cpus.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 /* Needed early for CONFIG_BSD etc. */
  26 #include "config-host.h"
  27
  28 #include "monitor.h"
  29 #include "sysemu.h"
  30 #include "gdbstub.h"
  31 #include "dma.h"
  32 #include "kvm.h"
  33 #include "exec-all.h"
  34
  35 #include "cpus.h"
  36
  37 #ifdef SIGRTMIN
  38 #define SIG_IPI (SIGRTMIN+4)
  39 #else
  40 #define SIG_IPI SIGUSR1
  41 #endif
  42
  43 static CPUState *cur_cpu;
  44 static CPUState *next_cpu;
  45
  46 /***********************************************************/
  47 void hw_error(const char *fmt, ...)
  48 {
  49     va_list ap;
  50     CPUState *env;
  51
  52     va_start(ap, fmt);
  53     fprintf(stderr, "qemu: hardware error: ");
  54     vfprintf(stderr, fmt, ap);
  55     fprintf(stderr, "\n");
  56     for(env = first_cpu; env != NULL; env = env->next_cpu) {
  57         fprintf(stderr, "CPU #%d:\n", env->cpu_index);
  58 #ifdef TARGET_I386
  59         cpu_dump_state(env, stderr, fprintf, X86_DUMP_FPU);
  60 #else
  61         cpu_dump_state(env, stderr, fprintf, 0);
  62 #endif
  63     }
  64     va_end(ap);
  65     abort();
  66 }
  67
  68 void cpu_synchronize_all_states(void)
  69 {
  70     CPUState *cpu;
  71
  72     for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
  73         cpu_synchronize_state(cpu);
  74     }
  75 }
  76
  77 void cpu_synchronize_all_post_reset(void)
  78 {
  79     CPUState *cpu;
  80
  81     for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
  82         cpu_synchronize_post_reset(cpu);
  83     }
  84 }
  85
  86 void cpu_synchronize_all_post_init(void)
  87 {
  88     CPUState *cpu;
  89
  90     for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
  91         cpu_synchronize_post_init(cpu);
  92     }
  93 }
  94
  95 int cpu_is_stopped(CPUState *env)
  96 {
  97     return !vm_running || env->stopped;
  98 }
  99
 100 static void do_vm_stop(int reason)
 101 {
 102     if (vm_running) {
 103         cpu_disable_ticks();
 104         vm_running = 0;
 105         pause_all_vcpus();
 106         vm_state_notify(0, reason);
 107         monitor_protocol_event(QEVENT_STOP, NULL);
 108     }
 109 }
 110
 111 static int cpu_can_run(CPUState *env)
 112 {
 113     if (env->stop)
 114         return 0;
 115     if (env->stopped || !vm_running)
 116         return 0;
 117     return 1;
 118 }
 119
 120 static int cpu_has_work(CPUState *env)
 121 {
 122     if (env->stop)
 123         return 1;
 124     if (env->queued_work_first)
 125         return 1;
 126     if (env->stopped || !vm_running)
 127         return 0;
 128     if (!env->halted)
 129         return 1;
 130     if (qemu_cpu_has_work(env))
 131         return 1;
 132     return 0;
 133 }
 134
 135 static int tcg_has_work(void)
 136 {
 137     CPUState *env;
 138
 139     for (env = first_cpu; env != NULL; env = env->next_cpu)
 140         if (cpu_has_work(env))
 141             return 1;
 142     return 0;
 143 }
 144
 145 #ifndef _WIN32
 146 static int io_thread_fd = -1;
 147
 148 static void qemu_event_increment(void)
 149 {
 150     /* Write 8 bytes to be compatible with eventfd.  */
 151     static const uint64_t val = 1;
 152     ssize_t ret;
 153
 154     if (io_thread_fd == -1)
 155         return;
 156
 157     do {
 158         ret = write(io_thread_fd, &val, sizeof(val));
 159     } while (ret < 0 && errno == EINTR);
 160
 161     /* EAGAIN is fine, a read must be pending.  */
 162     if (ret < 0 && errno != EAGAIN) {
 163         fprintf(stderr, "qemu_event_increment: write() filed: %s\n",
 164                 strerror(errno));
 165         exit (1);
 166     }
 167 }
 168
 169 static void qemu_event_read(void *opaque)
 170 {
 171     int fd = (unsigned long)opaque;
 172     ssize_t len;
 173     char buffer[512];
 174
 175     /* Drain the notify pipe.  For eventfd, only 8 bytes will be read.  */
 176     do {
 177         len = read(fd, buffer, sizeof(buffer));
 178     } while ((len == -1 && errno == EINTR) || len == sizeof(buffer));
 179 }
 180
 181 static int qemu_event_init(void)
 182 {
 183     int err;
 184     int fds[2];
 185
 186     err = qemu_eventfd(fds);
 187     if (err == -1)
 188         return -errno;
 189
 190     err = fcntl_setfl(fds[0], O_NONBLOCK);
 191     if (err < 0)
 192         goto fail;
 193
 194     err = fcntl_setfl(fds[1], O_NONBLOCK);
 195     if (err < 0)
 196         goto fail;
 197
 198     qemu_set_fd_handler2(fds[0], NULL, qemu_event_read, NULL,
 199                          (void *)(unsigned long)fds[0]);
 200
 201     io_thread_fd = fds[1];
 202     return 0;
 203
 204 fail:
 205     close(fds[0]);
 206     close(fds[1]);
 207     return err;
 208 }
 209 #else
 210 HANDLE qemu_event_handle;
 211
 212 static void dummy_event_handler(void *opaque)
 213 {
 214 }
 215
 216 static int qemu_event_init(void)
 217 {
 218     qemu_event_handle = CreateEvent(NULL, FALSE, FALSE, NULL);
 219     if (!qemu_event_handle) {
 220         fprintf(stderr, "Failed CreateEvent: %ld\n", GetLastError());
 221         return -1;
 222     }
 223     qemu_add_wait_object(qemu_event_handle, dummy_event_handler, NULL);
 224     return 0;
 225 }
 226
 227 static void qemu_event_increment(void)
 228 {
 229     if (!SetEvent(qemu_event_handle)) {
 230         fprintf(stderr, "qemu_event_increment: SetEvent failed: %ld\n",
 231                 GetLastError());
 232         exit (1);
 233     }
 234 }
 235 #endif
 236
 237 #ifndef CONFIG_IOTHREAD
 238 int qemu_init_main_loop(void)
 239 {
 240     return qemu_event_init();
 241 }
 242
 243 void qemu_main_loop_start(void)
 244 {
 245 }
 246
 247 void qemu_init_vcpu(void *_env)
 248 {
 249     CPUState *env = _env;
 250
 251     env->nr_cores = smp_cores;
 252     env->nr_threads = smp_threads;
 253     if (kvm_enabled())
 254         kvm_init_vcpu(env);
 255     return;
 256 }
 257
 258 int qemu_cpu_self(void *env)
 259 {
 260     return 1;
 261 }
 262
 263 void run_on_cpu(CPUState *env, void (*func)(void *data), void *data)
 264 {
 265     func(data);
 266 }
 267
 268 void resume_all_vcpus(void)
 269 {
 270 }
 271
 272 void pause_all_vcpus(void)
 273 {
 274 }
 275
 276 void qemu_cpu_kick(void *env)
 277 {
 278     return;
 279 }
 280
 281 void qemu_notify_event(void)
 282 {
 283     CPUState *env = cpu_single_env;
 284
 285     qemu_event_increment ();
 286     if (env) {
 287         cpu_exit(env);
 288     }
 289     if (next_cpu && env != next_cpu) {
 290         cpu_exit(next_cpu);
 291     }
 292 }
 293
 294 void qemu_mutex_lock_iothread(void) {}
 295 void qemu_mutex_unlock_iothread(void) {}
 296
 297 void vm_stop(int reason)
 298 {
 299     do_vm_stop(reason);
 300 }
 301
 302 #else /* CONFIG_IOTHREAD */
 303
 304 #include "qemu-thread.h"
 305
 306 QemuMutex qemu_global_mutex;
 307 static QemuMutex qemu_fair_mutex;
 308
 309 static QemuThread io_thread;
 310
 311 static QemuThread *tcg_cpu_thread;
 312 static QemuCond *tcg_halt_cond;
 313
 314 static int qemu_system_ready;
 315 /* cpu creation */
 316 static QemuCond qemu_cpu_cond;
 317 /* system init */
 318 static QemuCond qemu_system_cond;
 319 static QemuCond qemu_pause_cond;
 320 static QemuCond qemu_work_cond;
 321
 322 static void tcg_init_ipi(void);
 323 static void kvm_init_ipi(CPUState *env);
 324 static void unblock_io_signals(void);
 325
 326 int qemu_init_main_loop(void)
 327 {
 328     int ret;
 329
 330     ret = qemu_event_init();
 331     if (ret)
 332         return ret;
 333
 334     qemu_cond_init(&qemu_pause_cond);
 335     qemu_mutex_init(&qemu_fair_mutex);
 336     qemu_mutex_init(&qemu_global_mutex);
 337     qemu_mutex_lock(&qemu_global_mutex);
 338
 339     unblock_io_signals();
 340     qemu_thread_self(&io_thread);
 341
 342     return 0;
 343 }
 344
 345 void qemu_main_loop_start(void)
 346 {
 347     qemu_system_ready = 1;
 348     qemu_cond_broadcast(&qemu_system_cond);
 349 }
 350
 351 void run_on_cpu(CPUState *env, void (*func)(void *data), void *data)
 352 {
 353     struct qemu_work_item wi;
 354
 355     if (qemu_cpu_self(env)) {
 356         func(data);
 357         return;
 358     }
 359
 360     wi.func = func;
 361     wi.data = data;
 362     if (!env->queued_work_first)
 363         env->queued_work_first = &wi;
 364     else
 365         env->queued_work_last->next = &wi;
 366     env->queued_work_last = &wi;
 367     wi.next = NULL;
 368     wi.done = false;
 369
 370     qemu_cpu_kick(env);
 371     while (!wi.done) {
 372         CPUState *self_env = cpu_single_env;
 373
 374         qemu_cond_wait(&qemu_work_cond, &qemu_global_mutex);
 375         cpu_single_env = self_env;
 376     }
 377 }
 378
 379 static void flush_queued_work(CPUState *env)
 380 {
 381     struct qemu_work_item *wi;
 382
 383     if (!env->queued_work_first)
 384         return;
 385
 386     while ((wi = env->queued_work_first)) {
 387         env->queued_work_first = wi->next;
 388         wi->func(wi->data);
 389         wi->done = true;
 390     }
 391     env->queued_work_last = NULL;
 392     qemu_cond_broadcast(&qemu_work_cond);
 393 }
 394
 395 static void qemu_wait_io_event_common(CPUState *env)
 396 {
 397     if (env->stop) {
 398         env->stop = 0;
 399         env->stopped = 1;
 400         qemu_cond_signal(&qemu_pause_cond);
 401     }
 402     flush_queued_work(env);
 403 }
 404
 405 static void qemu_wait_io_event(CPUState *env)
 406 {
 407     while (!tcg_has_work())
 408         qemu_cond_timedwait(env->halt_cond, &qemu_global_mutex, 1000);
 409
 410     qemu_mutex_unlock(&qemu_global_mutex);
 411
 412     /*
 413      * Users of qemu_global_mutex can be starved, having no chance
 414      * to acquire it since this path will get to it first.
 415      * So use another lock to provide fairness.
 416      */
 417     qemu_mutex_lock(&qemu_fair_mutex);
 418     qemu_mutex_unlock(&qemu_fair_mutex);
 419
 420     qemu_mutex_lock(&qemu_global_mutex);
 421     qemu_wait_io_event_common(env);
 422 }
 423
 424 static void qemu_kvm_eat_signal(CPUState *env, int timeout)
 425 {
 426     struct timespec ts;
 427     int r, e;
 428     siginfo_t siginfo;
 429     sigset_t waitset;
 430
 431     ts.tv_sec = timeout / 1000;
 432     ts.tv_nsec = (timeout % 1000) * 1000000;
 433
 434     sigemptyset(&waitset);
 435     sigaddset(&waitset, SIG_IPI);
 436
 437     qemu_mutex_unlock(&qemu_global_mutex);
 438     r = sigtimedwait(&waitset, &siginfo, &ts);
 439     e = errno;
 440     qemu_mutex_lock(&qemu_global_mutex);
 441
 442     if (r == -1 && !(e == EAGAIN || e == EINTR)) {
 443         fprintf(stderr, "sigtimedwait: %s\n", strerror(e));
 444         exit(1);
 445     }
 446 }
 447
 448 static void qemu_kvm_wait_io_event(CPUState *env)
 449 {
 450     while (!cpu_has_work(env))
 451         qemu_cond_timedwait(env->halt_cond, &qemu_global_mutex, 1000);
 452
 453     qemu_kvm_eat_signal(env, 0);
 454     qemu_wait_io_event_common(env);
 455 }
 456
 457 static int qemu_cpu_exec(CPUState *env);
 458
 459 static void *kvm_cpu_thread_fn(void *arg)
 460 {
 461     CPUState *env = arg;
 462
 463     qemu_mutex_lock(&qemu_global_mutex);
 464     qemu_thread_self(env->thread);
 465     if (kvm_enabled())
 466         kvm_init_vcpu(env);
 467
 468     kvm_init_ipi(env);
 469
 470     /* signal CPU creation */
 471     env->created = 1;
 472     qemu_cond_signal(&qemu_cpu_cond);
 473
 474     /* and wait for machine initialization */
 475     while (!qemu_system_ready)
 476         qemu_cond_timedwait(&qemu_system_cond, &qemu_global_mutex, 100);
 477
 478     while (1) {
 479         if (cpu_can_run(env))
 480             qemu_cpu_exec(env);
 481         qemu_kvm_wait_io_event(env);
 482     }
 483
 484     return NULL;
 485 }
 486
 487 static void *tcg_cpu_thread_fn(void *arg)
 488 {
 489     CPUState *env = arg;
 490
 491     tcg_init_ipi();
 492     qemu_thread_self(env->thread);
 493
 494     /* signal CPU creation */
 495     qemu_mutex_lock(&qemu_global_mutex);
 496     for (env = first_cpu; env != NULL; env = env->next_cpu)
 497         env->created = 1;
 498     qemu_cond_signal(&qemu_cpu_cond);
 499
 500     /* and wait for machine initialization */
 501     while (!qemu_system_ready)
 502         qemu_cond_timedwait(&qemu_system_cond, &qemu_global_mutex, 100);
 503
 504     while (1) {
 505         tcg_cpu_exec();
 506         qemu_wait_io_event(cur_cpu);
 507     }
 508
 509     return NULL;
 510 }
 511
 512 void qemu_cpu_kick(void *_env)
 513 {
 514     CPUState *env = _env;
 515     qemu_cond_broadcast(env->halt_cond);
 516     qemu_thread_signal(env->thread, SIG_IPI);
 517 }
 518
 519 int qemu_cpu_self(void *_env)
 520 {
 521     CPUState *env = _env;
 522     QemuThread this;
 523
 524     qemu_thread_self(&this);
 525
 526     return qemu_thread_equal(&this, env->thread);
 527 }
 528
 529 static void cpu_signal(int sig)
 530 {
 531     if (cpu_single_env)
 532         cpu_exit(cpu_single_env);
 533     exit_request = 1;
 534 }
 535
 536 static void tcg_init_ipi(void)
 537 {
 538     sigset_t set;
 539     struct sigaction sigact;
 540
 541     memset(&sigact, 0, sizeof(sigact));
 542     sigact.sa_handler = cpu_signal;
 543     sigaction(SIG_IPI, &sigact, NULL);
 544
 545     sigemptyset(&set);
 546     sigaddset(&set, SIG_IPI);
 547     pthread_sigmask(SIG_UNBLOCK, &set, NULL);
 548 }
 549
 550 static void dummy_signal(int sig)
 551 {
 552 }
 553
 554 static void kvm_init_ipi(CPUState *env)
 555 {
 556     int r;
 557     sigset_t set;
 558     struct sigaction sigact;
 559
 560     memset(&sigact, 0, sizeof(sigact));
 561     sigact.sa_handler = dummy_signal;
 562     sigaction(SIG_IPI, &sigact, NULL);
 563
 564     pthread_sigmask(SIG_BLOCK, NULL, &set);
 565     sigdelset(&set, SIG_IPI);
 566     r = kvm_set_signal_mask(env, &set);
 567     if (r) {
 568         fprintf(stderr, "kvm_set_signal_mask: %s\n", strerror(r));
 569         exit(1);
 570     }
 571 }
 572
 573 static void unblock_io_signals(void)
 574 {
 575     sigset_t set;
 576
 577     sigemptyset(&set);
 578     sigaddset(&set, SIGUSR2);
 579     sigaddset(&set, SIGIO);
 580     sigaddset(&set, SIGALRM);
 581     pthread_sigmask(SIG_UNBLOCK, &set, NULL);
 582
 583     sigemptyset(&set);
 584     sigaddset(&set, SIG_IPI);
 585     pthread_sigmask(SIG_BLOCK, &set, NULL);
 586 }
 587
 588 void qemu_mutex_lock_iothread(void)
 589 {
 590     if (kvm_enabled()) {
 591         qemu_mutex_lock(&qemu_fair_mutex);
 592         qemu_mutex_lock(&qemu_global_mutex);
 593         qemu_mutex_unlock(&qemu_fair_mutex);
 594     } else {
 595         qemu_mutex_lock(&qemu_fair_mutex);
 596         if (qemu_mutex_trylock(&qemu_global_mutex)) {
 597             qemu_thread_signal(tcg_cpu_thread, SIG_IPI);
 598             qemu_mutex_lock(&qemu_global_mutex);
 599         }
 600         qemu_mutex_unlock(&qemu_fair_mutex);
 601     }
 602 }
 603
 604 void qemu_mutex_unlock_iothread(void)
 605 {
 606     qemu_mutex_unlock(&qemu_global_mutex);
 607 }
 608
 609 static int all_vcpus_paused(void)
 610 {
 611     CPUState *penv = first_cpu;
 612
 613     while (penv) {
 614         if (!penv->stopped)
 615             return 0;
 616         penv = (CPUState *)penv->next_cpu;
 617     }
 618
 619     return 1;
 620 }
 621
 622 void pause_all_vcpus(void)
 623 {
 624     CPUState *penv = first_cpu;
 625
 626     while (penv) {
 627         penv->stop = 1;
 628         qemu_cpu_kick(penv);
 629         penv = (CPUState *)penv->next_cpu;
 630     }
 631
 632     while (!all_vcpus_paused()) {
 633         qemu_cond_timedwait(&qemu_pause_cond, &qemu_global_mutex, 100);
 634         penv = first_cpu;
 635         while (penv) {
 636             qemu_cpu_kick(penv);
 637             penv = (CPUState *)penv->next_cpu;
 638         }
 639     }
 640 }
 641
 642 void resume_all_vcpus(void)
 643 {
 644     CPUState *penv = first_cpu;
 645
 646     while (penv) {
 647         penv->stop = 0;
 648         penv->stopped = 0;
 649         qemu_cpu_kick(penv);
 650         penv = (CPUState *)penv->next_cpu;
 651     }
 652 }
 653
 654 static void tcg_init_vcpu(void *_env)
 655 {
 656     CPUState *env = _env;
 657     /* share a single thread for all cpus with TCG */
 658     if (!tcg_cpu_thread) {
 659         env->thread = qemu_mallocz(sizeof(QemuThread));
 660         env->halt_cond = qemu_mallocz(sizeof(QemuCond));
 661         qemu_cond_init(env->halt_cond);
 662         qemu_thread_create(env->thread, tcg_cpu_thread_fn, env);
 663         while (env->created == 0)
 664             qemu_cond_timedwait(&qemu_cpu_cond, &qemu_global_mutex, 100);
 665         tcg_cpu_thread = env->thread;
 666         tcg_halt_cond = env->halt_cond;
 667     } else {
 668         env->thread = tcg_cpu_thread;
 669         env->halt_cond = tcg_halt_cond;
 670     }
 671 }
 672
 673 static void kvm_start_vcpu(CPUState *env)
 674 {
 675     env->thread = qemu_mallocz(sizeof(QemuThread));
 676     env->halt_cond = qemu_mallocz(sizeof(QemuCond));
 677     qemu_cond_init(env->halt_cond);
 678     qemu_thread_create(env->thread, kvm_cpu_thread_fn, env);
 679     while (env->created == 0)
 680         qemu_cond_timedwait(&qemu_cpu_cond, &qemu_global_mutex, 100);
 681 }
 682
 683 void qemu_init_vcpu(void *_env)
 684 {
 685     CPUState *env = _env;
 686
 687     env->nr_cores = smp_cores;
 688     env->nr_threads = smp_threads;
 689     if (kvm_enabled())
 690         kvm_start_vcpu(env);
 691     else
 692         tcg_init_vcpu(env);
 693 }
 694
 695 void qemu_notify_event(void)
 696 {
 697     qemu_event_increment();
 698 }
 699
 700 static void qemu_system_vmstop_request(int reason)
 701 {
 702     vmstop_requested = reason;
 703     qemu_notify_event();
 704 }
 705
 706 void vm_stop(int reason)
 707 {
 708     QemuThread me;
 709     qemu_thread_self(&me);
 710
 711     if (!qemu_thread_equal(&me, &io_thread)) {
 712         qemu_system_vmstop_request(reason);
 713         /*
 714          * FIXME: should not return to device code in case
 715          * vm_stop() has been requested.
 716          */
 717         if (cpu_single_env) {
 718             cpu_exit(cpu_single_env);
 719             cpu_single_env->stop = 1;
 720         }
 721         return;
 722     }
 723     do_vm_stop(reason);
 724 }
 725
 726 #endif
 727
 728 static int qemu_cpu_exec(CPUState *env)
 729 {
 730     int ret;
 731 #ifdef CONFIG_PROFILER
 732     int64_t ti;
 733 #endif
 734
 735 #ifdef CONFIG_PROFILER
 736     ti = profile_getclock();
 737 #endif
 738     if (use_icount) {
 739         int64_t count;
 740         int decr;
 741         qemu_icount -= (env->icount_decr.u16.low + env->icount_extra);
 742         env->icount_decr.u16.low = 0;
 743         env->icount_extra = 0;
 744         count = qemu_icount_round (qemu_next_deadline());
 745         qemu_icount += count;
 746         decr = (count > 0xffff) ? 0xffff : count;
 747         count -= decr;
 748         env->icount_decr.u16.low = decr;
 749         env->icount_extra = count;
 750     }
 751     ret = cpu_exec(env);
 752 #ifdef CONFIG_PROFILER
 753     qemu_time += profile_getclock() - ti;
 754 #endif
 755     if (use_icount) {
 756         /* Fold pending instructions back into the
 757            instruction counter, and clear the interrupt flag.  */
 758         qemu_icount -= (env->icount_decr.u16.low
 759                         + env->icount_extra);
 760         env->icount_decr.u32 = 0;
 761         env->icount_extra = 0;
 762     }
 763     return ret;
 764 }
 765
 766 bool tcg_cpu_exec(void)
 767 {
 768     int ret = 0;
 769
 770     if (next_cpu == NULL)
 771         next_cpu = first_cpu;
 772     for (; next_cpu != NULL; next_cpu = next_cpu->next_cpu) {
 773         CPUState *env = cur_cpu = next_cpu;
 774
 775         qemu_clock_enable(vm_clock,
 776                           (cur_cpu->singlestep_enabled & SSTEP_NOTIMER) == 0);
 777
 778         if (qemu_alarm_pending())
 779             break;
 780         if (cpu_can_run(env))
 781             ret = qemu_cpu_exec(env);
 782         else if (env->stop)
 783             break;
 784
 785         if (ret == EXCP_DEBUG) {
 786             gdb_set_stop_cpu(env);
 787             debug_requested = EXCP_DEBUG;
 788             break;
 789         }
 790     }
 791     return tcg_has_work();
 792 }
 793
 794 void set_numa_modes(void)
 795 {
 796     CPUState *env;
 797     int i;
 798
 799     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 800         for (i = 0; i < nb_numa_nodes; i++) {
 801             if (node_cpumask[i] & (1 << env->cpu_index)) {
 802                 env->numa_node = i;
 803             }
 804         }
 805     }
 806 }
 807
 808 void set_cpu_log(const char *optarg)
 809 {
 810     int mask;
 811     const CPULogItem *item;
 812
 813     mask = cpu_str_to_log_mask(optarg);
 814     if (!mask) {
 815         printf("Log items (comma separated):\n");
 816         for (item = cpu_log_items; item->mask != 0; item++) {
 817             printf("%-10s %s\n", item->name, item->help);
 818         }
 819         exit(1);
 820     }
 821     cpu_set_log(mask);
 822 }
 823
 824 /* Return the virtual CPU time, based on the instruction counter.  */
 825 int64_t cpu_get_icount(void)
 826 {
 827     int64_t icount;
 828     CPUState *env = cpu_single_env;;
 829
 830     icount = qemu_icount;
 831     if (env) {
 832         if (!can_do_io(env)) {
 833             fprintf(stderr, "Bad clock read\n");
 834         }
 835         icount -= (env->icount_decr.u16.low + env->icount_extra);
 836     }
 837     return qemu_icount_bias + (icount << icount_time_shift);
 838 }
 839
 840 void list_cpus(FILE *f, int (*cpu_fprintf)(FILE *f, const char *fmt, ...),
 841                const char *optarg)
 842 {
 843     /* XXX: implement xxx_cpu_list for targets that still miss it */
 844 #if defined(cpu_list_id)
 845     cpu_list_id(f, cpu_fprintf, optarg);
 846 #elif defined(cpu_list)
 847     cpu_list(f, cpu_fprintf); /* deprecated */
 848 #endif
 849 }