From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758824AbYAAPte (ORCPT ); Tue, 1 Jan 2008 10:49:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755368AbYAAPg4 (ORCPT ); Tue, 1 Jan 2008 10:36:56 -0500 Received: from il.qumranet.com ([82.166.9.18]:33802 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755188AbYAAPga (ORCPT ); Tue, 1 Jan 2008 10:36:30 -0500 From: Avi Kivity To: linux-kernel@vger.kernel.org, kvm-devel@lists.sourceforge.net Subject: [PATCH 43/54] KVM: MMU: Set nx bit correctly on shadow ptes Date: Tue, 1 Jan 2008 17:36:09 +0200 Message-Id: <1199201780-14001-44-git-send-email-avi@qumranet.com> X-Mailer: git-send-email 1.5.3.7 In-Reply-To: <1199201780-14001-1-git-send-email-avi@qumranet.com> References: <1199201780-14001-1-git-send-email-avi@qumranet.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org While the page table walker correctly generates a guest page fault if a guest tries to execute a non-executable page, the shadow code does not mark it non-executable. This means that if a guest accesses an nx page first with a read access, then subsequent code fetch accesses will succeed. Fix by setting the nx bit on shadow ptes. Signed-off-by: Avi Kivity --- drivers/kvm/paging_tmpl.h | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h index 7688cbf..59ba752 100644 --- a/drivers/kvm/paging_tmpl.h +++ b/drivers/kvm/paging_tmpl.h @@ -255,6 +255,8 @@ static void FNAME(set_pte)(struct kvm_vcpu *vcpu, pt_element_t gpte, spte |= gpte & PT64_NX_MASK; if (!dirty) pte_access &= ~ACC_WRITE_MASK; + if (!(pte_access & ACC_EXEC_MASK)) + spte |= PT64_NX_MASK; page = gfn_to_page(vcpu->kvm, gfn); -- 1.5.3.7