From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755124Ab1ABHdU (ORCPT ); Sun, 2 Jan 2011 02:33:20 -0500 Received: from mail.windriver.com ([147.11.1.11]:37123 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754867Ab1ABHZj (ORCPT ); Sun, 2 Jan 2011 02:25:39 -0500 From: Paul Gortmaker To: stable@kernel.org, linux-kernel@vger.kernel.org Cc: stable-review@kernel.org, Xiao Guangrong , Marcelo Tosatti , Paul Gortmaker Subject: [34-longterm 234/260] KVM: MMU: fix conflict access permissions in direct sp Date: Sun, 2 Jan 2011 02:18:50 -0500 Message-Id: <1293952756-15010-235-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.3.3 In-Reply-To: <1293952756-15010-1-git-send-email-paul.gortmaker@windriver.com> References: <1293952756-15010-1-git-send-email-paul.gortmaker@windriver.com> X-OriginalArrivalTime: 02 Jan 2011 07:24:26.0027 (UTC) FILETIME=[15CF4FB0:01CBAA4E] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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: Paul Gortmaker --- arch/x86/kvm/paging_tmpl.h | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index a535c87..2bd2b3e 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -356,6 +356,8 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, direct = 1; if (!is_dirty_gpte(gw->ptes[level - delta])) access &= ~ACC_WRITE_MASK; + access &= gw->pte_access; + table_gfn = gpte_to_gfn(gw->ptes[level - delta]); /* advance table_gfn when emulating 1gb pages with 4k */ if (delta == 0) -- 1.7.3.3