[PATCH 3/3] KVM: x86: thoroughly disarm LAPIC timer around TSC deadline switch

From: Radim KrÄmÃÅ
Date: Fri Oct 06 2017 - 13:26:28 EST


Our routines look at tscdeadline and period when deciding state of a
timer. The timer is disarmed when switching between TSC deadline and
other modes, so we should set everything to disarmed state.

Signed-off-by: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
---
arch/x86/kvm/lapic.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 96ade848ae0b..a778f1ae2927 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1330,8 +1330,10 @@ static void apic_update_lvtt(struct kvm_lapic *apic)
if (apic->lapic_timer.timer_mode != timer_mode) {
if (apic_lvtt_tscdeadline(apic) != (timer_mode ==
APIC_LVT_TIMER_TSCDEADLINE)) {
- kvm_lapic_set_reg(apic, APIC_TMICT, 0);
hrtimer_cancel(&apic->lapic_timer.timer);
+ kvm_lapic_set_reg(apic, APIC_TMICT, 0);
+ apic->lapic_timer.period = 0;
+ apic->lapic_timer.tscdeadline = 0;
}
apic->lapic_timer.timer_mode = timer_mode;
limit_periodic_timer_frequency(apic);
--
2.14.2