From: Wanpeng Li <kernellwp@gmail.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>
Subject: [PATCH v3] KVM: LAPIC: Keep stored TMCCT register value 0 after KVM_SET_LAPIC
Date: Wed, 9 Jun 2021 00:16:40 -0700 [thread overview]
Message-ID: <1623223000-18116-1-git-send-email-wanpengli@tencent.com> (raw)
From: Wanpeng Li <wanpengli@tencent.com>
KVM_GET_LAPIC stores the current value of TMCCT and KVM_SET_LAPIC's memcpy
stores it in vcpu->arch.apic->regs, KVM_SET_LAPIC could store zero in
vcpu->arch.apic->regs after it uses it, and then the stored value would
always be zero. In addition, the TMCCT is always computed on-demand and
never directly readable.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
---
arch/x86/kvm/lapic.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 6d72d8f43310..9bd29b3ca790 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2628,6 +2628,7 @@ int kvm_apic_set_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s)
apic_manage_nmi_watchdog(apic, kvm_lapic_get_reg(apic, APIC_LVT0));
update_divide_count(apic);
__start_apic_timer(apic, APIC_TMCCT);
+ kvm_lapic_set_reg(apic, APIC_TMCCT, 0);
kvm_apic_update_apicv(vcpu);
apic->highest_isr_cache = -1;
if (vcpu->arch.apicv_active) {
--
2.25.1
next reply other threads:[~2021-06-09 7:18 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-09 7:16 Wanpeng Li [this message]
2021-06-17 4:33 ` [PATCH v3] KVM: LAPIC: Keep stored TMCCT register value 0 after KVM_SET_LAPIC Wanpeng Li
2021-06-17 18:26 ` Paolo Bonzini
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