static void icount_warp_rt(void *opaque)
{
if (vm_clock_warp_start == -1) {
return;
}
if (vm_running) {
int64_t clock = qemu_get_clock_ns(rt_clock);
int64_t warp_delta = clock - vm_clock_warp_start;
if (use_icount == 1) {
qemu_icount_bias += warp_delta;
} else {
/*
* In adaptive mode, do not let the vm_clock run too
* far ahead of real time.
*/
int64_t cur_time = cpu_get_clock();
int64_t cur_icount = qemu_get_clock_ns(vm_clock);
int64_t delta = cur_time - cur_icount;
qemu_icount_bias += MIN(warp_delta, delta);
}
if (qemu_timer_expired(active_timers[QEMU_CLOCK_VIRTUAL],
qemu_get_clock_ns(vm_clock))) {
qemu_notify_event();
}
}
vm_clock_warp_start = -1;
}
static void icount_warp_rt(void *opaque)
{
if (vm_clock_warp_start == -1) {
return;
}
if (runstate_is_running()) {
int64_t clock = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
int64_t warp_delta = clock - vm_clock_warp_start;
if (use_icount == 1) {
qemu_icount_bias += warp_delta;
} else {
/*
* In adaptive mode, do not let QEMU_CLOCK_VIRTUAL run too
* far ahead of real time.
*/
int64_t cur_time = cpu_get_clock();
int64_t cur_icount = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
int64_t delta = cur_time - cur_icount;
qemu_icount_bias += MIN(warp_delta, delta);
}
if (qemu_clock_expired(QEMU_CLOCK_VIRTUAL)) {
qemu_clock_notify(QEMU_CLOCK_VIRTUAL);
}
}
vm_clock_warp_start = -1;
}
static void icount_adjust(void)
{
int64_t cur_time;
int64_t cur_icount;
int64_t delta;
static int64_t last_delta;
/* If the VM is not running, then do nothing. */
if (!vm_running)
return;
cur_time = cpu_get_clock();
cur_icount = qemu_get_clock_ns(vm_clock);
delta = cur_icount - cur_time;
/* FIXME: This is a very crude algorithm, somewhat prone to oscillation. */
if (delta > 0
&& last_delta + ICOUNT_WOBBLE < delta * 2
&& icount_time_shift > 0) {
/* The guest is getting too far ahead. Slow time down. */
icount_time_shift--;
}
if (delta < 0
&& last_delta - ICOUNT_WOBBLE > delta * 2
&& icount_time_shift < MAX_ICOUNT_SHIFT) {
/* The guest is getting too far behind. Speed time up. */
icount_time_shift++;
}
last_delta = delta;
qemu_icount_bias = cur_icount - (qemu_icount << icount_time_shift);
}
/* disable cpu_get_ticks() : the clock is stopped. You must not call
cpu_get_ticks() after that. */
void cpu_disable_ticks(void)
{
if (timers_state.cpu_ticks_enabled) {
timers_state.cpu_ticks_offset = cpu_get_ticks();
timers_state.cpu_clock_offset = cpu_get_clock();
timers_state.cpu_ticks_enabled = 0;
}
}
/**
* Allows S2E to slow down the VM clock while executing LLVM instructions.
* Assumes that rt_clock == vm_clock.
* scale == 1 is the normal speed.
*/
void cpu_enable_scaling(int scale)
{
assert(scale >= 1);
if (!timers_state.clock_scale_enable) {
timers_state.cpu_clock_prev = cpu_get_clock();
timers_state.cpu_clock_prev_scaled = timers_state.cpu_clock_prev;
}
timers_state.clock_scale = scale;
timers_state.clock_scale_enable = 1;
}
static int64_t qemu_icount_delta(void)
{
if (use_icount == 1) {
/* When not using an adaptive execution frequency
we tend to get badly out of sync with real time,
so just delay for a reasonable amount of time. */
return 0;
} else {
return cpu_get_icount() - cpu_get_clock();
}
}
int64_t qemu_get_clock_ns(QEMUClock *clock)
{
switch(clock->type) {
case QEMU_CLOCK_REALTIME:
return get_clock();
default:
case QEMU_CLOCK_VIRTUAL:
return cpu_get_clock();
case QEMU_CLOCK_HOST:
return get_clock_realtime();
}
}
int64_t qemu_get_clock(QEMUClock *clock)
{
switch(clock->type) {
case QEMU_CLOCK_REALTIME:
return get_clock() / 1000000;
default:
case QEMU_CLOCK_VIRTUAL:
if (use_icount) {
return cpu_get_icount();
} else {
return cpu_get_clock();
}
case QEMU_CLOCK_HOST:
return get_clock_realtime();
}
}
int64_t qemu_get_clock(QEMUClock *clock)
{
switch(clock->type) {
case QEMU_CLOCK_REALTIME:
return get_clock() / 1000000;
default:
case QEMU_CLOCK_VIRTUAL:
#ifdef MARSS_QEMU
if (in_simulation) {
return cpu_get_sim_clock();
}
#endif
if (use_icount) {
return cpu_get_icount();
} else {
return cpu_get_clock();
}
case QEMU_CLOCK_HOST:
return get_clock_realtime();
}
}
int64_t qemu_get_clock_ns(QEMUClock *clock)
{
int64_t now, last;
switch(clock->type) {
case QEMU_CLOCK_REALTIME:
return get_clock();
default:
case QEMU_CLOCK_VIRTUAL:
if (use_icount) {
return cpu_get_icount();
} else {
return cpu_get_clock();
}
case QEMU_CLOCK_HOST:
now = get_clock_realtime();
last = clock->last;
clock->last = now;
if (now < last) {
notifier_list_notify(&clock->reset_notifiers, &now);
}
return now;
}
}
