Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758403Ab0KQEGe (ORCPT ); Tue, 16 Nov 2010 23:06:34 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:58882 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755529Ab0KQEGd (ORCPT ); Tue, 16 Nov 2010 23:06:33 -0500 Message-ID: <4CE355CA.80106@cn.fujitsu.com> Date: Wed, 17 Nov 2010 12:10:50 +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 v2 2/6] KVM: MMU: don't drop spte if overwrite it from W to RO References: <4CE355A0.6020907@cn.fujitsu.com> In-Reply-To: <4CE355A0.6020907@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2010-11-17 12:06:54, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2010-11-17 12:06:55, Serialize complete at 2010-11-17 12:06:55 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2092 Lines: 63 We just need flush tlb if overwrite a writable spte with a read-only one. And we should move this operation to set_spte() for sync_page path Signed-off-by: Xiao Guangrong --- arch/x86/kvm/mmu.c | 20 +++++++++----------- 1 files changed, 9 insertions(+), 11 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index e008ae7..9bad960 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1966,7 +1966,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn, pfn_t pfn, bool speculative, bool can_unsync, bool reset_host_protection) { - u64 spte; + u64 spte, entry = *sptep; int ret = 0; /* @@ -2039,6 +2039,14 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, set_pte: update_spte(sptep, spte); + /* + * If we overwrite a writable spte with a read-only one we + * should 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. + */ + if (is_writable_pte(entry) && !is_writable_pte(*sptep)) + kvm_flush_remote_tlbs(vcpu->kvm); done: return ret; } @@ -2077,16 +2085,6 @@ 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; } -- 1.7.0.4 -- 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/