X-Git-Url: https://repo.jachan.dev/qemu.git/blobdiff_plain/3d30395f7fb3315e4ecf0de4e48790e1326bbd47..06b008d941fd3e9684d38a9b3181a1cf301c78d1:/cpus.c diff --git a/cpus.c b/cpus.c index 1cd9867893..b85fb5f03f 100644 --- a/cpus.c +++ b/cpus.c @@ -105,6 +105,7 @@ static bool all_cpu_threads_idle(void) /* Protected by TimersState seqlock */ +static bool icount_sleep = true; static int64_t vm_clock_warp_start = -1; /* Conversion factor from emulated instructions to virtual clock ticks. */ static int icount_time_shift; @@ -393,15 +394,18 @@ void qemu_clock_warp(QEMUClockType type) return; } - /* - * If the CPUs have been sleeping, advance QEMU_CLOCK_VIRTUAL 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 QEMU_CLOCK_VIRTUAL timer. - */ - icount_warp_rt(NULL); - timer_del(icount_warp_timer); + if (icount_sleep) { + /* + * If the CPUs have been sleeping, advance QEMU_CLOCK_VIRTUAL 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 QEMU_CLOCK_VIRTUAL timer. + */ + icount_warp_rt(NULL); + timer_del(icount_warp_timer); + } if (!all_cpu_threads_idle()) { return; } @@ -415,6 +419,11 @@ void qemu_clock_warp(QEMUClockType type) clock = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL_RT); deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL); if (deadline < 0) { + static bool notified; + if (!icount_sleep && !notified) { + error_report("WARNING: icount sleep disabled and no active timers"); + notified = true; + } return; } @@ -425,23 +434,35 @@ void qemu_clock_warp(QEMUClockType type) * interrupt to wake it up, but the interrupt never comes because * the vCPU isn't running any insns and thus doesn't advance the * QEMU_CLOCK_VIRTUAL. - * - * An extreme solution for this problem would be to never let VCPUs - * sleep in icount mode if there is a pending QEMU_CLOCK_VIRTUAL - * timer; rather time could just advance to the next QEMU_CLOCK_VIRTUAL - * event. Instead, we do stop VCPUs and only advance QEMU_CLOCK_VIRTUAL - * after some "real" time, (related to the time left until the next - * event) has passed. The QEMU_CLOCK_VIRTUAL_RT clock will do this. - * This avoids that the warps are visible externally; for example, - * you will not be sending network packets continuously instead of - * every 100ms. */ - seqlock_write_lock(&timers_state.vm_clock_seqlock); - if (vm_clock_warp_start == -1 || vm_clock_warp_start > clock) { - vm_clock_warp_start = clock; + if (!icount_sleep) { + /* + * We never let VCPUs sleep in no sleep icount mode. + * If there is a pending QEMU_CLOCK_VIRTUAL timer we just advance + * to the next QEMU_CLOCK_VIRTUAL event and notify it. + * It is useful when we want a deterministic execution time, + * isolated from host latencies. + */ + seqlock_write_lock(&timers_state.vm_clock_seqlock); + timers_state.qemu_icount_bias += deadline; + seqlock_write_unlock(&timers_state.vm_clock_seqlock); + qemu_clock_notify(QEMU_CLOCK_VIRTUAL); + } else { + /* + * We do stop VCPUs and only advance QEMU_CLOCK_VIRTUAL after some + * "real" time, (related to the time left until the next event) has + * passed. The QEMU_CLOCK_VIRTUAL_RT clock will do this. + * This avoids that the warps are visible externally; for example, + * you will not be sending network packets continuously instead of + * every 100ms. + */ + seqlock_write_lock(&timers_state.vm_clock_seqlock); + if (vm_clock_warp_start == -1 || vm_clock_warp_start > clock) { + vm_clock_warp_start = clock; + } + seqlock_write_unlock(&timers_state.vm_clock_seqlock); + timer_mod_anticipate(icount_warp_timer, clock + deadline); } - seqlock_write_unlock(&timers_state.vm_clock_seqlock); - timer_mod_anticipate(icount_warp_timer, clock + deadline); } else if (deadline == 0) { qemu_clock_notify(QEMU_CLOCK_VIRTUAL); } @@ -459,6 +480,7 @@ static const VMStateDescription icount_vmstate_timers = { .name = "timer/icount", .version_id = 1, .minimum_version_id = 1, + .needed = icount_state_needed, .fields = (VMStateField[]) { VMSTATE_INT64(qemu_icount_bias, TimersState), VMSTATE_INT64(qemu_icount, TimersState), @@ -476,13 +498,9 @@ static const VMStateDescription vmstate_timers = { VMSTATE_INT64_V(cpu_clock_offset, TimersState, 2), VMSTATE_END_OF_LIST() }, - .subsections = (VMStateSubsection[]) { - { - .vmsd = &icount_vmstate_timers, - .needed = icount_state_needed, - }, { - /* empty */ - } + .subsections = (const VMStateDescription*[]) { + &icount_vmstate_timers, + NULL } }; @@ -504,9 +522,18 @@ void configure_icount(QemuOpts *opts, Error **errp) } return; } + + icount_sleep = qemu_opt_get_bool(opts, "sleep", true); + if (icount_sleep) { + icount_warp_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL_RT, + icount_warp_rt, NULL); + } + icount_align_option = qemu_opt_get_bool(opts, "align", false); - icount_warp_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL_RT, - icount_warp_rt, NULL); + + if (icount_align_option && !icount_sleep) { + error_setg(errp, "align=on and sleep=no are incompatible"); + } if (strcmp(option, "auto") != 0) { errno = 0; icount_time_shift = strtol(option, &rem_str, 0); @@ -517,6 +544,8 @@ void configure_icount(QemuOpts *opts, Error **errp) return; } else if (icount_align_option) { error_setg(errp, "shift=auto and align=on are incompatible"); + } else if (!icount_sleep) { + error_setg(errp, "shift=auto and sleep=no are incompatible"); } use_icount = 2; @@ -778,7 +807,7 @@ static void qemu_tcg_init_cpu_signals(void) static QemuMutex qemu_global_mutex; static QemuCond qemu_io_proceeded_cond; -static bool iothread_requesting_mutex; +static unsigned iothread_requesting_mutex; static QemuThread io_thread; @@ -1016,7 +1045,7 @@ static void *qemu_tcg_cpu_thread_fn(void *arg) qemu_cond_signal(&qemu_cpu_cond); /* wait for initial kick-off after machine start */ - while (QTAILQ_FIRST(&cpus)->stopped) { + while (first_cpu->stopped) { qemu_cond_wait(tcg_halt_cond, &qemu_global_mutex); /* process any pending work */ @@ -1025,6 +1054,9 @@ static void *qemu_tcg_cpu_thread_fn(void *arg) } } + /* process any pending work */ + exit_request = 1; + while (1) { tcg_exec_all(); @@ -1115,15 +1147,16 @@ bool qemu_in_vcpu_thread(void) void qemu_mutex_lock_iothread(void) { - if (!tcg_enabled()) { + atomic_inc(&iothread_requesting_mutex); + if (!tcg_enabled() || !first_cpu || !first_cpu->thread) { qemu_mutex_lock(&qemu_global_mutex); + atomic_dec(&iothread_requesting_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; + atomic_dec(&iothread_requesting_mutex); qemu_cond_broadcast(&qemu_io_proceeded_cond); } } @@ -1349,7 +1382,7 @@ static int tcg_cpu_exec(CPUArchState *env) } ret = cpu_exec(env); #ifdef CONFIG_PROFILER - qemu_time += profile_getclock() - ti; + tcg_time += profile_getclock() - ti; #endif if (use_icount) { /* Fold pending instructions back into the @@ -1431,6 +1464,7 @@ CpuInfoList *qmp_query_cpus(Error **errp) info->value->CPU = cpu->cpu_index; info->value->current = (cpu == first_cpu); info->value->halted = cpu->halted; + info->value->qom_path = object_get_canonical_path(OBJECT(cpu)); info->value->thread_id = cpu->thread_id; #if defined(TARGET_I386) info->value->has_pc = true; @@ -1470,6 +1504,7 @@ void qmp_memsave(int64_t addr, int64_t size, const char *filename, uint32_t l; CPUState *cpu; uint8_t buf[1024]; + int64_t orig_addr = addr, orig_size = size; if (!has_cpu) { cpu_index = 0; @@ -1493,7 +1528,8 @@ void qmp_memsave(int64_t addr, int64_t size, const char *filename, if (l > size) l = size; if (cpu_memory_rw_debug(cpu, addr, buf, l, 0) != 0) { - error_setg(errp, "Invalid addr 0x%016" PRIx64 "specified", addr); + error_setg(errp, "Invalid addr 0x%016" PRIx64 "/size %" PRId64 + " specified", orig_addr, orig_size); goto exit; } if (fwrite(buf, 1, l, f) != l) {