]> git.proxmox.com Git - qemu.git/blobdiff - cpus.c
Version 1.0.1
[qemu.git] / cpus.c
diff --git a/cpus.c b/cpus.c
index 09ce6fe9d36d7c362920cb882a99ec835b9c01da..82530c4a039f4d5b8adcd3e3ea273919d5c46ac4 100644 (file)
--- a/cpus.c
+++ b/cpus.c
 #include "gdbstub.h"
 #include "dma.h"
 #include "kvm.h"
-#include "exec-all.h"
+#include "qmp-commands.h"
 
+#include "qemu-thread.h"
 #include "cpus.h"
-#include "compatfd.h"
+#include "main-loop.h"
 
-#ifdef SIGRTMIN
-#define SIG_IPI (SIGRTMIN+4)
-#else
-#define SIG_IPI SIGUSR1
+#ifndef _WIN32
+#include "compatfd.h"
 #endif
 
 #ifdef CONFIG_LINUX
 
 static CPUState *next_cpu;
 
+/***********************************************************/
+/* guest cycle counter */
+
+/* Conversion factor from emulated instructions to virtual clock ticks.  */
+static int icount_time_shift;
+/* Arbitrarily pick 1MIPS as the minimum allowable speed.  */
+#define MAX_ICOUNT_SHIFT 10
+/* Compensate for varying guest execution speed.  */
+static int64_t qemu_icount_bias;
+static QEMUTimer *icount_rt_timer;
+static QEMUTimer *icount_vm_timer;
+static QEMUTimer *icount_warp_timer;
+static int64_t vm_clock_warp_start;
+static int64_t qemu_icount;
+
+typedef struct TimersState {
+    int64_t cpu_ticks_prev;
+    int64_t cpu_ticks_offset;
+    int64_t cpu_clock_offset;
+    int32_t cpu_ticks_enabled;
+    int64_t dummy;
+} TimersState;
+
+TimersState timers_state;
+
+/* Return the 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);
+}
+
+/* return the host CPU cycle counter and handle stop/restart */
+int64_t cpu_get_ticks(void)
+{
+    if (use_icount) {
+        return cpu_get_icount();
+    }
+    if (!timers_state.cpu_ticks_enabled) {
+        return timers_state.cpu_ticks_offset;
+    } else {
+        int64_t ticks;
+        ticks = cpu_get_real_ticks();
+        if (timers_state.cpu_ticks_prev > ticks) {
+            /* Note: non increasing ticks may happen if the host uses
+               software suspend */
+            timers_state.cpu_ticks_offset += timers_state.cpu_ticks_prev - ticks;
+        }
+        timers_state.cpu_ticks_prev = ticks;
+        return ticks + timers_state.cpu_ticks_offset;
+    }
+}
+
+/* return the host CPU monotonic timer and handle stop/restart */
+int64_t cpu_get_clock(void)
+{
+    int64_t ti;
+    if (!timers_state.cpu_ticks_enabled) {
+        return timers_state.cpu_clock_offset;
+    } else {
+        ti = get_clock();
+        return ti + timers_state.cpu_clock_offset;
+    }
+}
+
+/* enable cpu_get_ticks() */
+void cpu_enable_ticks(void)
+{
+    if (!timers_state.cpu_ticks_enabled) {
+        timers_state.cpu_ticks_offset -= cpu_get_real_ticks();
+        timers_state.cpu_clock_offset -= get_clock();
+        timers_state.cpu_ticks_enabled = 1;
+    }
+}
+
+/* disable cpu_get_ticks() : the clock is stopped. You must not call
+   cpu_get_ticks() after that.  */
+void cpu_disable_ticks(void)
+{
+    if (timers_state.cpu_ticks_enabled) {
+        timers_state.cpu_ticks_offset = cpu_get_ticks();
+        timers_state.cpu_clock_offset = cpu_get_clock();
+        timers_state.cpu_ticks_enabled = 0;
+    }
+}
+
+/* Correlation between real and virtual time is always going to be
+   fairly approximate, so ignore small variation.
+   When the guest is idle real and virtual time will be aligned in
+   the IO wait loop.  */
+#define ICOUNT_WOBBLE (get_ticks_per_sec() / 10)
+
+static void icount_adjust(void)
+{
+    int64_t cur_time;
+    int64_t cur_icount;
+    int64_t delta;
+    static int64_t last_delta;
+    /* If the VM is not running, then do nothing.  */
+    if (!runstate_is_running()) {
+        return;
+    }
+    cur_time = cpu_get_clock();
+    cur_icount = qemu_get_clock_ns(vm_clock);
+    delta = cur_icount - cur_time;
+    /* FIXME: This is a very crude algorithm, somewhat prone to oscillation.  */
+    if (delta > 0
+        && last_delta + ICOUNT_WOBBLE < delta * 2
+        && icount_time_shift > 0) {
+        /* The guest is getting too far ahead.  Slow time down.  */
+        icount_time_shift--;
+    }
+    if (delta < 0
+        && last_delta - ICOUNT_WOBBLE > delta * 2
+        && icount_time_shift < MAX_ICOUNT_SHIFT) {
+        /* The guest is getting too far behind.  Speed time up.  */
+        icount_time_shift++;
+    }
+    last_delta = delta;
+    qemu_icount_bias = cur_icount - (qemu_icount << icount_time_shift);
+}
+
+static void icount_adjust_rt(void *opaque)
+{
+    qemu_mod_timer(icount_rt_timer,
+                   qemu_get_clock_ms(rt_clock) + 1000);
+    icount_adjust();
+}
+
+static void icount_adjust_vm(void *opaque)
+{
+    qemu_mod_timer(icount_vm_timer,
+                   qemu_get_clock_ns(vm_clock) + get_ticks_per_sec() / 10);
+    icount_adjust();
+}
+
+static int64_t qemu_icount_round(int64_t count)
+{
+    return (count + (1 << icount_time_shift) - 1) >> icount_time_shift;
+}
+
+static void icount_warp_rt(void *opaque)
+{
+    if (vm_clock_warp_start == -1) {
+        return;
+    }
+
+    if (runstate_is_running()) {
+        int64_t clock = qemu_get_clock_ns(rt_clock);
+        int64_t warp_delta = clock - vm_clock_warp_start;
+        if (use_icount == 1) {
+            qemu_icount_bias += warp_delta;
+        } else {
+            /*
+             * In adaptive mode, do not let the vm_clock run too
+             * far ahead of real time.
+             */
+            int64_t cur_time = cpu_get_clock();
+            int64_t cur_icount = qemu_get_clock_ns(vm_clock);
+            int64_t delta = cur_time - cur_icount;
+            qemu_icount_bias += MIN(warp_delta, delta);
+        }
+        if (qemu_clock_expired(vm_clock)) {
+            qemu_notify_event();
+        }
+    }
+    vm_clock_warp_start = -1;
+}
+
+void qemu_clock_warp(QEMUClock *clock)
+{
+    int64_t deadline;
+
+    /*
+     * There are too many global variables to make the "warp" behavior
+     * applicable to other clocks.  But a clock argument removes the
+     * need for if statements all over the place.
+     */
+    if (clock != vm_clock || !use_icount) {
+        return;
+    }
+
+    /*
+     * If the CPUs have been sleeping, advance the vm_clock timer now.  This
+     * ensures that the deadline for the timer is computed correctly below.
+     * This also makes sure that the insn counter is synchronized before the
+     * CPU starts running, in case the CPU is woken by an event other than
+     * the earliest vm_clock timer.
+     */
+    icount_warp_rt(NULL);
+    if (!all_cpu_threads_idle() || !qemu_clock_has_timers(vm_clock)) {
+        qemu_del_timer(icount_warp_timer);
+        return;
+    }
+
+    vm_clock_warp_start = qemu_get_clock_ns(rt_clock);
+    deadline = qemu_clock_deadline(vm_clock);
+    if (deadline > 0) {
+        /*
+         * Ensure the vm_clock proceeds even when the virtual CPU goes to
+         * sleep.  Otherwise, the CPU might be waiting for a future timer
+         * interrupt to wake it up, but the interrupt never comes because
+         * the vCPU isn't running any insns and thus doesn't advance the
+         * vm_clock.
+         *
+         * An extreme solution for this problem would be to never let VCPUs
+         * sleep in icount mode if there is a pending vm_clock timer; rather
+         * time could just advance to the next vm_clock event.  Instead, we
+         * do stop VCPUs and only advance vm_clock after some "real" time,
+         * (related to the time left until the next event) has passed.  This
+         * rt_clock timer will do this.  This avoids that the warps are too
+         * visible externally---for example, you will not be sending network
+         * packets continously instead of every 100ms.
+         */
+        qemu_mod_timer(icount_warp_timer, vm_clock_warp_start + deadline);
+    } else {
+        qemu_notify_event();
+    }
+}
+
+static const VMStateDescription vmstate_timers = {
+    .name = "timer",
+    .version_id = 2,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .fields      = (VMStateField[]) {
+        VMSTATE_INT64(cpu_ticks_offset, TimersState),
+        VMSTATE_INT64(dummy, TimersState),
+        VMSTATE_INT64_V(cpu_clock_offset, TimersState, 2),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+void configure_icount(const char *option)
+{
+    vmstate_register(NULL, 0, &vmstate_timers, &timers_state);
+    if (!option) {
+        return;
+    }
+
+    icount_warp_timer = qemu_new_timer_ns(rt_clock, icount_warp_rt, NULL);
+    if (strcmp(option, "auto") != 0) {
+        icount_time_shift = strtol(option, NULL, 0);
+        use_icount = 1;
+        return;
+    }
+
+    use_icount = 2;
+
+    /* 125MIPS seems a reasonable initial guess at the guest speed.
+       It will be corrected fairly quickly anyway.  */
+    icount_time_shift = 3;
+
+    /* Have both realtime and virtual time triggers for speed adjustment.
+       The realtime trigger catches emulated time passing too slowly,
+       the virtual time trigger catches emulated time passing too fast.
+       Realtime triggers occur even when idle, so use them less frequently
+       than VM triggers.  */
+    icount_rt_timer = qemu_new_timer_ms(rt_clock, icount_adjust_rt, NULL);
+    qemu_mod_timer(icount_rt_timer,
+                   qemu_get_clock_ms(rt_clock) + 1000);
+    icount_vm_timer = qemu_new_timer_ns(vm_clock, icount_adjust_vm, NULL);
+    qemu_mod_timer(icount_vm_timer,
+                   qemu_get_clock_ns(vm_clock) + get_ticks_per_sec() / 10);
+}
+
 /***********************************************************/
 void hw_error(const char *fmt, ...)
 {
@@ -112,16 +386,16 @@ void cpu_synchronize_all_post_init(void)
 
 int cpu_is_stopped(CPUState *env)
 {
-    return !vm_running || env->stopped;
+    return !runstate_is_running() || env->stopped;
 }
 
-static void do_vm_stop(int reason)
+static void do_vm_stop(RunState state)
 {
-    if (vm_running) {
+    if (runstate_is_running()) {
         cpu_disable_ticks();
-        vm_running = 0;
         pause_all_vcpus();
-        vm_state_notify(0, reason);
+        runstate_set(state);
+        vm_state_notify(0, state);
         qemu_aio_flush();
         bdrv_flush_all();
         monitor_protocol_event(QEVENT_STOP, NULL);
@@ -133,7 +407,7 @@ static int cpu_can_run(CPUState *env)
     if (env->stop) {
         return 0;
     }
-    if (env->stopped || !vm_running) {
+    if (env->stopped || !runstate_is_running()) {
         return 0;
     }
     return 1;
@@ -144,16 +418,17 @@ static bool cpu_thread_is_idle(CPUState *env)
     if (env->stop || env->queued_work_first) {
         return false;
     }
-    if (env->stopped || !vm_running) {
+    if (env->stopped || !runstate_is_running()) {
         return true;
     }
-    if (!env->halted || qemu_cpu_has_work(env)) {
+    if (!env->halted || qemu_cpu_has_work(env) ||
+        (kvm_enabled() && kvm_irqchip_in_kernel())) {
         return false;
     }
     return true;
 }
 
-static bool all_cpu_threads_idle(void)
+bool all_cpu_threads_idle(void)
 {
     CPUState *env;
 
@@ -165,34 +440,19 @@ static bool all_cpu_threads_idle(void)
     return true;
 }
 
-static CPUDebugExcpHandler *debug_excp_handler;
-
-CPUDebugExcpHandler *cpu_set_debug_excp_handler(CPUDebugExcpHandler *handler)
+static void cpu_handle_guest_debug(CPUState *env)
 {
-    CPUDebugExcpHandler *old_handler = debug_excp_handler;
-
-    debug_excp_handler = handler;
-    return old_handler;
+    gdb_set_stop_cpu(env);
+    qemu_system_debug_request();
+    env->stopped = 1;
 }
 
-static void cpu_handle_debug_exception(CPUState *env)
+static void cpu_signal(int sig)
 {
-    CPUWatchpoint *wp;
-
-    if (!env->watchpoint_hit) {
-        QTAILQ_FOREACH(wp, &env->watchpoints, entry) {
-            wp->flags &= ~BP_WATCHPOINT_HIT;
-        }
-    }
-    if (debug_excp_handler) {
-        debug_excp_handler(env);
+    if (cpu_single_env) {
+        cpu_exit(cpu_single_env);
     }
-
-    gdb_set_stop_cpu(env);
-    qemu_system_debug_request();
-#ifdef CONFIG_IOTHREAD
-    env->stopped = 1;
-#endif
+    exit_request = 1;
 }
 
 #ifdef CONFIG_LINUX
@@ -234,135 +494,6 @@ static void qemu_init_sigbus(void)
     prctl(PR_MCE_KILL, PR_MCE_KILL_SET, PR_MCE_KILL_EARLY, 0, 0);
 }
 
-#else /* !CONFIG_LINUX */
-
-static void qemu_init_sigbus(void)
-{
-}
-#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() filed: %s\n",
-                strerror(errno));
-        exit (1);
-    }
-}
-
-static void qemu_event_read(void *opaque)
-{
-    int fd = (unsigned long)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 *)(unsigned long)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 = (unsigned long) 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_signalfd_init(sigset_t mask)
-{
-    int sigfd;
-
-    sigfd = qemu_signalfd(&mask);
-    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 *)(unsigned long) sigfd);
-
-    return 0;
-}
-
 static void qemu_kvm_eat_signals(CPUState *env)
 {
     struct timespec ts = { 0, 0 };
@@ -398,51 +529,26 @@ static void qemu_kvm_eat_signals(CPUState *env)
             exit(1);
         }
     } while (sigismember(&chkset, SIG_IPI) || sigismember(&chkset, SIGBUS));
-
-#ifndef CONFIG_IOTHREAD
-    if (sigismember(&chkset, SIGIO) || sigismember(&chkset, SIGALRM)) {
-        qemu_notify_event();
-    }
-#endif
 }
 
-#else /* _WIN32 */
-
-HANDLE qemu_event_handle;
-
-static void dummy_event_handler(void *opaque)
-{
-}
+#else /* !CONFIG_LINUX */
 
-static int qemu_event_init(void)
+static void qemu_init_sigbus(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)
+static void qemu_kvm_eat_signals(CPUState *env)
 {
-    if (!SetEvent(qemu_event_handle)) {
-        fprintf(stderr, "qemu_event_increment: SetEvent failed: %ld\n",
-                GetLastError());
-        exit (1);
-    }
 }
+#endif /* !CONFIG_LINUX */
 
-static void qemu_kvm_eat_signals(CPUState *env)
+#ifndef _WIN32
+static void dummy_signal(int sig)
 {
 }
-#endif /* _WIN32 */
 
-#ifndef CONFIG_IOTHREAD
 static void qemu_kvm_init_cpu_signals(CPUState *env)
 {
-#ifndef _WIN32
     int r;
     sigset_t set;
     struct sigaction sigact;
@@ -451,184 +557,15 @@ static void qemu_kvm_init_cpu_signals(CPUState *env)
     sigact.sa_handler = dummy_signal;
     sigaction(SIG_IPI, &sigact, NULL);
 
-    sigemptyset(&set);
-    sigaddset(&set, SIG_IPI);
-    sigaddset(&set, SIGIO);
-    sigaddset(&set, SIGALRM);
-    pthread_sigmask(SIG_BLOCK, &set, NULL);
-
     pthread_sigmask(SIG_BLOCK, NULL, &set);
     sigdelset(&set, SIG_IPI);
     sigdelset(&set, SIGBUS);
-    sigdelset(&set, SIGIO);
-    sigdelset(&set, SIGALRM);
     r = kvm_set_signal_mask(env, &set);
     if (r) {
         fprintf(stderr, "kvm_set_signal_mask: %s\n", strerror(-r));
         exit(1);
     }
-#endif
-}
 
-#ifndef _WIN32
-static sigset_t block_synchronous_signals(void)
-{
-    sigset_t set;
-
-    sigemptyset(&set);
-    sigaddset(&set, SIGBUS);
-    if (kvm_enabled()) {
-        /*
-         * We need to process timer signals synchronously to avoid a race
-         * between exit_request check and KVM vcpu entry.
-         */
-        sigaddset(&set, SIGIO);
-        sigaddset(&set, SIGALRM);
-    }
-
-    return set;
-}
-#endif
-
-int qemu_init_main_loop(void)
-{
-#ifndef _WIN32
-    sigset_t blocked_signals;
-    int ret;
-
-    blocked_signals = block_synchronous_signals();
-
-    ret = qemu_signalfd_init(blocked_signals);
-    if (ret) {
-        return ret;
-    }
-#endif
-
-    qemu_init_sigbus();
-
-    return qemu_event_init();
-}
-
-void qemu_main_loop_start(void)
-{
-}
-
-void qemu_init_vcpu(void *_env)
-{
-    CPUState *env = _env;
-    int r;
-
-    env->nr_cores = smp_cores;
-    env->nr_threads = smp_threads;
-
-    if (kvm_enabled()) {
-        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);
-    }
-}
-
-int qemu_cpu_is_self(void *env)
-{
-    return 1;
-}
-
-void run_on_cpu(CPUState *env, void (*func)(void *data), void *data)
-{
-    func(data);
-}
-
-void resume_all_vcpus(void)
-{
-}
-
-void pause_all_vcpus(void)
-{
-}
-
-void qemu_cpu_kick(void *env)
-{
-}
-
-void qemu_cpu_kick_self(void)
-{
-#ifndef _WIN32
-    assert(cpu_single_env);
-
-    raise(SIG_IPI);
-#else
-    abort();
-#endif
-}
-
-void qemu_notify_event(void)
-{
-    CPUState *env = cpu_single_env;
-
-    qemu_event_increment ();
-    if (env) {
-        cpu_exit(env);
-    }
-    if (next_cpu && env != next_cpu) {
-        cpu_exit(next_cpu);
-    }
-    exit_request = 1;
-}
-
-void qemu_mutex_lock_iothread(void) {}
-void qemu_mutex_unlock_iothread(void) {}
-
-void cpu_stop_current(void)
-{
-}
-
-void vm_stop(int reason)
-{
-    do_vm_stop(reason);
-}
-
-#else /* CONFIG_IOTHREAD */
-
-#include "qemu-thread.h"
-
-QemuMutex qemu_global_mutex;
-static QemuMutex qemu_fair_mutex;
-
-static QemuThread io_thread;
-
-static QemuThread *tcg_cpu_thread;
-static QemuCond *tcg_halt_cond;
-
-static int qemu_system_ready;
-/* cpu creation */
-static QemuCond qemu_cpu_cond;
-/* system init */
-static QemuCond qemu_system_cond;
-static QemuCond qemu_pause_cond;
-static QemuCond qemu_work_cond;
-
-static void cpu_signal(int sig)
-{
-    if (cpu_single_env) {
-        cpu_exit(cpu_single_env);
-    }
-    exit_request = 1;
-}
-
-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);
@@ -652,62 +589,42 @@ static void qemu_tcg_init_cpu_signals(void)
     pthread_sigmask(SIG_UNBLOCK, &set, NULL);
 }
 
-static sigset_t block_io_signals(void)
+#else /* _WIN32 */
+static void qemu_kvm_init_cpu_signals(CPUState *env)
 {
-    sigset_t set;
-
-    /* SIGUSR2 used by posix-aio-compat.c */
-    sigemptyset(&set);
-    sigaddset(&set, SIGUSR2);
-    pthread_sigmask(SIG_UNBLOCK, &set, NULL);
-
-    sigemptyset(&set);
-    sigaddset(&set, SIGIO);
-    sigaddset(&set, SIGALRM);
-    sigaddset(&set, SIG_IPI);
-    sigaddset(&set, SIGBUS);
-    pthread_sigmask(SIG_BLOCK, &set, NULL);
-
-    return set;
+    abort();
 }
 
-int qemu_init_main_loop(void)
+static void qemu_tcg_init_cpu_signals(void)
 {
-    int ret;
-    sigset_t blocked_signals;
+}
+#endif /* _WIN32 */
 
-    qemu_init_sigbus();
+QemuMutex qemu_global_mutex;
+static QemuCond qemu_io_proceeded_cond;
+static bool iothread_requesting_mutex;
 
-    blocked_signals = block_io_signals();
+static QemuThread io_thread;
 
-    ret = qemu_signalfd_init(blocked_signals);
-    if (ret) {
-        return ret;
-    }
+static QemuThread *tcg_cpu_thread;
+static QemuCond *tcg_halt_cond;
 
-    /* Note eventfd must be drained before signalfd handlers run */
-    ret = qemu_event_init();
-    if (ret) {
-        return ret;
-    }
+/* cpu creation */
+static QemuCond qemu_cpu_cond;
+/* system init */
+static QemuCond qemu_pause_cond;
+static QemuCond qemu_work_cond;
 
+void qemu_init_cpu_loop(void)
+{
+    qemu_init_sigbus();
     qemu_cond_init(&qemu_cpu_cond);
-    qemu_cond_init(&qemu_system_cond);
     qemu_cond_init(&qemu_pause_cond);
     qemu_cond_init(&qemu_work_cond);
-    qemu_mutex_init(&qemu_fair_mutex);
+    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)
-{
-    qemu_system_ready = 1;
-    qemu_cond_broadcast(&qemu_system_cond);
 }
 
 void run_on_cpu(CPUState *env, void (*func)(void *data), void *data)
@@ -772,20 +689,15 @@ static void qemu_tcg_wait_io_event(void)
     CPUState *env;
 
     while (all_cpu_threads_idle()) {
-        qemu_cond_timedwait(tcg_halt_cond, &qemu_global_mutex, 1000);
+       /* 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);
     }
 
-    qemu_mutex_unlock(&qemu_global_mutex);
-
-    /*
-     * Users of qemu_global_mutex can be starved, having no chance
-     * to acquire it since this path will get to it first.
-     * So use another lock to provide fairness.
-     */
-    qemu_mutex_lock(&qemu_fair_mutex);
-    qemu_mutex_unlock(&qemu_fair_mutex);
-
-    qemu_mutex_lock(&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);
@@ -795,7 +707,7 @@ static void qemu_tcg_wait_io_event(void)
 static void qemu_kvm_wait_io_event(CPUState *env)
 {
     while (cpu_thread_is_idle(env)) {
-        qemu_cond_timedwait(env->halt_cond, &qemu_global_mutex, 1000);
+        qemu_cond_wait(env->halt_cond, &qemu_global_mutex);
     }
 
     qemu_kvm_eat_signals(env);
@@ -809,6 +721,7 @@ static void *qemu_kvm_cpu_thread_fn(void *arg)
 
     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) {
@@ -822,16 +735,11 @@ static void *qemu_kvm_cpu_thread_fn(void *arg)
     env->created = 1;
     qemu_cond_signal(&qemu_cpu_cond);
 
-    /* and wait for machine initialization */
-    while (!qemu_system_ready) {
-        qemu_cond_timedwait(&qemu_system_cond, &qemu_global_mutex, 100);
-    }
-
     while (1) {
         if (cpu_can_run(env)) {
             r = kvm_cpu_exec(env);
             if (r == EXCP_DEBUG) {
-                cpu_handle_debug_exception(env);
+                cpu_handle_guest_debug(env);
             }
         }
         qemu_kvm_wait_io_event(env);
@@ -840,6 +748,8 @@ static void *qemu_kvm_cpu_thread_fn(void *arg)
     return NULL;
 }
 
+static void tcg_exec_all(void);
+
 static void *qemu_tcg_cpu_thread_fn(void *arg)
 {
     CPUState *env = arg;
@@ -850,42 +760,69 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
     /* 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);
 
-    /* and wait for machine initialization */
-    while (!qemu_system_ready) {
-        qemu_cond_timedwait(&qemu_system_cond, &qemu_global_mutex, 100);
+    /* 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();
+        tcg_exec_all();
+        if (use_icount && qemu_clock_deadline(vm_clock) <= 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 (!env->thread_kicked) {
-        qemu_thread_signal(env->thread, SIG_IPI);
+    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_thread_signal(cpu_single_env->thread, SIG_IPI);
+        qemu_cpu_kick_thread(cpu_single_env);
         cpu_single_env->thread_kicked = true;
     }
+#else
+    abort();
+#endif
 }
 
 int qemu_cpu_is_self(void *_env)
@@ -900,12 +837,13 @@ void qemu_mutex_lock_iothread(void)
     if (kvm_enabled()) {
         qemu_mutex_lock(&qemu_global_mutex);
     } else {
-        qemu_mutex_lock(&qemu_fair_mutex);
+        iothread_requesting_mutex = true;
         if (qemu_mutex_trylock(&qemu_global_mutex)) {
-            qemu_thread_signal(tcg_cpu_thread, SIG_IPI);
+            qemu_cpu_kick_thread(first_cpu);
             qemu_mutex_lock(&qemu_global_mutex);
         }
-        qemu_mutex_unlock(&qemu_fair_mutex);
+        iothread_requesting_mutex = false;
+        qemu_cond_broadcast(&qemu_io_proceeded_cond);
     }
 }
 
@@ -932,6 +870,7 @@ void pause_all_vcpus(void)
 {
     CPUState *penv = first_cpu;
 
+    qemu_clock_enable(vm_clock, false);
     while (penv) {
         penv->stop = 1;
         qemu_cpu_kick(penv);
@@ -939,7 +878,7 @@ void pause_all_vcpus(void)
     }
 
     while (!all_vcpus_paused()) {
-        qemu_cond_timedwait(&qemu_pause_cond, &qemu_global_mutex, 100);
+        qemu_cond_wait(&qemu_pause_cond, &qemu_global_mutex);
         penv = first_cpu;
         while (penv) {
             qemu_cpu_kick(penv);
@@ -952,6 +891,7 @@ void resume_all_vcpus(void)
 {
     CPUState *penv = first_cpu;
 
+    qemu_clock_enable(vm_clock, true);
     while (penv) {
         penv->stop = 0;
         penv->stopped = 0;
@@ -966,15 +906,15 @@ static void qemu_tcg_init_vcpu(void *_env)
 
     /* share a single thread for all cpus with TCG */
     if (!tcg_cpu_thread) {
-        env->thread = qemu_mallocz(sizeof(QemuThread));
-        env->halt_cond = qemu_mallocz(sizeof(QemuCond));
+        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_timedwait(&qemu_cpu_cond, &qemu_global_mutex, 100);
+            qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex);
         }
         tcg_cpu_thread = env->thread;
-        tcg_halt_cond = env->halt_cond;
     } else {
         env->thread = tcg_cpu_thread;
         env->halt_cond = tcg_halt_cond;
@@ -983,12 +923,12 @@ static void qemu_tcg_init_vcpu(void *_env)
 
 static void qemu_kvm_start_vcpu(CPUState *env)
 {
-    env->thread = qemu_mallocz(sizeof(QemuThread));
-    env->halt_cond = qemu_mallocz(sizeof(QemuCond));
+    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_timedwait(&qemu_cpu_cond, &qemu_global_mutex, 100);
+        qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex);
     }
 }
 
@@ -998,6 +938,7 @@ void qemu_init_vcpu(void *_env)
 
     env->nr_cores = smp_cores;
     env->nr_threads = smp_threads;
+    env->stopped = 1;
     if (kvm_enabled()) {
         qemu_kvm_start_vcpu(env);
     } else {
@@ -1005,23 +946,20 @@ void qemu_init_vcpu(void *_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(int reason)
+void vm_stop(RunState state)
 {
     if (!qemu_thread_is_self(&io_thread)) {
-        qemu_system_vmstop_request(reason);
+        qemu_system_vmstop_request(state);
         /*
          * FIXME: should not return to device code in case
          * vm_stop() has been requested.
@@ -1029,10 +967,19 @@ void vm_stop(int reason)
         cpu_stop_current();
         return;
     }
-    do_vm_stop(reason);
+    do_vm_stop(state);
 }
 
-#endif
+/* does a state transition even if the VM is already stopped,
+   current state is forgotten forever */
+void vm_stop_force_state(RunState state)
+{
+    if (runstate_is_running()) {
+        vm_stop(state);
+    } else {
+        runstate_set(state);
+    }
+}
 
 static int tcg_cpu_exec(CPUState *env)
 {
@@ -1050,7 +997,7 @@ static int tcg_cpu_exec(CPUState *env)
         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_deadline());
+        count = qemu_icount_round(qemu_clock_deadline(vm_clock));
         qemu_icount += count;
         decr = (count > 0xffff) ? 0xffff : count;
         count -= decr;
@@ -1072,10 +1019,13 @@ static int tcg_cpu_exec(CPUState *env)
     return ret;
 }
 
-bool cpu_exec_all(void)
+static void tcg_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;
     }
@@ -1085,26 +1035,17 @@ bool cpu_exec_all(void)
         qemu_clock_enable(vm_clock,
                           (env->singlestep_enabled & SSTEP_NOTIMER) == 0);
 
-        if (qemu_alarm_pending()) {
-            break;
-        }
         if (cpu_can_run(env)) {
-            if (kvm_enabled()) {
-                r = kvm_cpu_exec(env);
-                qemu_kvm_eat_signals(env);
-            } else {
-                r = tcg_cpu_exec(env);
-            }
+            r = tcg_cpu_exec(env);
             if (r == EXCP_DEBUG) {
-                cpu_handle_debug_exception(env);
+                cpu_handle_guest_debug(env);
                 break;
             }
-        } else if (env->stop) {
+        } else if (env->stop || env->stopped) {
             break;
         }
     }
     exit_request = 0;
-    return !all_cpu_threads_idle();
 }
 
 void set_numa_modes(void)
@@ -1137,20 +1078,9 @@ void set_cpu_log(const char *optarg)
     cpu_set_log(mask);
 }
 
-/* Return the virtual CPU time, based on the instruction counter.  */
-int64_t cpu_get_icount(void)
+void set_cpu_log_filename(const char *optarg)
 {
-    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);
+    cpu_set_log_filename(optarg);
 }
 
 void list_cpus(FILE *f, fprintf_function cpu_fprintf, const char *optarg)
@@ -1162,3 +1092,47 @@ void list_cpus(FILE *f, fprintf_function cpu_fprintf, const char *optarg)
     cpu_list(f, cpu_fprintf); /* deprecated */
 #endif
 }
+
+CpuInfoList *qmp_query_cpus(Error **errp)
+{
+    CpuInfoList *head = NULL, *cur_item = NULL;
+    CPUState *env;
+
+    for(env = first_cpu; env != NULL; env = env->next_cpu) {
+        CpuInfoList *info;
+
+        cpu_synchronize_state(env);
+
+        info = g_malloc0(sizeof(*info));
+        info->value = g_malloc0(sizeof(*info->value));
+        info->value->CPU = env->cpu_index;
+        info->value->current = (env == first_cpu);
+        info->value->halted = env->halted;
+        info->value->thread_id = env->thread_id;
+#if defined(TARGET_I386)
+        info->value->has_pc = true;
+        info->value->pc = env->eip + env->segs[R_CS].base;
+#elif defined(TARGET_PPC)
+        info->value->has_nip = true;
+        info->value->nip = env->nip;
+#elif defined(TARGET_SPARC)
+        info->value->has_pc = true;
+        info->value->pc = env->pc;
+        info->value->has_npc = true;
+        info->value->npc = env->npc;
+#elif defined(TARGET_MIPS)
+        info->value->has_PC = true;
+        info->value->PC = env->active_tc.PC;
+#endif
+
+        /* XXX: waiting for the qapi to support GSList */
+        if (!cur_item) {
+            head = cur_item = info;
+        } else {
+            cur_item->next = info;
+            cur_item = info;
+        }
+    }
+
+    return head;
+}