From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1MlVa1-0008C6-Ts
	for qemu-devel@nongnu.org; Wed, 09 Sep 2009 18:23:58 -0400
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1MlVZx-00089F-D1
	for qemu-devel@nongnu.org; Wed, 09 Sep 2009 18:23:57 -0400
Received: from [199.232.76.173] (port=43954 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1MlVZx-000890-4q
	for qemu-devel@nongnu.org; Wed, 09 Sep 2009 18:23:53 -0400
Received: from mail2.shareable.org ([80.68.89.115]:60812)
	by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32)
	(Exim 4.60) (envelope-from <jamie@shareable.org>) id 1MlVZv-0004mB-HX
	for qemu-devel@nongnu.org; Wed, 09 Sep 2009 18:23:52 -0400
Date: Wed, 9 Sep 2009 23:23:33 +0100
From: Jamie Lokier <jamie@shareable.org>
Subject: Re: [Qemu-devel] Re: [PATCH 0/5] Refactor and enhance RTC
	configuration
Message-ID: <20090909222333.GA19385@shareable.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <4AA7ECF8.6040504@us.ibm.com>
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: Anthony Liguori <aliguori@us.ibm.com>
Cc: Blue Swirl <blauwirbel@gmail.com>, Jan Kiszka <jan.kiszka@siemens.com>, Glauber Costa <glommer@redhat.com>, Dor Laor <dlaor@redhat.com>, qemu-devel@nongnu.org

Anthony Liguori wrote:
> >Besides the interface thing, I'm also interesting in comments on the
> >other core idea, the selectable RTC base clock. Do we want this knob? Do
> >we want host_clock unconditionally? Or should the other RTC that
> >currently use the host time already also gain vm_clock support over the
> >time?
> >  
> Hard to say.  Doesn't the rtc keep track of wallclock time even on power 
> off?  I think using host_clock unconditionally does actually make sense.

Sometimes it's useful to offset the emulated clock for one reason or
another, hence the -startdate options.  But having it run at the
correct speed is usually useful :-)

Also, sometimes (due to licenses with wallclock limits) it's useful
for a guest to not see much time pass when the guest is powered off,
although it still needs to be positive.

Will the -startdate functionality be maintained with the RTC changes?

-- Jamie