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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 "qemu/lockable.h"
29 #include "system/cpu-timers.h"
30 #include "exec/icount.h"
31 #include "system/replay.h"
32 #include "system/cpus.h"
33 #include "hw/core/cpu.h"
34
35 #ifdef CONFIG_POSIX
36 #include <pthread.h>
37 #endif
38
39 #ifdef CONFIG_PPOLL
40 #include <poll.h>
41 #endif
42
43 #ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK
44 #include <sys/prctl.h>
45 #endif
46
47 /***********************************************************/
48 /* timers */
49
50 typedef struct QEMUClock {
51 /* We rely on BQL to protect the timerlists */
52 QLIST_HEAD(, QEMUTimerList) timerlists;
53
54 QEMUClockType type;
55 bool enabled;
56 } QEMUClock;
57
58 QEMUTimerListGroup main_loop_tlg;
59 static QEMUClock qemu_clocks[QEMU_CLOCK_MAX];
60
61 /* A QEMUTimerList is a list of timers attached to a clock. More
62 * than one QEMUTimerList can be attached to each clock, for instance
63 * used by different AioContexts / threads. Each clock also has
64 * a list of the QEMUTimerLists associated with it, in order that
65 * reenabling the clock can call all the notifiers.
66 */
67
68 struct QEMUTimerList {
69 QEMUClock *clock;
70 QemuMutex active_timers_lock;
71 QEMUTimer *active_timers;
72 QLIST_ENTRY(QEMUTimerList) list;
73 QEMUTimerListNotifyCB *notify_cb;
74 void *notify_opaque;
75
76 /* lightweight method to mark the end of timerlist's running */
77 QemuEvent timers_done_ev;
78 };
79
80 /**
81 * qemu_clock_ptr:
82 * @type: type of clock
83 *
84 * Translate a clock type into a pointer to QEMUClock object.
85 *
86 * Returns: a pointer to the QEMUClock object
87 */
88 static inline QEMUClock *qemu_clock_ptr(QEMUClockType type)
89 {
90 return &qemu_clocks[type];
91 }
92
93 static bool timer_expired_ns(const QEMUTimer *timer_head, int64_t current_time)
94 {
95 return timer_head && (timer_head->expire_time <= current_time);
96 }
97
98 QEMUTimerList *timerlist_new(QEMUClockType type,
99 QEMUTimerListNotifyCB *cb,
100 void *opaque)
101 {
102 QEMUTimerList *timer_list;
103 QEMUClock *clock = qemu_clock_ptr(type);
104
105 timer_list = g_new0(QEMUTimerList, 1);
106 qemu_event_init(&timer_list->timers_done_ev, true);
107 timer_list->clock = clock;
108 timer_list->notify_cb = cb;
109 timer_list->notify_opaque = opaque;
110 qemu_mutex_init(&timer_list->active_timers_lock);
111 QLIST_INSERT_HEAD(&clock->timerlists, timer_list, list);
112 return timer_list;
113 }
114
115 void timerlist_free(QEMUTimerList *timer_list)
116 {
117 assert(!timerlist_has_timers(timer_list));
118 if (timer_list->clock) {
119 QLIST_REMOVE(timer_list, list);
120 }
121 qemu_mutex_destroy(&timer_list->active_timers_lock);
122 g_free(timer_list);
123 }
124
125 static void qemu_clock_init(QEMUClockType type, QEMUTimerListNotifyCB *notify_cb)
126 {
127 QEMUClock *clock = qemu_clock_ptr(type);
128
129 /* Assert that the clock of type TYPE has not been initialized yet. */
130 assert(main_loop_tlg.tl[type] == NULL);
131
132 clock->type = type;
133 clock->enabled = (type == QEMU_CLOCK_VIRTUAL ? false : true);
134 QLIST_INIT(&clock->timerlists);
135 main_loop_tlg.tl[type] = timerlist_new(type, notify_cb, NULL);
136 }
137
138 bool qemu_clock_use_for_deadline(QEMUClockType type)
139 {
140 return !(icount_enabled() && (type == QEMU_CLOCK_VIRTUAL));
141 }
142
143 void qemu_clock_notify(QEMUClockType type)
144 {
145 QEMUTimerList *timer_list;
146 QEMUClock *clock = qemu_clock_ptr(type);
147 QLIST_FOREACH(timer_list, &clock->timerlists, list) {
148 timerlist_notify(timer_list);
149 }
150 }
151
152 /* Disabling the clock will wait for related timerlists to stop
153 * executing qemu_run_timers. Thus, this functions should not
154 * be used from the callback of a timer that is based on @clock.
155 * Doing so would cause a deadlock.
156 *
157 * Caller should hold BQL.
158 */
159 void qemu_clock_enable(QEMUClockType type, bool enabled)
160 {
161 QEMUClock *clock = qemu_clock_ptr(type);
162 QEMUTimerList *tl;
163 bool old = clock->enabled;
164 clock->enabled = enabled;
165 if (enabled && !old) {
166 qemu_clock_notify(type);
167 } else if (!enabled && old) {
168 QLIST_FOREACH(tl, &clock->timerlists, list) {
169 qemu_event_wait(&tl->timers_done_ev);
170 }
171 }
172 }
173
174 bool timerlist_has_timers(QEMUTimerList *timer_list)
175 {
176 return !!qatomic_read(&timer_list->active_timers);
177 }
178
179 bool qemu_clock_has_timers(QEMUClockType type)
180 {
181 return timerlist_has_timers(
182 main_loop_tlg.tl[type]);
183 }
184
185 bool timerlist_expired(QEMUTimerList *timer_list)
186 {
187 int64_t expire_time = 0;
188
189 if (!qatomic_read(&timer_list->active_timers)) {
190 return false;
191 }
192
193 WITH_QEMU_LOCK_GUARD(&timer_list->active_timers_lock) {
194 if (!timer_list->active_timers) {
195 return false;
196 }
197 expire_time = timer_list->active_timers->expire_time;
198 }
199
200 return expire_time <= qemu_clock_get_ns(timer_list->clock->type);
201 }
202
203 bool qemu_clock_expired(QEMUClockType type)
204 {
205 return timerlist_expired(
206 main_loop_tlg.tl[type]);
207 }
208
209 /*
210 * As above, but return -1 for no deadline, and do not cap to 2^32
211 * as we know the result is always positive.
212 */
213
214 int64_t timerlist_deadline_ns(QEMUTimerList *timer_list)
215 {
216 int64_t delta;
217 int64_t expire_time = 0;
218
219 if (!qatomic_read(&timer_list->active_timers)) {
220 return -1;
221 }
222
223 if (!timer_list->clock->enabled) {
224 return -1;
225 }
226
227 /* The active timers list may be modified before the caller uses our return
228 * value but ->notify_cb() is called when the deadline changes. Therefore
229 * the caller should notice the change and there is no race condition.
230 */
231 WITH_QEMU_LOCK_GUARD(&timer_list->active_timers_lock) {
232 if (!timer_list->active_timers) {
233 return -1;
234 }
235 expire_time = timer_list->active_timers->expire_time;
236 }
237
238 delta = expire_time - qemu_clock_get_ns(timer_list->clock->type);
239
240 if (delta <= 0) {
241 return 0;
242 }
243
244 return delta;
245 }
246
247 /* Calculate the soonest deadline across all timerlists attached
248 * to the clock. This is used for the icount timeout so we
249 * ignore whether or not the clock should be used in deadline
250 * calculations.
251 */
252 int64_t qemu_clock_deadline_ns_all(QEMUClockType type, int attr_mask)
253 {
254 int64_t deadline = -1;
255 int64_t delta;
256 int64_t expire_time;
257 QEMUTimer *ts;
258 QEMUTimerList *timer_list;
259 QEMUClock *clock = qemu_clock_ptr(type);
260
261 if (!clock->enabled) {
262 return -1;
263 }
264
265 QLIST_FOREACH(timer_list, &clock->timerlists, list) {
266 if (!qatomic_read(&timer_list->active_timers)) {
267 continue;
268 }
269 qemu_mutex_lock(&timer_list->active_timers_lock);
270 ts = timer_list->active_timers;
271 /* Skip all external timers */
272 while (ts && (ts->attributes & ~attr_mask)) {
273 ts = ts->next;
274 }
275 if (!ts) {
276 qemu_mutex_unlock(&timer_list->active_timers_lock);
277 continue;
278 }
279 expire_time = ts->expire_time;
280 qemu_mutex_unlock(&timer_list->active_timers_lock);
281
282 delta = expire_time - qemu_clock_get_ns(type);
283 if (delta <= 0) {
284 delta = 0;
285 }
286 deadline = qemu_soonest_timeout(deadline, delta);
287 }
288 return deadline;
289 }
290
291 void timerlist_notify(QEMUTimerList *timer_list)
292 {
293 if (timer_list->notify_cb) {
294 timer_list->notify_cb(timer_list->notify_opaque, timer_list->clock->type);
295 } else {
296 qemu_notify_event();
297 }
298 }
299
300 /* Transition function to convert a nanosecond timeout to ms
301 * This is used where a system does not support ppoll
302 */
303 int qemu_timeout_ns_to_ms(int64_t ns)
304 {
305 int64_t ms;
306 if (ns < 0) {
307 return -1;
308 }
309
310 if (!ns) {
311 return 0;
312 }
313
314 /* Always round up, because it's better to wait too long than to wait too
315 * little and effectively busy-wait
316 */
317 ms = DIV_ROUND_UP(ns, SCALE_MS);
318
319 /* To avoid overflow problems, limit this to 2^31, i.e. approx 25 days */
320 return MIN(ms, INT32_MAX);
321 }
322
323
324 /* qemu implementation of g_poll which uses a nanosecond timeout but is
325 * otherwise identical to g_poll
326 */
327 int qemu_poll_ns(GPollFD *fds, guint nfds, int64_t timeout)
328 {
329 #ifdef CONFIG_PPOLL
330 if (timeout < 0) {
331 return ppoll((struct pollfd *)fds, nfds, NULL, NULL);
332 } else {
333 struct timespec ts;
334 int64_t tvsec = timeout / 1000000000LL;
335 /* Avoid possibly overflowing and specifying a negative number of
336 * seconds, which would turn a very long timeout into a busy-wait.
337 */
338 if (tvsec > (int64_t)INT32_MAX) {
339 tvsec = INT32_MAX;
340 }
341 ts.tv_sec = tvsec;
342 ts.tv_nsec = timeout % 1000000000LL;
343 return ppoll((struct pollfd *)fds, nfds, &ts, NULL);
344 }
345 #else
346 return g_poll(fds, nfds, qemu_timeout_ns_to_ms(timeout));
347 #endif
348 }
349
350
351 void timer_init_full(QEMUTimer *ts,
352 QEMUTimerListGroup *timer_list_group, QEMUClockType type,
353 int scale, int attributes,
354 QEMUTimerCB *cb, void *opaque)
355 {
356 if (!timer_list_group) {
357 timer_list_group = &main_loop_tlg;
358 }
359 ts->timer_list = timer_list_group->tl[type];
360 ts->cb = cb;
361 ts->opaque = opaque;
362 ts->scale = scale;
363 ts->attributes = attributes;
364 ts->expire_time = -1;
365 }
366
367 void timer_deinit(QEMUTimer *ts)
368 {
369 assert(ts->expire_time == -1);
370 ts->timer_list = NULL;
371 }
372
373 static void timer_del_locked(QEMUTimerList *timer_list, QEMUTimer *ts)
374 {
375 QEMUTimer **pt, *t;
376
377 ts->expire_time = -1;
378 pt = &timer_list->active_timers;
379 for(;;) {
380 t = *pt;
381 if (!t)
382 break;
383 if (t == ts) {
384 qatomic_set(pt, t->next);
385 break;
386 }
387 pt = &t->next;
388 }
389 }
390
391 static void timer_fire(CPUState *cpu, run_on_cpu_data data)
392 {
393 QEMUTimer *t = data.host_ptr;
394
395 t->cb(t->opaque);
396 }
397
398 static bool timer_mod_ns_locked(QEMUTimerList *timer_list,
399 QEMUTimer *ts, int64_t expire_time)
400 {
401 QEMUTimer **pt, *t;
402
403 /*
404 * Normally during record-replay virtual clock timers and CPU work are
405 * deterministically ordered. This is because the virtual clock can be
406 * advanced only by instructions running on a CPU.
407 *
408 * A notable exception are timers that are armed already expired. Their
409 * expiration is not constrained by instruction execution, and, therefore,
410 * their ordering relative to CPU work is affected by what the
411 * record-replay thread is doing when they are armed. This introduces
412 * non-determinism.
413 *
414 * Convert such timers to CPU work in order to avoid it.
415 */
416 if (replay_mode != REPLAY_MODE_NONE &&
417 timer_list->clock->type == QEMU_CLOCK_VIRTUAL &&
418 !(ts->attributes & QEMU_TIMER_ATTR_EXTERNAL) &&
419 expire_time <= qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)) {
420 async_run_on_cpu(first_cpu, timer_fire,
421 RUN_ON_CPU_HOST_PTR(ts));
422 return false;
423 }
424
425 /* add the timer in the sorted list */
426 pt = &timer_list->active_timers;
427 for (;;) {
428 t = *pt;
429 if (!timer_expired_ns(t, expire_time)) {
430 break;
431 }
432 pt = &t->next;
433 }
434 ts->expire_time = MAX(expire_time, 0);
435 ts->next = *pt;
436 qatomic_set(pt, ts);
437
438 return pt == &timer_list->active_timers;
439 }
440
441 static void timerlist_rearm(QEMUTimerList *timer_list)
442 {
443 timerlist_notify(timer_list);
444 }
445
446 /* stop a timer, but do not dealloc it */
447 void timer_del(QEMUTimer *ts)
448 {
449 QEMUTimerList *timer_list = ts->timer_list;
450
451 if (timer_list) {
452 qemu_mutex_lock(&timer_list->active_timers_lock);
453 timer_del_locked(timer_list, ts);
454 qemu_mutex_unlock(&timer_list->active_timers_lock);
455 }
456 }
457
458 /* modify the current timer so that it will be fired when current_time
459 >= expire_time. The corresponding callback will be called. */
460 void timer_mod_ns(QEMUTimer *ts, int64_t expire_time)
461 {
462 QEMUTimerList *timer_list = ts->timer_list;
463 bool rearm;
464
465 qemu_mutex_lock(&timer_list->active_timers_lock);
466 timer_del_locked(timer_list, ts);
467 rearm = timer_mod_ns_locked(timer_list, ts, expire_time);
468 qemu_mutex_unlock(&timer_list->active_timers_lock);
469
470 if (rearm) {
471 timerlist_rearm(timer_list);
472 }
473 }
474
475 /* modify the current timer so that it will be fired when current_time
476 >= expire_time or the current deadline, whichever comes earlier.
477 The corresponding callback will be called. */
478 void timer_mod_anticipate_ns(QEMUTimer *ts, int64_t expire_time)
479 {
480 QEMUTimerList *timer_list = ts->timer_list;
481 bool rearm = false;
482
483 WITH_QEMU_LOCK_GUARD(&timer_list->active_timers_lock) {
484 if (ts->expire_time == -1 || ts->expire_time > expire_time) {
485 if (ts->expire_time != -1) {
486 timer_del_locked(timer_list, ts);
487 }
488 rearm = timer_mod_ns_locked(timer_list, ts, expire_time);
489 } else {
490 rearm = false;
491 }
492 }
493 if (rearm) {
494 timerlist_rearm(timer_list);
495 }
496 }
497
498 void timer_mod(QEMUTimer *ts, int64_t expire_time)
499 {
500 timer_mod_ns(ts, expire_time * ts->scale);
501 }
502
503 void timer_mod_anticipate(QEMUTimer *ts, int64_t expire_time)
504 {
505 timer_mod_anticipate_ns(ts, expire_time * ts->scale);
506 }
507
508 bool timer_pending(const QEMUTimer *ts)
509 {
510 return ts->expire_time >= 0;
511 }
512
513 bool timer_expired(const QEMUTimer *timer_head, int64_t current_time)
514 {
515 return timer_expired_ns(timer_head, current_time * timer_head->scale);
516 }
517
518 bool timerlist_run_timers(QEMUTimerList *timer_list)
519 {
520 QEMUTimer *ts;
521 int64_t current_time;
522 bool progress = false;
523 QEMUTimerCB *cb;
524 void *opaque;
525
526 if (!qatomic_read(&timer_list->active_timers)) {
527 return false;
528 }
529
530 qemu_event_reset(&timer_list->timers_done_ev);
531 if (!timer_list->clock->enabled) {
532 goto out;
533 }
534
535 switch (timer_list->clock->type) {
536 case QEMU_CLOCK_REALTIME:
537 break;
538 default:
539 case QEMU_CLOCK_VIRTUAL:
540 break;
541 case QEMU_CLOCK_HOST:
542 if (!replay_checkpoint(CHECKPOINT_CLOCK_HOST)) {
543 goto out;
544 }
545 break;
546 case QEMU_CLOCK_VIRTUAL_RT:
547 if (!replay_checkpoint(CHECKPOINT_CLOCK_VIRTUAL_RT)) {
548 goto out;
549 }
550 break;
551 }
552
553 /*
554 * Extract expired timers from active timers list and process them.
555 *
556 * In rr mode we need "filtered" checkpointing for virtual clock. The
557 * checkpoint must be recorded/replayed before processing any non-EXTERNAL timer,
558 * and that must only be done once since the clock value stays the same. Because
559 * non-EXTERNAL timers may appear in the timers list while it being processed,
560 * the checkpoint can be issued at a time until no timers are left and we are
561 * done".
562 */
563 current_time = qemu_clock_get_ns(timer_list->clock->type);
564 qemu_mutex_lock(&timer_list->active_timers_lock);
565 while ((ts = timer_list->active_timers)) {
566 if (!timer_expired_ns(ts, current_time)) {
567 /* No expired timers left. The checkpoint can be skipped
568 * if no timers fired or they were all external.
569 */
570 break;
571 }
572 /* Checkpoint for virtual clock is redundant in cases where
573 * it's being triggered with only non-EXTERNAL timers, because
574 * these timers don't change guest state directly.
575 */
576 if (replay_mode != REPLAY_MODE_NONE
577 && timer_list->clock->type == QEMU_CLOCK_VIRTUAL
578 && !(ts->attributes & QEMU_TIMER_ATTR_EXTERNAL)
579 && !replay_checkpoint(CHECKPOINT_CLOCK_VIRTUAL)) {
580 qemu_mutex_unlock(&timer_list->active_timers_lock);
581 goto out;
582 }
583
584 /* remove timer from the list before calling the callback */
585 timer_list->active_timers = ts->next;
586 ts->next = NULL;
587 ts->expire_time = -1;
588 cb = ts->cb;
589 opaque = ts->opaque;
590
591 /* run the callback (the timer list can be modified) */
592 qemu_mutex_unlock(&timer_list->active_timers_lock);
593 cb(opaque);
594 qemu_mutex_lock(&timer_list->active_timers_lock);
595
596 progress = true;
597 }
598 qemu_mutex_unlock(&timer_list->active_timers_lock);
599
600 out:
601 qemu_event_set(&timer_list->timers_done_ev);
602 return progress;
603 }
604
605 bool qemu_clock_run_timers(QEMUClockType type)
606 {
607 return timerlist_run_timers(main_loop_tlg.tl[type]);
608 }
609
610 void timerlistgroup_init(QEMUTimerListGroup *tlg,
611 QEMUTimerListNotifyCB *cb, void *opaque)
612 {
613 QEMUClockType type;
614 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
615 tlg->tl[type] = timerlist_new(type, cb, opaque);
616 }
617 }
618
619 void timerlistgroup_deinit(QEMUTimerListGroup *tlg)
620 {
621 QEMUClockType type;
622 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
623 timerlist_free(tlg->tl[type]);
624 }
625 }
626
627 bool timerlistgroup_run_timers(QEMUTimerListGroup *tlg)
628 {
629 QEMUClockType type;
630 bool progress = false;
631 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
632 progress |= timerlist_run_timers(tlg->tl[type]);
633 }
634 return progress;
635 }
636
637 int64_t timerlistgroup_deadline_ns(QEMUTimerListGroup *tlg)
638 {
639 int64_t deadline = -1;
640 QEMUClockType type;
641 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
642 if (qemu_clock_use_for_deadline(type)) {
643 deadline = qemu_soonest_timeout(deadline,
644 timerlist_deadline_ns(tlg->tl[type]));
645 }
646 }
647 return deadline;
648 }
649
650 int64_t qemu_clock_get_ns(QEMUClockType type)
651 {
652 switch (type) {
653 case QEMU_CLOCK_REALTIME:
654 return get_clock();
655 default:
656 case QEMU_CLOCK_VIRTUAL:
657 return cpus_get_virtual_clock();
658 case QEMU_CLOCK_HOST:
659 return REPLAY_CLOCK(REPLAY_CLOCK_HOST, get_clock_realtime());
660 case QEMU_CLOCK_VIRTUAL_RT:
661 return REPLAY_CLOCK(REPLAY_CLOCK_VIRTUAL_RT, cpu_get_clock());
662 }
663 }
664
665 static void qemu_virtual_clock_set_ns(int64_t time)
666 {
667 return cpus_set_virtual_clock(time);
668 }
669
670 void qemu_init_clocks(QEMUTimerListNotifyCB *notify_cb)
671 {
672 QEMUClockType type;
673 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
674 qemu_clock_init(type, notify_cb);
675 }
676
677 #ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK
678 prctl(PR_SET_TIMERSLACK, 1, 0, 0, 0);
679 #endif
680 }
681
682 uint64_t timer_expire_time_ns(const QEMUTimer *ts)
683 {
684 return timer_pending(ts) ? ts->expire_time : -1;
685 }
686
687 bool qemu_clock_run_all_timers(void)
688 {
689 bool progress = false;
690 QEMUClockType type;
691
692 for (type = 0; type < QEMU_CLOCK_MAX; type++) {
693 if (qemu_clock_use_for_deadline(type)) {
694 progress |= qemu_clock_run_timers(type);
695 }
696 }
697
698 return progress;
699 }
700
701 int64_t qemu_clock_advance_virtual_time(int64_t dest)
702 {
703 int64_t clock = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
704 AioContext *aio_context;
705 aio_context = qemu_get_aio_context();
706 while (clock < dest) {
707 int64_t deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL,
708 QEMU_TIMER_ATTR_ALL);
709 int64_t warp = qemu_soonest_timeout(dest - clock, deadline);
710
711 qemu_virtual_clock_set_ns(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + warp);
712
713 qemu_clock_run_timers(QEMU_CLOCK_VIRTUAL);
714 timerlist_run_timers(aio_context->tlg.tl[QEMU_CLOCK_VIRTUAL]);
715 clock = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
716 }
717 qemu_clock_notify(QEMU_CLOCK_VIRTUAL);
718
719 return clock;
720 }