cpus.c - qemu - Git at Google

 /*
  * 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.
  */

 /* Needed early for CONFIG_BSD etc. */
 #include "config-host.h"

 #include "monitor.h"
 #include "sysemu.h"
 #include "gdbstub.h"
 #include "dma.h"
 #include "kvm.h"

 #include "qemu-thread.h"
 #include "cpus.h"

 #ifndef _WIN32
 #include "compatfd.h"
 #endif

 #ifdef SIGRTMIN
 #define SIG_IPI (SIGRTMIN+4)
 #else
 #define SIG_IPI SIGUSR1
 #endif

 #ifdef CONFIG_LINUX

 #include <sys/prctl.h>

 #ifndef PR_MCE_KILL
 #define PR_MCE_KILL 33
 #endif

 #ifndef PR_MCE_KILL_SET
 #define PR_MCE_KILL_SET 1
 #endif

 #ifndef PR_MCE_KILL_EARLY
 #define PR_MCE_KILL_EARLY 1
 #endif

 #endif /* CONFIG_LINUX */

 static CPUState *next_cpu;

 /***********************************************************/
 void hw_error(const char *fmt, ...)
 {
     va_list ap;
     CPUState *env;

     va_start(ap, fmt);
     fprintf(stderr, "qemu: hardware error: ");
     vfprintf(stderr, fmt, ap);
     fprintf(stderr, "\n");
     for(env = first_cpu; env != NULL; env = env->next_cpu) {
         fprintf(stderr, "CPU #%d:\n", env->cpu_index);
 #ifdef TARGET_I386
         cpu_dump_state(env, stderr, fprintf, X86_DUMP_FPU);
 #else
         cpu_dump_state(env, stderr, fprintf, 0);
 #endif
     }
     va_end(ap);
     abort();
 }

 void cpu_synchronize_all_states(void)
 {
     CPUState *cpu;

     for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
         cpu_synchronize_state(cpu);
     }
 }

 void cpu_synchronize_all_post_reset(void)
 {
     CPUState *cpu;

     for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
         cpu_synchronize_post_reset(cpu);
     }
 }

 void cpu_synchronize_all_post_init(void)
 {
     CPUState *cpu;

     for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
         cpu_synchronize_post_init(cpu);
     }
 }

 int cpu_is_stopped(CPUState *env)
 {
     return !runstate_is_running() || env->stopped;
 }

 static void do_vm_stop(RunState state)
 {
     if (runstate_is_running()) {
         cpu_disable_ticks();
         pause_all_vcpus();
         runstate_set(state);
         vm_state_notify(0, state);
         qemu_aio_flush();
         bdrv_flush_all();
         monitor_protocol_event(QEVENT_STOP, NULL);
     }
 }

 static int cpu_can_run(CPUState *env)
 {
     if (env->stop) {
         return 0;
     }
     if (env->stopped || !runstate_is_running()) {
         return 0;
     }
     return 1;
 }

 static bool cpu_thread_is_idle(CPUState *env)
 {
     if (env->stop || env->queued_work_first) {
         return false;
     }
     if (env->stopped || !runstate_is_running()) {
         return true;
     }
     if (!env->halted || qemu_cpu_has_work(env) ||
         (kvm_enabled() && kvm_irqchip_in_kernel())) {
         return false;
     }
     return true;
 }

 bool all_cpu_threads_idle(void)
 {
     CPUState *env;

     for (env = first_cpu; env != NULL; env = env->next_cpu) {
         if (!cpu_thread_is_idle(env)) {
             return false;
         }
     }
     return true;
 }

 static void cpu_handle_guest_debug(CPUState *env)
 {
     gdb_set_stop_cpu(env);
     qemu_system_debug_request();
     env->stopped = 1;
 }

 static void cpu_signal(int sig)
 {
     if (cpu_single_env) {
         cpu_exit(cpu_single_env);
     }
     exit_request = 1;
 }

 #ifdef CONFIG_LINUX
 static void sigbus_reraise(void)
 {
     sigset_t set;
     struct sigaction action;

     memset(&action, 0, sizeof(action));
     action.sa_handler = SIG_DFL;
     if (!sigaction(SIGBUS, &action, NULL)) {
         raise(SIGBUS);
         sigemptyset(&set);
         sigaddset(&set, SIGBUS);
         sigprocmask(SIG_UNBLOCK, &set, NULL);
     }
     perror("Failed to re-raise SIGBUS!\n");
     abort();
 }

 static void sigbus_handler(int n, struct qemu_signalfd_siginfo *siginfo,
                            void *ctx)
 {
     if (kvm_on_sigbus(siginfo->ssi_code,
                       (void *)(intptr_t)siginfo->ssi_addr)) {
         sigbus_reraise();
     }
 }

 static void qemu_init_sigbus(void)
 {
     struct sigaction action;

     memset(&action, 0, sizeof(action));
     action.sa_flags = SA_SIGINFO;
     action.sa_sigaction = (void (*)(int, siginfo_t*, void*))sigbus_handler;
     sigaction(SIGBUS, &action, NULL);

     prctl(PR_MCE_KILL, PR_MCE_KILL_SET, PR_MCE_KILL_EARLY, 0, 0);
 }

 static void qemu_kvm_eat_signals(CPUState *env)
 {
     struct timespec ts = { 0, 0 };
     siginfo_t siginfo;
     sigset_t waitset;
     sigset_t chkset;
     int r;

     sigemptyset(&waitset);
     sigaddset(&waitset, SIG_IPI);
     sigaddset(&waitset, SIGBUS);

     do {
         r = sigtimedwait(&waitset, &siginfo, &ts);
         if (r == -1 && !(errno == EAGAIN || errno == EINTR)) {
             perror("sigtimedwait");
             exit(1);
         }

         switch (r) {
         case SIGBUS:
             if (kvm_on_sigbus_vcpu(env, siginfo.si_code, siginfo.si_addr)) {
                 sigbus_reraise();
             }
             break;
         default:
             break;
         }

         r = sigpending(&chkset);
         if (r == -1) {
             perror("sigpending");
             exit(1);
         }
     } while (sigismember(&chkset, SIG_IPI) || sigismember(&chkset, SIGBUS));
 }

 #else /* !CONFIG_LINUX */

 static void qemu_init_sigbus(void)
 {
 }

 static void qemu_kvm_eat_signals(CPUState *env)
 {
 }
 #endif /* !CONFIG_LINUX */

 #ifndef _WIN32
 static int io_thread_fd = -1;

 static void qemu_event_increment(void)
 {
     /* Write 8 bytes to be compatible with eventfd.  */
     static const uint64_t val = 1;
     ssize_t ret;

     if (io_thread_fd == -1) {
         return;
     }
     do {
         ret = write(io_thread_fd, &val, sizeof(val));
     } while (ret < 0 && errno == EINTR);

     /* EAGAIN is fine, a read must be pending.  */
     if (ret < 0 && errno != EAGAIN) {
         fprintf(stderr, "qemu_event_increment: write() failed: %s\n",
                 strerror(errno));
         exit (1);
     }
 }

 static void qemu_event_read(void *opaque)
 {
     int fd = (intptr_t)opaque;
     ssize_t len;
     char buffer[512];

     /* Drain the notify pipe.  For eventfd, only 8 bytes will be read.  */
     do {
         len = read(fd, buffer, sizeof(buffer));
     } while ((len == -1 && errno == EINTR) || len == sizeof(buffer));
 }

 static int qemu_event_init(void)
 {
     int err;
     int fds[2];

     err = qemu_eventfd(fds);
     if (err == -1) {
         return -errno;
     }
     err = fcntl_setfl(fds[0], O_NONBLOCK);
     if (err < 0) {
         goto fail;
     }
     err = fcntl_setfl(fds[1], O_NONBLOCK);
     if (err < 0) {
         goto fail;
     }
     qemu_set_fd_handler2(fds[0], NULL, qemu_event_read, NULL,
                          (void *)(intptr_t)fds[0]);

     io_thread_fd = fds[1];
     return 0;

 fail:
     close(fds[0]);
     close(fds[1]);
     return err;
 }

 static void dummy_signal(int sig)
 {
 }

 /* If we have signalfd, we mask out the signals we want to handle and then
  * use signalfd to listen for them.  We rely on whatever the current signal
  * handler is to dispatch the signals when we receive them.
  */
 static void sigfd_handler(void *opaque)
 {
     int fd = (intptr_t)opaque;
     struct qemu_signalfd_siginfo info;
     struct sigaction action;
     ssize_t len;

     while (1) {
         do {
             len = read(fd, &info, sizeof(info));
         } while (len == -1 && errno == EINTR);

         if (len == -1 && errno == EAGAIN) {
             break;
         }

         if (len != sizeof(info)) {
             printf("read from sigfd returned %zd: %m\n", len);
             return;
         }

         sigaction(info.ssi_signo, NULL, &action);
         if ((action.sa_flags & SA_SIGINFO) && action.sa_sigaction) {
             action.sa_sigaction(info.ssi_signo,
                                 (siginfo_t *)&info, NULL);
         } else if (action.sa_handler) {
             action.sa_handler(info.ssi_signo);
         }
     }
 }

 static int qemu_signal_init(void)
 {
     int sigfd;
     sigset_t set;

     /*
      * SIG_IPI must be blocked in the main thread and must not be caught
      * by sigwait() in the signal thread. Otherwise, the cpu thread will
      * not catch it reliably.
      */
     sigemptyset(&set);
     sigaddset(&set, SIG_IPI);
     pthread_sigmask(SIG_BLOCK, &set, NULL);

     sigemptyset(&set);
     sigaddset(&set, SIGIO);
     sigaddset(&set, SIGALRM);
     sigaddset(&set, SIGBUS);
     pthread_sigmask(SIG_BLOCK, &set, NULL);

     sigfd = qemu_signalfd(&set);
     if (sigfd == -1) {
         fprintf(stderr, "failed to create signalfd\n");
         return -errno;
     }

     fcntl_setfl(sigfd, O_NONBLOCK);

     qemu_set_fd_handler2(sigfd, NULL, sigfd_handler, NULL,
                          (void *)(intptr_t)sigfd);

     return 0;
 }

 static void qemu_kvm_init_cpu_signals(CPUState *env)
 {
     int r;
     sigset_t set;
     struct sigaction sigact;

     memset(&sigact, 0, sizeof(sigact));
     sigact.sa_handler = dummy_signal;
     sigaction(SIG_IPI, &sigact, NULL);

     pthread_sigmask(SIG_BLOCK, NULL, &set);
     sigdelset(&set, SIG_IPI);
     sigdelset(&set, SIGBUS);
     r = kvm_set_signal_mask(env, &set);
     if (r) {
         fprintf(stderr, "kvm_set_signal_mask: %s\n", strerror(-r));
         exit(1);
     }

     sigdelset(&set, SIG_IPI);
     sigdelset(&set, SIGBUS);
     r = kvm_set_signal_mask(env, &set);
     if (r) {
         fprintf(stderr, "kvm_set_signal_mask: %s\n", strerror(-r));
         exit(1);
     }
 }

 static void qemu_tcg_init_cpu_signals(void)
 {
     sigset_t set;
     struct sigaction sigact;

     memset(&sigact, 0, sizeof(sigact));
     sigact.sa_handler = cpu_signal;
     sigaction(SIG_IPI, &sigact, NULL);

     sigemptyset(&set);
     sigaddset(&set, SIG_IPI);
     pthread_sigmask(SIG_UNBLOCK, &set, NULL);
 }

 #else /* _WIN32 */

 HANDLE qemu_event_handle;

 static void dummy_event_handler(void *opaque)
 {
 }

 static int qemu_event_init(void)
 {
     qemu_event_handle = CreateEvent(NULL, FALSE, FALSE, NULL);
     if (!qemu_event_handle) {
         fprintf(stderr, "Failed CreateEvent: %ld\n", GetLastError());
         return -1;
     }
     qemu_add_wait_object(qemu_event_handle, dummy_event_handler, NULL);
     return 0;
 }

 static void qemu_event_increment(void)
 {
     if (!SetEvent(qemu_event_handle)) {
         fprintf(stderr, "qemu_event_increment: SetEvent failed: %ld\n",
                 GetLastError());
         exit (1);
     }
 }

 static int qemu_signal_init(void)
 {
     return 0;
 }

 static void qemu_kvm_init_cpu_signals(CPUState *env)
 {
     abort();
 }

 static void qemu_tcg_init_cpu_signals(void)
 {
 }
 #endif /* _WIN32 */

 QemuMutex qemu_global_mutex;
 static QemuCond qemu_io_proceeded_cond;
 static bool iothread_requesting_mutex;

 static QemuThread io_thread;

 static QemuThread *tcg_cpu_thread;
 static QemuCond *tcg_halt_cond;

 /* cpu creation */
 static QemuCond qemu_cpu_cond;
 /* system init */
 static QemuCond qemu_pause_cond;
 static QemuCond qemu_work_cond;

 int qemu_init_main_loop(void)
 {
     int ret;

     qemu_init_sigbus();

     ret = qemu_signal_init();
     if (ret) {
         return ret;
     }

     /* Note eventfd must be drained before signalfd handlers run */
     ret = qemu_event_init();
     if (ret) {
         return ret;
     }

     qemu_cond_init(&qemu_cpu_cond);
     qemu_cond_init(&qemu_pause_cond);
     qemu_cond_init(&qemu_work_cond);
     qemu_cond_init(&qemu_io_proceeded_cond);
     qemu_mutex_init(&qemu_global_mutex);
     qemu_mutex_lock(&qemu_global_mutex);

     qemu_thread_get_self(&io_thread);

     return 0;
 }

 void qemu_main_loop_start(void)
 {
     resume_all_vcpus();
 }

 void run_on_cpu(CPUState *env, void (*func)(void *data), void *data)
 {
     struct qemu_work_item wi;

     if (qemu_cpu_is_self(env)) {
         func(data);
         return;
     }

     wi.func = func;
     wi.data = data;
     if (!env->queued_work_first) {
         env->queued_work_first = &wi;
     } else {
         env->queued_work_last->next = &wi;
     }
     env->queued_work_last = &wi;
     wi.next = NULL;
     wi.done = false;

     qemu_cpu_kick(env);
     while (!wi.done) {
         CPUState *self_env = cpu_single_env;

         qemu_cond_wait(&qemu_work_cond, &qemu_global_mutex);
         cpu_single_env = self_env;
     }
 }

 static void flush_queued_work(CPUState *env)
 {
     struct qemu_work_item *wi;

     if (!env->queued_work_first) {
         return;
     }

     while ((wi = env->queued_work_first)) {
         env->queued_work_first = wi->next;
         wi->func(wi->data);
         wi->done = true;
     }
     env->queued_work_last = NULL;
     qemu_cond_broadcast(&qemu_work_cond);
 }

 static void qemu_wait_io_event_common(CPUState *env)
 {
     if (env->stop) {
         env->stop = 0;
         env->stopped = 1;
         qemu_cond_signal(&qemu_pause_cond);
     }
     flush_queued_work(env);
     env->thread_kicked = false;
 }

 static void qemu_tcg_wait_io_event(void)
 {
     CPUState *env;

     while (all_cpu_threads_idle()) {
        /* Start accounting real time to the virtual clock if the CPUs
           are idle.  */
         qemu_clock_warp(vm_clock);
         qemu_cond_wait(tcg_halt_cond, &qemu_global_mutex);
     }

     while (iothread_requesting_mutex) {
         qemu_cond_wait(&qemu_io_proceeded_cond, &qemu_global_mutex);
     }

     for (env = first_cpu; env != NULL; env = env->next_cpu) {
         qemu_wait_io_event_common(env);
     }
 }

 static void qemu_kvm_wait_io_event(CPUState *env)
 {
     while (cpu_thread_is_idle(env)) {
         qemu_cond_wait(env->halt_cond, &qemu_global_mutex);
     }

     qemu_kvm_eat_signals(env);
     qemu_wait_io_event_common(env);
 }

 static void *qemu_kvm_cpu_thread_fn(void *arg)
 {
     CPUState *env = arg;
     int r;

     qemu_mutex_lock(&qemu_global_mutex);
     qemu_thread_get_self(env->thread);
     env->thread_id = qemu_get_thread_id();

     r = kvm_init_vcpu(env);
     if (r < 0) {
         fprintf(stderr, "kvm_init_vcpu failed: %s\n", strerror(-r));
         exit(1);
     }

     qemu_kvm_init_cpu_signals(env);

     /* signal CPU creation */
     env->created = 1;
     qemu_cond_signal(&qemu_cpu_cond);

     while (1) {
         if (cpu_can_run(env)) {
             r = kvm_cpu_exec(env);
             if (r == EXCP_DEBUG) {
                 cpu_handle_guest_debug(env);
             }
         }
         qemu_kvm_wait_io_event(env);
     }

     return NULL;
 }

 static void *qemu_tcg_cpu_thread_fn(void *arg)
 {
     CPUState *env = arg;

     qemu_tcg_init_cpu_signals();
     qemu_thread_get_self(env->thread);

     /* signal CPU creation */
     qemu_mutex_lock(&qemu_global_mutex);
     for (env = first_cpu; env != NULL; env = env->next_cpu) {
         env->thread_id = qemu_get_thread_id();
         env->created = 1;
     }
     qemu_cond_signal(&qemu_cpu_cond);

     /* wait for initial kick-off after machine start */
     while (first_cpu->stopped) {
         qemu_cond_wait(tcg_halt_cond, &qemu_global_mutex);
     }

     while (1) {
         cpu_exec_all();
         if (use_icount && qemu_next_icount_deadline() <= 0) {
             qemu_notify_event();
         }
         qemu_tcg_wait_io_event();
     }

     return NULL;
 }

 static void qemu_cpu_kick_thread(CPUState *env)
 {
 #ifndef _WIN32
     int err;

     err = pthread_kill(env->thread->thread, SIG_IPI);
     if (err) {
         fprintf(stderr, "qemu:%s: %s", __func__, strerror(err));
         exit(1);
     }
 #else /* _WIN32 */
     if (!qemu_cpu_is_self(env)) {
         SuspendThread(env->thread->thread);
         cpu_signal(0);
         ResumeThread(env->thread->thread);
     }
 #endif
 }

 void qemu_cpu_kick(void *_env)
 {
     CPUState *env = _env;

     qemu_cond_broadcast(env->halt_cond);
     if (kvm_enabled() && !env->thread_kicked) {
         qemu_cpu_kick_thread(env);
         env->thread_kicked = true;
     }
 }

 void qemu_cpu_kick_self(void)
 {
 #ifndef _WIN32
     assert(cpu_single_env);

     if (!cpu_single_env->thread_kicked) {
         qemu_cpu_kick_thread(cpu_single_env);
         cpu_single_env->thread_kicked = true;
     }
 #else
     abort();
 #endif
 }

 int qemu_cpu_is_self(void *_env)
 {
     CPUState *env = _env;

     return qemu_thread_is_self(env->thread);
 }

 void qemu_mutex_lock_iothread(void)
 {
     if (kvm_enabled()) {
         qemu_mutex_lock(&qemu_global_mutex);
     } else {
         iothread_requesting_mutex = true;
         if (qemu_mutex_trylock(&qemu_global_mutex)) {
             qemu_cpu_kick_thread(first_cpu);
             qemu_mutex_lock(&qemu_global_mutex);
         }
         iothread_requesting_mutex = false;
         qemu_cond_broadcast(&qemu_io_proceeded_cond);
     }
 }

 void qemu_mutex_unlock_iothread(void)
 {
     qemu_mutex_unlock(&qemu_global_mutex);
 }

 static int all_vcpus_paused(void)
 {
     CPUState *penv = first_cpu;

     while (penv) {
         if (!penv->stopped) {
             return 0;
         }
         penv = (CPUState *)penv->next_cpu;
     }

     return 1;
 }

 void pause_all_vcpus(void)
 {
     CPUState *penv = first_cpu;

     while (penv) {
         penv->stop = 1;
         qemu_cpu_kick(penv);
         penv = (CPUState *)penv->next_cpu;
     }

     while (!all_vcpus_paused()) {
         qemu_cond_wait(&qemu_pause_cond, &qemu_global_mutex);
         penv = first_cpu;
         while (penv) {
             qemu_cpu_kick(penv);
             penv = (CPUState *)penv->next_cpu;
         }
     }
 }

 void resume_all_vcpus(void)
 {
     CPUState *penv = first_cpu;

     while (penv) {
         penv->stop = 0;
         penv->stopped = 0;
         qemu_cpu_kick(penv);
         penv = (CPUState *)penv->next_cpu;
     }
 }

 static void qemu_tcg_init_vcpu(void *_env)
 {
     CPUState *env = _env;

     /* share a single thread for all cpus with TCG */
     if (!tcg_cpu_thread) {
         env->thread = g_malloc0(sizeof(QemuThread));
         env->halt_cond = g_malloc0(sizeof(QemuCond));
         qemu_cond_init(env->halt_cond);
         tcg_halt_cond = env->halt_cond;
         qemu_thread_create(env->thread, qemu_tcg_cpu_thread_fn, env);
         while (env->created == 0) {
             qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex);
         }
         tcg_cpu_thread = env->thread;
     } else {
         env->thread = tcg_cpu_thread;
         env->halt_cond = tcg_halt_cond;
     }
 }

 static void qemu_kvm_start_vcpu(CPUState *env)
 {
     env->thread = g_malloc0(sizeof(QemuThread));
     env->halt_cond = g_malloc0(sizeof(QemuCond));
     qemu_cond_init(env->halt_cond);
     qemu_thread_create(env->thread, qemu_kvm_cpu_thread_fn, env);
     while (env->created == 0) {
         qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex);
     }
 }

 void qemu_init_vcpu(void *_env)
 {
     CPUState *env = _env;

     env->nr_cores = smp_cores;
     env->nr_threads = smp_threads;
     env->stopped = 1;
     if (kvm_enabled()) {
         qemu_kvm_start_vcpu(env);
     } else {
         qemu_tcg_init_vcpu(env);
     }
 }

 void qemu_notify_event(void)
 {
     qemu_event_increment();
 }

 void cpu_stop_current(void)
 {
     if (cpu_single_env) {
         cpu_single_env->stop = 0;
         cpu_single_env->stopped = 1;
         cpu_exit(cpu_single_env);
         qemu_cond_signal(&qemu_pause_cond);
     }
 }

 void vm_stop(RunState state)
 {
     if (!qemu_thread_is_self(&io_thread)) {
         qemu_system_vmstop_request(state);
         /*
          * FIXME: should not return to device code in case
          * vm_stop() has been requested.
          */
         cpu_stop_current();
         return;
     }
     do_vm_stop(state);
 }

 static int tcg_cpu_exec(CPUState *env)
 {
     int ret;
 #ifdef CONFIG_PROFILER
     int64_t ti;
 #endif

 #ifdef CONFIG_PROFILER
     ti = profile_getclock();
 #endif
     if (use_icount) {
         int64_t count;
         int decr;
         qemu_icount -= (env->icount_decr.u16.low + env->icount_extra);
         env->icount_decr.u16.low = 0;
         env->icount_extra = 0;
         count = qemu_icount_round(qemu_next_icount_deadline());
         qemu_icount += count;
         decr = (count > 0xffff) ? 0xffff : count;
         count -= decr;
         env->icount_decr.u16.low = decr;
         env->icount_extra = count;
     }
     ret = cpu_exec(env);
 #ifdef CONFIG_PROFILER
     qemu_time += profile_getclock() - ti;
 #endif
     if (use_icount) {
         /* Fold pending instructions back into the
            instruction counter, and clear the interrupt flag.  */
         qemu_icount -= (env->icount_decr.u16.low
                         + env->icount_extra);
         env->icount_decr.u32 = 0;
         env->icount_extra = 0;
     }
     return ret;
 }

 bool cpu_exec_all(void)
 {
     int r;

     /* Account partial waits to the vm_clock.  */
     qemu_clock_warp(vm_clock);

     if (next_cpu == NULL) {
         next_cpu = first_cpu;
     }
     for (; next_cpu != NULL && !exit_request; next_cpu = next_cpu->next_cpu) {
         CPUState *env = next_cpu;

         qemu_clock_enable(vm_clock,
                           (env->singlestep_enabled & SSTEP_NOTIMER) == 0);

         if (cpu_can_run(env)) {
             if (kvm_enabled()) {
                 r = kvm_cpu_exec(env);
                 qemu_kvm_eat_signals(env);
             } else {
                 r = tcg_cpu_exec(env);
             }
             if (r == EXCP_DEBUG) {
                 cpu_handle_guest_debug(env);
                 break;
             }
         } else if (env->stop || env->stopped) {
             break;
         }
     }
     exit_request = 0;
     return !all_cpu_threads_idle();
 }

 void set_numa_modes(void)
 {
     CPUState *env;
     int i;

     for (env = first_cpu; env != NULL; env = env->next_cpu) {
         for (i = 0; i < nb_numa_nodes; i++) {
             if (node_cpumask[i] & (1 << env->cpu_index)) {
                 env->numa_node = i;
             }
         }
     }
 }

 void set_cpu_log(const char *optarg)
 {
     int mask;
     const CPULogItem *item;

     mask = cpu_str_to_log_mask(optarg);
     if (!mask) {
         printf("Log items (comma separated):\n");
         for (item = cpu_log_items; item->mask != 0; item++) {
             printf("%-10s %s\n", item->name, item->help);
         }
         exit(1);
     }
     cpu_set_log(mask);
 }

 void set_cpu_log_filename(const char *optarg)
 {
     cpu_set_log_filename(optarg);
 }

 /* Return the virtual CPU time, based on the instruction counter.  */
 int64_t cpu_get_icount(void)
 {
     int64_t icount;
     CPUState *env = cpu_single_env;;

     icount = qemu_icount;
     if (env) {
         if (!can_do_io(env)) {
             fprintf(stderr, "Bad clock read\n");
         }
         icount -= (env->icount_decr.u16.low + env->icount_extra);
     }
     return qemu_icount_bias + (icount << icount_time_shift);
 }

 void list_cpus(FILE *f, fprintf_function cpu_fprintf, const char *optarg)
 {
     /* XXX: implement xxx_cpu_list for targets that still miss it */
 #if defined(cpu_list_id)
     cpu_list_id(f, cpu_fprintf, optarg);
 #elif defined(cpu_list)
     cpu_list(f, cpu_fprintf); /* deprecated */
 #endif
 }
	/*
	* 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.
	*/

	/* Needed early for CONFIG_BSD etc. */
	#include "config-host.h"

	#include "monitor.h"
	#include "sysemu.h"
	#include "gdbstub.h"
	#include "dma.h"
	#include "kvm.h"

	#include "qemu-thread.h"
	#include "cpus.h"

	#ifndef _WIN32
	#include "compatfd.h"
	#endif

	#ifdef SIGRTMIN
	#define SIG_IPI (SIGRTMIN+4)
	#else
	#define SIG_IPI SIGUSR1
	#endif

	#ifdef CONFIG_LINUX

	#include <sys/prctl.h>

	#ifndef PR_MCE_KILL
	#define PR_MCE_KILL 33
	#endif

	#ifndef PR_MCE_KILL_SET
	#define PR_MCE_KILL_SET 1
	#endif

	#ifndef PR_MCE_KILL_EARLY
	#define PR_MCE_KILL_EARLY 1
	#endif

	#endif /* CONFIG_LINUX */

	static CPUState *next_cpu;

	/***********************************************************/
	void hw_error(const char *fmt, ...)
	{
	va_list ap;
	CPUState *env;

	va_start(ap, fmt);
	fprintf(stderr, "qemu: hardware error: ");
	vfprintf(stderr, fmt, ap);
	fprintf(stderr, "\n");
	for(env = first_cpu; env != NULL; env = env->next_cpu) {
	fprintf(stderr, "CPU #%d:\n", env->cpu_index);
	#ifdef TARGET_I386
	cpu_dump_state(env, stderr, fprintf, X86_DUMP_FPU);
	#else
	cpu_dump_state(env, stderr, fprintf, 0);
	#endif
	}
	va_end(ap);
	abort();
	}

	void cpu_synchronize_all_states(void)
	{
	CPUState *cpu;

	for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
	cpu_synchronize_state(cpu);
	}
	}

	void cpu_synchronize_all_post_reset(void)
	{
	CPUState *cpu;

	for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
	cpu_synchronize_post_reset(cpu);
	}
	}

	void cpu_synchronize_all_post_init(void)
	{
	CPUState *cpu;

	for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
	cpu_synchronize_post_init(cpu);
	}
	}

	int cpu_is_stopped(CPUState *env)
	{
	return !runstate_is_running() \|\| env->stopped;
	}

	static void do_vm_stop(RunState state)
	{
	if (runstate_is_running()) {
	cpu_disable_ticks();
	pause_all_vcpus();
	runstate_set(state);
	vm_state_notify(0, state);
	qemu_aio_flush();
	bdrv_flush_all();
	monitor_protocol_event(QEVENT_STOP, NULL);
	}
	}

	static int cpu_can_run(CPUState *env)
	{
	if (env->stop) {
	return 0;
	}
	if (env->stopped \|\| !runstate_is_running()) {
	return 0;
	}
	return 1;
	}

	static bool cpu_thread_is_idle(CPUState *env)
	{
	if (env->stop \|\| env->queued_work_first) {
	return false;
	}
	if (env->stopped \|\| !runstate_is_running()) {
	return true;
	}
	if (!env->halted \|\| qemu_cpu_has_work(env) \|\|
	(kvm_enabled() && kvm_irqchip_in_kernel())) {
	return false;
	}
	return true;
	}

	bool all_cpu_threads_idle(void)
	{
	CPUState *env;

	for (env = first_cpu; env != NULL; env = env->next_cpu) {
	if (!cpu_thread_is_idle(env)) {
	return false;
	}
	}
	return true;
	}

	static void cpu_handle_guest_debug(CPUState *env)
	{
	gdb_set_stop_cpu(env);
	qemu_system_debug_request();
	env->stopped = 1;
	}

	static void cpu_signal(int sig)
	{
	if (cpu_single_env) {
	cpu_exit(cpu_single_env);
	}
	exit_request = 1;
	}

	#ifdef CONFIG_LINUX
	static void sigbus_reraise(void)
	{
	sigset_t set;
	struct sigaction action;

	memset(&action, 0, sizeof(action));
	action.sa_handler = SIG_DFL;
	if (!sigaction(SIGBUS, &action, NULL)) {
	raise(SIGBUS);
	sigemptyset(&set);
	sigaddset(&set, SIGBUS);
	sigprocmask(SIG_UNBLOCK, &set, NULL);
	}
	perror("Failed to re-raise SIGBUS!\n");
	abort();
	}

	static void sigbus_handler(int n, struct qemu_signalfd_siginfo *siginfo,
	void *ctx)
	{
	if (kvm_on_sigbus(siginfo->ssi_code,
	(void *)(intptr_t)siginfo->ssi_addr)) {
	sigbus_reraise();
	}
	}

	static void qemu_init_sigbus(void)
	{
	struct sigaction action;

	memset(&action, 0, sizeof(action));
	action.sa_flags = SA_SIGINFO;
	action.sa_sigaction = (void ()(int, siginfo_t, void*))sigbus_handler;
	sigaction(SIGBUS, &action, NULL);

	prctl(PR_MCE_KILL, PR_MCE_KILL_SET, PR_MCE_KILL_EARLY, 0, 0);
	}

	static void qemu_kvm_eat_signals(CPUState *env)
	{
	struct timespec ts = { 0, 0 };
	siginfo_t siginfo;
	sigset_t waitset;
	sigset_t chkset;
	int r;

	sigemptyset(&waitset);
	sigaddset(&waitset, SIG_IPI);
	sigaddset(&waitset, SIGBUS);

	do {
	r = sigtimedwait(&waitset, &siginfo, &ts);
	if (r == -1 && !(errno == EAGAIN \|\| errno == EINTR)) {
	perror("sigtimedwait");
	exit(1);
	}

	switch (r) {
	case SIGBUS:
	if (kvm_on_sigbus_vcpu(env, siginfo.si_code, siginfo.si_addr)) {
	sigbus_reraise();
	}
	break;
	default:
	break;
	}

	r = sigpending(&chkset);
	if (r == -1) {
	perror("sigpending");
	exit(1);
	}
	} while (sigismember(&chkset, SIG_IPI) \|\| sigismember(&chkset, SIGBUS));
	}

	#else /* !CONFIG_LINUX */

	static void qemu_init_sigbus(void)
	{
	}

	static void qemu_kvm_eat_signals(CPUState *env)
	{
	}
	#endif /* !CONFIG_LINUX */

	#ifndef _WIN32
	static int io_thread_fd = -1;

	static void qemu_event_increment(void)
	{
	/* Write 8 bytes to be compatible with eventfd. */
	static const uint64_t val = 1;
	ssize_t ret;

	if (io_thread_fd == -1) {
	return;
	}
	do {
	ret = write(io_thread_fd, &val, sizeof(val));
	} while (ret < 0 && errno == EINTR);

	/* EAGAIN is fine, a read must be pending. */
	if (ret < 0 && errno != EAGAIN) {
	fprintf(stderr, "qemu_event_increment: write() failed: %s\n",
	strerror(errno));
	exit (1);
	}
	}

	static void qemu_event_read(void *opaque)
	{
	int fd = (intptr_t)opaque;
	ssize_t len;
	char buffer[512];

	/* Drain the notify pipe. For eventfd, only 8 bytes will be read. */
	do {
	len = read(fd, buffer, sizeof(buffer));
	} while ((len == -1 && errno == EINTR) \|\| len == sizeof(buffer));
	}

	static int qemu_event_init(void)
	{
	int err;
	int fds[2];

	err = qemu_eventfd(fds);
	if (err == -1) {
	return -errno;
	}
	err = fcntl_setfl(fds[0], O_NONBLOCK);
	if (err < 0) {
	goto fail;
	}
	err = fcntl_setfl(fds[1], O_NONBLOCK);
	if (err < 0) {
	goto fail;
	}
	qemu_set_fd_handler2(fds[0], NULL, qemu_event_read, NULL,
	(void *)(intptr_t)fds[0]);

	io_thread_fd = fds[1];
	return 0;

	fail:
	close(fds[0]);
	close(fds[1]);
	return err;
	}

	static void dummy_signal(int sig)
	{
	}

	/* If we have signalfd, we mask out the signals we want to handle and then
	* use signalfd to listen for them. We rely on whatever the current signal
	* handler is to dispatch the signals when we receive them.
	*/
	static void sigfd_handler(void *opaque)
	{
	int fd = (intptr_t)opaque;
	struct qemu_signalfd_siginfo info;
	struct sigaction action;
	ssize_t len;

	while (1) {
	do {
	len = read(fd, &info, sizeof(info));
	} while (len == -1 && errno == EINTR);

	if (len == -1 && errno == EAGAIN) {
	break;
	}

	if (len != sizeof(info)) {
	printf("read from sigfd returned %zd: %m\n", len);
	return;
	}

	sigaction(info.ssi_signo, NULL, &action);
	if ((action.sa_flags & SA_SIGINFO) && action.sa_sigaction) {
	action.sa_sigaction(info.ssi_signo,
	(siginfo_t *)&info, NULL);
	} else if (action.sa_handler) {
	action.sa_handler(info.ssi_signo);
	}
	}
	}

	static int qemu_signal_init(void)
	{
	int sigfd;
	sigset_t set;

	/*
	* SIG_IPI must be blocked in the main thread and must not be caught
	* by sigwait() in the signal thread. Otherwise, the cpu thread will
	* not catch it reliably.
	*/
	sigemptyset(&set);
	sigaddset(&set, SIG_IPI);
	pthread_sigmask(SIG_BLOCK, &set, NULL);

	sigemptyset(&set);
	sigaddset(&set, SIGIO);
	sigaddset(&set, SIGALRM);
	sigaddset(&set, SIGBUS);
	pthread_sigmask(SIG_BLOCK, &set, NULL);

	sigfd = qemu_signalfd(&set);
	if (sigfd == -1) {
	fprintf(stderr, "failed to create signalfd\n");
	return -errno;
	}

	fcntl_setfl(sigfd, O_NONBLOCK);

	qemu_set_fd_handler2(sigfd, NULL, sigfd_handler, NULL,
	(void *)(intptr_t)sigfd);

	return 0;
	}

	static void qemu_kvm_init_cpu_signals(CPUState *env)
	{
	int r;
	sigset_t set;
	struct sigaction sigact;

	memset(&sigact, 0, sizeof(sigact));
	sigact.sa_handler = dummy_signal;
	sigaction(SIG_IPI, &sigact, NULL);

	pthread_sigmask(SIG_BLOCK, NULL, &set);
	sigdelset(&set, SIG_IPI);
	sigdelset(&set, SIGBUS);
	r = kvm_set_signal_mask(env, &set);
	if (r) {
	fprintf(stderr, "kvm_set_signal_mask: %s\n", strerror(-r));
	exit(1);
	}

	sigdelset(&set, SIG_IPI);
	sigdelset(&set, SIGBUS);
	r = kvm_set_signal_mask(env, &set);
	if (r) {
	fprintf(stderr, "kvm_set_signal_mask: %s\n", strerror(-r));
	exit(1);
	}
	}

	static void qemu_tcg_init_cpu_signals(void)
	{
	sigset_t set;
	struct sigaction sigact;

	memset(&sigact, 0, sizeof(sigact));
	sigact.sa_handler = cpu_signal;
	sigaction(SIG_IPI, &sigact, NULL);

	sigemptyset(&set);
	sigaddset(&set, SIG_IPI);
	pthread_sigmask(SIG_UNBLOCK, &set, NULL);
	}

	#else /* _WIN32 */

	HANDLE qemu_event_handle;

	static void dummy_event_handler(void *opaque)
	{
	}

	static int qemu_event_init(void)
	{
	qemu_event_handle = CreateEvent(NULL, FALSE, FALSE, NULL);
	if (!qemu_event_handle) {
	fprintf(stderr, "Failed CreateEvent: %ld\n", GetLastError());
	return -1;
	}
	qemu_add_wait_object(qemu_event_handle, dummy_event_handler, NULL);
	return 0;
	}

	static void qemu_event_increment(void)
	{
	if (!SetEvent(qemu_event_handle)) {
	fprintf(stderr, "qemu_event_increment: SetEvent failed: %ld\n",
	GetLastError());
	exit (1);
	}
	}

	static int qemu_signal_init(void)
	{
	return 0;
	}

	static void qemu_kvm_init_cpu_signals(CPUState *env)
	{
	abort();
	}

	static void qemu_tcg_init_cpu_signals(void)
	{
	}
	#endif /* _WIN32 */

	QemuMutex qemu_global_mutex;
	static QemuCond qemu_io_proceeded_cond;
	static bool iothread_requesting_mutex;

	static QemuThread io_thread;

	static QemuThread *tcg_cpu_thread;
	static QemuCond *tcg_halt_cond;

	/* cpu creation */
	static QemuCond qemu_cpu_cond;
	/* system init */
	static QemuCond qemu_pause_cond;
	static QemuCond qemu_work_cond;

	int qemu_init_main_loop(void)
	{
	int ret;

	qemu_init_sigbus();

	ret = qemu_signal_init();
	if (ret) {
	return ret;
	}

	/* Note eventfd must be drained before signalfd handlers run */
	ret = qemu_event_init();
	if (ret) {
	return ret;
	}

	qemu_cond_init(&qemu_cpu_cond);
	qemu_cond_init(&qemu_pause_cond);
	qemu_cond_init(&qemu_work_cond);
	qemu_cond_init(&qemu_io_proceeded_cond);
	qemu_mutex_init(&qemu_global_mutex);
	qemu_mutex_lock(&qemu_global_mutex);

	qemu_thread_get_self(&io_thread);

	return 0;
	}

	void qemu_main_loop_start(void)
	{
	resume_all_vcpus();
	}

	void run_on_cpu(CPUState env, void (func)(void data), void data)
	{
	struct qemu_work_item wi;

	if (qemu_cpu_is_self(env)) {
	func(data);
	return;
	}

	wi.func = func;
	wi.data = data;
	if (!env->queued_work_first) {
	env->queued_work_first = &wi;
	} else {
	env->queued_work_last->next = &wi;
	}
	env->queued_work_last = &wi;
	wi.next = NULL;
	wi.done = false;

	qemu_cpu_kick(env);
	while (!wi.done) {
	CPUState *self_env = cpu_single_env;

	qemu_cond_wait(&qemu_work_cond, &qemu_global_mutex);
	cpu_single_env = self_env;
	}
	}

	static void flush_queued_work(CPUState *env)
	{
	struct qemu_work_item *wi;

	if (!env->queued_work_first) {
	return;
	}

	while ((wi = env->queued_work_first)) {
	env->queued_work_first = wi->next;
	wi->func(wi->data);
	wi->done = true;
	}
	env->queued_work_last = NULL;
	qemu_cond_broadcast(&qemu_work_cond);
	}

	static void qemu_wait_io_event_common(CPUState *env)
	{
	if (env->stop) {
	env->stop = 0;
	env->stopped = 1;
	qemu_cond_signal(&qemu_pause_cond);
	}
	flush_queued_work(env);
	env->thread_kicked = false;
	}

	static void qemu_tcg_wait_io_event(void)
	{
	CPUState *env;

	while (all_cpu_threads_idle()) {
	/* Start accounting real time to the virtual clock if the CPUs
	are idle. */
	qemu_clock_warp(vm_clock);
	qemu_cond_wait(tcg_halt_cond, &qemu_global_mutex);
	}

	while (iothread_requesting_mutex) {
	qemu_cond_wait(&qemu_io_proceeded_cond, &qemu_global_mutex);
	}

	for (env = first_cpu; env != NULL; env = env->next_cpu) {
	qemu_wait_io_event_common(env);
	}
	}

	static void qemu_kvm_wait_io_event(CPUState *env)
	{
	while (cpu_thread_is_idle(env)) {
	qemu_cond_wait(env->halt_cond, &qemu_global_mutex);
	}

	qemu_kvm_eat_signals(env);
	qemu_wait_io_event_common(env);
	}

	static void qemu_kvm_cpu_thread_fn(void arg)
	{
	CPUState *env = arg;
	int r;

	qemu_mutex_lock(&qemu_global_mutex);
	qemu_thread_get_self(env->thread);
	env->thread_id = qemu_get_thread_id();

	r = kvm_init_vcpu(env);
	if (r < 0) {
	fprintf(stderr, "kvm_init_vcpu failed: %s\n", strerror(-r));
	exit(1);
	}

	qemu_kvm_init_cpu_signals(env);

	/* signal CPU creation */
	env->created = 1;
	qemu_cond_signal(&qemu_cpu_cond);

	while (1) {
	if (cpu_can_run(env)) {
	r = kvm_cpu_exec(env);
	if (r == EXCP_DEBUG) {
	cpu_handle_guest_debug(env);
	}
	}
	qemu_kvm_wait_io_event(env);
	}

	return NULL;
	}

	static void qemu_tcg_cpu_thread_fn(void arg)
	{
	CPUState *env = arg;

	qemu_tcg_init_cpu_signals();
	qemu_thread_get_self(env->thread);

	/* signal CPU creation */
	qemu_mutex_lock(&qemu_global_mutex);
	for (env = first_cpu; env != NULL; env = env->next_cpu) {
	env->thread_id = qemu_get_thread_id();
	env->created = 1;
	}
	qemu_cond_signal(&qemu_cpu_cond);

	/* wait for initial kick-off after machine start */
	while (first_cpu->stopped) {
	qemu_cond_wait(tcg_halt_cond, &qemu_global_mutex);
	}

	while (1) {
	cpu_exec_all();
	if (use_icount && qemu_next_icount_deadline() <= 0) {
	qemu_notify_event();
	}
	qemu_tcg_wait_io_event();
	}

	return NULL;
	}

	static void qemu_cpu_kick_thread(CPUState *env)
	{
	#ifndef _WIN32
	int err;

	err = pthread_kill(env->thread->thread, SIG_IPI);
	if (err) {
	fprintf(stderr, "qemu:%s: %s", __func__, strerror(err));
	exit(1);
	}
	#else /* _WIN32 */
	if (!qemu_cpu_is_self(env)) {
	SuspendThread(env->thread->thread);
	cpu_signal(0);
	ResumeThread(env->thread->thread);
	}
	#endif
	}

	void qemu_cpu_kick(void *_env)
	{
	CPUState *env = _env;

	qemu_cond_broadcast(env->halt_cond);
	if (kvm_enabled() && !env->thread_kicked) {
	qemu_cpu_kick_thread(env);
	env->thread_kicked = true;
	}
	}

	void qemu_cpu_kick_self(void)
	{
	#ifndef _WIN32
	assert(cpu_single_env);

	if (!cpu_single_env->thread_kicked) {
	qemu_cpu_kick_thread(cpu_single_env);
	cpu_single_env->thread_kicked = true;
	}
	#else
	abort();
	#endif
	}

	int qemu_cpu_is_self(void *_env)
	{
	CPUState *env = _env;

	return qemu_thread_is_self(env->thread);
	}

	void qemu_mutex_lock_iothread(void)
	{
	if (kvm_enabled()) {
	qemu_mutex_lock(&qemu_global_mutex);
	} else {
	iothread_requesting_mutex = true;
	if (qemu_mutex_trylock(&qemu_global_mutex)) {
	qemu_cpu_kick_thread(first_cpu);
	qemu_mutex_lock(&qemu_global_mutex);
	}
	iothread_requesting_mutex = false;
	qemu_cond_broadcast(&qemu_io_proceeded_cond);
	}
	}

	void qemu_mutex_unlock_iothread(void)
	{
	qemu_mutex_unlock(&qemu_global_mutex);
	}

	static int all_vcpus_paused(void)
	{
	CPUState *penv = first_cpu;

	while (penv) {
	if (!penv->stopped) {
	return 0;
	}
	penv = (CPUState *)penv->next_cpu;
	}

	return 1;
	}

	void pause_all_vcpus(void)
	{
	CPUState *penv = first_cpu;

	while (penv) {
	penv->stop = 1;
	qemu_cpu_kick(penv);
	penv = (CPUState *)penv->next_cpu;
	}

	while (!all_vcpus_paused()) {
	qemu_cond_wait(&qemu_pause_cond, &qemu_global_mutex);
	penv = first_cpu;
	while (penv) {
	qemu_cpu_kick(penv);
	penv = (CPUState *)penv->next_cpu;
	}
	}
	}

	void resume_all_vcpus(void)
	{
	CPUState *penv = first_cpu;

	while (penv) {
	penv->stop = 0;
	penv->stopped = 0;
	qemu_cpu_kick(penv);
	penv = (CPUState *)penv->next_cpu;
	}
	}

	static void qemu_tcg_init_vcpu(void *_env)
	{
	CPUState *env = _env;

	/* share a single thread for all cpus with TCG */
	if (!tcg_cpu_thread) {
	env->thread = g_malloc0(sizeof(QemuThread));
	env->halt_cond = g_malloc0(sizeof(QemuCond));
	qemu_cond_init(env->halt_cond);
	tcg_halt_cond = env->halt_cond;
	qemu_thread_create(env->thread, qemu_tcg_cpu_thread_fn, env);
	while (env->created == 0) {
	qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex);
	}
	tcg_cpu_thread = env->thread;
	} else {
	env->thread = tcg_cpu_thread;
	env->halt_cond = tcg_halt_cond;
	}
	}

	static void qemu_kvm_start_vcpu(CPUState *env)
	{
	env->thread = g_malloc0(sizeof(QemuThread));
	env->halt_cond = g_malloc0(sizeof(QemuCond));
	qemu_cond_init(env->halt_cond);
	qemu_thread_create(env->thread, qemu_kvm_cpu_thread_fn, env);
	while (env->created == 0) {
	qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex);
	}
	}

	void qemu_init_vcpu(void *_env)
	{
	CPUState *env = _env;

	env->nr_cores = smp_cores;
	env->nr_threads = smp_threads;
	env->stopped = 1;
	if (kvm_enabled()) {
	qemu_kvm_start_vcpu(env);
	} else {
	qemu_tcg_init_vcpu(env);
	}
	}

	void qemu_notify_event(void)
	{
	qemu_event_increment();
	}

	void cpu_stop_current(void)
	{
	if (cpu_single_env) {
	cpu_single_env->stop = 0;
	cpu_single_env->stopped = 1;
	cpu_exit(cpu_single_env);
	qemu_cond_signal(&qemu_pause_cond);
	}
	}

	void vm_stop(RunState state)
	{
	if (!qemu_thread_is_self(&io_thread)) {
	qemu_system_vmstop_request(state);
	/*
	* FIXME: should not return to device code in case
	* vm_stop() has been requested.
	*/
	cpu_stop_current();
	return;
	}
	do_vm_stop(state);
	}

	static int tcg_cpu_exec(CPUState *env)
	{
	int ret;
	#ifdef CONFIG_PROFILER
	int64_t ti;
	#endif

	#ifdef CONFIG_PROFILER
	ti = profile_getclock();
	#endif
	if (use_icount) {
	int64_t count;
	int decr;
	qemu_icount -= (env->icount_decr.u16.low + env->icount_extra);
	env->icount_decr.u16.low = 0;
	env->icount_extra = 0;
	count = qemu_icount_round(qemu_next_icount_deadline());
	qemu_icount += count;
	decr = (count > 0xffff) ? 0xffff : count;
	count -= decr;
	env->icount_decr.u16.low = decr;
	env->icount_extra = count;
	}
	ret = cpu_exec(env);
	#ifdef CONFIG_PROFILER
	qemu_time += profile_getclock() - ti;
	#endif
	if (use_icount) {
	/* Fold pending instructions back into the
	instruction counter, and clear the interrupt flag. */
	qemu_icount -= (env->icount_decr.u16.low
	+ env->icount_extra);
	env->icount_decr.u32 = 0;
	env->icount_extra = 0;
	}
	return ret;
	}

	bool cpu_exec_all(void)
	{
	int r;

	/* Account partial waits to the vm_clock. */
	qemu_clock_warp(vm_clock);

	if (next_cpu == NULL) {
	next_cpu = first_cpu;
	}
	for (; next_cpu != NULL && !exit_request; next_cpu = next_cpu->next_cpu) {
	CPUState *env = next_cpu;

	qemu_clock_enable(vm_clock,
	(env->singlestep_enabled & SSTEP_NOTIMER) == 0);

	if (cpu_can_run(env)) {
	if (kvm_enabled()) {
	r = kvm_cpu_exec(env);
	qemu_kvm_eat_signals(env);
	} else {
	r = tcg_cpu_exec(env);
	}
	if (r == EXCP_DEBUG) {
	cpu_handle_guest_debug(env);
	break;
	}
	} else if (env->stop \|\| env->stopped) {
	break;
	}
	}
	exit_request = 0;
	return !all_cpu_threads_idle();
	}

	void set_numa_modes(void)
	{
	CPUState *env;
	int i;

	for (env = first_cpu; env != NULL; env = env->next_cpu) {
	for (i = 0; i < nb_numa_nodes; i++) {
	if (node_cpumask[i] & (1 << env->cpu_index)) {
	env->numa_node = i;
	}
	}
	}
	}

	void set_cpu_log(const char *optarg)
	{
	int mask;
	const CPULogItem *item;

	mask = cpu_str_to_log_mask(optarg);
	if (!mask) {
	printf("Log items (comma separated):\n");
	for (item = cpu_log_items; item->mask != 0; item++) {
	printf("%-10s %s\n", item->name, item->help);
	}
	exit(1);
	}
	cpu_set_log(mask);
	}

	void set_cpu_log_filename(const char *optarg)
	{
	cpu_set_log_filename(optarg);
	}

	/* Return the virtual CPU time, based on the instruction counter. */
	int64_t cpu_get_icount(void)
	{
	int64_t icount;
	CPUState *env = cpu_single_env;;

	icount = qemu_icount;
	if (env) {
	if (!can_do_io(env)) {
	fprintf(stderr, "Bad clock read\n");
	}
	icount -= (env->icount_decr.u16.low + env->icount_extra);
	}
	return qemu_icount_bias + (icount << icount_time_shift);
	}

	void list_cpus(FILE f, fprintf_function cpu_fprintf, const char optarg)
	{
	/* XXX: implement xxx_cpu_list for targets that still miss it */
	#if defined(cpu_list_id)
	cpu_list_id(f, cpu_fprintf, optarg);
	#elif defined(cpu_list)
	cpu_list(f, cpu_fprintf); /* deprecated */
	#endif
	}