Re: [Stable-review] [patch 00/26] 2.6.31.4-stable review

Chuck Ebbert
2009-10-12T12:37:55Z

On Mon, 12 Oct 2009 13:09:56 +0200 (CEST)
Thomas Voegtle <tv@lio96.de> wrote:

> arch/x86/kvm/svm.c: In function 'svm_vcpu_load':
> arch/x86/kvm/svm.c:713: error: 'struct vcpu_svm' has no member named
> 'nested'

Replacement patch for:
kvm-svm-fix-tsc-offset-adjustment-when-running-nested.patch

Fixes:
arch/x86/kvm/svm.c: In function 'svm_vcpu_load':
arch/x86/kvm/svm.c:713: error: 'struct vcpu_svm' has no member named 'nested'

>From 77b1ab1732feb5e3dcbaf31d2f7547c5229f5f3a Mon Sep 17 00:00:00 2001
From: Joerg Roedel <joerg.roedel@amd.com>
Date: Wed, 16 Sep 2009 15:24:17 +0200
Subject: KVM: SVM: Fix tsc offset adjustment when running nested

From: Joerg Roedel <joerg.roedel@amd.com>

commit 77b1ab1732feb5e3dcbaf31d2f7547c5229f5f3a upstream.
[ backport to 2.6.31 by Chuck Ebbert <cebbert@redhat.com> ]

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>

---
arch/x86/kvm/svm.c | 2 ++
1 file changed, 2 insertions(+)

--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -709,6 +709,8 @@ static void svm_vcpu_load(struct kvm_vcp
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;