linux-kernel - [PATCH 2/2] KVM: LAPIC: Guarantee the timer is in tsc-deadline mode when setting

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Message-Id: <1596521448-4010-2-git-send-email-wanpengli@tencent.com>
Date:   Tue,  4 Aug 2020 14:10:48 +0800
From:   Wanpeng Li <kernellwp@...il.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <sean.j.christopherson@...el.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>
Subject: [PATCH 2/2] KVM: LAPIC: Guarantee the timer is in tsc-deadline mode when setting

From: Wanpeng Li <wanpengli@...cent.com>

Check apic_lvtt_tscdeadline() mode directly instead of apic_lvtt_oneshot()
and apic_lvtt_period() to guarantee the timer is in tsc-deadline mode when
wrmsr MSR_IA32_TSCDEADLINE.

Signed-off-by: Wanpeng Li <wanpengli@...cent.com>
---
 arch/x86/kvm/lapic.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index d89ab48..7b11fa8 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2193,8 +2193,8 @@ void kvm_set_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu, u64 data)
 {
 	struct kvm_lapic *apic = vcpu->arch.apic;
 
-	if (!kvm_apic_present(vcpu) || apic_lvtt_oneshot(apic) ||
-			apic_lvtt_period(apic))
+	if (!kvm_apic_present(vcpu) ||
+		!apic_lvtt_tscdeadline(apic))
 		return;
 
 	hrtimer_cancel(&apic->lapic_timer.timer);
-- 
2.7.4