From: Radim Krčmář <rkrcmar@redhat.com>
Date: Fri, 6 Oct 2017 17:25:53 +0000 (+0200)
Subject: KVM: x86: handle 0 write to TSC_DEADLINE MSR
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=86bbc1e6d7ce016f1b2e8c29864cd7b75b00ff96;p=linux.git

KVM: x86: handle 0 write to TSC_DEADLINE MSR

0 should disable the timer, but start_hv_timer will recognize it as an
expired timer instead.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 2c9e88a82738d..39c1ae11ce1d9 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1549,6 +1549,9 @@ static bool start_hv_timer(struct kvm_lapic *apic)
 	if (!apic_lvtt_period(apic) && atomic_read(&ktimer->pending))
 		return false;
 
+	if (!ktimer->tscdeadline)
+		return false;
+
 	r = kvm_x86_ops->set_hv_timer(apic->vcpu, ktimer->tscdeadline);
 	if (r < 0)
 		return false;