static void *qemu_tcg_cpu_thread_fn(void *arg)
{
CPUState *env = arg;
qemu_tcg_init_cpu_signals();
qemu_thread_get_self(env->thread);
/* 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);
/* 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();
if (use_icount && qemu_next_icount_deadline() <= 0) {
qemu_notify_event();
}
qemu_tcg_wait_io_event();
}
return NULL;
}
void qemu_clock_warp(QEMUClock *clock)
{
int64_t deadline;
if (!clock->warp_timer) {
return;
}
/*
* 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.
*/
assert(clock == vm_clock);
/*
* 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() || !active_timers[clock->type]) {
qemu_del_timer(clock->warp_timer);
return;
}
vm_clock_warp_start = qemu_get_clock_ns(rt_clock);
deadline = qemu_next_icount_deadline();
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(clock->warp_timer, vm_clock_warp_start + deadline);
} else {
qemu_notify_event();
}
}
static int qemu_cpu_exec(CPUState *env)
{
int ret;
#ifdef CONFIG_PROFILER
int64_t ti;
#endif
#ifdef CONFIG_PROFILER
ti = profile_getclock();
#endif
if (use_icount) {
int64_t count;
int decr;
qemu_icount -= (env->icount_decr.u16.low + env->icount_extra);
env->icount_decr.u16.low = 0;
env->icount_extra = 0;
count = qemu_next_icount_deadline();
count = (count + (1 << icount_time_shift) - 1)
>> icount_time_shift;
qemu_icount += count;
decr = (count > 0xffff) ? 0xffff : count;
count -= decr;
env->icount_decr.u16.low = decr;
env->icount_extra = count;
}
#ifdef CONFIG_TRACE
if (tbflush_requested) {
tbflush_requested = 0;
tb_flush(env);
return EXCP_INTERRUPT;
}
#endif
ret = cpu_exec(env);
#ifdef CONFIG_PROFILER
qemu_time += profile_getclock() - ti;
#endif
if (use_icount) {
/* Fold pending instructions back into the
instruction counter, and clear the interrupt flag. */
qemu_icount -= (env->icount_decr.u16.low
+ env->icount_extra);
env->icount_decr.u32 = 0;
env->icount_extra = 0;
}
return ret;
}
int qemu_calculate_timeout(void)
{
#ifndef CONFIG_IOTHREAD
int timeout;
if (!vm_running)
timeout = 5000;
else {
/* XXX: use timeout computed from timers */
int64_t add;
int64_t delta;
/* Advance virtual time to the next event. */
delta = qemu_icount_delta();
if (delta > 0) {
/* If virtual time is ahead of real time then just
wait for IO. */
timeout = (delta + 999999) / 1000000;
} else {
/* Wait for either IO to occur or the next
timer event. */
add = qemu_next_icount_deadline();
/* We advance the timer before checking for IO.
Limit the amount we advance so that early IO
activity won't get the guest too far ahead. */
if (add > 10000000)
add = 10000000;
delta += add;
qemu_icount += qemu_icount_round (add);
timeout = delta / 1000000;
if (timeout < 0)
timeout = 0;
}
}
return timeout;
#else /* CONFIG_IOTHREAD */
return 1000;
#endif
}
static int tcg_cpu_exec(CPUState *env)
{
int ret;
#ifdef CONFIG_PROFILER
int64_t ti;
#endif
#ifdef CONFIG_PROFILER
ti = profile_getclock();
#endif
if (use_icount) {
int64_t count;
int decr;
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_icount_deadline());
qemu_icount += count;
decr = (count > 0xffff) ? 0xffff : count;
count -= decr;
env->icount_decr.u16.low = decr;
env->icount_extra = count;
}
ret = cpu_exec(env);
#ifdef CONFIG_PROFILER
qemu_time += profile_getclock() - ti;
#endif
if (use_icount) {
/* Fold pending instructions back into the
instruction counter, and clear the interrupt flag. */
qemu_icount -= (env->icount_decr.u16.low
+ env->icount_extra);
env->icount_decr.u32 = 0;
env->icount_extra = 0;
}
return ret;
}