@@ -59,6 +59,7 @@ typedef struct HPETTimer { /* timers */
uint8_t wrap_flag; /* timer pop will indicate wrap for one-shot 32-bit
* mode. Next pop will be actual timer expiration.
*/
+ uint64_t last; /* last value armed, to avoid timer storms */
} HPETTimer;
struct HPETState {
@@ -266,6 +267,7 @@ static int hpet_post_load(void *opaque, int version_id)
for (i = 0; i < s->num_timers; i++) {
HPETTimer *t = &s->timer[i];
t->cmp64 = hpet_calculate_cmp64(t, s->hpet_counter, t->cmp);
+ t->last = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) - NANOSECONDS_PER_SECOND;
}
/* Recalculate the offset between the main counter and guest time */
if (!s->hpet_offset_saved) {
@@ -364,8 +366,15 @@ static const VMStateDescription vmstate_hpet = {
static void hpet_arm(HPETTimer *t, uint64_t tick)
{
- /* FIXME: Clamp period to reasonable min value? */
- timer_mod(t->qemu_timer, hpet_get_ns(t->state, tick));
+ uint64_t ns = hpet_get_ns(t->state, tick);
+
+ /* Clamp period to reasonable min value (1 us) */
+ if (timer_is_periodic(t) && ns - t->last < 1000) {
+ ns = t->last + 1000;
+ }
+
+ t->last = ns;
+ timer_mod(t->qemu_timer, ns);
}
/*
If the period is set to a value that is too low, there could be no time left to run the rest of QEMU. Do not trigger interrupts faster than 1 MHz. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- hw/timer/hpet.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)