From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757337Ab0IHJSd (ORCPT ); Wed, 8 Sep 2010 05:18:33 -0400 Received: from va3ehsobe006.messaging.microsoft.com ([216.32.180.16]:58287 "EHLO VA3EHSOBE008.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751089Ab0IHJSb (ORCPT ); Wed, 8 Sep 2010 05:18:31 -0400 X-SpamScore: -16 X-BigFish: VS-16(zz1432N98dN148cMzz1202hzz8275bhz32i87h2a8h61h) X-Spam-TCS-SCL: 0:0 X-FB-SS: 0, X-FB-DOMAIN-IP-MATCH: fail X-WSS-ID: 0L8F899-02-3BJ-02 X-M-MSG: Date: Wed, 8 Sep 2010 11:12:52 +0200 From: "Roedel, Joerg" To: Marcelo Tosatti CC: Avi Kivity , Alexander Graf , "joro@8bytes.org" , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 14/27] KVM: MMU: Make walk_addr_generic capable for two-level walking Message-ID: <20100908091252.GH2177@amd.com> References: <1283788566-29186-1-git-send-email-joerg.roedel@amd.com> <1283788566-29186-15-git-send-email-joerg.roedel@amd.com> <20100907174805.GA11215@amt.cnet> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20100907174805.GA11215@amt.cnet> Organization: Advanced Micro Devices =?iso-8859-1?Q?GmbH?= =?iso-8859-1?Q?=2C_Karl-Hammerschmidt-Str=2E_34=2C_85609_Dornach_bei_M=FC?= =?iso-8859-1?Q?nchen=2C_Gesch=E4ftsf=FChrer=3A_Thomas_M=2E_McCoy=2C_Giuli?= =?iso-8859-1?Q?ano_Meroni=2C_Andrew_Bowd=2C_Sitz=3A_Dornach=2C_Gemeinde_A?= =?iso-8859-1?Q?schheim=2C_Landkreis_M=FCnchen=2C_Registergericht_M=FCnche?= =?iso-8859-1?Q?n=2C?= HRB Nr. 43632 User-Agent: Mutt/1.5.20 (2009-06-14) X-Reverse-DNS: ausb3extmailp02.amd.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 07, 2010 at 01:48:05PM -0400, Marcelo Tosatti wrote: > On Mon, Sep 06, 2010 at 05:55:53PM +0200, Joerg Roedel wrote: > > This patch uses kvm_read_guest_page_tdp to make the > > walk_addr_generic functions suitable for two-level page > > table walking. > > > > Signed-off-by: Joerg Roedel > > --- > > arch/x86/kvm/paging_tmpl.h | 27 ++++++++++++++++++++------- > > 1 files changed, 20 insertions(+), 7 deletions(-) > > > > diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h > > index cd59af1..a5b5759 100644 > > --- a/arch/x86/kvm/paging_tmpl.h > > +++ b/arch/x86/kvm/paging_tmpl.h > > @@ -124,6 +124,8 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker, > > unsigned index, pt_access, uninitialized_var(pte_access); > > gpa_t pte_gpa; > > bool eperm, present, rsvd_fault; > > + int offset; > > + u32 error = 0; > > > > trace_kvm_mmu_pagetable_walk(addr, write_fault, user_fault, > > fetch_fault); > > @@ -153,12 +155,13 @@ walk: > > index = PT_INDEX(addr, walker->level); > > > > table_gfn = gpte_to_gfn(pte); > > - pte_gpa = gfn_to_gpa(table_gfn); > > - pte_gpa += index * sizeof(pt_element_t); > > + offset = index * sizeof(pt_element_t); > > + pte_gpa = gfn_to_gpa(table_gfn) + offset; > > walker->table_gfn[walker->level - 1] = table_gfn; > > walker->pte_gpa[walker->level - 1] = pte_gpa; > > > > - if (kvm_read_guest(vcpu->kvm, pte_gpa, &pte, sizeof(pte))) { > > + if (kvm_read_guest_page_mmu(vcpu, mmu, table_gfn, &pte, offset, > > + sizeof(pte), &error)) { > > present = false; > > break; > > } > > If there is failure reading the nested page tables here, you fill > vcpu->arch.fault. But the nested fault error values will be overwritten > at the end of walk_addr() by the original fault values? True. Thanks for pointing that out. I will write a test-case for that too. The results from my implemented tests show that sometimes the error code is not reported correctly too. So I decided to do a v4 of this patch-set with all found issues fixed. Thanks for your review. Joerg