;
132
133 int qemu_init_main_loop(Error **errp)
134 {
135 int ret;
136 GSource *src;
137 Error *local_error = NULL;
138
139 init_clocks();
140
141 ret = qemu_signal_init();
142 if (ret) {
143 return ret;
144 }
145
146 qemu_aio_context = aio_context_new(&local_error);
147 if (!qemu_aio_context) {
148 error_propagate(errp, local_error);
149 return -EMFILE;
150 }
151 gpollfds = g_array_new(FALSE, FALSE, sizeof(GPollFD));
152 src = aio_get_g_source(qemu_aio_context);
153 g_source_attach(src, NULL);
154 g_source_unref(src);
155 return 0;
156 }
157
158 static int max_priority;
159
160 #ifndef _WIN32
161 static int glib_pollfds_idx;
162 static int glib_n_poll_fds;
163
164 static void glib_pollfds_fill(int64_t *cur_timeout)
165 {
166 GMainContext *context = g_main_context_default();
167 int timeout = 0;
168 int64_t timeout_ns;
169 int n;
170
171 g_main_context_prepare(context, &max_priority);
172
173 glib_pollfds_idx = gpollfds->len;
174 n = glib_n_poll_fds;
175 do {
176 GPollFD *pfds;
177 glib_n_poll_fds = n;
178 g_array_set_size(gpollfds, glib_pollfds_idx + glib_n_poll_fds);
179 pfds = &g_array_index(gpollfds, GPollFD, glib_pollfds_idx);
180 n = g_main_context_query(context, max_priority, &timeout, pfds,
181 glib_n_poll_fds);
182 } while (n != glib_n_poll_fds);
183
184 if (timeout < 0) {
185 timeout_ns = -1;
186 } else {
187 timeout_ns = (int64_t)timeout * (int64_t)SCALE_MS;
188 }
189
190 *cur_timeout = qemu_soonest_timeout(timeout_ns, *cur_timeout);
191 }
192
193 static void glib_pollfds_poll(void)
194 {
195 GMainContext *context = g_main_context_default();
196 GPollFD *pfds = &g_array_index(gpollfds, GPollFD, glib_pollfds_idx);
197
198 if (g_main_context_check(context, max_priority, pfds, glib_n_poll_fds)) {
199 g_main_context_dispatch(context);
200 }
201 }
202
203 #define MAX_MAIN_LOOP_SPIN (1000)
204
205 static int os_host_main_loop_wait(int64_t timeout)
206 {
207 int ret;
208 static int spin_counter;
209
210 glib_pollfds_fill(&timeout);
211
212 /* If the I/O thread is very busy or we are incorrectly busy waiting in
213 * the I/O thread, this can lead to starvation of the BQL such that the
214 * VCPU threads never run. To make sure we can detect the later case,
215 * print a message to the screen. If we run into this condition, create
216 * a fake timeout in order to give the VCPU threads a chance to run.
217 */
218 if (!timeout && (spin_counter > MAX_MAIN_LOOP_SPIN)) {
219 static bool notified;
220
221 if (!notified && !qtest_enabled()) {
222 fprintf(stderr,
223 "main-loop: WARNING: I/O thread spun for %d iterations\n",
224 MAX_MAIN_LOOP_SPIN);
225 notified = true;
226 }
227
228 timeout = SCALE_MS;
229 }
230
231 if (timeout) {
232 spin_counter = 0;
233 qemu_mutex_unlock_iothread();
234 } else {
235 spin_counter++;
236 }
237
238 ret = qemu_poll_ns((GPollFD *)gpollfds->data, gpollfds->len, timeout);
239
240 if (timeout) {
241 qemu_mutex_lock_iothread();
242 }
243
244 glib_pollfds_poll();
245 return ret;
246 }
247 #else
248 /***********************************************************/
249 /* Polling handling */
250
251 typedef struct PollingEntry {
252 PollingFunc *func;
253 void *opaque;
254 struct PollingEntry *next;
255 } PollingEntry;
256
257 static PollingEntry *first_polling_entry;
258
259 int qemu_add_polling_cb(PollingFunc *func, void *opaque)
260 {
261 PollingEntry **ppe, *pe;
262 pe = g_malloc0(sizeof(PollingEntry));
263 pe->func = func;
264 pe->opaque = opaque;
265 for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next);
266 *ppe = pe;
267 return 0;
268 }
269
270 void qemu_del_polling_cb(PollingFunc *func, void *opaque)
271 {
272 PollingEntry **ppe, *pe;
273 for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next) {
274 pe = *ppe;
275 if (pe->func == func && pe->opaque == opaque) {
276 *ppe = pe->next;
277 g_free(pe);
278 break;
279 }
280 }
281 }
282
283 /***********************************************************/
284 /* Wait objects support */
285 typedef struct WaitObjects {
286 int num;
287 int revents[MAXIMUM_WAIT_OBJECTS + 1];
288 HANDLE events[MAXIMUM_WAIT_OBJECTS + 1];
289 WaitObjectFunc *func[MAXIMUM_WAIT_OBJECTS + 1];
290 void *opaque[MAXIMUM_WAIT_OBJECTS + 1];
291 } WaitObjects;
292
293 static WaitObjects wait_objects = {0};
294
295 int qemu_add_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
296 {
297 WaitObjects *w = &wait_objects;
298 if (w->num >= MAXIMUM_WAIT_OBJECTS) {
299 return -1;
300 }
301 w->events[w->num] = handle;
302 w->func[w->num] = func;
303 w->opaque[w->num] = opaque;
304 w->revents[w->num] = 0;
305 w->num++;
306 return 0;
307 }
308
309 void qemu_del_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
310 {
311 int i, found;
312 WaitObjects *w = &wait_objects;
313
314 found = 0;
315 for (i = 0; i < w->num; i++) {
316 if (w->events[i] == handle) {
317 found = 1;
318 }
319 if (found) {
320 w->events[i] = w->events[i + 1];
321 w->func[i] = w->func[i + 1];
322 w->opaque[i] = w->opaque[i + 1];
323 w->revents[i] = w->revents[i + 1];
324 }
325 }
326 if (found) {
327 w->num--;
328 }
329 }
330
331 void qemu_fd_register(int fd)
332 {
333 WSAEventSelect(fd, event_notifier_get_handle(&qemu_aio_context->notifier),
334 FD_READ | FD_ACCEPT | FD_CLOSE |
335 FD_CONNECT | FD_WRITE | FD_OOB);
336 }
337
338 static int pollfds_fill(GArray *pollfds, fd_set *rfds, fd_set *wfds,
339 fd_set *xfds)
340 {
341 int nfds = -1;
342 int i;
343
344 for (i = 0; i < pollfds->len; i++) {
345 GPollFD *pfd = &g_array_index(pollfds, GPollFD, i);
346 int fd = pfd->fd;
347 int events = pfd->events;
348 if (events & G_IO_IN) {
349 FD_SET(fd, rfds);
350 nfds = MAX(nfds, fd);
351 }
352 if (events & G_IO_OUT) {
353 FD_SET(fd, wfds);
354 nfds = MAX(nfds, fd);
355 }
356 if (events & G_IO_PRI) {
357 FD_SET(fd, xfds);
358 nfds = MAX(nfds, fd);
359 }
360 }
361 return nfds;
362 }
363
364 static void pollfds_poll(GArray *pollfds, int nfds, fd_set *rfds,
365 fd_set *wfds, fd_set *xfds)
366 {
367 int i;
368
369 for (i = 0; i < pollfds->len; i++) {
370 GPollFD *pfd = &g_array_index(pollfds, GPollFD, i);
371 int fd = pfd->fd;
372 int revents = 0;
373
374 if (FD_ISSET(fd, rfds)) {
375 revents |= G_IO_IN;
376 }
377 if (FD_ISSET(fd, wfds)) {
378 revents |= G_IO_OUT;
379 }
380 if (FD_ISSET(fd, xfds)) {
381 revents |= G_IO_PRI;
382 }
383 pfd->revents = revents & pfd->events;
384 }
385 }
386
387 static int os_host_main_loop_wait(int64_t timeout)
388 {
389 GMainContext *context = g_main_context_default();
390 GPollFD poll_fds[1024 * 2]; /* this is probably overkill */
391 int select_ret = 0;
392 int g_poll_ret, ret, i, n_poll_fds;
393 PollingEntry *pe;
394 WaitObjects *w = &wait_objects;
395 gint poll_timeout;
396 int64_t poll_timeout_ns;
397 static struct timeval tv0;
398 fd_set rfds, wfds, xfds;
399 int nfds;
400
401 /* XXX: need to suppress polling by better using win32 events */
402 ret = 0;
403 for (pe = first_polling_entry; pe != NULL; pe = pe->next) {
404 ret |= pe->func(pe->opaque);
405 }
406 if (ret != 0) {
407 return ret;
408 }
409
410 FD_ZERO(&rfds);
411 FD_ZERO(&wfds);
412 FD_ZERO(&xfds);
413 nfds = pollfds_fill(gpollfds, &rfds, &wfds, &xfds);
414 if (nfds >= 0) {
415 select_ret = select(nfds + 1, &rfds, &wfds, &xfds, &tv0);
416 if (select_ret != 0) {
417 timeout = 0;
418 }
419 if (select_ret > 0) {
420 pollfds_poll(gpollfds, nfds, &rfds, &wfds, &xfds);
421 }
422 }
423
424 g_main_context_prepare(context, &max_priority);
425 n_poll_fds = g_main_context_query(context, max_priority, &poll_timeout,
426 poll_fds, ARRAY_SIZE(poll_fds));
427 g_assert(n_poll_fds <= ARRAY_SIZE(poll_fds));
428
429 for (i = 0; i < w->num; i++) {
430 poll_fds[n_poll_fds + i].fd = (DWORD_PTR)w->events[i];
431 poll_fds[n_poll_fds + i].events = G_IO_IN;
432 }
433
434 if (poll_timeout < 0) {
435 poll_timeout_ns = -1;
436 } else {
437 poll_timeout_ns = (int64_t)poll_timeout * (int64_t)SCALE_MS;
438 }
439
440 poll_timeout_ns = qemu_soonest_timeout(poll_timeout_ns, timeout);
441
442 qemu_mutex_unlock_iothread();
443 g_poll_ret = qemu_poll_ns(poll_fds, n_poll_fds + w->num, poll_timeout_ns);
444
445 qemu_mutex_lock_iothread();
446 if (g_poll_ret > 0) {
447 for (i = 0; i < w->num; i++) {
448 w->revents[i] = poll_fds[n_poll_fds + i].revents;
449 }
450 for (i = 0; i < w->num; i++) {
451 if (w->revents[i] && w->func[i]) {
452 w->func[i](w->opaque[i]);
453 }
454 }
455 }
456
457 if (g_main_context_check(context, max_priority, poll_fds, n_poll_fds)) {
458 g_main_context_dispatch(context);
459 }
460
461 return select_ret || g_poll_ret;
462 }
463 #endif
464
465 int main_loop_wait(int nonblocking)
466 {
467 int ret;
468 uint32_t timeout = UINT32_MAX;
469 int64_t timeout_ns;
470
471 if (nonblocking) {
472 timeout = 0;
473 }
474
475 /* poll any events */
476 g_array_set_size(gpollfds, 0); /* reset for new iteration */
477 /* XXX: separate device handlers from system ones */
478 #ifdef CONFIG_SLIRP
479 slirp_pollfds_fill(gpollfds, &timeout);
480 #endif
481 qemu_iohandler_fill(gpollfds);
482
483 if (timeout == UINT32_MAX) {
484 timeout_ns = -1;
485 } else {
486 timeout_ns = (uint64_t)timeout * (int64_t)(SCALE_MS);
487 }
488
489 timeout_ns = qemu_soonest_timeout(timeout_ns,
490 timerlistgroup_deadline_ns(
491 &main_loop_tlg));
492
493 ret = os_host_main_loop_wait(timeout_ns);
494 qemu_iohandler_poll(gpollfds, ret);
495 #ifdef CONFIG_SLIRP
496 slirp_pollfds_poll(gpollfds, (ret < 0));
497 #endif
498
499 qemu_clock_run_all_timers();
500
501 return ret;
502 }
503
504 /* Functions to operate on the main QEMU AioContext. */
505
506 QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque)
507 {
508 return aio_bh_new(qemu_aio_context, cb, opaque);
509 }