public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Joerg Roedel <joerg.roedel@amd.com>
To: Stefan Lippers-Hollmann <s.L-H@gmx.de>
Cc: gregkh@suse.de, linux-kernel@vger.kernel.org,
	mtosatti@redhat.com, stable@kernel.org
Subject: Re: patch kvm-svm-fix-tsc-offset-adjustment-when-running-nested.patch added to 2.6.31-stable tree
Date: Mon, 12 Oct 2009 11:41:51 +0200	[thread overview]
Message-ID: <20091012094151.GA32228@amd.com> (raw)
In-Reply-To: <200910101540.06686.s.L-H@gmx.de>

All the nested stuff was moved into its own sub-struct in 2.6.32. Here
is a version that works with 2.6.31.3:

>From 4505a73070f341674e0d22a8c9ee51b2beeb843e Mon Sep 17 00:00:00 2001
From: Joerg Roedel <joerg.roedel@amd.com>
Date: Mon, 12 Oct 2009 11:19:07 +0200
Subject: [PATCH 1/2] KVM: SVM: Fix tsc offset adjustment when running nested

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>
---
 arch/x86/kvm/svm.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index b1f658a..aafd8bf 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;
-- 
1.6.4.3



  parent reply	other threads:[~2009-10-12  9:42 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20091009223815.20569488DB@coco.kroah.org>
2009-10-10 13:40 ` patch kvm-svm-fix-tsc-offset-adjustment-when-running-nested.patch added to 2.6.31-stable tree Stefan Lippers-Hollmann
2009-10-10 15:32   ` Marcelo Tosatti
2009-10-12  9:41   ` Joerg Roedel [this message]
2009-10-12 14:55     ` [stable] " Greg KH
2009-10-12 19:13     ` Greg KH

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20091012094151.GA32228@amd.com \
    --to=joerg.roedel@amd.com \
    --cc=gregkh@suse.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mtosatti@redhat.com \
    --cc=s.L-H@gmx.de \
    --cc=stable@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox