From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751304AbWERHjk (ORCPT ); Thu, 18 May 2006 03:39:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751302AbWERHjk (ORCPT ); Thu, 18 May 2006 03:39:40 -0400 Received: from 216-99-217-87.dsl.aracnet.com ([216.99.217.87]:33408 "EHLO sous-sol.org") by vger.kernel.org with ESMTP id S1751300AbWERHjj (ORCPT ); Thu, 18 May 2006 03:39:39 -0400 Date: Thu, 18 May 2006 00:42:36 -0700 From: Chris Wright To: Pete Zaitcev Cc: Chris Wright , linux-kernel@vger.kernel.org, virtualization@lists.osdl.org, Christian.Limpach@cl.cam.ac.uk, xen-devel@lists.xensource.com, ian.pratt@xensource.com Subject: Re: [RFC PATCH 08/35] Add Xen-specific memory management definitions Message-ID: <20060518074236.GU23243@moss.sous-sol.org> References: <20060509084945.373541000@sous-sol.org> <20060509085151.047254000@sous-sol.org> <20060517090645.0b72bd2d.zaitcev@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060517090645.0b72bd2d.zaitcev@redhat.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Pete Zaitcev (zaitcev@redhat.com) wrote: > On Tue, 09 May 2006 00:00:08 -0700, Chris Wright wrote: > > > +static inline unsigned long pfn_to_mfn(unsigned long pfn) > > +{ > > +#ifndef CONFIG_XEN_SHADOW_MODE > > + if (xen_feature(XENFEAT_auto_translated_physmap)) > > + return pfn; > > + return phys_to_machine_mapping[(unsigned int)(pfn)] & > > + ~FOREIGN_FRAME_BIT; > > +#else > > + return pfn; > > +#endif > > +} > > Why do we need several modes in Linux guests? This patchset only supports shadow translated mode, so the extra CONFIG is just an artifact of this simplied patchset. Ultimately, this is not the preferred mode (performance wise), but shadow mode is simpler to port to.