From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757146Ab1AMPXQ (ORCPT ); Thu, 13 Jan 2011 10:23:16 -0500 Received: from tx2ehsobe004.messaging.microsoft.com ([65.55.88.14]:41123 "EHLO TX2EHSOBE007.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757096Ab1AMPXI (ORCPT ); Thu, 13 Jan 2011 10:23:08 -0500 X-SpamScore: -2 X-BigFish: VPS-2(zzbb2cKzz1202hzz8275bh8275dhz32i668h61h) X-Spam-TCS-SCL: 0:0 X-Forefront-Antispam-Report: KIP:(null);UIP:(null);IPVD:NLI;H:ausb3twp01.amd.com;RD:none;EFVD:NLI X-WSS-ID: 0LEYW2B-01-NNN-02 X-M-MSG: From: Joerg Roedel To: Avi Kivity , Marcelo Tosatti CC: , , Joerg Roedel , Subject: [PATCH 1/2] KVM: SVM: Fix NMI path when NMI happens in guest mode Date: Thu, 13 Jan 2011 16:22:57 +0100 Message-ID: <1294932178-26866-2-git-send-email-joerg.roedel@amd.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1294932178-26866-1-git-send-email-joerg.roedel@amd.com> References: <1294932178-26866-1-git-send-email-joerg.roedel@amd.com> MIME-Version: 1.0 Content-Type: text/plain X-OriginatorOrg: amd.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The vmexit path on SVM needs to restore the KERNEL_GS_BASE MSR in order to savely execute the NMI handler. Otherwise a pending NMI can occur after the STGI instruction and crash the machine. This makes it impossible to run perf and kvm in parallel on an AMD machine in a stable way. Cc: stable@kernel.org Signed-off-by: Joerg Roedel --- arch/x86/kvm/svm.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 25bd1bc..8b9bc72 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3637,6 +3637,7 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu) #ifdef CONFIG_X86_64 wrmsrl(MSR_GS_BASE, svm->host.gs_base); + wrmsrl(MSR_KERNEL_GS_BASE, current->thread.gs); #else loadsegment(fs, svm->host.fs); #endif -- 1.7.1