/* 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;
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;
}
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;
}
* 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);
}
.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),
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
}
};
}
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);
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;
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;
projects / qemu.git / blobdiff