diff options
Diffstat (limited to 'cpus.c')
| -rw-r--r-- | cpus.c | 130 |
1 files changed, 51 insertions, 79 deletions
@@ -661,14 +661,6 @@ static void cpu_handle_guest_debug(CPUState *cpu) 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) { @@ -781,29 +773,11 @@ static void qemu_kvm_init_cpu_signals(CPUState *cpu) } } -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; @@ -812,9 +786,6 @@ static unsigned 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 */ @@ -845,6 +816,8 @@ void run_on_cpu(CPUState *cpu, void (*func)(void *data), void *data) 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 { @@ -853,9 +826,10 @@ void run_on_cpu(CPUState *cpu, void (*func)(void *data), void *data) 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); @@ -876,6 +850,8 @@ void async_run_on_cpu(CPUState *cpu, void (*func)(void *data), void *data) 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 { @@ -884,6 +860,7 @@ void async_run_on_cpu(CPUState *cpu, void (*func)(void *data), void *data) cpu->queued_work_last = wi; wi->next = NULL; wi->done = false; + qemu_mutex_unlock(&cpu->work_mutex); qemu_cpu_kick(cpu); } @@ -896,15 +873,23 @@ static void flush_queued_work(CPUState *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); } @@ -919,15 +904,13 @@ static void qemu_wait_io_event_common(CPUState *cpu) 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) { @@ -1041,7 +1024,6 @@ static void *qemu_tcg_cpu_thread_fn(void *arg) rcu_register_thread(); qemu_mutex_lock_iothread(); - qemu_tcg_init_cpu_signals(); qemu_thread_get_self(cpu->thread); CPU_FOREACH(cpu) { @@ -1053,7 +1035,7 @@ static void *qemu_tcg_cpu_thread_fn(void *arg) /* 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) { @@ -1062,7 +1044,7 @@ static void *qemu_tcg_cpu_thread_fn(void *arg) } /* process any pending work */ - exit_request = 1; + atomic_mb_set(&exit_request, 1); while (1) { tcg_exec_all(); @@ -1074,7 +1056,7 @@ static void *qemu_tcg_cpu_thread_fn(void *arg) qemu_clock_notify(QEMU_CLOCK_VIRTUAL); } } - qemu_tcg_wait_io_event(); + qemu_tcg_wait_io_event(QTAILQ_FIRST(&cpus)); } return NULL; @@ -1085,61 +1067,47 @@ static void qemu_cpu_kick_thread(CPUState *cpu) #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) @@ -1166,12 +1134,12 @@ void qemu_mutex_lock_iothread(void) * 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); @@ -1251,6 +1219,8 @@ void resume_all_vcpus(void) 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); @@ -1440,7 +1410,9 @@ static void tcg_exec_all(void) 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) |