Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752603AbcD1WSa (ORCPT ); Thu, 28 Apr 2016 18:18:30 -0400 Received: from prv-mh.provo.novell.com ([137.65.248.74]:38310 "EHLO prv-mh.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752327AbcD1WS3 convert rfc822-to-8bit (ORCPT ); Thu, 28 Apr 2016 18:18:29 -0400 Message-Id: <572237CF02000048001298DC@prv-mh.provo.novell.com> X-Mailer: Novell GroupWise Internet Agent 14.2.0 Date: Thu, 28 Apr 2016 16:18:23 -0600 From: "Bruce Rogers" To: "Wanpeng Li" Cc: "Nadav Amit" , "Paolo Bonzini" , "J. Kiszka" , "kvm" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 1/2] KVM: x86: fix ordering of cr0 initialization code in vmx_cpu_reset References: <1454539876-8310-1-git-send-email-brogers@suse.com> <56B8AFAF.7090509@redhat.com> <56B85FFA02000048001251CE@prv-mh.provo.novell.com> In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1506 Lines: 38 >>> On 4/26/2016 at 08:54 PM, Wanpeng Li wrote: > 2016-02-09 0:29 GMT+08:00 Bruce Rogers : >>>>> On 2/8/2016 at 08:09 AM, Paolo Bonzini wrote: >> >>> >>> 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. >> >> This is in the context of AP sending INIT to BSP with unrestricted_guest=N. > > BSP will broadcast INIT-SIPI-SIPI sequence to APs during > initialization, could you point out when "AP sending INIT to BSP" as > you mentioned above in SDM? > You should know that I abandoned this patch series as further investigation revealed that this was not as cut and dried as I had first hoped. Bruce