From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754598Ab2IOPlV (ORCPT ); Sat, 15 Sep 2012 11:41:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41862 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753485Ab2IOPlU (ORCPT ); Sat, 15 Sep 2012 11:41:20 -0400 Date: Sat, 15 Sep 2012 12:13:38 -0300 From: Marcelo Tosatti To: Xiao Guangrong Cc: Avi Kivity , LKML , KVM Subject: Re: [PATCH v2 1/5] KVM: MMU: release noslot pfn on the fail path properly Message-ID: <20120915151338.GA3037@amt.cnet> References: <5052FF61.3070600@linux.vnet.ibm.com> <5052FF82.1060106@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5052FF82.1060106@linux.vnet.ibm.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 14, 2012 at 05:57:22PM +0800, Xiao Guangrong wrote: > We can not directly call kvm_release_pfn_clean to release the pfn > since we can meet noslot pfn which is used to cache mmio info into > spte > > Signed-off-by: Xiao Guangrong > --- > arch/x86/kvm/mmu.c | 6 ++++-- > arch/x86/kvm/paging_tmpl.h | 6 ++++-- > 2 files changed, 8 insertions(+), 4 deletions(-) Its clearer to the reader if is_invalid_pfn() is used instead of is_error_pfn. BTW how about killing this unused helper static bool mmu_invalid_pfn(pfn_t pfn) { return unlikely(is_invalid_pfn(pfn)); } This can be done inlined. > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index aa0b469..f74c63a 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -2877,7 +2877,8 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, u32 error_code, > > out_unlock: > spin_unlock(&vcpu->kvm->mmu_lock); > - kvm_release_pfn_clean(pfn); > + if (!is_error_pfn(pfn)) > + kvm_release_pfn_clean(pfn); > return 0; > }