Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757327Ab0KSVwR (ORCPT ); Fri, 19 Nov 2010 16:52:17 -0500 Received: from kroah.org ([198.145.64.141]:51771 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757299Ab0KSVp2 (ORCPT ); Fri, 19 Nov 2010 16:45:28 -0500 X-Mailbox-Line: From gregkh@clark.site Fri Nov 19 13:44:10 2010 Message-Id: <20101119214410.822848883@clark.site> User-Agent: quilt/0.48-11.2 Date: Fri, 19 Nov 2010 13:42:57 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org, greg@kroah.com Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, avi@redhat.com, mtosatti@redhat.com, Xiao Guangrong Subject: [17/45] KVM: MMU: fix conflict access permissions in direct sp In-Reply-To: <20101119214439.GA26350@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1982 Lines: 59 2.6.32-stable review patch. If anyone has any objections, please let us know. ------------------ From: Xiao Guangrong commit 5fd5387c89ec99ff6cb82d2477ffeb7211b781c2 upstream. In no-direct mapping, we mark sp is 'direct' when we mapping the guest's larger page, but its access is encoded form upper page-struct entire not include the last mapping, it will cause access conflict. For example, have this mapping: [W] / PDE1 -> |---| P[W] | | LPA \ PDE2 -> |---| [R] P have two children, PDE1 and PDE2, both PDE1 and PDE2 mapping the same lage page(LPA). The P's access is WR, PDE1's access is WR, PDE2's access is RO(just consider read-write permissions here) When guest access PDE1, we will create a direct sp for LPA, the sp's access is from P, is W, then we will mark the ptes is W in this sp. Then, guest access PDE2, we will find LPA's shadow page, is the same as PDE's, and mark the ptes is RO. So, if guest access PDE1, the incorrect #PF is occured. Fixed by encode the last mapping access into direct shadow page Signed-off-by: Xiao Guangrong Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/paging_tmpl.h | 1 + 1 file changed, 1 insertion(+) --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -360,6 +360,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu /* advance table_gfn when emulating 1gb pages with 4k */ if (delta == 0) table_gfn += PT_INDEX(addr, level); + access &= gw->pte_access; } else { direct = 0; table_gfn = gw->table_gfn[level - 2]; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/