diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 4b53b811d1c1a2b53ea14235fa8ecffa0b42e618..2fb20caae5d8b7453efa989ac44e1ba029577b26 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -68,6 +68,9 @@ #define VEC_POS(v) ((v) & (32 - 1)) #define REG_POS(v) (((v) >> 5) << 4) +static unsigned int min_timer_period_us = 500; +module_param(min_timer_period_us, uint, S_IRUGO | S_IWUSR); + static inline u32 apic_get_reg(struct kvm_lapic *apic, int reg_off) { return *((u32 *) (apic->regs + reg_off)); @@ -677,8 +680,16 @@ static void start_apic_timer(struct kvm_lapic *apic) * scheduler. */ if (apic_lvtt_period(apic)) { - if (apic->lapic_timer.period < NSEC_PER_MSEC/2) - apic->lapic_timer.period = NSEC_PER_MSEC/2; + s64 min_period = min_timer_period_us * 1000LL; + + if (apic->lapic_timer.period < min_period) { + pr_info_ratelimited( + "kvm: vcpu %i: requested %lld ns " + "lapic timer period limited to %lld ns\n", + apic->vcpu->vcpu_id, apic->lapic_timer.period, + min_period); + apic->lapic_timer.period = min_period; + } } hrtimer_start(&apic->lapic_timer.timer,