[PATCH] KVM: LAPIC: Reset timer_advance_ns to 1000 after adaptive tuning goes insane

From: Wanpeng Li
Date: Fri Jul 05 2019 - 05:41:02 EST


From: Wanpeng Li <wanpengli@xxxxxxxxxxx>

Reset timer_advance_ns to the default value 1000ns after adaptive tuning
goes insane which can happen sporadically in product environment.

Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx>
Signed-off-by: Wanpeng Li <wanpengli@xxxxxxxxxxx>
---
arch/x86/kvm/lapic.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 05d8934..454d3dd 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1549,7 +1549,7 @@ static inline void adjust_lapic_timer_advance(struct kvm_vcpu *vcpu,
if (abs(advance_expire_delta) < LAPIC_TIMER_ADVANCE_ADJUST_DONE)
apic->lapic_timer.timer_advance_adjust_done = true;
if (unlikely(timer_advance_ns > 5000)) {
- timer_advance_ns = 0;
+ timer_advance_ns = 1000;
apic->lapic_timer.timer_advance_adjust_done = true;
}
apic->lapic_timer.timer_advance_ns = timer_advance_ns;
--
2.7.4