From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([140.186.70.92]:48938)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <kwolf@redhat.com>) id 1REfrI-00084B-LU
	for qemu-devel@nongnu.org; Fri, 14 Oct 2011 07:23:25 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <kwolf@redhat.com>) id 1REfrH-0002U7-FW
	for qemu-devel@nongnu.org; Fri, 14 Oct 2011 07:23:24 -0400
Received: from mx1.redhat.com ([209.132.183.28]:54629)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <kwolf@redhat.com>) id 1REfrH-0002Tz-5i
	for qemu-devel@nongnu.org; Fri, 14 Oct 2011 07:23:23 -0400
Message-ID: <4E981C5A.40805@redhat.com>
Date: Fri, 14 Oct 2011 13:26:18 +0200
From: Kevin Wolf <kwolf@redhat.com>
MIME-Version: 1.0
References: <20111011031046.9587.44474.sendpatchset@skannery.in.ibm.com>
	<20111011031145.9587.93507.sendpatchset@skannery.in.ibm.com>
	<4E95A495.3050403@redhat.com> <4E981ABD.1070301@linux.vnet.ibm.com>
In-Reply-To: <4E981ABD.1070301@linux.vnet.ibm.com>
Content-Type: text/plain; charset=ISO-8859-15
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [v7 Patch 4/5]Qemu: Add commandline -drive option
 'hostcache'
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: supriyak@linux.vnet.ibm.com
Cc: Stefan Hajnoczi <stefanha@gmail.com>, qemu-devel@nongnu.org, Christoph Hellwig <hch@lst.de>

Am 14.10.2011 13:19, schrieb Supriya Kannery:
> On 10/12/2011 08:00 PM, Kevin Wolf wrote:
>> Am 11.10.2011 05:11, schrieb Supriya Kannery:
>>> qemu command option 'hostcache' added to -drive for block devices.
>>> While starting a VM from qemu commandline, this option can be used
>>> for setting host cache usage for block data access. Simultaneous
>>> use of 'hostcache' and 'cache' options not allowed.
>>>
>>> Signed-off-by: Supriya Kannery<supriyak@linux.vnet.ibm.com>
>>
>> I'm not sure if introducing this alone makes sense. I think I would only
>> do it when we introduce more options that allow replacing all cache=...
>> options by other parameters.
>>
> 
> Can we do transition to alternatives for 'cache=' in a phased manner?
> Until all other params are ready, we can allow hostcache (as well
> as other params as and when they are ready) in cmdline with the
> condition that 'cache=x', if specified, overrides these params.
> Once we have all other params ready, 'cache=' can be replaced completely.

I guess that would be good enough. There's still not much use in
specifying hostcache=... at the same time as cache=... but at least it
doesn't take away other options then.

Kevin