qemu-timer.c 30.5 KB
Newer Older
Paolo Bonzini's avatar
Paolo Bonzini committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37
/*
 * QEMU System Emulator
 *
 * Copyright (c) 2003-2008 Fabrice Bellard
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "sysemu.h"
#include "net.h"
#include "monitor.h"
#include "console.h"

#include "hw/hw.h"

#include <unistd.h>
#include <fcntl.h>
#include <time.h>
#include <errno.h>
#include <sys/time.h>
#include <signal.h>
38 39 40
#ifdef __FreeBSD__
#include <sys/param.h>
#endif
Paolo Bonzini's avatar
Paolo Bonzini committed
41 42 43 44 45 46 47 48 49

#ifdef _WIN32
#include <windows.h>
#include <mmsystem.h>
#endif

#include "qemu-timer.h"

/* Conversion factor from emulated instructions to virtual clock ticks.  */
Blue Swirl's avatar
Blue Swirl committed
50
int icount_time_shift;
Paolo Bonzini's avatar
Paolo Bonzini committed
51 52 53
/* Arbitrarily pick 1MIPS as the minimum allowable speed.  */
#define MAX_ICOUNT_SHIFT 10
/* Compensate for varying guest execution speed.  */
Blue Swirl's avatar
Blue Swirl committed
54
int64_t qemu_icount_bias;
Paolo Bonzini's avatar
Paolo Bonzini committed
55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134
static QEMUTimer *icount_rt_timer;
static QEMUTimer *icount_vm_timer;

/***********************************************************/
/* guest cycle counter */

typedef struct TimersState {
    int64_t cpu_ticks_prev;
    int64_t cpu_ticks_offset;
    int64_t cpu_clock_offset;
    int32_t cpu_ticks_enabled;
    int64_t dummy;
} TimersState;

TimersState timers_state;

/* return the host CPU cycle counter and handle stop/restart */
int64_t cpu_get_ticks(void)
{
    if (use_icount) {
        return cpu_get_icount();
    }
    if (!timers_state.cpu_ticks_enabled) {
        return timers_state.cpu_ticks_offset;
    } else {
        int64_t ticks;
        ticks = cpu_get_real_ticks();
        if (timers_state.cpu_ticks_prev > ticks) {
            /* Note: non increasing ticks may happen if the host uses
               software suspend */
            timers_state.cpu_ticks_offset += timers_state.cpu_ticks_prev - ticks;
        }
        timers_state.cpu_ticks_prev = ticks;
        return ticks + timers_state.cpu_ticks_offset;
    }
}

/* return the host CPU monotonic timer and handle stop/restart */
static int64_t cpu_get_clock(void)
{
    int64_t ti;
    if (!timers_state.cpu_ticks_enabled) {
        return timers_state.cpu_clock_offset;
    } else {
        ti = get_clock();
        return ti + timers_state.cpu_clock_offset;
    }
}

/* enable cpu_get_ticks() */
void cpu_enable_ticks(void)
{
    if (!timers_state.cpu_ticks_enabled) {
        timers_state.cpu_ticks_offset -= cpu_get_real_ticks();
        timers_state.cpu_clock_offset -= get_clock();
        timers_state.cpu_ticks_enabled = 1;
    }
}

/* disable cpu_get_ticks() : the clock is stopped. You must not call
   cpu_get_ticks() after that.  */
void cpu_disable_ticks(void)
{
    if (timers_state.cpu_ticks_enabled) {
        timers_state.cpu_ticks_offset = cpu_get_ticks();
        timers_state.cpu_clock_offset = cpu_get_clock();
        timers_state.cpu_ticks_enabled = 0;
    }
}

/***********************************************************/
/* timers */

#define QEMU_CLOCK_REALTIME 0
#define QEMU_CLOCK_VIRTUAL  1
#define QEMU_CLOCK_HOST     2

struct QEMUClock {
    int type;
    int enabled;
135 136

    QEMUTimer *warp_timer;
137 138 139

    NotifierList reset_notifiers;
    int64_t last;
Paolo Bonzini's avatar
Paolo Bonzini committed
140 141 142 143
};

struct QEMUTimer {
    QEMUClock *clock;
144 145
    int64_t expire_time;	/* in nanoseconds */
    int scale;
Paolo Bonzini's avatar
Paolo Bonzini committed
146 147 148 149 150 151 152 153 154 155
    QEMUTimerCB *cb;
    void *opaque;
    struct QEMUTimer *next;
};

struct qemu_alarm_timer {
    char const *name;
    int (*start)(struct qemu_alarm_timer *t);
    void (*stop)(struct qemu_alarm_timer *t);
    void (*rearm)(struct qemu_alarm_timer *t);
Stefan Weil's avatar
Stefan Weil committed
156 157 158 159 160 161
#if defined(__linux__)
    int fd;
    timer_t timer;
#elif defined(_WIN32)
    HANDLE timer;
#endif
Paolo Bonzini's avatar
Paolo Bonzini committed
162 163 164 165 166 167
    char expired;
    char pending;
};

static struct qemu_alarm_timer *alarm_timer;

168 169 170 171 172
static bool qemu_timer_expired_ns(QEMUTimer *timer_head, int64_t current_time)
{
    return timer_head && (timer_head->expire_time <= current_time);
}

Paolo Bonzini's avatar
Paolo Bonzini committed
173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190
int qemu_alarm_pending(void)
{
    return alarm_timer->pending;
}

static inline int alarm_has_dynticks(struct qemu_alarm_timer *t)
{
    return !!t->rearm;
}

static void qemu_rearm_alarm_timer(struct qemu_alarm_timer *t)
{
    if (!alarm_has_dynticks(t))
        return;

    t->rearm(t);
}

191 192
/* TODO: MIN_TIMER_REARM_NS should be optimized */
#define MIN_TIMER_REARM_NS 250000
Paolo Bonzini's avatar
Paolo Bonzini committed
193 194 195

#ifdef _WIN32

Stefan Weil's avatar
Stefan Weil committed
196 197 198 199
static int mm_start_timer(struct qemu_alarm_timer *t);
static void mm_stop_timer(struct qemu_alarm_timer *t);
static void mm_rearm_timer(struct qemu_alarm_timer *t);

Paolo Bonzini's avatar
Paolo Bonzini committed
200 201 202 203 204 205 206 207
static int win32_start_timer(struct qemu_alarm_timer *t);
static void win32_stop_timer(struct qemu_alarm_timer *t);
static void win32_rearm_timer(struct qemu_alarm_timer *t);

#else

static int unix_start_timer(struct qemu_alarm_timer *t);
static void unix_stop_timer(struct qemu_alarm_timer *t);
208
static void unix_rearm_timer(struct qemu_alarm_timer *t);
Paolo Bonzini's avatar
Paolo Bonzini committed
209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232

#ifdef __linux__

static int dynticks_start_timer(struct qemu_alarm_timer *t);
static void dynticks_stop_timer(struct qemu_alarm_timer *t);
static void dynticks_rearm_timer(struct qemu_alarm_timer *t);

#endif /* __linux__ */

#endif /* _WIN32 */

/* Correlation between real and virtual time is always going to be
   fairly approximate, so ignore small variation.
   When the guest is idle real and virtual time will be aligned in
   the IO wait loop.  */
#define ICOUNT_WOBBLE (get_ticks_per_sec() / 10)

static void icount_adjust(void)
{
    int64_t cur_time;
    int64_t cur_icount;
    int64_t delta;
    static int64_t last_delta;
    /* If the VM is not running, then do nothing.  */
233
    if (!runstate_is_running())
Paolo Bonzini's avatar
Paolo Bonzini committed
234 235 236
        return;

    cur_time = cpu_get_clock();
237
    cur_icount = qemu_get_clock_ns(vm_clock);
Paolo Bonzini's avatar
Paolo Bonzini committed
238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258
    delta = cur_icount - cur_time;
    /* FIXME: This is a very crude algorithm, somewhat prone to oscillation.  */
    if (delta > 0
        && last_delta + ICOUNT_WOBBLE < delta * 2
        && icount_time_shift > 0) {
        /* The guest is getting too far ahead.  Slow time down.  */
        icount_time_shift--;
    }
    if (delta < 0
        && last_delta - ICOUNT_WOBBLE > delta * 2
        && icount_time_shift < MAX_ICOUNT_SHIFT) {
        /* The guest is getting too far behind.  Speed time up.  */
        icount_time_shift++;
    }
    last_delta = delta;
    qemu_icount_bias = cur_icount - (qemu_icount << icount_time_shift);
}

static void icount_adjust_rt(void * opaque)
{
    qemu_mod_timer(icount_rt_timer,
259
                   qemu_get_clock_ms(rt_clock) + 1000);
Paolo Bonzini's avatar
Paolo Bonzini committed
260 261 262 263 264 265
    icount_adjust();
}

static void icount_adjust_vm(void * opaque)
{
    qemu_mod_timer(icount_vm_timer,
266
                   qemu_get_clock_ns(vm_clock) + get_ticks_per_sec() / 10);
Paolo Bonzini's avatar
Paolo Bonzini committed
267 268 269 270 271 272 273 274 275 276 277 278
    icount_adjust();
}

int64_t qemu_icount_round(int64_t count)
{
    return (count + (1 << icount_time_shift) - 1) >> icount_time_shift;
}

static struct qemu_alarm_timer alarm_timers[] = {
#ifndef _WIN32
#ifdef __linux__
    {"dynticks", dynticks_start_timer,
Stefan Weil's avatar
Stefan Weil committed
279
     dynticks_stop_timer, dynticks_rearm_timer},
Paolo Bonzini's avatar
Paolo Bonzini committed
280
#endif
281
    {"unix", unix_start_timer, unix_stop_timer, unix_rearm_timer},
Paolo Bonzini's avatar
Paolo Bonzini committed
282
#else
Stefan Weil's avatar
Stefan Weil committed
283 284
    {"mmtimer", mm_start_timer, mm_stop_timer, NULL},
    {"mmtimer2", mm_start_timer, mm_stop_timer, mm_rearm_timer},
Stefan Weil's avatar
Stefan Weil committed
285 286
    {"dynticks", win32_start_timer, win32_stop_timer, win32_rearm_timer},
    {"win32", win32_start_timer, win32_stop_timer, NULL},
Paolo Bonzini's avatar
Paolo Bonzini committed
287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313
#endif
    {NULL, }
};

static void show_available_alarms(void)
{
    int i;

    printf("Available alarm timers, in order of precedence:\n");
    for (i = 0; alarm_timers[i].name; i++)
        printf("%s\n", alarm_timers[i].name);
}

void configure_alarms(char const *opt)
{
    int i;
    int cur = 0;
    int count = ARRAY_SIZE(alarm_timers) - 1;
    char *arg;
    char *name;
    struct qemu_alarm_timer tmp;

    if (!strcmp(opt, "?")) {
        show_available_alarms();
        exit(0);
    }

314
    arg = g_strdup(opt);
Paolo Bonzini's avatar
Paolo Bonzini committed
315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342

    /* Reorder the array */
    name = strtok(arg, ",");
    while (name) {
        for (i = 0; i < count && alarm_timers[i].name; i++) {
            if (!strcmp(alarm_timers[i].name, name))
                break;
        }

        if (i == count) {
            fprintf(stderr, "Unknown clock %s\n", name);
            goto next;
        }

        if (i < cur)
            /* Ignore */
            goto next;

	/* Swap */
        tmp = alarm_timers[i];
        alarm_timers[i] = alarm_timers[cur];
        alarm_timers[cur] = tmp;

        cur++;
next:
        name = strtok(NULL, ",");
    }

343
    g_free(arg);
Paolo Bonzini's avatar
Paolo Bonzini committed
344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365

    if (cur) {
        /* Disable remaining timers */
        for (i = cur; i < count; i++)
            alarm_timers[i].name = NULL;
    } else {
        show_available_alarms();
        exit(1);
    }
}

#define QEMU_NUM_CLOCKS 3

QEMUClock *rt_clock;
QEMUClock *vm_clock;
QEMUClock *host_clock;

static QEMUTimer *active_timers[QEMU_NUM_CLOCKS];

static QEMUClock *qemu_new_clock(int type)
{
    QEMUClock *clock;
366

367
    clock = g_malloc0(sizeof(QEMUClock));
Paolo Bonzini's avatar
Paolo Bonzini committed
368 369
    clock->type = type;
    clock->enabled = 1;
370 371 372 373 374
    notifier_list_init(&clock->reset_notifiers);
    /* required to detect & report backward jumps */
    if (type == QEMU_CLOCK_HOST) {
        clock->last = get_clock_realtime();
    }
Paolo Bonzini's avatar
Paolo Bonzini committed
375 376 377 378 379 380 381 382
    return clock;
}

void qemu_clock_enable(QEMUClock *clock, int enabled)
{
    clock->enabled = enabled;
}

383 384 385 386 387 388 389 390
static int64_t vm_clock_warp_start;

static void icount_warp_rt(void *opaque)
{
    if (vm_clock_warp_start == -1) {
        return;
    }

391
    if (runstate_is_running()) {
392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442
        int64_t clock = qemu_get_clock_ns(rt_clock);
        int64_t warp_delta = clock - vm_clock_warp_start;
        if (use_icount == 1) {
            qemu_icount_bias += warp_delta;
        } else {
            /*
             * In adaptive mode, do not let the vm_clock run too
             * far ahead of real time.
             */
            int64_t cur_time = cpu_get_clock();
            int64_t cur_icount = qemu_get_clock_ns(vm_clock);
            int64_t delta = cur_time - cur_icount;
            qemu_icount_bias += MIN(warp_delta, delta);
        }
        if (qemu_timer_expired(active_timers[QEMU_CLOCK_VIRTUAL],
                               qemu_get_clock_ns(vm_clock))) {
            qemu_notify_event();
        }
    }
    vm_clock_warp_start = -1;
}

void qemu_clock_warp(QEMUClock *clock)
{
    int64_t deadline;

    if (!clock->warp_timer) {
        return;
    }

    /*
     * There are too many global variables to make the "warp" behavior
     * applicable to other clocks.  But a clock argument removes the
     * need for if statements all over the place.
     */
    assert(clock == vm_clock);

    /*
     * If the CPUs have been sleeping, advance the vm_clock timer now.  This
     * ensures that the deadline for the timer is computed correctly below.
     * This also makes sure that the insn counter is synchronized before the
     * CPU starts running, in case the CPU is woken by an event other than
     * the earliest vm_clock timer.
     */
    icount_warp_rt(NULL);
    if (!all_cpu_threads_idle() || !active_timers[clock->type]) {
        qemu_del_timer(clock->warp_timer);
        return;
    }

    vm_clock_warp_start = qemu_get_clock_ns(rt_clock);
443
    deadline = qemu_next_icount_deadline();
444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466
    if (deadline > 0) {
        /*
         * Ensure the vm_clock proceeds even when the virtual CPU goes to
         * sleep.  Otherwise, the CPU might be waiting for a future timer
         * interrupt to wake it up, but the interrupt never comes because
         * the vCPU isn't running any insns and thus doesn't advance the
         * vm_clock.
         *
         * An extreme solution for this problem would be to never let VCPUs
         * sleep in icount mode if there is a pending vm_clock timer; rather
         * time could just advance to the next vm_clock event.  Instead, we
         * do stop VCPUs and only advance vm_clock after some "real" time,
         * (related to the time left until the next event) has passed.  This
         * rt_clock timer will do this.  This avoids that the warps are too
         * visible externally---for example, you will not be sending network
         * packets continously instead of every 100ms.
         */
        qemu_mod_timer(clock->warp_timer, vm_clock_warp_start + deadline);
    } else {
        qemu_notify_event();
    }
}

467 468
QEMUTimer *qemu_new_timer(QEMUClock *clock, int scale,
                          QEMUTimerCB *cb, void *opaque)
Paolo Bonzini's avatar
Paolo Bonzini committed
469 470 471
{
    QEMUTimer *ts;

472
    ts = g_malloc0(sizeof(QEMUTimer));
Paolo Bonzini's avatar
Paolo Bonzini committed
473 474 475
    ts->clock = clock;
    ts->cb = cb;
    ts->opaque = opaque;
476
    ts->scale = scale;
Paolo Bonzini's avatar
Paolo Bonzini committed
477 478 479 480 481
    return ts;
}

void qemu_free_timer(QEMUTimer *ts)
{
482
    g_free(ts);
Paolo Bonzini's avatar
Paolo Bonzini committed
483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506
}

/* stop a timer, but do not dealloc it */
void qemu_del_timer(QEMUTimer *ts)
{
    QEMUTimer **pt, *t;

    /* NOTE: this code must be signal safe because
       qemu_timer_expired() can be called from a signal. */
    pt = &active_timers[ts->clock->type];
    for(;;) {
        t = *pt;
        if (!t)
            break;
        if (t == ts) {
            *pt = t->next;
            break;
        }
        pt = &t->next;
    }
}

/* modify the current timer so that it will be fired when current_time
   >= expire_time. The corresponding callback will be called. */
507
static void qemu_mod_timer_ns(QEMUTimer *ts, int64_t expire_time)
Paolo Bonzini's avatar
Paolo Bonzini committed
508 509 510 511 512 513 514 515 516 517 518
{
    QEMUTimer **pt, *t;

    qemu_del_timer(ts);

    /* add the timer in the sorted list */
    /* NOTE: this code must be signal safe because
       qemu_timer_expired() can be called from a signal. */
    pt = &active_timers[ts->clock->type];
    for(;;) {
        t = *pt;
519
        if (!qemu_timer_expired_ns(t, expire_time)) {
Paolo Bonzini's avatar
Paolo Bonzini committed
520
            break;
521
        }
Paolo Bonzini's avatar
Paolo Bonzini committed
522 523 524 525 526 527 528 529 530 531 532 533
        pt = &t->next;
    }
    ts->expire_time = expire_time;
    ts->next = *pt;
    *pt = ts;

    /* Rearm if necessary  */
    if (pt == &active_timers[ts->clock->type]) {
        if (!alarm_timer->pending) {
            qemu_rearm_alarm_timer(alarm_timer);
        }
        /* Interrupt execution to force deadline recalculation.  */
534 535
        qemu_clock_warp(ts->clock);
        if (use_icount) {
Paolo Bonzini's avatar
Paolo Bonzini committed
536
            qemu_notify_event();
537
        }
Paolo Bonzini's avatar
Paolo Bonzini committed
538 539 540
    }
}

541 542 543 544 545 546 547
/* modify the current timer so that it will be fired when current_time
   >= expire_time. The corresponding callback will be called. */
void qemu_mod_timer(QEMUTimer *ts, int64_t expire_time)
{
    qemu_mod_timer_ns(ts, expire_time * ts->scale);
}

Paolo Bonzini's avatar
Paolo Bonzini committed
548 549 550 551 552 553 554 555 556 557 558 559
int qemu_timer_pending(QEMUTimer *ts)
{
    QEMUTimer *t;
    for(t = active_timers[ts->clock->type]; t != NULL; t = t->next) {
        if (t == ts)
            return 1;
    }
    return 0;
}

int qemu_timer_expired(QEMUTimer *timer_head, int64_t current_time)
{
560
    return qemu_timer_expired_ns(timer_head, current_time * timer_head->scale);
Paolo Bonzini's avatar
Paolo Bonzini committed
561 562 563 564 565 566 567 568 569 570
}

static void qemu_run_timers(QEMUClock *clock)
{
    QEMUTimer **ptimer_head, *ts;
    int64_t current_time;
   
    if (!clock->enabled)
        return;

571
    current_time = qemu_get_clock_ns(clock);
Paolo Bonzini's avatar
Paolo Bonzini committed
572 573 574
    ptimer_head = &active_timers[clock->type];
    for(;;) {
        ts = *ptimer_head;
575
        if (!qemu_timer_expired_ns(ts, current_time)) {
Paolo Bonzini's avatar
Paolo Bonzini committed
576
            break;
577
        }
Paolo Bonzini's avatar
Paolo Bonzini committed
578 579 580 581 582 583 584 585 586 587 588
        /* remove timer from the list before calling the callback */
        *ptimer_head = ts->next;
        ts->next = NULL;

        /* run the callback (the timer list can be modified) */
        ts->cb(ts->opaque);
    }
}

int64_t qemu_get_clock_ns(QEMUClock *clock)
{
589 590
    int64_t now, last;

Paolo Bonzini's avatar
Paolo Bonzini committed
591 592 593 594 595 596 597 598 599 600 601
    switch(clock->type) {
    case QEMU_CLOCK_REALTIME:
        return get_clock();
    default:
    case QEMU_CLOCK_VIRTUAL:
        if (use_icount) {
            return cpu_get_icount();
        } else {
            return cpu_get_clock();
        }
    case QEMU_CLOCK_HOST:
602 603 604 605 606 607 608
        now = get_clock_realtime();
        last = clock->last;
        clock->last = now;
        if (now < last) {
            notifier_list_notify(&clock->reset_notifiers, &now);
        }
        return now;
Paolo Bonzini's avatar
Paolo Bonzini committed
609 610 611
    }
}

612 613 614 615 616 617 618 619 620 621
void qemu_register_clock_reset_notifier(QEMUClock *clock, Notifier *notifier)
{
    notifier_list_add(&clock->reset_notifiers, notifier);
}

void qemu_unregister_clock_reset_notifier(QEMUClock *clock, Notifier *notifier)
{
    notifier_list_remove(&clock->reset_notifiers, notifier);
}

Paolo Bonzini's avatar
Paolo Bonzini committed
622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649
void init_clocks(void)
{
    rt_clock = qemu_new_clock(QEMU_CLOCK_REALTIME);
    vm_clock = qemu_new_clock(QEMU_CLOCK_VIRTUAL);
    host_clock = qemu_new_clock(QEMU_CLOCK_HOST);

    rtc_clock = host_clock;
}

/* save a timer */
void qemu_put_timer(QEMUFile *f, QEMUTimer *ts)
{
    uint64_t expire_time;

    if (qemu_timer_pending(ts)) {
        expire_time = ts->expire_time;
    } else {
        expire_time = -1;
    }
    qemu_put_be64(f, expire_time);
}

void qemu_get_timer(QEMUFile *f, QEMUTimer *ts)
{
    uint64_t expire_time;

    expire_time = qemu_get_be64(f);
    if (expire_time != -1) {
650
        qemu_mod_timer_ns(ts, expire_time);
Paolo Bonzini's avatar
Paolo Bonzini committed
651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670
    } else {
        qemu_del_timer(ts);
    }
}

static const VMStateDescription vmstate_timers = {
    .name = "timer",
    .version_id = 2,
    .minimum_version_id = 1,
    .minimum_version_id_old = 1,
    .fields      = (VMStateField []) {
        VMSTATE_INT64(cpu_ticks_offset, TimersState),
        VMSTATE_INT64(dummy, TimersState),
        VMSTATE_INT64_V(cpu_clock_offset, TimersState, 2),
        VMSTATE_END_OF_LIST()
    }
};

void configure_icount(const char *option)
{
671
    vmstate_register(NULL, 0, &vmstate_timers, &timers_state);
Paolo Bonzini's avatar
Paolo Bonzini committed
672 673 674
    if (!option)
        return;

675 676
    vm_clock->warp_timer = qemu_new_timer_ns(rt_clock, icount_warp_rt, NULL);

Paolo Bonzini's avatar
Paolo Bonzini committed
677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693
    if (strcmp(option, "auto") != 0) {
        icount_time_shift = strtol(option, NULL, 0);
        use_icount = 1;
        return;
    }

    use_icount = 2;

    /* 125MIPS seems a reasonable initial guess at the guest speed.
       It will be corrected fairly quickly anyway.  */
    icount_time_shift = 3;

    /* Have both realtime and virtual time triggers for speed adjustment.
       The realtime trigger catches emulated time passing too slowly,
       the virtual time trigger catches emulated time passing too fast.
       Realtime triggers occur even when idle, so use them less frequently
       than VM triggers.  */
694
    icount_rt_timer = qemu_new_timer_ms(rt_clock, icount_adjust_rt, NULL);
Paolo Bonzini's avatar
Paolo Bonzini committed
695
    qemu_mod_timer(icount_rt_timer,
696
                   qemu_get_clock_ms(rt_clock) + 1000);
697
    icount_vm_timer = qemu_new_timer_ns(vm_clock, icount_adjust_vm, NULL);
Paolo Bonzini's avatar
Paolo Bonzini committed
698
    qemu_mod_timer(icount_vm_timer,
699
                   qemu_get_clock_ns(vm_clock) + get_ticks_per_sec() / 10);
Paolo Bonzini's avatar
Paolo Bonzini committed
700 701 702 703
}

void qemu_run_all_timers(void)
{
704 705
    alarm_timer->pending = 0;

Paolo Bonzini's avatar
Paolo Bonzini committed
706 707 708 709 710 711 712
    /* rearm timer, if not periodic */
    if (alarm_timer->expired) {
        alarm_timer->expired = 0;
        qemu_rearm_alarm_timer(alarm_timer);
    }

    /* vm time timers */
713
    if (runstate_is_running()) {
Paolo Bonzini's avatar
Paolo Bonzini committed
714 715 716 717 718 719 720
        qemu_run_timers(vm_clock);
    }

    qemu_run_timers(rt_clock);
    qemu_run_timers(host_clock);
}

721 722
static int64_t qemu_next_alarm_deadline(void);

Paolo Bonzini's avatar
Paolo Bonzini committed
723
#ifdef _WIN32
Paolo Bonzini's avatar
Paolo Bonzini committed
724
static void CALLBACK host_alarm_handler(PVOID lpParam, BOOLEAN unused)
Paolo Bonzini's avatar
Paolo Bonzini committed
725 726 727 728 729 730 731 732 733 734 735 736 737 738
#else
static void host_alarm_handler(int host_signum)
#endif
{
    struct qemu_alarm_timer *t = alarm_timer;
    if (!t)
	return;

#if 0
#define DISP_FREQ 1000
    {
        static int64_t delta_min = INT64_MAX;
        static int64_t delta_max, delta_cum, last_clock, delta, ti;
        static int count;
739
        ti = qemu_get_clock_ns(vm_clock);
Paolo Bonzini's avatar
Paolo Bonzini committed
740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762
        if (last_clock != 0) {
            delta = ti - last_clock;
            if (delta < delta_min)
                delta_min = delta;
            if (delta > delta_max)
                delta_max = delta;
            delta_cum += delta;
            if (++count == DISP_FREQ) {
                printf("timer: min=%" PRId64 " us max=%" PRId64 " us avg=%" PRId64 " us avg_freq=%0.3f Hz\n",
                       muldiv64(delta_min, 1000000, get_ticks_per_sec()),
                       muldiv64(delta_max, 1000000, get_ticks_per_sec()),
                       muldiv64(delta_cum, 1000000 / DISP_FREQ, get_ticks_per_sec()),
                       (double)get_ticks_per_sec() / ((double)delta_cum / DISP_FREQ));
                count = 0;
                delta_min = INT64_MAX;
                delta_max = 0;
                delta_cum = 0;
            }
        }
        last_clock = ti;
    }
#endif
    if (alarm_has_dynticks(t) ||
763
        qemu_next_alarm_deadline () <= 0) {
Paolo Bonzini's avatar
Paolo Bonzini committed
764 765 766 767 768 769
        t->expired = alarm_has_dynticks(t);
        t->pending = 1;
        qemu_notify_event();
    }
}

770
int64_t qemu_next_icount_deadline(void)
Paolo Bonzini's avatar
Paolo Bonzini committed
771 772 773 774
{
    /* To avoid problems with overflow limit this to 2^32.  */
    int64_t delta = INT32_MAX;

775
    assert(use_icount);
Paolo Bonzini's avatar
Paolo Bonzini committed
776 777
    if (active_timers[QEMU_CLOCK_VIRTUAL]) {
        delta = active_timers[QEMU_CLOCK_VIRTUAL]->expire_time -
778
                     qemu_get_clock_ns(vm_clock);
Paolo Bonzini's avatar
Paolo Bonzini committed
779 780 781 782 783 784 785 786
    }

    if (delta < 0)
        delta = 0;

    return delta;
}

787
static int64_t qemu_next_alarm_deadline(void)
Paolo Bonzini's avatar
Paolo Bonzini committed
788 789 790 791
{
    int64_t delta;
    int64_t rtdelta;

792 793
    if (!use_icount && active_timers[QEMU_CLOCK_VIRTUAL]) {
        delta = active_timers[QEMU_CLOCK_VIRTUAL]->expire_time -
794
                     qemu_get_clock_ns(vm_clock);
795
    } else {
Paolo Bonzini's avatar
Paolo Bonzini committed
796
        delta = INT32_MAX;
797 798 799 800 801 802 803
    }
    if (active_timers[QEMU_CLOCK_HOST]) {
        int64_t hdelta = active_timers[QEMU_CLOCK_HOST]->expire_time -
                 qemu_get_clock_ns(host_clock);
        if (hdelta < delta)
            delta = hdelta;
    }
Paolo Bonzini's avatar
Paolo Bonzini committed
804
    if (active_timers[QEMU_CLOCK_REALTIME]) {
805
        rtdelta = (active_timers[QEMU_CLOCK_REALTIME]->expire_time -
806
                 qemu_get_clock_ns(rt_clock));
Paolo Bonzini's avatar
Paolo Bonzini committed
807 808 809 810 811 812 813
        if (rtdelta < delta)
            delta = rtdelta;
    }

    return delta;
}

814 815
#if defined(__linux__)

816 817
#include "compatfd.h"

Paolo Bonzini's avatar
Paolo Bonzini committed
818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836
static int dynticks_start_timer(struct qemu_alarm_timer *t)
{
    struct sigevent ev;
    timer_t host_timer;
    struct sigaction act;

    sigfillset(&act.sa_mask);
    act.sa_flags = 0;
    act.sa_handler = host_alarm_handler;

    sigaction(SIGALRM, &act, NULL);

    /* 
     * Initialize ev struct to 0 to avoid valgrind complaining
     * about uninitialized data in timer_create call
     */
    memset(&ev, 0, sizeof(ev));
    ev.sigev_value.sival_int = 0;
    ev.sigev_notify = SIGEV_SIGNAL;
837 838 839 840 841 842
#ifdef SIGEV_THREAD_ID
    if (qemu_signalfd_available()) {
        ev.sigev_notify = SIGEV_THREAD_ID;
        ev._sigev_un._tid = qemu_get_thread_id();
    }
#endif /* SIGEV_THREAD_ID */
Paolo Bonzini's avatar
Paolo Bonzini committed
843 844 845 846 847 848 849 850 851 852 853
    ev.sigev_signo = SIGALRM;

    if (timer_create(CLOCK_REALTIME, &ev, &host_timer)) {
        perror("timer_create");

        /* disable dynticks */
        fprintf(stderr, "Dynamic Ticks disabled\n");

        return -1;
    }

Stefan Weil's avatar
Stefan Weil committed
854
    t->timer = host_timer;
Paolo Bonzini's avatar
Paolo Bonzini committed
855 856 857 858 859 860

    return 0;
}

static void dynticks_stop_timer(struct qemu_alarm_timer *t)
{
Stefan Weil's avatar
Stefan Weil committed
861
    timer_t host_timer = t->timer;
Paolo Bonzini's avatar
Paolo Bonzini committed
862 863 864 865 866 867

    timer_delete(host_timer);
}

static void dynticks_rearm_timer(struct qemu_alarm_timer *t)
{
Stefan Weil's avatar
Stefan Weil committed
868
    timer_t host_timer = t->timer;
Paolo Bonzini's avatar
Paolo Bonzini committed
869
    struct itimerspec timeout;
870 871
    int64_t nearest_delta_ns = INT64_MAX;
    int64_t current_ns;
Paolo Bonzini's avatar
Paolo Bonzini committed
872 873 874 875 876 877 878

    assert(alarm_has_dynticks(t));
    if (!active_timers[QEMU_CLOCK_REALTIME] &&
        !active_timers[QEMU_CLOCK_VIRTUAL] &&
        !active_timers[QEMU_CLOCK_HOST])
        return;

879 880 881
    nearest_delta_ns = qemu_next_alarm_deadline();
    if (nearest_delta_ns < MIN_TIMER_REARM_NS)
        nearest_delta_ns = MIN_TIMER_REARM_NS;
Paolo Bonzini's avatar
Paolo Bonzini committed
882 883 884 885 886 887 888

    /* check whether a timer is already running */
    if (timer_gettime(host_timer, &timeout)) {
        perror("gettime");
        fprintf(stderr, "Internal timer error: aborting\n");
        exit(1);
    }
889 890
    current_ns = timeout.it_value.tv_sec * 1000000000LL + timeout.it_value.tv_nsec;
    if (current_ns && current_ns <= nearest_delta_ns)
Paolo Bonzini's avatar
Paolo Bonzini committed
891 892 893 894
        return;

    timeout.it_interval.tv_sec = 0;
    timeout.it_interval.tv_nsec = 0; /* 0 for one-shot timer */
895 896
    timeout.it_value.tv_sec =  nearest_delta_ns / 1000000000;
    timeout.it_value.tv_nsec = nearest_delta_ns % 1000000000;
Paolo Bonzini's avatar
Paolo Bonzini committed
897 898 899 900 901 902 903 904 905
    if (timer_settime(host_timer, 0 /* RELATIVE */, &timeout, NULL)) {
        perror("settime");
        fprintf(stderr, "Internal timer error: aborting\n");
        exit(1);
    }
}

#endif /* defined(__linux__) */

906 907
#if !defined(_WIN32)

Paolo Bonzini's avatar
Paolo Bonzini committed
908 909 910 911 912 913 914 915 916 917
static int unix_start_timer(struct qemu_alarm_timer *t)
{
    struct sigaction act;

    /* timer signal */
    sigfillset(&act.sa_mask);
    act.sa_flags = 0;
    act.sa_handler = host_alarm_handler;

    sigaction(SIGALRM, &act, NULL);
918 919
    return 0;
}
Paolo Bonzini's avatar
Paolo Bonzini committed
920

921 922 923 924 925
static void unix_rearm_timer(struct qemu_alarm_timer *t)
{
    struct itimerval itv;
    int64_t nearest_delta_ns = INT64_MAX;
    int err;
Paolo Bonzini's avatar
Paolo Bonzini committed
926

927 928 929 930 931
    assert(alarm_has_dynticks(t));
    if (!active_timers[QEMU_CLOCK_REALTIME] &&
        !active_timers[QEMU_CLOCK_VIRTUAL] &&
        !active_timers[QEMU_CLOCK_HOST])
        return;
Paolo Bonzini's avatar
Paolo Bonzini committed
932

933 934 935 936 937 938 939 940 941 942 943 944 945 946
    nearest_delta_ns = qemu_next_alarm_deadline();
    if (nearest_delta_ns < MIN_TIMER_REARM_NS)
        nearest_delta_ns = MIN_TIMER_REARM_NS;

    itv.it_interval.tv_sec = 0;
    itv.it_interval.tv_usec = 0; /* 0 for one-shot timer */
    itv.it_value.tv_sec =  nearest_delta_ns / 1000000000;
    itv.it_value.tv_usec = (nearest_delta_ns % 1000000000) / 1000;
    err = setitimer(ITIMER_REAL, &itv, NULL);
    if (err) {
        perror("setitimer");
        fprintf(stderr, "Internal timer error: aborting\n");
        exit(1);
    }
Paolo Bonzini's avatar
Paolo Bonzini committed
947 948 949 950 951 952 953 954 955 956 957 958 959 960 961
}

static void unix_stop_timer(struct qemu_alarm_timer *t)
{
    struct itimerval itv;

    memset(&itv, 0, sizeof(itv));
    setitimer(ITIMER_REAL, &itv, NULL);
}

#endif /* !defined(_WIN32) */


#ifdef _WIN32

Stefan Weil's avatar
Stefan Weil committed
962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051
static MMRESULT mm_timer;
static unsigned mm_period;

static void CALLBACK mm_alarm_handler(UINT uTimerID, UINT uMsg,
                                      DWORD_PTR dwUser, DWORD_PTR dw1,
                                      DWORD_PTR dw2)
{
    struct qemu_alarm_timer *t = alarm_timer;
    if (!t) {
        return;
    }
    if (alarm_has_dynticks(t) || qemu_next_alarm_deadline() <= 0) {
        t->expired = alarm_has_dynticks(t);
        t->pending = 1;
        qemu_notify_event();
    }
}

static int mm_start_timer(struct qemu_alarm_timer *t)
{
    TIMECAPS tc;
    UINT flags;

    memset(&tc, 0, sizeof(tc));
    timeGetDevCaps(&tc, sizeof(tc));

    mm_period = tc.wPeriodMin;
    timeBeginPeriod(mm_period);

    flags = TIME_CALLBACK_FUNCTION;
    if (alarm_has_dynticks(t)) {
        flags |= TIME_ONESHOT;
    } else {
        flags |= TIME_PERIODIC;
    }

    mm_timer = timeSetEvent(1,                  /* interval (ms) */
                            mm_period,          /* resolution */
                            mm_alarm_handler,   /* function */
                            (DWORD_PTR)t,       /* parameter */
                            flags);

    if (!mm_timer) {
        fprintf(stderr, "Failed to initialize win32 alarm timer: %ld\n",
                GetLastError());
        timeEndPeriod(mm_period);
        return -1;
    }

    return 0;
}

static void mm_stop_timer(struct qemu_alarm_timer *t)
{
    timeKillEvent(mm_timer);
    timeEndPeriod(mm_period);
}

static void mm_rearm_timer(struct qemu_alarm_timer *t)
{
    int nearest_delta_ms;

    assert(alarm_has_dynticks(t));
    if (!active_timers[QEMU_CLOCK_REALTIME] &&
        !active_timers[QEMU_CLOCK_VIRTUAL] &&
        !active_timers[QEMU_CLOCK_HOST]) {
        return;
    }

    timeKillEvent(mm_timer);

    nearest_delta_ms = (qemu_next_alarm_deadline() + 999999) / 1000000;
    if (nearest_delta_ms < 1) {
        nearest_delta_ms = 1;
    }
    mm_timer = timeSetEvent(nearest_delta_ms,
                            mm_period,
                            mm_alarm_handler,
                            (DWORD_PTR)t,
                            TIME_ONESHOT | TIME_CALLBACK_FUNCTION);

    if (!mm_timer) {
        fprintf(stderr, "Failed to re-arm win32 alarm timer %ld\n",
                GetLastError());

        timeEndPeriod(mm_period);
        exit(1);
    }
}

Paolo Bonzini's avatar
Paolo Bonzini committed
1052 1053
static int win32_start_timer(struct qemu_alarm_timer *t)
{
Paolo Bonzini's avatar
Paolo Bonzini committed
1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069
    HANDLE hTimer;
    BOOLEAN success;

    /* If you call ChangeTimerQueueTimer on a one-shot timer (its period
       is zero) that has already expired, the timer is not updated.  Since
       creating a new timer is relatively expensive, set a bogus one-hour
       interval in the dynticks case.  */
    success = CreateTimerQueueTimer(&hTimer,
                          NULL,
                          host_alarm_handler,
                          t,
                          1,
                          alarm_has_dynticks(t) ? 3600000 : 1,
                          WT_EXECUTEINTIMERTHREAD);

    if (!success) {
Paolo Bonzini's avatar
Paolo Bonzini committed
1070 1071 1072 1073 1074
        fprintf(stderr, "Failed to initialize win32 alarm timer: %ld\n",
                GetLastError());
        return -1;
    }

Stefan Weil's avatar
Stefan Weil committed
1075
    t->timer = hTimer;
Paolo Bonzini's avatar
Paolo Bonzini committed
1076 1077 1078 1079 1080
    return 0;
}

static void win32_stop_timer(struct qemu_alarm_timer *t)
{
Stefan Weil's avatar
Stefan Weil committed
1081
    HANDLE hTimer = t->timer;
Paolo Bonzini's avatar
Paolo Bonzini committed
1082

Paolo Bonzini's avatar
Paolo Bonzini committed
1083 1084 1085
    if (hTimer) {
        DeleteTimerQueueTimer(NULL, hTimer, NULL);
    }
Paolo Bonzini's avatar
Paolo Bonzini committed
1086 1087 1088 1089
}

static void win32_rearm_timer(struct qemu_alarm_timer *t)
{
Stefan Weil's avatar
Stefan Weil committed
1090
    HANDLE hTimer = t->timer;
1091
    int nearest_delta_ms;
Paolo Bonzini's avatar
Paolo Bonzini committed
1092
    BOOLEAN success;
Paolo Bonzini's avatar
Paolo Bonzini committed
1093 1094 1095 1096 1097 1098 1099

    assert(alarm_has_dynticks(t));
    if (!active_timers[QEMU_CLOCK_REALTIME] &&
        !active_timers[QEMU_CLOCK_VIRTUAL] &&
        !active_timers[QEMU_CLOCK_HOST])
        return;

1100 1101 1102 1103
    nearest_delta_ms = (qemu_next_alarm_deadline() + 999999) / 1000000;
    if (nearest_delta_ms < 1) {
        nearest_delta_ms = 1;
    }
Paolo Bonzini's avatar
Paolo Bonzini committed
1104 1105 1106 1107
    success = ChangeTimerQueueTimer(NULL,
                                    hTimer,
                                    nearest_delta_ms,
                                    3600000);
Paolo Bonzini's avatar
Paolo Bonzini committed
1108

Paolo Bonzini's avatar
Paolo Bonzini committed
1109 1110 1111 1112
    if (!success) {
        fprintf(stderr, "Failed to rearm win32 alarm timer: %ld\n",
                GetLastError());
        exit(-1);
Paolo Bonzini's avatar
Paolo Bonzini committed
1113
    }
Paolo Bonzini's avatar
Paolo Bonzini committed
1114

Paolo Bonzini's avatar
Paolo Bonzini committed
1115 1116 1117 1118
}

#endif /* _WIN32 */

1119 1120
static void alarm_timer_on_change_state_rearm(void *opaque, int running,
                                              RunState state)
Paolo Bonzini's avatar
Paolo Bonzini committed
1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163
{
    if (running)
        qemu_rearm_alarm_timer((struct qemu_alarm_timer *) opaque);
}

int init_timer_alarm(void)
{
    struct qemu_alarm_timer *t = NULL;
    int i, err = -1;

    for (i = 0; alarm_timers[i].name; i++) {
        t = &alarm_timers[i];

        err = t->start(t);
        if (!err)
            break;
    }

    if (err) {
        err = -ENOENT;
        goto fail;
    }

    /* first event is at time 0 */
    t->pending = 1;
    alarm_timer = t;
    qemu_add_vm_change_state_handler(alarm_timer_on_change_state_rearm, t);

    return 0;

fail:
    return err;
}

void quit_timers(void)
{
    struct qemu_alarm_timer *t = alarm_timer;
    alarm_timer = NULL;
    t->stop(t);
}

int qemu_calculate_timeout(void)
{
1164
    return 1000;
Paolo Bonzini's avatar
Paolo Bonzini committed
1165 1166
}