From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757875AbcBCXic (ORCPT ); Wed, 3 Feb 2016 18:38:32 -0500 Received: from prv-mh.provo.novell.com ([137.65.248.74]:35671 "EHLO prv-mh.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755328AbcBCXi3 convert rfc822-to-8bit (ORCPT ); Wed, 3 Feb 2016 18:38:29 -0500 Message-Id: <56B22D020200004800124F32@prv-mh.provo.novell.com> X-Mailer: Novell GroupWise Internet Agent 14.2.0 Date: Wed, 03 Feb 2016 16:38:26 -0700 From: "Bruce Rogers" To: "Nadav Amit" Cc: "Nadav Amit" , , , 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> 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 I hadn't noticed that one - my testcase didn't encounter any issues on AMD. Anyways, it's probably best to revert that change as well. I'll add that in for a v2. Bruce >>> On 2/3/2016 at 04:18 PM, Nadav Amit wrote: > Oops. > > Anyhow, I see my patch has done a similar change in init_vmcb() , so you may > want to revert it as well. > > Nadav > > Bruce Rogers wrote: > >> Commit d28bc9dd25ce reversed the order of two lines which initialize cr0, >> allowing the current (old) cr0 value to mess up vcpu initialization. >> This was observed in the checks for cr0 X86_CR0_WP bit in the context of >> kvm_mmu_reset_context(). Besides, setting vcpu->arch.cr0 after vmx_set_cr0() >> is completely redundant. Change the order back to ensure proper vcpu >> intiialization. >> >> Signed-off-by: Bruce Rogers >> --- >> arch/x86/kvm/vmx.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> 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 */ >> vmx_set_cr4(vcpu, 0); >> vmx_set_efer(vcpu, 0); >> vmx_fpu_activate(vcpu); >> -- >> 1.9.0 > > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html