vfio: Create device specific region info helper
[qemu.git] / qemu-timer.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 "qemu/main-loop.h"
27 #include "qemu/timer.h"
28 #include "sysemu/replay.h"
29 #include "sysemu/sysemu.h"
30
31 #ifdef CONFIG_POSIX
32 #include <pthread.h>
33 #endif
34
35 #ifdef CONFIG_PPOLL
36 #include <poll.h>
37 #endif
38
39 #ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK
40 #include <sys/prctl.h>
41 #endif
42
43 /***********************************************************/
44 /* timers */
45
46 typedef struct QEMUClock {
47 /* We rely on BQL to protect the timerlists */
48 QLIST_HEAD(, QEMUTimerList) timerlists;
49
50 NotifierList reset_notifiers;
51 int64_t last;
52
53 QEMUClockType type;
54 bool enabled;
55 } QEMUClock;
56
57 QEMUTimerListGroup main_loop_tlg;
58 static QEMUClock qemu_clocks[QEMU_CLOCK_MAX];
59
60 /* A QEMUTimerList is a list of timers attached to a clock. More
61 * than one QEMUTimerList can be attached to each clock, for instance
62 * used by different AioContexts / threads. Each clock also has
63 * a list of the QEMUTimerLists associated with it, in order that
64 * reenabling the clock can call all the notifiers.
65 */
66
67 struct QEMUTimerList {
68 QEMUClock *clock;
69 QemuMutex active_timers_lock;
70 QEMUTimer *active_timers;
71 QLIST_ENTRY(QEMUTimerList) list;
72 QEMUTimerListNotifyCB *notify_cb;
73 void *notify_opaque;
74
75 /* lightweight method to mark the end of timerlist's running */
76 QemuEvent timers_done_ev;
77 };
78
79 /**
80 * qemu_clock_ptr:
81 * @type: type of clock
82 *
83 * Translate a clock type into a pointer to QEMUClock object.
84 *
85 * Returns: a pointer to the QEMUClock object
86 */
87 static inline QEMUClock *qemu_clock_ptr(QEMUClockType type)
88 {
89 return &qemu_clocks[type];
90 }
91
92 static bool timer_expired_ns(QEMUTimer *timer_head, int64_t current_time)
93 {
94 return timer_head && (timer_head->expire_time <= current_time);
95 }
96
97 QEMUTimerList *timerlist_new(QEMUClockType type,
98 QEMUTimerListNotifyCB *cb,
99 void *opaque)
100 {
101 QEMUTimerList *timer_list;
102 QEMUClock *clock = qemu_clock_ptr(type);
103
104 timer_list = g_malloc0(sizeof(QEMUTimerList));
105 qemu_event_init(&timer_list->timers_done_ev, true);
106 timer_list->clock = clock;
107 timer_list->notify_cb = cb;
108 timer_list->notify_opaque = opaque;
109 qemu_mutex_init(&timer_list->active_timers_lock);
110 QLIST_INSERT_HEAD(&clock->timerlists, timer_list, list);
111 return timer_list;
112 }
113
114 void timerlist_free(QEMUTimerList *timer_list)
115 {
116 assert(!timerlist_has_timers(timer_list));
117 if (timer_list->clock) {
118 QLIST_REMOVE(timer_list, list);
119 }
120 qemu_mutex_destroy(&timer_list->active_timers_lock);
121 g_free(timer_list);
122 }
123
124 static void qemu_clock_init(QEMUClockType type)
125 {
126 QEMUClock *clock = qemu_clock_ptr(type);
127
128 /* Assert that the clock of type TYPE has not been initialized yet. */
129 assert(main_loop_tlg.tl[type] == NULL);
130
131 clock->type = type;
132 clock->enabled = true;
133 clock->last = INT64_MIN;
134 QLIST_INIT(&clock->timerlists);
135 notifier_list_init(&clock->reset_notifiers);
136 main_loop_tlg.tl[type] = timerlist_new(type, NULL, NULL);
137 }
138
139 bool qemu_clock_use_for_deadline(QEMUClockType type)
140 {
141 return !(use_icount && (type == QEMU_CLOCK_VIRTUAL));
142 }
143
144 void qemu_clock_notify(QEMUClockType type)
145 {
146 QEMUTimerList *timer_list;
147 QEMUClock *clock = qemu_clock_ptr(type);
148 QLIST_FOREACH(timer_list, &clock->timerlists, list) {
149 timerlist_notify(timer_list);
150 }
151 }
152
153 /* Disabling the clock will wait for related timerlists to stop
154 * executing qemu_run_timers. Thus, this functions should not
155 * be used from the callback of a timer that is based on @clock.
156 * Doing so would cause a deadlock.
157 *
158 * Caller should hold BQL.
159 */
160 void qemu_clock_enable(QEMUClockType type, bool enabled)
161 {
162 QEMUClock *clock = qemu_clock_ptr(type);
163 QEMUTimerList *tl;
164 bool old = clock->enabled;
165 clock->enabled = enabled;
166 if (enabled && !old) {
167 qemu_clock_notify(type);
168 } else if (!enabled && old) {
169 QLIST_FOREACH(tl, &clock->timerlists, list) {
170 qemu_event_wait(&tl->timers_done_ev);
171 }
172 }
173 }
174
175 bool timerlist_has_timers(QEMUTimerList *timer_list)
176 {
177 return !!timer_list->active_timers;
178 }
179
180 bool qemu_clock_has_timers(QEMUClockType type)
181 {
182 return timerlist_has_timers(
183 main_loop_tlg.tl[type]);
184 }
185
186 bool timerlist_expired(QEMUTimerList *timer_list)
187 {
188 int64_t expire_time;
189
190 qemu_mutex_lock(&timer_list->active_timers_lock);
191 if (!timer_list->active_timers) {
192 qemu_mutex_unlock(&timer_list->active_timers_lock);
193 return false;
194 }
195 expire_time = timer_list->active_timers->expire_time;
196 qemu_mutex_unlock(&timer_list->active_timers_lock);
197
198 return expire_time < qemu_clock_get_ns(timer_list->clock->type);
199 }
200
201 bool qemu_clock_expired(QEMUClockType type)
202 {
203 return timerlist_expired(
204 main_loop_tlg.tl[type]);
205 }
206
207 /*
208 * As above, but return -1 for no deadline, and do not cap to 2^32
209 * as we know the result is always positive.
210 */
211
212 int64_t timerlist_deadline_ns(QEMUTimerList *timer_list)
213 {
214 int64_t delta;
215 int64_t expire_time;
216
217 if (!timer_list->clock->enabled) {
218 return -1;
219 }
220
221 /* The active timers list may be modified before the caller uses our return
222 * value but ->notify_cb() is called when the deadline changes. Therefore
223 * the caller should notice the change and there is no race condition.
224 */
225 qemu_mutex_lock(&timer_list->active_timers_lock);
226 if (!timer_list->active_timers) {
227 qemu_mutex_unlock(&timer_list->active_timers_lock);
228 return -1;
229 }
230 expire_time = timer_list->active_timers->expire_time;
231 qemu_mutex_unlock(&timer_list->active_timers_lock);
232
233 delta = expire_time - qemu_clock_get_ns(timer_list->clock->type);
234
235 if (delta <= 0) {
236 return 0;
237 }
238
239 return delta;
240 }
241
242 /* Calculate the soonest deadline across all timerlists attached
243 * to the clock. This is used for the icount timeout so we
244 * ignore whether or not the clock should be used in deadline
245 * calculations.
246 */
247 int64_t qemu_clock_deadline_ns_all(QEMUClockType type)
248 {
249 int64_t deadline = -1;
250 QEMUTimerList *timer_list;
251 QEMUClock *clock = qemu_clock_ptr(type);
252 QLIST_FOREACH(timer_list, &clock->timerlists, list) {
253 deadline = qemu_soonest_timeout(deadline,
254 timerlist_deadline_ns(timer_list));
255 }
256 return deadline;
257 }
258
259 QEMUClockType timerlist_get_clock(QEMUTimerList *timer_list)
260 {
261 return timer_list->clock->type;
262 }
263
264 QEMUTimerList *qemu_clock_get_main_loop_timerlist(QEMUClockType type)
265 {
266 return main_loop_tlg.tl[type];
267 }
268
269 void timerlist_notify(QEMUTimerList *timer_list)
270 {
271 if (timer_list->notify_cb) {
272 timer_list->notify_cb(timer_list->notify_opaque);
273 } else {
274 qemu_notify_event();
275 }
276 }
277
278 /* Transition function to convert a nanosecond timeout to ms
279 * This is used where a system does not support ppoll
280 */
281 int qemu_timeout_ns_to_ms(int64_t ns)
282 {
283 int64_t ms;
284 if (ns < 0) {
285 return -1;
286 }
287
288 if (!ns) {
289 return 0;
290 }
291
292 /* Always round up, because it's better to wait too long than to wait too
293 * little and effectively busy-wait
294 */
295 ms = (ns + SCALE_MS - 1) / SCALE_MS;
296
297 /* To avoid overflow problems, limit this to 2^31, i.e. approx 25 days */
298 if (ms > (int64_t) INT32_MAX) {
299 ms = INT32_MAX;
300 }
301
302 return (int) ms;
303 }
304
305
306 /* qemu implementation of g_poll which uses a nanosecond timeout but is
307 * otherwise identical to g_poll
308 */
309 int qemu_poll_ns(GPollFD *fds, guint nfds, int64_t timeout)
310 {
311 #ifdef CONFIG_PPOLL
312 if (timeout < 0) {
313 return ppoll((struct pollfd *)fds, nfds, NULL, NULL);
314 } else {
315 struct timespec ts;
316 int64_t tvsec = timeout / 1000000000LL;
317 /* Avoid possibly overflowing and specifying a negative number of
318 * seconds, which would turn a very long timeout into a busy-wait.
319 */
320 if (tvsec > (int64_t)INT32_MAX) {
321 tvsec = INT32_MAX;
322 }
323 ts.tv_sec = tvsec;
324 ts.tv_nsec = timeout % 1000000000LL;
325 return ppoll((struct pollfd *)fds, nfds, &ts, NULL);
326 }
327 #else
328 return g_poll(fds, nfds, qemu_timeout_ns_to_ms(timeout));
329 #endif
330 }
331
332
333 void timer_init_tl(QEMUTimer *ts,
334 QEMUTimerList *timer_list, int scale,
335 QEMUTimerCB *cb, void *opaque)
336 {
337 ts->timer_list = timer_list;
338 ts->cb = cb;
339 ts->opaque = opaque;
340 ts->scale = scale;
341 ts->expire_time = -1;
342 }
343
344 void timer_deinit(QEMUTimer *ts)
345 {
346 assert(ts->expire_time == -1);
347 ts->timer_list = NULL;
348 }
349
350 void timer_free(QEMUTimer *ts)
351 {
352 g_free(ts);
353 }
354
355 static void timer_del_locked(QEMUTimerList *timer_list, QEMUTimer *ts)
356 {
357 QEMUTimer **pt, *t;
358
359 ts->expire_time = -1;
360 pt = &timer_list->active_timers;
361 for(;;) {
362 t = *pt;
363 if (!t)
364 break;
365 if (t == ts) {
366 *pt = t->next;
367 break;
368 }
369 pt = &t->next;
370 }
371 }
372
373 static bool timer_mod_ns_locked(QEMUTimerList *timer_list,
374 QEMUTimer *ts, int64_t expire_time)
375 {
376 QEMUTimer **pt, *t;
377
378 /* add the timer in the sorted list */
379 pt = &timer_list->active_timers;
380 for (;;) {
381 t = *pt;
382 if (!timer_expired_ns(t, expire_time)) {
383 break;
384 }
385 pt = &t->next;
386 }
387 ts->expire_time = MAX(expire_time, 0);
388 ts->next = *pt;
389 *pt = ts;
390
391 return pt == &timer_list->active_timers;
392 }
393
394 static void timerlist_rearm(QEMUTimerList *timer_list)
395 {
396 /* Interrupt execution to force deadline recalculation. */
397 if (timer_list->clock->type == QEMU_CLOCK_VIRTUAL) {
398 qemu_start_warp_timer();
399 }
400 timerlist_notify(timer_list);
401 }
402
403 /* stop a timer, but do not dealloc it */
404 void timer_del(QEMUTimer *ts)
405 {
406 QEMUTimerList *timer_list = ts->timer_list;
407
408 if (timer_list) {
409 qemu_mutex_lock(&timer_list->active_timers_lock);
410 timer_del_locked(timer_list, ts);
411 qemu_mutex_unlock(&timer_list->active_timers_lock);
412 }
413 }
414
415 /* modify the current timer so that it will be fired when current_time
416 >= expire_time. The corresponding callback will be called. */
417 void timer_mod_ns(QEMUTimer *ts, int64_t expire_time)
418 {
419 QEMUTimerList *timer_list = ts->timer_list;
420 bool rearm;
421
422 qemu_mutex_lock(&timer_list->active_timers_lock);
423 timer_del_locked(timer_list, ts);
424 rearm = timer_mod_ns_locked(timer_list, ts, expire_time);
425 qemu_mutex_unlock(&timer_list->active_timers_lock);
426
427 if (rearm) {
428 timerlist_rearm(timer_list);
429 }
430 }
431
432 /* modify the current timer so that it will be fired when current_time
433 >= expire_time or the current deadline, whichever comes earlier.
434 The corresponding callback will be called. */
435 void timer_mod_anticipate_ns(QEMUTimer *ts, int64_t expire_time)
436 {
437 QEMUTimerList *timer_list = ts->timer_list;
438 bool rearm;
439
440 qemu_mutex_lock(&timer_list->active_timers_lock);
441 if (ts->expire_time == -1 || ts->expire_time > expire_time) {
442 if (ts->expire_time != -1) {
443 timer_del_locked(timer_list, ts);
444 }
445 rearm = timer_mod_ns_locked(timer_list, ts, expire_time);
446 } else {
447 rearm = false;
448 }
449 qemu_mutex_unlock(&timer_list->active_timers_lock);
450
451 if (rearm) {
452 timerlist_rearm(timer_list);
453 }
454 }
455
456 void timer_mod(QEMUTimer *ts, int64_t expire_time)
457 {
458 timer_mod_ns(ts, expire_time * ts->scale);
459 }
460
461 void timer_mod_anticipate(QEMUTimer *ts, int64_t expire_time)
462 {
463 timer_mod_anticipate_ns(ts, expire_time * ts->scale);
464 }
465
466 bool timer_pending(QEMUTimer *ts)
467 {
468 return ts->expire_time >= 0;
469 }
470
471 bool timer_expired(QEMUTimer *timer_head, int64_t current_time)
472 {
473 return timer_expired_ns(timer_head, current_time * timer_head->scale);
474 }
475
476 bool timerlist_run_timers(QEMUTimerList *timer_list)
477 {
478 QEMUTimer *ts;
479 int64_t current_time;
480 bool progress = false;
481 QEMUTimerCB *cb;
482 void *opaque;
483
484 qemu_event_reset(&timer_list->timers_done_ev);
485 if (!timer_list->clock->enabled || !timer_list->active_timers) {
486 goto out;
487 }
488
489 switch (timer_list->clock->type) {
490 case QEMU_CLOCK_REALTIME:
491 break;
492 default:
493 case QEMU_CLOCK_VIRTUAL:
494 if (!replay_checkpoint(CHECKPOINT_CLOCK_VIRTUAL)) {
495 goto out;
496 }
497 break;
498 case QEMU_CLOCK_HOST:
499 if (!replay_checkpoint(CHECKPOINT_CLOCK_HOST)) {
500 goto out;
501 }
502 break;
503 case QEMU_CLOCK_VIRTUAL_RT:
504 if (!replay_checkpoint(CHECKPOINT_CLOCK_VIRTUAL_RT)) {
505 goto out;
506 }
507 break;
508 }
509
510 current_time = qemu_clock_get_ns(timer_list->clock->type);
511 for(;;) {
512 qemu_mutex_lock(&timer_list->active_timers_lock);
513 ts = timer_list->active_timers;
514 if (!timer_expired_ns(ts, current_time)) {
515 qemu_mutex_unlock(&timer_list->active_timers_lock);
516 break;
517 }
518
519 /* remove timer from the list before calling the callback */
520 timer_list->active_timers = ts->next;
521 ts->next = NULL;
522 ts->expire_time = -1;
523 cb = ts->cb;
524 opaque = ts->opaque;
525 qemu_mutex_unlock(&timer_list->active_timers_lock);
526
527 /* run the callback (the timer list can be modified) */
528 cb(opaque);
529 progress = true;
530 }
531
532 out:
533 qemu_event_set(&timer_list->timers_done_ev);
534 return progress;
535 }
536
537 bool qemu_clock_run_timers(QEMUClockType type)
538 {
539 return timerlist_run_timers(main_loop_tlg.tl[type]);
540 }
541
542 void timerlistgroup_init(QEMUTimerListGroup *tlg,
543 QEMUTimerListNotifyCB *cb, void *opaque)
544 {
545 QEMUClockType type;
546 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
547 tlg->tl[type] = timerlist_new(type, cb, opaque);
548 }
549 }
550
551 void timerlistgroup_deinit(QEMUTimerListGroup *tlg)
552 {
553 QEMUClockType type;
554 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
555 timerlist_free(tlg->tl[type]);
556 }
557 }
558
559 bool timerlistgroup_run_timers(QEMUTimerListGroup *tlg)
560 {
561 QEMUClockType type;
562 bool progress = false;
563 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
564 progress |= timerlist_run_timers(tlg->tl[type]);
565 }
566 return progress;
567 }
568
569 int64_t timerlistgroup_deadline_ns(QEMUTimerListGroup *tlg)
570 {
571 int64_t deadline = -1;
572 QEMUClockType type;
573 bool play = replay_mode == REPLAY_MODE_PLAY;
574 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
575 if (qemu_clock_use_for_deadline(type)) {
576 if (!play || type == QEMU_CLOCK_REALTIME) {
577 deadline = qemu_soonest_timeout(deadline,
578 timerlist_deadline_ns(tlg->tl[type]));
579 } else {
580 /* Read clock from the replay file and
581 do not calculate the deadline, based on virtual clock. */
582 qemu_clock_get_ns(type);
583 }
584 }
585 }
586 return deadline;
587 }
588
589 int64_t qemu_clock_get_ns(QEMUClockType type)
590 {
591 int64_t now, last;
592 QEMUClock *clock = qemu_clock_ptr(type);
593
594 switch (type) {
595 case QEMU_CLOCK_REALTIME:
596 return get_clock();
597 default:
598 case QEMU_CLOCK_VIRTUAL:
599 if (use_icount) {
600 return cpu_get_icount();
601 } else {
602 return cpu_get_clock();
603 }
604 case QEMU_CLOCK_HOST:
605 now = REPLAY_CLOCK(REPLAY_CLOCK_HOST, get_clock_realtime());
606 last = clock->last;
607 clock->last = now;
608 if (now < last || now > (last + get_max_clock_jump())) {
609 notifier_list_notify(&clock->reset_notifiers, &now);
610 }
611 return now;
612 case QEMU_CLOCK_VIRTUAL_RT:
613 return REPLAY_CLOCK(REPLAY_CLOCK_VIRTUAL_RT, cpu_get_clock());
614 }
615 }
616
617 void qemu_clock_register_reset_notifier(QEMUClockType type,
618 Notifier *notifier)
619 {
620 QEMUClock *clock = qemu_clock_ptr(type);
621 notifier_list_add(&clock->reset_notifiers, notifier);
622 }
623
624 void qemu_clock_unregister_reset_notifier(QEMUClockType type,
625 Notifier *notifier)
626 {
627 notifier_remove(notifier);
628 }
629
630 void init_clocks(void)
631 {
632 QEMUClockType type;
633 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
634 qemu_clock_init(type);
635 }
636
637 #ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK
638 prctl(PR_SET_TIMERSLACK, 1, 0, 0, 0);
639 #endif
640 }
641
642 uint64_t timer_expire_time_ns(QEMUTimer *ts)
643 {
644 return timer_pending(ts) ? ts->expire_time : -1;
645 }
646
647 bool qemu_clock_run_all_timers(void)
648 {
649 bool progress = false;
650 QEMUClockType type;
651
652 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
653 progress |= qemu_clock_run_timers(type);
654 }
655
656 return progress;
657 }