ppc/pnv: Add support for POWER8+ LPC Controller
[qemu.git] / util / 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 "sysemu/cpus.h"
32 #include "slirp/libslirp.h"
33 #include "qemu/main-loop.h"
34 #include "block/aio.h"
35
36 #ifndef _WIN32
37
38 /* If we have signalfd, we mask out the signals we want to handle and then
39 * use signalfd to listen for them. We rely on whatever the current signal
40 * handler is to dispatch the signals when we receive them.
41 */
42 static void sigfd_handler(void *opaque)
43 {
44 int fd = (intptr_t)opaque;
45 struct qemu_signalfd_siginfo info;
46 struct sigaction action;
47 ssize_t len;
48
49 while (1) {
50 do {
51 len = read(fd, &info, sizeof(info));
52 } while (len == -1 && errno == EINTR);
53
54 if (len == -1 && errno == EAGAIN) {
55 break;
56 }
57
58 if (len != sizeof(info)) {
59 printf("read from sigfd returned %zd: %m\n", len);
60 return;
61 }
62
63 sigaction(info.ssi_signo, NULL, &action);
64 if ((action.sa_flags & SA_SIGINFO) && action.sa_sigaction) {
65 sigaction_invoke(&action, &info);
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 static QEMUBH *qemu_notify_bh;
118
119 static void notify_event_cb(void *opaque)
120 {
121 /* No need to do anything; this bottom half is only used to
122 * kick the kernel out of ppoll/poll/WaitForMultipleObjects.
123 */
124 }
125
126 AioContext *qemu_get_aio_context(void)
127 {
128 return qemu_aio_context;
129 }
130
131 void qemu_notify_event(void)
132 {
133 if (!qemu_aio_context) {
134 return;
135 }
136 qemu_bh_schedule(qemu_notify_bh);
137 }
138
139 static GArray *gpollfds;
140
141 int qemu_init_main_loop(Error **errp)
142 {
143 int ret;
144 GSource *src;
145 Error *local_error = NULL;
146
147 init_clocks(qemu_timer_notify_cb);
148
149 ret = qemu_signal_init();
150 if (ret) {
151 return ret;
152 }
153
154 qemu_aio_context = aio_context_new(&local_error);
155 if (!qemu_aio_context) {
156 error_propagate(errp, local_error);
157 return -EMFILE;
158 }
159 qemu_notify_bh = qemu_bh_new(notify_event_cb, NULL);
160 gpollfds = g_array_new(FALSE, FALSE, sizeof(GPollFD));
161 src = aio_get_g_source(qemu_aio_context);
162 g_source_set_name(src, "aio-context");
163 g_source_attach(src, NULL);
164 g_source_unref(src);
165 src = iohandler_get_g_source();
166 g_source_set_name(src, "io-handler");
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 GMainContext *context = g_main_context_default();
222 int ret;
223 static int spin_counter;
224
225 g_main_context_acquire(context);
226
227 glib_pollfds_fill(&timeout);
228
229 /* If the I/O thread is very busy or we are incorrectly busy waiting in
230 * the I/O thread, this can lead to starvation of the BQL such that the
231 * VCPU threads never run. To make sure we can detect the later case,
232 * print a message to the screen. If we run into this condition, create
233 * a fake timeout in order to give the VCPU threads a chance to run.
234 */
235 if (!timeout && (spin_counter > MAX_MAIN_LOOP_SPIN)) {
236 static bool notified;
237
238 if (!notified && !qtest_enabled() && !qtest_driver()) {
239 fprintf(stderr,
240 "main-loop: WARNING: I/O thread spun for %d iterations\n",
241 MAX_MAIN_LOOP_SPIN);
242 notified = true;
243 }
244
245 timeout = SCALE_MS;
246 }
247
248 if (timeout) {
249 spin_counter = 0;
250 qemu_mutex_unlock_iothread();
251 } else {
252 spin_counter++;
253 }
254
255 ret = qemu_poll_ns((GPollFD *)gpollfds->data, gpollfds->len, timeout);
256
257 if (timeout) {
258 qemu_mutex_lock_iothread();
259 }
260
261 glib_pollfds_poll();
262
263 g_main_context_release(context);
264
265 return ret;
266 }
267 #else
268 /***********************************************************/
269 /* Polling handling */
270
271 typedef struct PollingEntry {
272 PollingFunc *func;
273 void *opaque;
274 struct PollingEntry *next;
275 } PollingEntry;
276
277 static PollingEntry *first_polling_entry;
278
279 int qemu_add_polling_cb(PollingFunc *func, void *opaque)
280 {
281 PollingEntry **ppe, *pe;
282 pe = g_malloc0(sizeof(PollingEntry));
283 pe->func = func;
284 pe->opaque = opaque;
285 for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next);
286 *ppe = pe;
287 return 0;
288 }
289
290 void qemu_del_polling_cb(PollingFunc *func, void *opaque)
291 {
292 PollingEntry **ppe, *pe;
293 for(ppe = &first_polling_entry; *ppe != NULL; ppe = &(*ppe)->next) {
294 pe = *ppe;
295 if (pe->func == func && pe->opaque == opaque) {
296 *ppe = pe->next;
297 g_free(pe);
298 break;
299 }
300 }
301 }
302
303 /***********************************************************/
304 /* Wait objects support */
305 typedef struct WaitObjects {
306 int num;
307 int revents[MAXIMUM_WAIT_OBJECTS + 1];
308 HANDLE events[MAXIMUM_WAIT_OBJECTS + 1];
309 WaitObjectFunc *func[MAXIMUM_WAIT_OBJECTS + 1];
310 void *opaque[MAXIMUM_WAIT_OBJECTS + 1];
311 } WaitObjects;
312
313 static WaitObjects wait_objects = {0};
314
315 int qemu_add_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
316 {
317 WaitObjects *w = &wait_objects;
318 if (w->num >= MAXIMUM_WAIT_OBJECTS) {
319 return -1;
320 }
321 w->events[w->num] = handle;
322 w->func[w->num] = func;
323 w->opaque[w->num] = opaque;
324 w->revents[w->num] = 0;
325 w->num++;
326 return 0;
327 }
328
329 void qemu_del_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
330 {
331 int i, found;
332 WaitObjects *w = &wait_objects;
333
334 found = 0;
335 for (i = 0; i < w->num; i++) {
336 if (w->events[i] == handle) {
337 found = 1;
338 }
339 if (found) {
340 w->events[i] = w->events[i + 1];
341 w->func[i] = w->func[i + 1];
342 w->opaque[i] = w->opaque[i + 1];
343 w->revents[i] = w->revents[i + 1];
344 }
345 }
346 if (found) {
347 w->num--;
348 }
349 }
350
351 void qemu_fd_register(int fd)
352 {
353 WSAEventSelect(fd, event_notifier_get_handle(&qemu_aio_context->notifier),
354 FD_READ | FD_ACCEPT | FD_CLOSE |
355 FD_CONNECT | FD_WRITE | FD_OOB);
356 }
357
358 static int pollfds_fill(GArray *pollfds, fd_set *rfds, fd_set *wfds,
359 fd_set *xfds)
360 {
361 int nfds = -1;
362 int i;
363
364 for (i = 0; i < pollfds->len; i++) {
365 GPollFD *pfd = &g_array_index(pollfds, GPollFD, i);
366 int fd = pfd->fd;
367 int events = pfd->events;
368 if (events & G_IO_IN) {
369 FD_SET(fd, rfds);
370 nfds = MAX(nfds, fd);
371 }
372 if (events & G_IO_OUT) {
373 FD_SET(fd, wfds);
374 nfds = MAX(nfds, fd);
375 }
376 if (events & G_IO_PRI) {
377 FD_SET(fd, xfds);
378 nfds = MAX(nfds, fd);
379 }
380 }
381 return nfds;
382 }
383
384 static void pollfds_poll(GArray *pollfds, int nfds, fd_set *rfds,
385 fd_set *wfds, fd_set *xfds)
386 {
387 int i;
388
389 for (i = 0; i < pollfds->len; i++) {
390 GPollFD *pfd = &g_array_index(pollfds, GPollFD, i);
391 int fd = pfd->fd;
392 int revents = 0;
393
394 if (FD_ISSET(fd, rfds)) {
395 revents |= G_IO_IN;
396 }
397 if (FD_ISSET(fd, wfds)) {
398 revents |= G_IO_OUT;
399 }
400 if (FD_ISSET(fd, xfds)) {
401 revents |= G_IO_PRI;
402 }
403 pfd->revents = revents & pfd->events;
404 }
405 }
406
407 static int os_host_main_loop_wait(int64_t timeout)
408 {
409 GMainContext *context = g_main_context_default();
410 GPollFD poll_fds[1024 * 2]; /* this is probably overkill */
411 int select_ret = 0;
412 int g_poll_ret, ret, i, n_poll_fds;
413 PollingEntry *pe;
414 WaitObjects *w = &wait_objects;
415 gint poll_timeout;
416 int64_t poll_timeout_ns;
417 static struct timeval tv0;
418 fd_set rfds, wfds, xfds;
419 int nfds;
420
421 g_main_context_acquire(context);
422
423 /* XXX: need to suppress polling by better using win32 events */
424 ret = 0;
425 for (pe = first_polling_entry; pe != NULL; pe = pe->next) {
426 ret |= pe->func(pe->opaque);
427 }
428 if (ret != 0) {
429 g_main_context_release(context);
430 return ret;
431 }
432
433 FD_ZERO(&rfds);
434 FD_ZERO(&wfds);
435 FD_ZERO(&xfds);
436 nfds = pollfds_fill(gpollfds, &rfds, &wfds, &xfds);
437 if (nfds >= 0) {
438 select_ret = select(nfds + 1, &rfds, &wfds, &xfds, &tv0);
439 if (select_ret != 0) {
440 timeout = 0;
441 }
442 if (select_ret > 0) {
443 pollfds_poll(gpollfds, nfds, &rfds, &wfds, &xfds);
444 }
445 }
446
447 g_main_context_prepare(context, &max_priority);
448 n_poll_fds = g_main_context_query(context, max_priority, &poll_timeout,
449 poll_fds, ARRAY_SIZE(poll_fds));
450 g_assert(n_poll_fds <= ARRAY_SIZE(poll_fds));
451
452 for (i = 0; i < w->num; i++) {
453 poll_fds[n_poll_fds + i].fd = (DWORD_PTR)w->events[i];
454 poll_fds[n_poll_fds + i].events = G_IO_IN;
455 }
456
457 if (poll_timeout < 0) {
458 poll_timeout_ns = -1;
459 } else {
460 poll_timeout_ns = (int64_t)poll_timeout * (int64_t)SCALE_MS;
461 }
462
463 poll_timeout_ns = qemu_soonest_timeout(poll_timeout_ns, timeout);
464
465 qemu_mutex_unlock_iothread();
466 g_poll_ret = qemu_poll_ns(poll_fds, n_poll_fds + w->num, poll_timeout_ns);
467
468 qemu_mutex_lock_iothread();
469 if (g_poll_ret > 0) {
470 for (i = 0; i < w->num; i++) {
471 w->revents[i] = poll_fds[n_poll_fds + i].revents;
472 }
473 for (i = 0; i < w->num; i++) {
474 if (w->revents[i] && w->func[i]) {
475 w->func[i](w->opaque[i]);
476 }
477 }
478 }
479
480 if (g_main_context_check(context, max_priority, poll_fds, n_poll_fds)) {
481 g_main_context_dispatch(context);
482 }
483
484 g_main_context_release(context);
485
486 return select_ret || g_poll_ret;
487 }
488 #endif
489
490 int main_loop_wait(int nonblocking)
491 {
492 int ret;
493 uint32_t timeout = UINT32_MAX;
494 int64_t timeout_ns;
495
496 if (nonblocking) {
497 timeout = 0;
498 }
499
500 /* poll any events */
501 g_array_set_size(gpollfds, 0); /* reset for new iteration */
502 /* XXX: separate device handlers from system ones */
503 #ifdef CONFIG_SLIRP
504 slirp_pollfds_fill(gpollfds, &timeout);
505 #endif
506
507 if (timeout == UINT32_MAX) {
508 timeout_ns = -1;
509 } else {
510 timeout_ns = (uint64_t)timeout * (int64_t)(SCALE_MS);
511 }
512
513 timeout_ns = qemu_soonest_timeout(timeout_ns,
514 timerlistgroup_deadline_ns(
515 &main_loop_tlg));
516
517 ret = os_host_main_loop_wait(timeout_ns);
518 #ifdef CONFIG_SLIRP
519 slirp_pollfds_poll(gpollfds, (ret < 0));
520 #endif
521
522 /* CPU thread can infinitely wait for event after
523 missing the warp */
524 qemu_start_warp_timer();
525 qemu_clock_run_all_timers();
526
527 return ret;
528 }
529
530 /* Functions to operate on the main QEMU AioContext. */
531
532 QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque)
533 {
534 return aio_bh_new(qemu_aio_context, cb, opaque);
535 }