From patchwork Fri Nov 12 10:30:22 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xiao Guangrong X-Patchwork-Id: 319352 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id oACAQguv017637 for ; Fri, 12 Nov 2010 10:26:42 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755743Ab0KLK0G (ORCPT ); Fri, 12 Nov 2010 05:26:06 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:58915 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752444Ab0KLK0E (ORCPT ); Fri, 12 Nov 2010 05:26:04 -0500 Received: from tang.cn.fujitsu.com (tang.cn.fujitsu.com [10.167.250.3]) by song.cn.fujitsu.com (Postfix) with ESMTP id 976A517011E; Fri, 12 Nov 2010 18:26:03 +0800 (CST) Received: from mailserver.fnst.cn.fujitus.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id oACALft8022618; Fri, 12 Nov 2010 18:21:41 +0800 Received: from [10.167.225.99] ([10.167.225.99]) by mailserver.fnst.cn.fujitus.com (Lotus Domino Release 8.5.1FP4) with ESMTP id 2010111218263012-55835 ; Fri, 12 Nov 2010 18:26:30 +0800 Message-ID: <4CDD173E.8010706@cn.fujitsu.com> Date: Fri, 12 Nov 2010 18:30:22 +0800 From: Xiao Guangrong User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.11) Gecko/20100713 Thunderbird/3.0.6 MIME-Version: 1.0 To: Avi Kivity CC: Marcelo Tosatti , LKML , KVM Subject: [PATCH 1/4] KVM: MMU: don't drop spte if overwrite it from W to RO X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2010-11-12 18:26:30, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2010-11-12 18:26:30, Serialize complete at 2010-11-12 18:26:30 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter1.kernel.org [140.211.167.41]); Fri, 12 Nov 2010 10:26:42 +0000 (UTC) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 4b6d54c..1a93ab4 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2044,6 +2044,15 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, if (pte_access & ACC_WRITE_MASK) mark_page_dirty(vcpu->kvm, gfn); + /* + * If we overwrite a writable spte with a read-only one, + * flush remote TLBs. Otherwise rmap_write_protect will + * find a read-only spte, even though the writable spte + * might be cached on a CPU's TLB. + */ + else if (is_writable_pte(*sptep)) + ret = 1; + set_pte: update_spte(sptep, spte); done: @@ -2084,16 +2093,6 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, spte_to_pfn(*sptep), pfn); drop_spte(vcpu->kvm, sptep, shadow_trap_nonpresent_pte); kvm_flush_remote_tlbs(vcpu->kvm); - /* - * If we overwrite a writable spte with a read-only one, - * drop it and flush remote TLBs. Otherwise rmap_write_protect - * will find a read-only spte, even though the writable spte - * might be cached on a CPU's TLB. - */ - } else if (is_writable_pte(*sptep) && - (!(pte_access & ACC_WRITE_MASK) || !dirty)) { - drop_spte(vcpu->kvm, sptep, shadow_trap_nonpresent_pte); - kvm_flush_remote_tlbs(vcpu->kvm); } else was_rmapped = 1; }