From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1MlRMO-0001JX-Qe
	for qemu-devel@nongnu.org; Wed, 09 Sep 2009 13:53:36 -0400
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1MlRMG-0001G8-7r
	for qemu-devel@nongnu.org; Wed, 09 Sep 2009 13:53:33 -0400
Received: from [199.232.76.173] (port=45609 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1MlRMF-0001Fz-Eg
	for qemu-devel@nongnu.org; Wed, 09 Sep 2009 13:53:27 -0400
Received: from mail-ew0-f221.google.com ([209.85.219.221]:37059)
	by monty-python.gnu.org with esmtp (Exim 4.60)
	(envelope-from <blauwirbel@gmail.com>) id 1MlR2r-0002Rl-4V
	for qemu-devel@nongnu.org; Wed, 09 Sep 2009 13:33:25 -0400
Received: by ewy21 with SMTP id 21so596704ewy.8
	for <qemu-devel@nongnu.org>; Wed, 09 Sep 2009 10:33:23 -0700 (PDT)
MIME-Version: 1.0
In-Reply-To: <20090909151111.26816.49862.stgit@mchn012c.ww002.siemens.net>
References: <20090909151111.26816.49862.stgit@mchn012c.ww002.siemens.net>
From: Blue Swirl <blauwirbel@gmail.com>
Date: Wed, 9 Sep 2009 20:33:03 +0300
Message-ID: <f43fc5580909091033g66e13435tfe78800797d87c1a@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8
Subject: [Qemu-devel] Re: [PATCH 0/5] Refactor and enhance RTC configuration
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/pipermail/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Jan Kiszka <jan.kiszka@web.de>
Cc: Dor Laor <dlaor@redhat.com>, Anthony Liguori <aliguori@us.ibm.com>, Glauber Costa <glommer@redhat.com>, qemu-devel@nongnu.org

On Wed, Sep 9, 2009 at 6:11 PM, Jan Kiszka<jan.kiszka@web.de> wrote:
> The aim of this series is to allow using the emulated PC RTC (MC146818)
> as a reliable time source for guests. This is particularly useful if the
> host runs NTP or has otherwise access to an accurate clock while the
> guest has not (no network, impossible to add an NTP implementation
> etc.).

What I meant in the earlier thread is that m48t59 port read for time
or date gets the data directly from host using  qemu_get_timedate().
PC RTC instead uses a timer: the timer callback updates the cmos_data
structure. It seems that you just replace the timer with a new one.
I'd remove the timer altogether and change the cmos_ioport_read to
call qemu_get_timedate().