From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrea Arcangeli Subject: Re: swapping with MMU Notifiers V2 Date: Tue, 29 Jan 2008 18:54:20 +0100 Message-ID: <20080129175420.GR7233@v2.random> References: <20080129145021.GJ7233@v2.random> <479F50D6.4020005@de.ibm.com> <479F532C.1020503@qumranet.com> <479F55D6.1090807@de.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, Avi Kivity To: carsteno-tA70FqPdS9bQT0dZR+AlfA@public.gmane.org Return-path: Content-Disposition: inline In-Reply-To: <479F55D6.1090807-tA70FqPdS9bQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org On Tue, Jan 29, 2008 at 05:35:34PM +0100, Carsten Otte wrote: > Avi Kivity wrote: > > Every arch except s390 needs it. An ugly #ifndef > > CONFIG_KVM_HARDWARE_TLB_SYNC is preferred to duplicating the code. > BTW, from reading AMDs spec I don't expect NPT to need this vehicle By your conclusion I suppose you thought NPT maps guest physical to host virtual. If it was the case the cpu would to walk three layer of pagetables (each layer is an arrow): guest virtual -> guest physical -> host virtual -> host physical. Instead it's just guest virtual -> guest physical -> host physical. Or even less for shadow: guest virtual -> host physical, which is why shadow should be faster for number crunching still (and definitely slower for dbms). ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/