KVM: LAPIC: Drop pending LAPIC timer injection when canceling the timer

Wanpeng Li · bonzini · commit 619f51da0979 · 2022-05-25T05:12:35.000-04:00
The timer is disarmed when switching between TSC deadline and other modes; however, the pending timer is still in-flight, so let's accurately remove any traces of the previous mode. Fixes: 4427593 ("KVM: x86: thoroughly disarm LAPIC timer around TSC deadline switch") Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
@@ -1548,6 +1548,7 @@ static void cancel_apic_timer(struct kvm_lapic *apic)
 	if (apic->lapic_timer.hv_timer_in_use)
 		cancel_hv_timer(apic);
 	preempt_enable();
+	atomic_set(&apic->lapic_timer.pending, 0);
 }
 
 static void apic_update_lvtt(struct kvm_lapic *apic)

Original file line number	Diff line number	Diff line change
`@@ -1548,6 +1548,7 @@ static void cancel_apic_timer(struct kvm_lapic *apic)`
`1548`	`1548`	`if (apic->lapic_timer.hv_timer_in_use)`
`1549`	`1549`	`cancel_hv_timer(apic);`
`1550`	`1550`	`preempt_enable();`
	`1551`	`+ atomic_set(&apic->lapic_timer.pending, 0);`
`1551`	`1552`	`}`
`1552`	`1553`
`1553`	`1554`	`static void apic_update_lvtt(struct kvm_lapic *apic)`