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authorWanpeng Li <wanpengli@tencent.com>2021-06-07 10:19:43 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2021-06-08 19:22:26 +0300
commite898da784aed0ea65f7672d941c01dc9b79e6299 (patch)
tree32206b1e1480ff8574a97ef8f569444858c117a4 /arch
parent4f13d471e5d11034d56161af56d0f9396bc0b384 (diff)
downloadlinux-e898da784aed0ea65f7672d941c01dc9b79e6299.tar.xz
KVM: LAPIC: Write 0 to TMICT should also cancel vmx-preemption timer
According to the SDM 10.5.4.1: A write of 0 to the initial-count register effectively stops the local APIC timer, in both one-shot and periodic mode. However, the lapic timer oneshot/periodic mode which is emulated by vmx-preemption timer doesn't stop by writing 0 to TMICT since vmx->hv_deadline_tsc is still programmed and the guest will receive the spurious timer interrupt later. This patch fixes it by also cancelling the vmx-preemption timer when writing 0 to the initial-count register. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Message-Id: <1623050385-100988-1-git-send-email-wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/lapic.c17
1 files changed, 11 insertions, 6 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 8120e8614b92..6d72d8f43310 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1494,6 +1494,15 @@ static void limit_periodic_timer_frequency(struct kvm_lapic *apic)
static void cancel_hv_timer(struct kvm_lapic *apic);
+static void cancel_apic_timer(struct kvm_lapic *apic)
+{
+ hrtimer_cancel(&apic->lapic_timer.timer);
+ preempt_disable();
+ if (apic->lapic_timer.hv_timer_in_use)
+ cancel_hv_timer(apic);
+ preempt_enable();
+}
+
static void apic_update_lvtt(struct kvm_lapic *apic)
{
u32 timer_mode = kvm_lapic_get_reg(apic, APIC_LVTT) &
@@ -1502,11 +1511,7 @@ 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)) {
- hrtimer_cancel(&apic->lapic_timer.timer);
- preempt_disable();
- if (apic->lapic_timer.hv_timer_in_use)
- cancel_hv_timer(apic);
- preempt_enable();
+ cancel_apic_timer(apic);
kvm_lapic_set_reg(apic, APIC_TMICT, 0);
apic->lapic_timer.period = 0;
apic->lapic_timer.tscdeadline = 0;
@@ -2092,7 +2097,7 @@ int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val)
if (apic_lvtt_tscdeadline(apic))
break;
- hrtimer_cancel(&apic->lapic_timer.timer);
+ cancel_apic_timer(apic);
kvm_lapic_set_reg(apic, APIC_TMICT, val);
start_apic_timer(apic);
break;