From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57540) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VHYNU-0005P3-V3 for qemu-devel@nongnu.org; Thu, 05 Sep 2013 08:09:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VHYNI-0003Tp-Nj for qemu-devel@nongnu.org; Thu, 05 Sep 2013 08:09:36 -0400 Received: from mail-pa0-f46.google.com ([209.85.220.46]:53285) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VHYNI-0003Th-Hh for qemu-devel@nongnu.org; Thu, 05 Sep 2013 08:09:24 -0400 Received: by mail-pa0-f46.google.com with SMTP id fa1so1829561pad.33 for ; Thu, 05 Sep 2013 05:09:23 -0700 (PDT) Message-ID: <5228746D.3060606@ozlabs.ru> Date: Thu, 05 Sep 2013 22:09:17 +1000 From: Alexey Kardashevskiy MIME-Version: 1.0 References: <1378193502-4968-1-git-send-email-aik@ozlabs.ru> <20130905043059.GC10158@voom.redhat.com> <52280E96.1030402@ozlabs.ru> <350E3728-BF3A-4B43-8E43-2622033970D0@suse.de> <52285369.1040907@ozlabs.ru> <1378381352.4321.156.camel@pasglop> In-Reply-To: <1378381352.4321.156.camel@pasglop> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH] spapr: support time base offset migration List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Benjamin Herrenschmidt Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org, Alexander Graf , Paul Mackerras , Paolo Bonzini , =?UTF-8?B?QW5k?= =?UTF-8?B?cmVhcyBGw6RyYmVy?= , David Gibson On 09/05/2013 09:42 PM, Benjamin Herrenschmidt wrote: > On Thu, 2013-09-05 at 19:48 +1000, Alexey Kardashevskiy wrote: >>>> I do not have pure guest timebase in QEMU and I need it on the destination. >>>> But I have host timebase + offset to calculate it. And tb_offset is already >>>> in ppc_tb_t. It looked logical to me to send the existing field and add >>>> only the missing part. >>> >>> I still don't understand. You want the guest visible timebase in the migration stream, no? >> >> >> Yes. I do not really understand the problem here (and I am not playing >> dump). Do you suggest sending just the guest timebase and do not send the >> host timebase and the offset (one number instead of two)? I can do that, >> makes sense, no problem, thanks for the idea. > > No, we want to send the guest TB and the corresponding "time of day" so that > the target can adjust the TB based on how long the migration took. Nobody is discussing time_of_the_day, it is there and transmitted. The only question is whether to send host_timebase and tb_offset (2 values) or just guest timebase (1 value). -- Alexey