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[3/6] KVM: X86: Make tsc_delta calculation a function of guest tsc

Message ID 1300952424-32014-4-git-send-email-joerg.roedel@amd.com (mailing list archive)
State New, archived
Headers show

Commit Message

Joerg Roedel March 24, 2011, 7:40 a.m. UTC 
None
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Patch

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 7979da4..4fae242 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2127,8 +2127,13 @@  void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 	kvm_x86_ops->vcpu_load(vcpu, cpu);
 	if (unlikely(vcpu->cpu != cpu) || check_tsc_unstable()) {
 		/* Make sure TSC doesn't go backwards */
-		s64 tsc_delta = !vcpu->arch.last_host_tsc ? 0 :
-				native_read_tsc() - vcpu->arch.last_host_tsc;
+		s64 tsc_delta;
+		u64 tsc;
+
+		kvm_get_msr(vcpu, MSR_IA32_TSC, &tsc);
+		tsc_delta = !vcpu->arch.last_guest_tsc ? 0 :
+			     tsc - vcpu->arch.last_guest_tsc;
+
 		if (tsc_delta < 0)
 			mark_tsc_unstable("KVM discovered backwards TSC");
 		if (check_tsc_unstable()) {