From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756181Ab1INJx2 (ORCPT ); Wed, 14 Sep 2011 05:53:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37313 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755127Ab1INJx0 (ORCPT ); Wed, 14 Sep 2011 05:53:26 -0400 Message-ID: <4E707991.10705@redhat.com> Date: Wed, 14 Sep 2011 12:53:21 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:6.0) Gecko/20110816 Thunderbird/6.0 MIME-Version: 1.0 To: Xiao Guangrong CC: Marcelo Tosatti , LKML , KVM Subject: Re: [PATCH v3 03/11] KVM: x86: retry non-page-table writing instruction References: <4E5C4C20.3000403@cn.fujitsu.com> <4E5C4C5C.8030602@cn.fujitsu.com> <4E6F34CF.1060302@redhat.com> <4E6F9FD2.4010407@cn.fujitsu.com> In-Reply-To: <4E6F9FD2.4010407@cn.fujitsu.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/13/2011 09:24 PM, Xiao Guangrong wrote: > >> > >> +static bool retry_instruction(struct x86_emulate_ctxt *ctxt, > >> + unsigned long cr2, int emulation_type) > >> +{ > >> + if (!vcpu->arch.mmu.direct_map&& !mmu_is_nested(vcpu)) > >> + gpa = kvm_mmu_gva_to_gpa_write(vcpu, cr2, NULL); > > > > If mmu_is_nested() cr2 is an ngpa, we have to translate it to a gpa, no? > > > > Yeah, will fix it. > > And this bug also exists in the current code: it always uses L2 gpa to emulate > write operation. Can you please send this fix separately, so it can be backported if needed? > I guess the reason that it is not triggered is: the gpa of L2's shadow page can > not be touched by L2, it means no page table is write-protected by L2. Yes. All real guest hypervisors will do that. But it is technically possible for a hypervisor to allow its guest access to the real page tables. > > btw, I don't see mmu.direct_map initialized for nested npt? > > > > nested_svm_vmrun() -> nested_svm_init_mmu_context(): > static int nested_svm_init_mmu_context(struct kvm_vcpu *vcpu) > { > int r; > > r = kvm_init_shadow_mmu(vcpu,&vcpu->arch.mmu); > > vcpu->arch.mmu.set_cr3 = nested_svm_set_tdp_cr3; > vcpu->arch.mmu.get_cr3 = nested_svm_get_tdp_cr3; > vcpu->arch.mmu.get_pdptr = nested_svm_get_tdp_pdptr; > vcpu->arch.mmu.inject_page_fault = nested_svm_inject_npf_exit; > vcpu->arch.mmu.shadow_root_level = get_npt_level(); > vcpu->arch.walk_mmu =&vcpu->arch.nested_mmu; > > return r; > } > > It is initialized in kvm_init_shadow_mmu　:-) Yes, need new eyeglasses. -- error compiling committee.c: too many arguments to function