Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755243Ab1CGDFS (ORCPT ); Sun, 6 Mar 2011 22:05:18 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:49441 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755047Ab1CGDFQ (ORCPT ); Sun, 6 Mar 2011 22:05:16 -0500 Message-ID: <4D744BA5.5020607@cn.fujitsu.com> Date: Mon, 07 Mar 2011 11:06:13 +0800 From: Xiao Guangrong User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20101209 Fedora/3.1.7-0.35.b3pre.fc14 Thunderbird/3.1.7 MIME-Version: 1.0 To: Marcelo Tosatti CC: Avi Kivity , LKML , KVM Subject: Re: [PATCH 2/10] KVM: MMU: fix kvm_mmu_get_spte_hierarchy References: <4D70C569.1030107@cn.fujitsu.com> <4D70C597.4070105@cn.fujitsu.com> <20110305164805.GB4607@amt.cnet> In-Reply-To: <20110305164805.GB4607@amt.cnet> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-03-07 11:04:01, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-03-07 11:04:02, Serialize complete at 2011-03-07 11:04:02 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: 1756 Lines: 53 On 03/06/2011 12:48 AM, Marcelo Tosatti wrote: > On Fri, Mar 04, 2011 at 06:57:27PM +0800, Xiao Guangrong wrote: >> Don not walk to the next level if spte is mapping to the large page >> >> Signed-off-by: Xiao Guangrong >> --- >> arch/x86/kvm/mmu.c | 3 ++- >> 1 files changed, 2 insertions(+), 1 deletions(-) >> >> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c >> index b9bf016..10e0982 100644 >> --- a/arch/x86/kvm/mmu.c >> +++ b/arch/x86/kvm/mmu.c >> @@ -3819,7 +3819,8 @@ int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu *vcpu, u64 addr, u64 sptes[4]) >> for_each_shadow_entry(vcpu, addr, iterator) { >> sptes[iterator.level-1] = *iterator.sptep; >> nr_sptes++; >> - if (!is_shadow_present_pte(*iterator.sptep)) >> + if (!is_shadow_present_pte(*iterator.sptep) || >> + is_last_spte(*iterator.sptep, iterator.level)) >> break; >> } >> spin_unlock(&vcpu->kvm->mmu_lock); > > shadow_walk_okay covers that case. > We can get the large mapping pte in the loop: static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) { if (iterator->level < PT_PAGE_TABLE_LEVEL) return false; if (iterator->level == PT_PAGE_TABLE_LEVEL) if (is_large_pte(*iterator->sptep)) return false; ...... } if level > 1 and pte.pse is set, it will return true. And, i think this judgment is useless: if (iterator->level == PT_PAGE_TABLE_LEVEL) if (is_large_pte(*iterator->sptep)) return false; since if level = 1, the pte bit7 is PAT. -- 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/