From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] kvm mmu: optimizations when tdp is in use Date: Thu, 27 May 2010 11:33:40 +0300 Message-ID: <4BFE2E64.1070303@redhat.com> References: <4BFE280A.3090607@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Gui Jianfeng Return-path: Received: from mx1.redhat.com ([209.132.183.28]:61504 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932227Ab0E0Ids (ORCPT ); Thu, 27 May 2010 04:33:48 -0400 In-Reply-To: <4BFE280A.3090607@cn.fujitsu.com> Sender: kvm-owner@vger.kernel.org List-ID: On 05/27/2010 11:06 AM, Gui Jianfeng wrote: > In case of using tdp, checking write protected page isn't needed and > quadrant also no need to be calculated. > > Signed-off-by: Gui Jianfeng > --- > arch/x86/kvm/mmu.c | 7 +++++-- > 1 files changed, 5 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index 0bb9f17..ce4bbd3 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -495,10 +495,13 @@ static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn) > max_level = kvm_x86_ops->get_lpage_level()< host_level ? > kvm_x86_ops->get_lpage_level() : host_level; > > + if (tdp_enabled) > + goto done; > + > for (level = PT_DIRECTORY_LEVEL; level<= max_level; ++level) > if (has_wrprotected_page(vcpu->kvm, large_gfn, level)) > break; > - > +done: > return level - 1; > } > > We also use ->write_count to prevent mapping the end of a non-large-page-aligned memslot with a large spte. Undocumented in mmu.txt, I'll post a patch. -- error compiling committee.c: too many arguments to function