From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754593Ab2IJIhz (ORCPT ); Mon, 10 Sep 2012 04:37:55 -0400 Received: from e28smtp05.in.ibm.com ([122.248.162.5]:49764 "EHLO e28smtp05.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752638Ab2IJIhx (ORCPT ); Mon, 10 Sep 2012 04:37:53 -0400 Message-ID: <504DA6D6.5030704@linux.vnet.ibm.com> Date: Mon, 10 Sep 2012 16:37:42 +0800 From: Xiao Guangrong User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120827 Thunderbird/15.0 MIME-Version: 1.0 To: Avi Kivity CC: Marcelo Tosatti , LKML , KVM Subject: Re: [PATCH 1/3] KVM: MMU: release noslot pfn on the fail path properly References: <5049908A.7070501@linux.vnet.ibm.com> <504DA343.9080602@redhat.com> In-Reply-To: <504DA343.9080602@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit x-cbid: 12091008-8256-0000-0000-0000041AAD80 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/10/2012 04:22 PM, Avi Kivity wrote: > On 09/07/2012 09:13 AM, 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 >> >> Introduce mmu_release_pfn_clean to do this kind of thing >> >> Signed-off-by: Xiao Guangrong >> --- >> arch/x86/kvm/mmu.c | 19 ++++++++++++++----- >> arch/x86/kvm/paging_tmpl.h | 4 ++-- >> 2 files changed, 16 insertions(+), 7 deletions(-) >> >> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c >> index 399c177..3c10bca 100644 >> --- a/arch/x86/kvm/mmu.c >> +++ b/arch/x86/kvm/mmu.c >> @@ -2432,6 +2432,16 @@ done: >> return ret; >> } >> >> +/* >> + * The primary user is page fault path which call it to properly >> + * release noslot_pfn. >> + */ >> +static void mmu_release_pfn_clean(pfn_t pfn) >> +{ >> + if (!is_error_pfn(pfn)) >> + kvm_release_pfn_clean(pfn); >> +} >> + > > Too many APIs, each slightly different. How do I know which one to call? It is only used in mmu and it is a static function. > > Please change kvm_release_pfn_*() instead, calling some arch hook (or > even #ifdef CONFIG_KVM_HAS_FAST_MMIO) to check for the special case. We only need to call it on page fault path. If we change the common API other x86 components have to suffer from it.