linux-kernel - [PATCH v3 2/5] KVM: LAPIC: guarantee the timer is in tsc-deadline mode

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Message-Id: <1477304593-3453-3-git-send-email-wanpeng.li@hotmail.com>
Date:   Mon, 24 Oct 2016 18:23:10 +0800
From:   Wanpeng Li <kernellwp@...il.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        Radim Krčmář <rkrcmar@...hat.com>,
        Yunhong Jiang <yunhong.jiang@...el.com>,
        Wanpeng Li <wanpeng.li@...mail.com>
Subject: [PATCH v3 2/5] KVM: LAPIC: guarantee the timer is in tsc-deadline mode

From: Wanpeng Li <wanpeng.li@...mail.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
rdmsr MSR_IA32_TSCDEADLINE.

Suggested-by: Radim Krčmář <rkrcmar@...hat.com>
Cc: Paolo Bonzini <pbonzini@...hat.com>
Cc: Radim Krčmář <rkrcmar@...hat.com>
Cc: Yunhong Jiang <yunhong.jiang@...el.com>
Signed-off-by: Wanpeng Li <wanpeng.li@...mail.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 dad743e..dce6c0b 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1711,8 +1711,8 @@ u64 kvm_get_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu)
 {
 	struct kvm_lapic *apic = vcpu->arch.apic;
 
-	if (!lapic_in_kernel(vcpu) || apic_lvtt_oneshot(apic) ||
-			apic_lvtt_period(apic))
+	if (!lapic_in_kernel(vcpu) ||
+		!apic_lvtt_tscdeadline(apic))
 		return 0;
 
 	return apic->lapic_timer.tscdeadline;
-- 
1.9.1