From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934693Ab0EEMwV (ORCPT ); Wed, 5 May 2010 08:52:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:7802 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934498Ab0EEMwS (ORCPT ); Wed, 5 May 2010 08:52:18 -0400 Message-ID: <4BE169FE.3020805@redhat.com> Date: Wed, 05 May 2010 15:52:14 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100330 Fedora/3.0.4-1.fc12 Thunderbird/3.0.4 MIME-Version: 1.0 To: Xiao Guangrong CC: Marcelo Tosatti , KVM list , LKML Subject: Re: [PATCH 2/2] KVM MMU: fix race in invlpg code References: <4BE16265.7060004@cn.fujitsu.com> <4BE162B9.201@cn.fujitsu.com> <4BE1650B.7080809@redhat.com> <4BE1686D.9000902@cn.fujitsu.com> In-Reply-To: <4BE1686D.9000902@cn.fujitsu.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/05/2010 03:45 PM, Xiao Guangrong wrote: > > Avi Kivity wrote: > > >>> spin_lock(&vcpu->kvm->mmu_lock); >>> + index = kvm_page_table_hashfn(gfn); >>> + bucket =&vcpu->kvm->arch.mmu_page_hash[index]; >>> + hlist_for_each_entry_safe(s, node, tmp, bucket, hash_link) >>> + if (s == sp) { >>> + if (s->gfn == gfn&& s->role.word == role.word) >>> + live = true; >>> + break; >>> + } >>> + >>> + if (!live) >>> + goto unlock_exit; >>> + >>> >>> >> Did you try the root_count method? I think it's cleaner. >> > Avi, Thanks for your idea. > > I have considered this method, but i'm not sure when it's the good time > to real free this page, and i think we also need a way to synchronize the > real free path and this path. Do you have any comment for it :-( > Same as mmu_free_roots(): --sp->root_count; if (!sp->root_count && sp->role.invalid) { kvm_mmu_zap_page(vcpu->kvm, sp); goto unlock_exit; } -- error compiling committee.c: too many arguments to function