Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934851Ab0KQPwg (ORCPT ); Wed, 17 Nov 2010 10:52:36 -0500 Received: from mx1.redhat.com ([209.132.183.28]:28410 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932380Ab0KQPwf (ORCPT ); Wed, 17 Nov 2010 10:52:35 -0500 Date: Wed, 17 Nov 2010 13:29:43 -0200 From: Marcelo Tosatti To: Xiao Guangrong Cc: Avi Kivity , LKML , KVM Subject: Re: [PATCH v2 1/6] KVM: MMU: fix forgot flush vcpu tlbs Message-ID: <20101117152943.GA18959@amt.cnet> References: <4CE355A0.6020907@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4CE355A0.6020907@cn.fujitsu.com> User-Agent: Mutt/1.5.20 (2009-08-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2384 Lines: 66 On Wed, Nov 17, 2010 at 12:10:08PM +0800, Xiao Guangrong wrote: > Some paths forgot to flush vcpu tlbs after remove rmap, this > patch fix it. > > Signed-off-by: Xiao Guangrong > --- > arch/x86/kvm/mmu.c | 14 +++++++++++--- > arch/x86/kvm/paging_tmpl.h | 1 + > 2 files changed, 12 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index bdb9fa9..e008ae7 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -736,10 +736,16 @@ static int set_spte_track_bits(u64 *sptep, u64 new_spte) > return 1; > } > > -static void drop_spte(struct kvm *kvm, u64 *sptep, u64 new_spte) > +static bool drop_spte(struct kvm *kvm, u64 *sptep, u64 new_spte) > { > - if (set_spte_track_bits(sptep, new_spte)) > + bool ret = false; > + > + if (set_spte_track_bits(sptep, new_spte)) { > rmap_remove(kvm, sptep); > + ret = true; > + } > + > + return ret; > } > > static u64 *rmap_next(struct kvm *kvm, unsigned long *rmapp, u64 *spte) > @@ -1997,7 +2003,9 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, > if (level > PT_PAGE_TABLE_LEVEL && > has_wrprotected_page(vcpu->kvm, gfn, level)) { > ret = 1; > - drop_spte(vcpu->kvm, sptep, shadow_trap_nonpresent_pte); > + if (drop_spte(vcpu->kvm, sptep, > + shadow_trap_nonpresent_pte)) > + kvm_flush_remote_tlbs(vcpu->kvm); > goto done; The spte should not be present before (this condition can happen if the has_wrprotected_page check from mapping_level races, which is possible since it runs without mmu_lock protection). > diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h > index ba00eef..58b4d9a 100644 > --- a/arch/x86/kvm/paging_tmpl.h > +++ b/arch/x86/kvm/paging_tmpl.h > @@ -781,6 +781,7 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, > else > nonpresent = shadow_notrap_nonpresent_pte; > drop_spte(vcpu->kvm, &sp->spt[i], nonpresent); > + kvm_flush_remote_tlbs(vcpu->kvm); > continue; > } This is not needed. Guest is responsible for flushing on present->nonpresent change. -- 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/