diff options
Diffstat (limited to 'arch/x86/kvm/lapic.c')
| -rw-r--r-- | arch/x86/kvm/lapic.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index ae99d83f81a3..9a65123b798e 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -464,7 +464,7 @@ static u32 apic_get_tmcct(struct kvm_lapic *apic) if (apic_get_reg(apic, APIC_TMICT) == 0) return 0; - remaining = hrtimer_expires_remaining(&apic->lapic_timer.timer); + remaining = hrtimer_get_remaining(&apic->lapic_timer.timer); if (ktime_to_ns(remaining) < 0) remaining = ktime_set(0, 0); @@ -567,12 +567,21 @@ static void start_apic_timer(struct kvm_lapic *apic) { ktime_t now = apic->lapic_timer.timer.base->get_time(); - apic->lapic_timer.period = apic_get_reg(apic, APIC_TMICT) * + apic->lapic_timer.period = (u64)apic_get_reg(apic, APIC_TMICT) * APIC_BUS_CYCLE_NS * apic->divide_count; atomic_set(&apic->lapic_timer.pending, 0); if (!apic->lapic_timer.period) return; + /* + * Do not allow the guest to program periodic timers with small + * interval, since the hrtimers are not throttled by the host + * scheduler. + */ + if (apic_lvtt_period(apic)) { + if (apic->lapic_timer.period < NSEC_PER_MSEC/2) + apic->lapic_timer.period = NSEC_PER_MSEC/2; + } hrtimer_start(&apic->lapic_timer.timer, ktime_add_ns(now, apic->lapic_timer.period), |