From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752798Ab1GOSXT (ORCPT ); Fri, 15 Jul 2011 14:23:19 -0400 Received: from mail-ww0-f44.google.com ([74.125.82.44]:53402 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750968Ab1GOSXS (ORCPT ); Fri, 15 Jul 2011 14:23:18 -0400 User-Agent: Microsoft-Entourage/12.30.0.110427 Date: Fri, 15 Jul 2011 19:23:06 +0100 Subject: Re: [Xen-devel] [PATCH] xen: update machine_to_phys_order on resume From: Keir Fraser To: Jan Beulich , , Konrad Rzeszutek Wilk , CC: , , Message-ID: Thread-Topic: [Xen-devel] [PATCH] xen: update machine_to_phys_order on resume Thread-Index: AcxDHD2w9ppdL4DyWkqbCq16XCM1bw== In-Reply-To: <4E20873F020000780007307B@nat28.tlf.novell.com> Mime-version: 1.0 Content-type: text/plain; charset="US-ASCII" Content-transfer-encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 15/07/2011 18:30, "Jan Beulich" wrote: > Actually, one more thought: What's the purpose of this hypercall if > it is set in stone what values it ought to return? Isn't a guest using > it (supposed to be) advertising that it can deal with the values being > variable (and it was just overlooked so far that this doesn't only > include varying values from boot to boot, but also migration)? Or in > other words, if we found a need to relocate the M2P table or grow > its static maximum size, it would be impossible to migrate guests > from an old to a new hypervisor. Fair point. There has to be a static fallback set of return values for old guests. -- Keir