From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xiao Guangrong Subject: Re: [PATCH v5 6/9] KVM: MMU: introduce pte_prefetch_topup_memory_cache() Date: Tue, 13 Jul 2010 14:10:51 +0800 Message-ID: <4C3C036B.5060108@cn.fujitsu.com> References: <4C330918.6040709@cn.fujitsu.com> <4C330A37.8080709@cn.fujitsu.com> <4C39C1AB.6000606@redhat.com> <4C3A8694.1000401@cn.fujitsu.com> <4C3B09FD.3060307@redhat.com> <4C3BBE84.30708@cn.fujitsu.com> <4C3BE9BD.40007@redhat.com> <4C3BEAC3.9000501@cn.fujitsu.com> <4C3BFB25.2010602@redhat.com> <4C3BFE12.4060009@cn.fujitsu.com> <4C3C021E.1000709@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , LKML , KVM list To: Avi Kivity Return-path: Received: from cn.fujitsu.com ([222.73.24.84]:60191 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751103Ab0GMGOv (ORCPT ); Tue, 13 Jul 2010 02:14:51 -0400 In-Reply-To: <4C3C021E.1000709@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Avi Kivity wrote: > On 07/13/2010 08:48 AM, Xiao Guangrong wrote: >> >>> Right. We should fix those too. >>> >>> Prefetch is much more worrying though, especially with ept. If a guest >>> is using just 1/8 of the pages, it can look to migration as if it's >>> using 100% of the pages. The impact can be pretty large. >>> >> We disabled prefetch if ept is enabled since it can break access bit >> tracking. >> > > Oh yes. > >> I'll fix the dirty bit tracking before post the new version of this >> patchset. >> > > Should be simple - disable prefetch for slots that have dirty tracking > enabled. Agree. > > What about the Linux accessed and dirty bits? Need to instantiate the > speculative sptes with accessed and dirty bits clear (and later examine > them when we release the page). > I see, will do :-)