From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754375AbcBHPJq (ORCPT ); Mon, 8 Feb 2016 10:09:46 -0500 Received: from mail-wm0-f65.google.com ([74.125.82.65]:35753 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753506AbcBHPJn (ORCPT ); Mon, 8 Feb 2016 10:09:43 -0500 Subject: Re: [PATCH 1/2] KVM: x86: fix ordering of cr0 initialization code in vmx_cpu_reset To: Bruce Rogers , kvm@vger.kernel.org, linux-kernel@vger.kernel.org References: <1454539876-8310-1-git-send-email-brogers@suse.com> Cc: jan.kiszka@siemens.com, namit@cs.technion.ac.il From: Paolo Bonzini Message-ID: <56B8AFAF.7090509@redhat.com> Date: Mon, 8 Feb 2016 16:09:35 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.0 MIME-Version: 1.0 In-Reply-To: <1454539876-8310-1-git-send-email-brogers@suse.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/02/2016 23:51, Bruce Rogers wrote: > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index e2951b6..21507b4 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -4993,8 +4993,8 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) > vmcs_write16(VIRTUAL_PROCESSOR_ID, vmx->vpid); > > cr0 = X86_CR0_NW | X86_CR0_CD | X86_CR0_ET; > - vmx_set_cr0(vcpu, cr0); /* enter rmode */ > vmx->vcpu.arch.cr0 = cr0; > + vmx_set_cr0(vcpu, cr0); /* enter rmode */ Your comment that the assignment is redundant is correct, but I am afraid that this fix is also wrong. In particular, it would not cause exit_lmode and enter_rmode to be called. You are not describing which call to kvm_mmu_reset_context was messed up, so I'm not sure how your patch is fixing things. Paolo