From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758125Ab3ENP7t (ORCPT ); Tue, 14 May 2013 11:59:49 -0400 Received: from mail-pa0-f52.google.com ([209.85.220.52]:43357 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752342Ab3ENP7r (ORCPT ); Tue, 14 May 2013 11:59:47 -0400 Message-ID: <51925F70.5000309@linaro.org> Date: Tue, 14 May 2013 08:59:44 -0700 From: John Stultz User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130404 Thunderbird/17.0.5 MIME-Version: 1.0 To: Jan Beulich CC: David Vrabel , Jeremy Fitzhardinge , Thomas Gleixner , xen-devel@lists.xen.org, Konrad Rzeszutek Wilk , linux-kernel@vger.kernel.org Subject: Re: [Xen-devel] [PATCH 3/3] x86/xen: sync the CMOS RTC as well as the Xen wallclock References: <1368467768-2316-1-git-send-email-david.vrabel@citrix.com> <1368467768-2316-4-git-send-email-david.vrabel@citrix.com> <51918ABB.5030501@linaro.org> <51920A9502000078000D5D84@nat28.tlf.novell.com> In-Reply-To: <51920A9502000078000D5D84@nat28.tlf.novell.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/14/2013 12:57 AM, Jan Beulich wrote: >>>> On 14.05.13 at 02:52, John Stultz wrote: >> Honestly, it seems a little strange to me. If you're running as dom0, >> why does HYPERVISOR_dom0_op() not cause the hypervisor to set the cmos >> its virtualizing? This seems to mess with the proper virtualization >> layering. > Thy hypervisor tries to control as little system and peripheral devices > as possible, and the CMOS (including the clock) is among those not > controlled by it, but by Dom0. Huh. So what does calling HYPERVISOR_dom0_op do then? Either way, I don't have the context to insightfully review this, so I'll want this to get some Acked-bys from additional Xen folks before I queue it. thanks -john