int64_t max_delay;
int64_t max_advance;
+/* vcpu throttling controls */
+static QEMUTimer *throttle_timer;
+static unsigned int throttle_percentage;
+
+#define CPU_THROTTLE_PCT_MIN 1
+#define CPU_THROTTLE_PCT_MAX 99
+#define CPU_THROTTLE_TIMESLICE_NS 10000000
+
bool cpu_is_stopped(CPUState *cpu)
{
return cpu->stopped || !runstate_is_running();
ticks = timers_state.cpu_ticks_offset;
if (timers_state.cpu_ticks_enabled) {
- ticks += cpu_get_real_ticks();
+ ticks += cpu_get_host_ticks();
}
if (timers_state.cpu_ticks_prev > ticks) {
/* Here, the really thing protected by seqlock is cpu_clock_offset. */
seqlock_write_lock(&timers_state.vm_clock_seqlock);
if (!timers_state.cpu_ticks_enabled) {
- timers_state.cpu_ticks_offset -= cpu_get_real_ticks();
+ timers_state.cpu_ticks_offset -= cpu_get_host_ticks();
timers_state.cpu_clock_offset -= get_clock();
timers_state.cpu_ticks_enabled = 1;
}
/* Here, the really thing protected by seqlock is cpu_clock_offset. */
seqlock_write_lock(&timers_state.vm_clock_seqlock);
if (timers_state.cpu_ticks_enabled) {
- timers_state.cpu_ticks_offset += cpu_get_real_ticks();
+ timers_state.cpu_ticks_offset += cpu_get_host_ticks();
timers_state.cpu_clock_offset = cpu_get_clock_locked();
timers_state.cpu_ticks_enabled = 0;
}
}
};
+static void cpu_throttle_thread(void *opaque)
+{
+ CPUState *cpu = opaque;
+ double pct;
+ double throttle_ratio;
+ long sleeptime_ns;
+
+ if (!cpu_throttle_get_percentage()) {
+ return;
+ }
+
+ pct = (double)cpu_throttle_get_percentage()/100;
+ throttle_ratio = pct / (1 - pct);
+ sleeptime_ns = (long)(throttle_ratio * CPU_THROTTLE_TIMESLICE_NS);
+
+ qemu_mutex_unlock_iothread();
+ atomic_set(&cpu->throttle_thread_scheduled, 0);
+ g_usleep(sleeptime_ns / 1000); /* Convert ns to us for usleep call */
+ qemu_mutex_lock_iothread();
+}
+
+static void cpu_throttle_timer_tick(void *opaque)
+{
+ CPUState *cpu;
+ double pct;
+
+ /* Stop the timer if needed */
+ if (!cpu_throttle_get_percentage()) {
+ return;
+ }
+ CPU_FOREACH(cpu) {
+ if (!atomic_xchg(&cpu->throttle_thread_scheduled, 1)) {
+ async_run_on_cpu(cpu, cpu_throttle_thread, cpu);
+ }
+ }
+
+ pct = (double)cpu_throttle_get_percentage()/100;
+ timer_mod(throttle_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL_RT) +
+ CPU_THROTTLE_TIMESLICE_NS / (1-pct));
+}
+
+void cpu_throttle_set(int new_throttle_pct)
+{
+ /* Ensure throttle percentage is within valid range */
+ new_throttle_pct = MIN(new_throttle_pct, CPU_THROTTLE_PCT_MAX);
+ new_throttle_pct = MAX(new_throttle_pct, CPU_THROTTLE_PCT_MIN);
+
+ atomic_set(&throttle_percentage, new_throttle_pct);
+
+ timer_mod(throttle_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL_RT) +
+ CPU_THROTTLE_TIMESLICE_NS);
+}
+
+void cpu_throttle_stop(void)
+{
+ atomic_set(&throttle_percentage, 0);
+}
+
+bool cpu_throttle_active(void)
+{
+ return (cpu_throttle_get_percentage() != 0);
+}
+
+int cpu_throttle_get_percentage(void)
+{
+ return atomic_read(&throttle_percentage);
+}
+
void cpu_ticks_init(void)
{
seqlock_init(&timers_state.vm_clock_seqlock, NULL);
vmstate_register(NULL, 0, &vmstate_timers, &timers_state);
+ throttle_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL_RT,
+ cpu_throttle_timer_tick, NULL);
}
void configure_icount(QemuOpts *opts, Error **errp)
cpu->stopped = true;
}
-static void cpu_signal(int sig)
-{
- if (current_cpu) {
- cpu_exit(current_cpu);
- }
- exit_request = 1;
-}
-
#ifdef CONFIG_LINUX
static void sigbus_reraise(void)
{
}
}
-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 */
static void qemu_kvm_init_cpu_signals(CPUState *cpu)
{
abort();
}
-
-static void qemu_tcg_init_cpu_signals(void)
-{
-}
#endif /* _WIN32 */
static QemuMutex qemu_global_mutex;
static QemuThread io_thread;
-static QemuThread *tcg_cpu_thread;
-static QemuCond *tcg_halt_cond;
-
/* cpu creation */
static QemuCond qemu_cpu_cond;
/* system init */
wi.func = func;
wi.data = data;
wi.free = false;
+
+ qemu_mutex_lock(&cpu->work_mutex);
if (cpu->queued_work_first == NULL) {
cpu->queued_work_first = &wi;
} else {
cpu->queued_work_last = &wi;
wi.next = NULL;
wi.done = false;
+ qemu_mutex_unlock(&cpu->work_mutex);
qemu_cpu_kick(cpu);
- while (!wi.done) {
+ while (!atomic_mb_read(&wi.done)) {
CPUState *self_cpu = current_cpu;
qemu_cond_wait(&qemu_work_cond, &qemu_global_mutex);
wi->func = func;
wi->data = data;
wi->free = true;
+
+ qemu_mutex_lock(&cpu->work_mutex);
if (cpu->queued_work_first == NULL) {
cpu->queued_work_first = wi;
} else {
cpu->queued_work_last = wi;
wi->next = NULL;
wi->done = false;
+ qemu_mutex_unlock(&cpu->work_mutex);
qemu_cpu_kick(cpu);
}
return;
}
- while ((wi = cpu->queued_work_first)) {
+ qemu_mutex_lock(&cpu->work_mutex);
+ while (cpu->queued_work_first != NULL) {
+ wi = cpu->queued_work_first;
cpu->queued_work_first = wi->next;
+ if (!cpu->queued_work_first) {
+ cpu->queued_work_last = NULL;
+ }
+ qemu_mutex_unlock(&cpu->work_mutex);
wi->func(wi->data);
- wi->done = true;
+ qemu_mutex_lock(&cpu->work_mutex);
if (wi->free) {
g_free(wi);
+ } else {
+ atomic_mb_set(&wi->done, true);
}
}
- cpu->queued_work_last = NULL;
+ qemu_mutex_unlock(&cpu->work_mutex);
qemu_cond_broadcast(&qemu_work_cond);
}
cpu->thread_kicked = false;
}
-static void qemu_tcg_wait_io_event(void)
+static void qemu_tcg_wait_io_event(CPUState *cpu)
{
- CPUState *cpu;
-
while (all_cpu_threads_idle()) {
/* Start accounting real time to the virtual clock if the CPUs
are idle. */
qemu_clock_warp(QEMU_CLOCK_VIRTUAL);
- qemu_cond_wait(tcg_halt_cond, &qemu_global_mutex);
+ qemu_cond_wait(cpu->halt_cond, &qemu_global_mutex);
}
while (iothread_requesting_mutex) {
rcu_register_thread();
qemu_mutex_lock_iothread();
- qemu_tcg_init_cpu_signals();
qemu_thread_get_self(cpu->thread);
CPU_FOREACH(cpu) {
/* wait for initial kick-off after machine start */
while (first_cpu->stopped) {
- qemu_cond_wait(tcg_halt_cond, &qemu_global_mutex);
+ qemu_cond_wait(first_cpu->halt_cond, &qemu_global_mutex);
/* process any pending work */
CPU_FOREACH(cpu) {
}
/* process any pending work */
- exit_request = 1;
+ atomic_mb_set(&exit_request, 1);
while (1) {
tcg_exec_all();
qemu_clock_notify(QEMU_CLOCK_VIRTUAL);
}
}
- qemu_tcg_wait_io_event();
+ qemu_tcg_wait_io_event(QTAILQ_FIRST(&cpus));
}
return NULL;
#ifndef _WIN32
int err;
+ if (cpu->thread_kicked) {
+ return;
+ }
+ cpu->thread_kicked = true;
err = pthread_kill(cpu->thread->thread, SIG_IPI);
if (err) {
fprintf(stderr, "qemu:%s: %s", __func__, strerror(err));
exit(1);
}
#else /* _WIN32 */
- if (!qemu_cpu_is_self(cpu)) {
- CONTEXT tcgContext;
-
- if (SuspendThread(cpu->hThread) == (DWORD)-1) {
- fprintf(stderr, "qemu:%s: GetLastError:%lu\n", __func__,
- GetLastError());
- exit(1);
- }
-
- /* On multi-core systems, we are not sure that the thread is actually
- * suspended until we can get the context.
- */
- tcgContext.ContextFlags = CONTEXT_CONTROL;
- while (GetThreadContext(cpu->hThread, &tcgContext) != 0) {
- continue;
- }
-
- cpu_signal(0);
+ abort();
+#endif
+}
- if (ResumeThread(cpu->hThread) == (DWORD)-1) {
- fprintf(stderr, "qemu:%s: GetLastError:%lu\n", __func__,
- GetLastError());
- exit(1);
- }
+static void qemu_cpu_kick_no_halt(void)
+{
+ CPUState *cpu;
+ /* Ensure whatever caused the exit has reached the CPU threads before
+ * writing exit_request.
+ */
+ atomic_mb_set(&exit_request, 1);
+ cpu = atomic_mb_read(&tcg_current_cpu);
+ if (cpu) {
+ cpu_exit(cpu);
}
-#endif
}
void qemu_cpu_kick(CPUState *cpu)
{
qemu_cond_broadcast(cpu->halt_cond);
- if (!tcg_enabled() && !cpu->thread_kicked) {
+ if (tcg_enabled()) {
+ qemu_cpu_kick_no_halt();
+ } else {
qemu_cpu_kick_thread(cpu);
- cpu->thread_kicked = true;
}
}
void qemu_cpu_kick_self(void)
{
-#ifndef _WIN32
assert(current_cpu);
-
- if (!current_cpu->thread_kicked) {
- qemu_cpu_kick_thread(current_cpu);
- current_cpu->thread_kicked = true;
- }
-#else
- abort();
-#endif
+ qemu_cpu_kick_thread(current_cpu);
}
bool qemu_cpu_is_self(CPUState *cpu)
* TCG code execution.
*/
if (!tcg_enabled() || qemu_in_vcpu_thread() ||
- !first_cpu || !first_cpu->thread) {
+ !first_cpu || !first_cpu->created) {
qemu_mutex_lock(&qemu_global_mutex);
atomic_dec(&iothread_requesting_mutex);
} else {
if (qemu_mutex_trylock(&qemu_global_mutex)) {
- qemu_cpu_kick_thread(first_cpu);
+ qemu_cpu_kick_no_halt();
qemu_mutex_lock(&qemu_global_mutex);
}
atomic_dec(&iothread_requesting_mutex);
static void qemu_tcg_init_vcpu(CPUState *cpu)
{
char thread_name[VCPU_THREAD_NAME_SIZE];
+ static QemuCond *tcg_halt_cond;
+ static QemuThread *tcg_cpu_thread;
tcg_cpu_address_space_init(cpu, cpu->as);
break;
}
}
- exit_request = 0;
+
+ /* Pairs with smp_wmb in qemu_cpu_kick. */
+ atomic_mb_set(&exit_request, 0);
}
void list_cpus(FILE *f, fprintf_function cpu_fprintf, const char *optarg)
projects / qemu.git / blobdiff