From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752009AbXB0SzW (ORCPT ); Tue, 27 Feb 2007 13:55:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752514AbXB0SzW (ORCPT ); Tue, 27 Feb 2007 13:55:22 -0500 Received: from gw.goop.org ([64.81.55.164]:58629 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752009AbXB0SzU (ORCPT ); Tue, 27 Feb 2007 13:55:20 -0500 Message-ID: <45E47E95.2060803@goop.org> Date: Tue, 27 Feb 2007 10:55:17 -0800 From: Jeremy Fitzhardinge User-Agent: Thunderbird 1.5.0.9 (X11/20070212) MIME-Version: 1.0 To: Ingo Molnar CC: Andi Kleen , Andrew Morton , linux-kernel@vger.kernel.org, virtualization@lists.osdl.org, xen-devel@lists.xensource.com, Chris Wright , Zachary Amsden , Rusty Russell Subject: Re: [patch 06/26] Xen-paravirt_ops: paravirt_ops: allocate a fixmap slot References: <20070227081337.434798469@goop.org> <20070227081631.122933982@goop.org> <20070227101143.GC10827@elte.hu> In-Reply-To: <20070227101143.GC10827@elte.hu> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Ingo Molnar wrote: > * Jeremy Fitzhardinge wrote: > > >> Allocate a fixmap slot for use by a paravirt_ops implementation. Xen >> uses this to map the hypervisor's shared info page, which doesn't have >> a pseudo-physical page number, and therefore can't be mapped >> ordinarily. >> > > why not vmalloc it on the guest side? fixmaps are bad for this purpose > for a general paravirt implementation, it limits the size of the shared > info page, etc. Yes. vmalloc would have the annoying side-effect of actually allocating some pages which would be shadowed by the remapping, but I guess get_vm_area would do the job. I'll give it a go. J