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
  34 #include "qemu-thread.h"
  35 #include "cpus.h"
  36
  37 #ifndef _WIN32
  38 #include "compatfd.h"
  39 #endif
  40
  41 #ifdef SIGRTMIN
  42 #define SIG_IPI (SIGRTMIN+4)
  43 #else
  44 #define SIG_IPI SIGUSR1
  45 #endif
  46
  47 #ifdef CONFIG_LINUX
  48
  49 #include <sys/prctl.h>
  50
  51 #ifndef PR_MCE_KILL
  52 #define PR_MCE_KILL 33
  53 #endif
  54
  55 #ifndef PR_MCE_KILL_SET
  56 #define PR_MCE_KILL_SET 1
  57 #endif
  58
  59 #ifndef PR_MCE_KILL_EARLY
  60 #define PR_MCE_KILL_EARLY 1
  61 #endif
  62
  63 #endif /* CONFIG_LINUX */
  64
  65 static CPUState *next_cpu;
  66
  67 /***********************************************************/
  68 void hw_error(const char *fmt, ...)
  69 {
  70     va_list ap;
  71     CPUState *env;
  72
  73     va_start(ap, fmt);
  74     fprintf(stderr, "qemu: hardware error: ");
  75     vfprintf(stderr, fmt, ap);
  76     fprintf(stderr, "\n");
  77     for(env = first_cpu; env != NULL; env = env->next_cpu) {
  78         fprintf(stderr, "CPU #%d:\n", env->cpu_index);
  79 #ifdef TARGET_I386
  80         cpu_dump_state(env, stderr, fprintf, X86_DUMP_FPU);
  81 #else
  82         cpu_dump_state(env, stderr, fprintf, 0);
  83 #endif
  84     }
  85     va_end(ap);
  86     abort();
  87 }
  88
  89 void cpu_synchronize_all_states(void)
  90 {
  91     CPUState *cpu;
  92
  93     for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
  94         cpu_synchronize_state(cpu);
  95     }
  96 }
  97
  98 void cpu_synchronize_all_post_reset(void)
  99 {
 100     CPUState *cpu;
 101
 102     for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
 103         cpu_synchronize_post_reset(cpu);
 104     }
 105 }
 106
 107 void cpu_synchronize_all_post_init(void)
 108 {
 109     CPUState *cpu;
 110
 111     for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
 112         cpu_synchronize_post_init(cpu);
 113     }
 114 }
 115
 116 int cpu_is_stopped(CPUState *env)
 117 {
 118     return !vm_running || env->stopped;
 119 }
 120
 121 static void do_vm_stop(int reason)
 122 {
 123     if (vm_running) {
 124         cpu_disable_ticks();
 125         vm_running = 0;
 126         pause_all_vcpus();
 127         vm_state_notify(0, reason);
 128         qemu_aio_flush();
 129         bdrv_flush_all();
 130         monitor_protocol_event(QEVENT_STOP, NULL);
 131     }
 132 }
 133
 134 static int cpu_can_run(CPUState *env)
 135 {
 136     if (env->stop) {
 137         return 0;
 138     }
 139     if (env->stopped || !vm_running) {
 140         return 0;
 141     }
 142     return 1;
 143 }
 144
 145 static bool cpu_thread_is_idle(CPUState *env)
 146 {
 147     if (env->stop || env->queued_work_first) {
 148         return false;
 149     }
 150     if (env->stopped || !vm_running) {
 151         return true;
 152     }
 153     if (!env->halted || qemu_cpu_has_work(env) ||
 154         (kvm_enabled() && kvm_irqchip_in_kernel())) {
 155         return false;
 156     }
 157     return true;
 158 }
 159
 160 bool all_cpu_threads_idle(void)
 161 {
 162     CPUState *env;
 163
 164     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 165         if (!cpu_thread_is_idle(env)) {
 166             return false;
 167         }
 168     }
 169     return true;
 170 }
 171
 172 static void cpu_handle_guest_debug(CPUState *env)
 173 {
 174     gdb_set_stop_cpu(env);
 175     qemu_system_debug_request();
 176     env->stopped = 1;
 177 }
 178
 179 static void cpu_signal(int sig)
 180 {
 181     if (cpu_single_env) {
 182         cpu_exit(cpu_single_env);
 183     }
 184     exit_request = 1;
 185 }
 186
 187 #ifdef CONFIG_LINUX
 188 static void sigbus_reraise(void)
 189 {
 190     sigset_t set;
 191     struct sigaction action;
 192
 193     memset(&action, 0, sizeof(action));
 194     action.sa_handler = SIG_DFL;
 195     if (!sigaction(SIGBUS, &action, NULL)) {
 196         raise(SIGBUS);
 197         sigemptyset(&set);
 198         sigaddset(&set, SIGBUS);
 199         sigprocmask(SIG_UNBLOCK, &set, NULL);
 200     }
 201     perror("Failed to re-raise SIGBUS!\n");
 202     abort();
 203 }
 204
 205 static void sigbus_handler(int n, struct qemu_signalfd_siginfo *siginfo,
 206                            void *ctx)
 207 {
 208     if (kvm_on_sigbus(siginfo->ssi_code,
 209                       (void *)(intptr_t)siginfo->ssi_addr)) {
 210         sigbus_reraise();
 211     }
 212 }
 213
 214 static void qemu_init_sigbus(void)
 215 {
 216     struct sigaction action;
 217
 218     memset(&action, 0, sizeof(action));
 219     action.sa_flags = SA_SIGINFO;
 220     action.sa_sigaction = (void (*)(int, siginfo_t*, void*))sigbus_handler;
 221     sigaction(SIGBUS, &action, NULL);
 222
 223     prctl(PR_MCE_KILL, PR_MCE_KILL_SET, PR_MCE_KILL_EARLY, 0, 0);
 224 }
 225
 226 static void qemu_kvm_eat_signals(CPUState *env)
 227 {
 228     struct timespec ts = { 0, 0 };
 229     siginfo_t siginfo;
 230     sigset_t waitset;
 231     sigset_t chkset;
 232     int r;
 233
 234     sigemptyset(&waitset);
 235     sigaddset(&waitset, SIG_IPI);
 236     sigaddset(&waitset, SIGBUS);
 237
 238     do {
 239         r = sigtimedwait(&waitset, &siginfo, &ts);
 240         if (r == -1 && !(errno == EAGAIN || errno == EINTR)) {
 241             perror("sigtimedwait");
 242             exit(1);
 243         }
 244
 245         switch (r) {
 246         case SIGBUS:
 247             if (kvm_on_sigbus_vcpu(env, siginfo.si_code, siginfo.si_addr)) {
 248                 sigbus_reraise();
 249             }
 250             break;
 251         default:
 252             break;
 253         }
 254
 255         r = sigpending(&chkset);
 256         if (r == -1) {
 257             perror("sigpending");
 258             exit(1);
 259         }
 260     } while (sigismember(&chkset, SIG_IPI) || sigismember(&chkset, SIGBUS));
 261 }
 262
 263 #else /* !CONFIG_LINUX */
 264
 265 static void qemu_init_sigbus(void)
 266 {
 267 }
 268
 269 static void qemu_kvm_eat_signals(CPUState *env)
 270 {
 271 }
 272 #endif /* !CONFIG_LINUX */
 273
 274 #ifndef _WIN32
 275 static int io_thread_fd = -1;
 276
 277 static void qemu_event_increment(void)
 278 {
 279     /* Write 8 bytes to be compatible with eventfd.  */
 280     static const uint64_t val = 1;
 281     ssize_t ret;
 282
 283     if (io_thread_fd == -1) {
 284         return;
 285     }
 286     do {
 287         ret = write(io_thread_fd, &val, sizeof(val));
 288     } while (ret < 0 && errno == EINTR);
 289
 290     /* EAGAIN is fine, a read must be pending.  */
 291     if (ret < 0 && errno != EAGAIN) {
 292         fprintf(stderr, "qemu_event_increment: write() failed: %s\n",
 293                 strerror(errno));
 294         exit (1);
 295     }
 296 }
 297
 298 static void qemu_event_read(void *opaque)
 299 {
 300     int fd = (intptr_t)opaque;
 301     ssize_t len;
 302     char buffer[512];
 303
 304     /* Drain the notify pipe.  For eventfd, only 8 bytes will be read.  */
 305     do {
 306         len = read(fd, buffer, sizeof(buffer));
 307     } while ((len == -1 && errno == EINTR) || len == sizeof(buffer));
 308 }
 309
 310 static int qemu_event_init(void)
 311 {
 312     int err;
 313     int fds[2];
 314
 315     err = qemu_eventfd(fds);
 316     if (err == -1) {
 317         return -errno;
 318     }
 319     err = fcntl_setfl(fds[0], O_NONBLOCK);
 320     if (err < 0) {
 321         goto fail;
 322     }
 323     err = fcntl_setfl(fds[1], O_NONBLOCK);
 324     if (err < 0) {
 325         goto fail;
 326     }
 327     qemu_set_fd_handler2(fds[0], NULL, qemu_event_read, NULL,
 328                          (void *)(intptr_t)fds[0]);
 329
 330     io_thread_fd = fds[1];
 331     return 0;
 332
 333 fail:
 334     close(fds[0]);
 335     close(fds[1]);
 336     return err;
 337 }
 338
 339 static void dummy_signal(int sig)
 340 {
 341 }
 342
 343 /* If we have signalfd, we mask out the signals we want to handle and then
 344  * use signalfd to listen for them.  We rely on whatever the current signal
 345  * handler is to dispatch the signals when we receive them.
 346  */
 347 static void sigfd_handler(void *opaque)
 348 {
 349     int fd = (intptr_t)opaque;
 350     struct qemu_signalfd_siginfo info;
 351     struct sigaction action;
 352     ssize_t len;
 353
 354     while (1) {
 355         do {
 356             len = read(fd, &info, sizeof(info));
 357         } while (len == -1 && errno == EINTR);
 358
 359         if (len == -1 && errno == EAGAIN) {
 360             break;
 361         }
 362
 363         if (len != sizeof(info)) {
 364             printf("read from sigfd returned %zd: %m\n", len);
 365             return;
 366         }
 367
 368         sigaction(info.ssi_signo, NULL, &action);
 369         if ((action.sa_flags & SA_SIGINFO) && action.sa_sigaction) {
 370             action.sa_sigaction(info.ssi_signo,
 371                                 (siginfo_t *)&info, NULL);
 372         } else if (action.sa_handler) {
 373             action.sa_handler(info.ssi_signo);
 374         }
 375     }
 376 }
 377
 378 static int qemu_signal_init(void)
 379 {
 380     int sigfd;
 381     sigset_t set;
 382
 383     /* SIGUSR2 used by posix-aio-compat.c */
 384     sigemptyset(&set);
 385     sigaddset(&set, SIGUSR2);
 386     pthread_sigmask(SIG_UNBLOCK, &set, NULL);
 387
 388     /*
 389      * SIG_IPI must be blocked in the main thread and must not be caught
 390      * by sigwait() in the signal thread. Otherwise, the cpu thread will
 391      * not catch it reliably.
 392      */
 393     sigemptyset(&set);
 394     sigaddset(&set, SIG_IPI);
 395     pthread_sigmask(SIG_BLOCK, &set, NULL);
 396
 397     sigemptyset(&set);
 398     sigaddset(&set, SIGIO);
 399     sigaddset(&set, SIGALRM);
 400     sigaddset(&set, SIGBUS);
 401     pthread_sigmask(SIG_BLOCK, &set, NULL);
 402
 403     sigfd = qemu_signalfd(&set);
 404     if (sigfd == -1) {
 405         fprintf(stderr, "failed to create signalfd\n");
 406         return -errno;
 407     }
 408
 409     fcntl_setfl(sigfd, O_NONBLOCK);
 410
 411     qemu_set_fd_handler2(sigfd, NULL, sigfd_handler, NULL,
 412                          (void *)(intptr_t)sigfd);
 413
 414     return 0;
 415 }
 416
 417 static void qemu_kvm_init_cpu_signals(CPUState *env)
 418 {
 419     int r;
 420     sigset_t set;
 421     struct sigaction sigact;
 422
 423     memset(&sigact, 0, sizeof(sigact));
 424     sigact.sa_handler = dummy_signal;
 425     sigaction(SIG_IPI, &sigact, NULL);
 426
 427     pthread_sigmask(SIG_BLOCK, NULL, &set);
 428     sigdelset(&set, SIG_IPI);
 429     sigdelset(&set, SIGBUS);
 430     r = kvm_set_signal_mask(env, &set);
 431     if (r) {
 432         fprintf(stderr, "kvm_set_signal_mask: %s\n", strerror(-r));
 433         exit(1);
 434     }
 435
 436     sigdelset(&set, SIG_IPI);
 437     sigdelset(&set, SIGBUS);
 438     r = kvm_set_signal_mask(env, &set);
 439     if (r) {
 440         fprintf(stderr, "kvm_set_signal_mask: %s\n", strerror(-r));
 441         exit(1);
 442     }
 443 }
 444
 445 static void qemu_tcg_init_cpu_signals(void)
 446 {
 447     sigset_t set;
 448     struct sigaction sigact;
 449
 450     memset(&sigact, 0, sizeof(sigact));
 451     sigact.sa_handler = cpu_signal;
 452     sigaction(SIG_IPI, &sigact, NULL);
 453
 454     sigemptyset(&set);
 455     sigaddset(&set, SIG_IPI);
 456     pthread_sigmask(SIG_UNBLOCK, &set, NULL);
 457 }
 458
 459 #else /* _WIN32 */
 460
 461 HANDLE qemu_event_handle;
 462
 463 static void dummy_event_handler(void *opaque)
 464 {
 465 }
 466
 467 static int qemu_event_init(void)
 468 {
 469     qemu_event_handle = CreateEvent(NULL, FALSE, FALSE, NULL);
 470     if (!qemu_event_handle) {
 471         fprintf(stderr, "Failed CreateEvent: %ld\n", GetLastError());
 472         return -1;
 473     }
 474     qemu_add_wait_object(qemu_event_handle, dummy_event_handler, NULL);
 475     return 0;
 476 }
 477
 478 static void qemu_event_increment(void)
 479 {
 480     if (!SetEvent(qemu_event_handle)) {
 481         fprintf(stderr, "qemu_event_increment: SetEvent failed: %ld\n",
 482                 GetLastError());
 483         exit (1);
 484     }
 485 }
 486
 487 static int qemu_signal_init(void)
 488 {
 489     return 0;
 490 }
 491
 492 static void qemu_kvm_init_cpu_signals(CPUState *env)
 493 {
 494     abort();
 495 }
 496
 497 static void qemu_tcg_init_cpu_signals(void)
 498 {
 499 }
 500 #endif /* _WIN32 */
 501
 502 QemuMutex qemu_global_mutex;
 503 static QemuCond qemu_io_proceeded_cond;
 504 static bool iothread_requesting_mutex;
 505
 506 static QemuThread io_thread;
 507
 508 static QemuThread *tcg_cpu_thread;
 509 static QemuCond *tcg_halt_cond;
 510
 511 /* cpu creation */
 512 static QemuCond qemu_cpu_cond;
 513 /* system init */
 514 static QemuCond qemu_pause_cond;
 515 static QemuCond qemu_work_cond;
 516
 517 int qemu_init_main_loop(void)
 518 {
 519     int ret;
 520
 521     qemu_init_sigbus();
 522
 523     ret = qemu_signal_init();
 524     if (ret) {
 525         return ret;
 526     }
 527
 528     /* Note eventfd must be drained before signalfd handlers run */
 529     ret = qemu_event_init();
 530     if (ret) {
 531         return ret;
 532     }
 533
 534     qemu_cond_init(&qemu_cpu_cond);
 535     qemu_cond_init(&qemu_pause_cond);
 536     qemu_cond_init(&qemu_work_cond);
 537     qemu_cond_init(&qemu_io_proceeded_cond);
 538     qemu_mutex_init(&qemu_global_mutex);
 539     qemu_mutex_lock(&qemu_global_mutex);
 540
 541     qemu_thread_get_self(&io_thread);
 542
 543     return 0;
 544 }
 545
 546 void qemu_main_loop_start(void)
 547 {
 548     resume_all_vcpus();
 549 }
 550
 551 void run_on_cpu(CPUState *env, void (*func)(void *data), void *data)
 552 {
 553     struct qemu_work_item wi;
 554
 555     if (qemu_cpu_is_self(env)) {
 556         func(data);
 557         return;
 558     }
 559
 560     wi.func = func;
 561     wi.data = data;
 562     if (!env->queued_work_first) {
 563         env->queued_work_first = &wi;
 564     } else {
 565         env->queued_work_last->next = &wi;
 566     }
 567     env->queued_work_last = &wi;
 568     wi.next = NULL;
 569     wi.done = false;
 570
 571     qemu_cpu_kick(env);
 572     while (!wi.done) {
 573         CPUState *self_env = cpu_single_env;
 574
 575         qemu_cond_wait(&qemu_work_cond, &qemu_global_mutex);
 576         cpu_single_env = self_env;
 577     }
 578 }
 579
 580 static void flush_queued_work(CPUState *env)
 581 {
 582     struct qemu_work_item *wi;
 583
 584     if (!env->queued_work_first) {
 585         return;
 586     }
 587
 588     while ((wi = env->queued_work_first)) {
 589         env->queued_work_first = wi->next;
 590         wi->func(wi->data);
 591         wi->done = true;
 592     }
 593     env->queued_work_last = NULL;
 594     qemu_cond_broadcast(&qemu_work_cond);
 595 }
 596
 597 static void qemu_wait_io_event_common(CPUState *env)
 598 {
 599     if (env->stop) {
 600         env->stop = 0;
 601         env->stopped = 1;
 602         qemu_cond_signal(&qemu_pause_cond);
 603     }
 604     flush_queued_work(env);
 605     env->thread_kicked = false;
 606 }
 607
 608 static void qemu_tcg_wait_io_event(void)
 609 {
 610     CPUState *env;
 611
 612     while (all_cpu_threads_idle()) {
 613        /* Start accounting real time to the virtual clock if the CPUs
 614           are idle.  */
 615         qemu_clock_warp(vm_clock);
 616         qemu_cond_wait(tcg_halt_cond, &qemu_global_mutex);
 617     }
 618
 619     while (iothread_requesting_mutex) {
 620         qemu_cond_wait(&qemu_io_proceeded_cond, &qemu_global_mutex);
 621     }
 622
 623     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 624         qemu_wait_io_event_common(env);
 625     }
 626 }
 627
 628 static void qemu_kvm_wait_io_event(CPUState *env)
 629 {
 630     while (cpu_thread_is_idle(env)) {
 631         qemu_cond_wait(env->halt_cond, &qemu_global_mutex);
 632     }
 633
 634     qemu_kvm_eat_signals(env);
 635     qemu_wait_io_event_common(env);
 636 }
 637
 638 static void *qemu_kvm_cpu_thread_fn(void *arg)
 639 {
 640     CPUState *env = arg;
 641     int r;
 642
 643     qemu_mutex_lock(&qemu_global_mutex);
 644     qemu_thread_get_self(env->thread);
 645     env->thread_id = qemu_get_thread_id();
 646
 647     r = kvm_init_vcpu(env);
 648     if (r < 0) {
 649         fprintf(stderr, "kvm_init_vcpu failed: %s\n", strerror(-r));
 650         exit(1);
 651     }
 652
 653     qemu_kvm_init_cpu_signals(env);
 654
 655     /* signal CPU creation */
 656     env->created = 1;
 657     qemu_cond_signal(&qemu_cpu_cond);
 658
 659     while (1) {
 660         if (cpu_can_run(env)) {
 661             r = kvm_cpu_exec(env);
 662             if (r == EXCP_DEBUG) {
 663                 cpu_handle_guest_debug(env);
 664             }
 665         }
 666         qemu_kvm_wait_io_event(env);
 667     }
 668
 669     return NULL;
 670 }
 671
 672 static void *qemu_tcg_cpu_thread_fn(void *arg)
 673 {
 674     CPUState *env = arg;
 675
 676     qemu_tcg_init_cpu_signals();
 677     qemu_thread_get_self(env->thread);
 678
 679     /* signal CPU creation */
 680     qemu_mutex_lock(&qemu_global_mutex);
 681     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 682         env->thread_id = qemu_get_thread_id();
 683         env->created = 1;
 684     }
 685     qemu_cond_signal(&qemu_cpu_cond);
 686
 687     /* wait for initial kick-off after machine start */
 688     while (first_cpu->stopped) {
 689         qemu_cond_wait(tcg_halt_cond, &qemu_global_mutex);
 690     }
 691
 692     while (1) {
 693         cpu_exec_all();
 694         if (use_icount && qemu_next_icount_deadline() <= 0) {
 695             qemu_notify_event();
 696         }
 697         qemu_tcg_wait_io_event();
 698     }
 699
 700     return NULL;
 701 }
 702
 703 static void qemu_cpu_kick_thread(CPUState *env)
 704 {
 705 #ifndef _WIN32
 706     int err;
 707
 708     err = pthread_kill(env->thread->thread, SIG_IPI);
 709     if (err) {
 710         fprintf(stderr, "qemu:%s: %s", __func__, strerror(err));
 711         exit(1);
 712     }
 713 #else /* _WIN32 */
 714     if (!qemu_cpu_is_self(env)) {
 715         SuspendThread(env->thread->thread);
 716         cpu_signal(0);
 717         ResumeThread(env->thread->thread);
 718     }
 719 #endif
 720 }
 721
 722 void qemu_cpu_kick(void *_env)
 723 {
 724     CPUState *env = _env;
 725
 726     qemu_cond_broadcast(env->halt_cond);
 727     if (kvm_enabled() && !env->thread_kicked) {
 728         qemu_cpu_kick_thread(env);
 729         env->thread_kicked = true;
 730     }
 731 }
 732
 733 void qemu_cpu_kick_self(void)
 734 {
 735 #ifndef _WIN32
 736     assert(cpu_single_env);
 737
 738     if (!cpu_single_env->thread_kicked) {
 739         qemu_cpu_kick_thread(cpu_single_env);
 740         cpu_single_env->thread_kicked = true;
 741     }
 742 #else
 743     abort();
 744 #endif
 745 }
 746
 747 int qemu_cpu_is_self(void *_env)
 748 {
 749     CPUState *env = _env;
 750
 751     return qemu_thread_is_self(env->thread);
 752 }
 753
 754 void qemu_mutex_lock_iothread(void)
 755 {
 756     if (kvm_enabled()) {
 757         qemu_mutex_lock(&qemu_global_mutex);
 758     } else {
 759         iothread_requesting_mutex = true;
 760         if (qemu_mutex_trylock(&qemu_global_mutex)) {
 761             qemu_cpu_kick_thread(first_cpu);
 762             qemu_mutex_lock(&qemu_global_mutex);
 763         }
 764         iothread_requesting_mutex = false;
 765         qemu_cond_broadcast(&qemu_io_proceeded_cond);
 766     }
 767 }
 768
 769 void qemu_mutex_unlock_iothread(void)
 770 {
 771     qemu_mutex_unlock(&qemu_global_mutex);
 772 }
 773
 774 static int all_vcpus_paused(void)
 775 {
 776     CPUState *penv = first_cpu;
 777
 778     while (penv) {
 779         if (!penv->stopped) {
 780             return 0;
 781         }
 782         penv = (CPUState *)penv->next_cpu;
 783     }
 784
 785     return 1;
 786 }
 787
 788 void pause_all_vcpus(void)
 789 {
 790     CPUState *penv = first_cpu;
 791
 792     while (penv) {
 793         penv->stop = 1;
 794         qemu_cpu_kick(penv);
 795         penv = (CPUState *)penv->next_cpu;
 796     }
 797
 798     while (!all_vcpus_paused()) {
 799         qemu_cond_wait(&qemu_pause_cond, &qemu_global_mutex);
 800         penv = first_cpu;
 801         while (penv) {
 802             qemu_cpu_kick(penv);
 803             penv = (CPUState *)penv->next_cpu;
 804         }
 805     }
 806 }
 807
 808 void resume_all_vcpus(void)
 809 {
 810     CPUState *penv = first_cpu;
 811
 812     while (penv) {
 813         penv->stop = 0;
 814         penv->stopped = 0;
 815         qemu_cpu_kick(penv);
 816         penv = (CPUState *)penv->next_cpu;
 817     }
 818 }
 819
 820 static void qemu_tcg_init_vcpu(void *_env)
 821 {
 822     CPUState *env = _env;
 823
 824     /* share a single thread for all cpus with TCG */
 825     if (!tcg_cpu_thread) {
 826         env->thread = g_malloc0(sizeof(QemuThread));
 827         env->halt_cond = g_malloc0(sizeof(QemuCond));
 828         qemu_cond_init(env->halt_cond);
 829         tcg_halt_cond = env->halt_cond;
 830         qemu_thread_create(env->thread, qemu_tcg_cpu_thread_fn, env);
 831         while (env->created == 0) {
 832             qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex);
 833         }
 834         tcg_cpu_thread = env->thread;
 835     } else {
 836         env->thread = tcg_cpu_thread;
 837         env->halt_cond = tcg_halt_cond;
 838     }
 839 }
 840
 841 static void qemu_kvm_start_vcpu(CPUState *env)
 842 {
 843     env->thread = g_malloc0(sizeof(QemuThread));
 844     env->halt_cond = g_malloc0(sizeof(QemuCond));
 845     qemu_cond_init(env->halt_cond);
 846     qemu_thread_create(env->thread, qemu_kvm_cpu_thread_fn, env);
 847     while (env->created == 0) {
 848         qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex);
 849     }
 850 }
 851
 852 void qemu_init_vcpu(void *_env)
 853 {
 854     CPUState *env = _env;
 855
 856     env->nr_cores = smp_cores;
 857     env->nr_threads = smp_threads;
 858     env->stopped = 1;
 859     if (kvm_enabled()) {
 860         qemu_kvm_start_vcpu(env);
 861     } else {
 862         qemu_tcg_init_vcpu(env);
 863     }
 864 }
 865
 866 void qemu_notify_event(void)
 867 {
 868     qemu_event_increment();
 869 }
 870
 871 void cpu_stop_current(void)
 872 {
 873     if (cpu_single_env) {
 874         cpu_single_env->stop = 0;
 875         cpu_single_env->stopped = 1;
 876         cpu_exit(cpu_single_env);
 877         qemu_cond_signal(&qemu_pause_cond);
 878     }
 879 }
 880
 881 void vm_stop(int reason)
 882 {
 883     if (!qemu_thread_is_self(&io_thread)) {
 884         qemu_system_vmstop_request(reason);
 885         /*
 886          * FIXME: should not return to device code in case
 887          * vm_stop() has been requested.
 888          */
 889         cpu_stop_current();
 890         return;
 891     }
 892     do_vm_stop(reason);
 893 }
 894
 895 static int tcg_cpu_exec(CPUState *env)
 896 {
 897     int ret;
 898 #ifdef CONFIG_PROFILER
 899     int64_t ti;
 900 #endif
 901
 902 #ifdef CONFIG_PROFILER
 903     ti = profile_getclock();
 904 #endif
 905     if (use_icount) {
 906         int64_t count;
 907         int decr;
 908         qemu_icount -= (env->icount_decr.u16.low + env->icount_extra);
 909         env->icount_decr.u16.low = 0;
 910         env->icount_extra = 0;
 911         count = qemu_icount_round(qemu_next_icount_deadline());
 912         qemu_icount += count;
 913         decr = (count > 0xffff) ? 0xffff : count;
 914         count -= decr;
 915         env->icount_decr.u16.low = decr;
 916         env->icount_extra = count;
 917     }
 918     ret = cpu_exec(env);
 919 #ifdef CONFIG_PROFILER
 920     qemu_time += profile_getclock() - ti;
 921 #endif
 922     if (use_icount) {
 923         /* Fold pending instructions back into the
 924            instruction counter, and clear the interrupt flag.  */
 925         qemu_icount -= (env->icount_decr.u16.low
 926                         + env->icount_extra);
 927         env->icount_decr.u32 = 0;
 928         env->icount_extra = 0;
 929     }
 930     return ret;
 931 }
 932
 933 bool cpu_exec_all(void)
 934 {
 935     int r;
 936
 937     /* Account partial waits to the vm_clock.  */
 938     qemu_clock_warp(vm_clock);
 939
 940     if (next_cpu == NULL) {
 941         next_cpu = first_cpu;
 942     }
 943     for (; next_cpu != NULL && !exit_request; next_cpu = next_cpu->next_cpu) {
 944         CPUState *env = next_cpu;
 945
 946         qemu_clock_enable(vm_clock,
 947                           (env->singlestep_enabled & SSTEP_NOTIMER) == 0);
 948
 949         if (cpu_can_run(env)) {
 950             if (kvm_enabled()) {
 951                 r = kvm_cpu_exec(env);
 952                 qemu_kvm_eat_signals(env);
 953             } else {
 954                 r = tcg_cpu_exec(env);
 955             }
 956             if (r == EXCP_DEBUG) {
 957                 cpu_handle_guest_debug(env);
 958                 break;
 959             }
 960         } else if (env->stop || env->stopped) {
 961             break;
 962         }
 963     }
 964     exit_request = 0;
 965     return !all_cpu_threads_idle();
 966 }
 967
 968 void set_numa_modes(void)
 969 {
 970     CPUState *env;
 971     int i;
 972
 973     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 974         for (i = 0; i < nb_numa_nodes; i++) {
 975             if (node_cpumask[i] & (1 << env->cpu_index)) {
 976                 env->numa_node = i;
 977             }
 978         }
 979     }
 980 }
 981
 982 void set_cpu_log(const char *optarg)
 983 {
 984     int mask;
 985     const CPULogItem *item;
 986
 987     mask = cpu_str_to_log_mask(optarg);
 988     if (!mask) {
 989         printf("Log items (comma separated):\n");
 990         for (item = cpu_log_items; item->mask != 0; item++) {
 991             printf("%-10s %s\n", item->name, item->help);
 992         }
 993         exit(1);
 994     }
 995     cpu_set_log(mask);
 996 }
 997
 998 void set_cpu_log_filename(const char *optarg)
 999 {
1000     cpu_set_log_filename(optarg);
1001 }
1002
1003 /* Return the virtual CPU time, based on the instruction counter.  */
1004 int64_t cpu_get_icount(void)
1005 {
1006     int64_t icount;
1007     CPUState *env = cpu_single_env;;
1008
1009     icount = qemu_icount;
1010     if (env) {
1011         if (!can_do_io(env)) {
1012             fprintf(stderr, "Bad clock read\n");
1013         }
1014         icount -= (env->icount_decr.u16.low + env->icount_extra);
1015     }
1016     return qemu_icount_bias + (icount << icount_time_shift);
1017 }
1018
1019 void list_cpus(FILE *f, fprintf_function cpu_fprintf, const char *optarg)
1020 {
1021     /* XXX: implement xxx_cpu_list for targets that still miss it */
1022 #if defined(cpu_list_id)
1023     cpu_list_id(f, cpu_fprintf, optarg);
1024 #elif defined(cpu_list)
1025     cpu_list(f, cpu_fprintf); /* deprecated */
1026 #endif
1027 }