From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [RFC PATCH 0/3] generic hypercall support Date: Fri, 8 May 2009 11:35:07 -0300 Message-ID: <20090508143507.GA8319@amt.cnet> References: <4A0049CD.3080003@gmail.com> <20090505231718.GT3036@sequoia.sous-sol.org> <4A010927.6020207@novell.com> <20090506072212.GV3036@sequoia.sous-sol.org> <4A018DF2.6010301@novell.com> <20090506160712.GW3036@sequoia.sous-sol.org> <4A031471.7000406@novell.com> <20090507233503.GA9103@amt.cnet> <20090507234311.GA9517@amt.cnet> <4A03E579.8030201@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Gregory Haskins , Chris Wright , Gregory Haskins , kvm@vger.kernel.org, Anthony Liguori To: Avi Kivity Return-path: Received: from mx2.redhat.com ([66.187.237.31]:40066 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757433AbZEHOgg (ORCPT ); Fri, 8 May 2009 10:36:36 -0400 Content-Disposition: inline In-Reply-To: <4A03E579.8030201@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Fri, May 08, 2009 at 10:55:37AM +0300, Avi Kivity wrote: > Marcelo Tosatti wrote: >> Also it would be interesting to see the MMIO comparison with EPT/NPT, >> it probably sucks much less than what you're seeing. >> > > Why would NPT improve mmio? If anything, it would be worse, since the > processor has to do the nested walk. > > Of course, these are newer machines, so the absolute results as well as > the difference will be smaller. Quad-Core AMD Opteron(tm) Processor 2358 SE 2.4GHz: NPT enabled: test 0: 3088633284634 - 3059375712321 = 29257572313 test 1: 3121754636397 - 3088633419760 = 33121216637 test 2: 3204666462763 - 3121754668573 = 82911794190 NPT disabled: test 0: 3638061646250 - 3609416811687 = 28644834563 test 1: 3669413430258 - 3638061771291 = 31351658967 test 2: 3736287253287 - 3669413463506 = 66873789781