From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759784AbXLWPDw (ORCPT ); Sun, 23 Dec 2007 10:03:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756135AbXLWOwW (ORCPT ); Sun, 23 Dec 2007 09:52:22 -0500 Received: from il.qumranet.com ([82.166.9.18]:35897 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753462AbXLWOvo (ORCPT ); Sun, 23 Dec 2007 09:51:44 -0500 From: Avi Kivity To: linux-kernel@vger.kernel.org, kvm-devel@lists.sourceforge.net Subject: [PATCH 33/50] KVM: MMU: Disable write access on clean large pages Date: Sun, 23 Dec 2007 16:51:18 +0200 Message-Id: <1198421495-31481-34-git-send-email-avi@qumranet.com> X-Mailer: git-send-email 1.5.3.7 In-Reply-To: <1198421495-31481-1-git-send-email-avi@qumranet.com> References: <1198421495-31481-1-git-send-email-avi@qumranet.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org By forcing clean huge pages to be read-only, we have separate roles for the shadow of a clean large page and the shadow of a dirty large page. This is necessary because different ptes will be instantiated for the two cases, even for read faults. 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 e07cb2e..4538b15 100644 --- a/drivers/kvm/paging_tmpl.h +++ b/drivers/kvm/paging_tmpl.h @@ -382,6 +382,8 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, metaphysical = 1; hugepage_access = walker->pte; hugepage_access &= PT_USER_MASK | PT_WRITABLE_MASK; + if (!is_dirty_pte(walker->pte)) + hugepage_access &= ~PT_WRITABLE_MASK; hugepage_access >>= PT_WRITABLE_SHIFT; if (walker->pte & PT64_NX_MASK) hugepage_access |= (1 << 2); -- 1.5.3.7