From: Joerg Roedel <joerg.roedel@amd.com>
Date: Mon, 12 Oct 2009 09:41:51 +0000 (+0200)
Subject: KVM: SVM: Fix tsc offset adjustment when running nested
X-Git-Tag: v2.6.31.4~20
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=89cc56416e963a723b568157e53fa4c796ffefa5;p=thirdparty%2Fkernel%2Fstable.git

KVM: SVM: Fix tsc offset adjustment when running nested

commit 77b1ab1732feb5e3dcbaf31d2f7547c5229f5f3a upstream.

When svm_vcpu_load is called while the vcpu is running in
guest mode the tsc adjustment made there is lost on the next
emulated #vmexit. This causes the tsc running backwards in
the guest. This patch fixes the issue by also adjusting the
tsc_offset in the emulated hsave area so that it will not
get lost.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index b1f658ad2f06b..aafd8bf47e774 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -709,6 +709,8 @@ static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 		rdtscll(tsc_this);
 		delta = vcpu->arch.host_tsc - tsc_this;
 		svm->vmcb->control.tsc_offset += delta;
+		if (is_nested(svm))
+			svm->hsave->control.tsc_offset += delta;
 		vcpu->cpu = cpu;
 		kvm_migrate_timers(vcpu);
 		svm->asid_generation = 0;