From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([208.118.235.92]:49721)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <kwolf@redhat.com>) id 1SoAox-0004uR-5c
	for qemu-devel@nongnu.org; Mon, 09 Jul 2012 06:04:03 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <kwolf@redhat.com>) id 1SoAos-0007Oz-EC
	for qemu-devel@nongnu.org; Mon, 09 Jul 2012 06:03:58 -0400
Received: from mx1.redhat.com ([209.132.183.28]:21334)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <kwolf@redhat.com>) id 1SoAos-0007Of-6J
	for qemu-devel@nongnu.org; Mon, 09 Jul 2012 06:03:54 -0400
Message-ID: <4FFAAC85.6040102@redhat.com>
Date: Mon, 09 Jul 2012 12:03:49 +0200
From: Kevin Wolf <kwolf@redhat.com>
MIME-Version: 1.0
References: <1340714974-25489-1-git-send-email-agraf@suse.de>
	<m3zk79wc6i.fsf@blackfin.pond.sub.org>
	<4FFAA03D.6020302@redhat.com>
	<B8C26002-A2D4-470C-A350-DE216D075A0E@suse.de>
	<4FFAA40E.4070901@redhat.com>
	<583552B4-7D4C-4030-8792-203BB922000E@suse.de>
	<4FFAA9E0.1000406@redhat.com> <20120709100202.GK15459@redhat.com>
In-Reply-To: <20120709100202.GK15459@redhat.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH v2] ahci: add -drive support
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: Gleb Natapov <gleb@redhat.com>
Cc: qemu-devel qemu-devel <qemu-devel@nongnu.org>, Alexander Graf <agraf@suse.de>, Markus Armbruster <armbru@redhat.com>

Am 09.07.2012 12:02, schrieb Gleb Natapov:
> On Mon, Jul 09, 2012 at 11:52:32AM +0200, Kevin Wolf wrote:
>>> If -hda has the semantics of "create an IDE device", then no, we can't change it. It doesn't however. IIRC on -M pseries -hda creates SCSI devices. On s390 -hda creates virtio devices. So if on -M q35 -hda would create if=ahci, I don't see how that breaks the CLI.
>>
>> It doesn't per se, that is as long as you need to explicitly specify -M
>> q35. But then changing the default machine from the existing pc to q35
>> would break the command line.
>>
> Would break it how?

A guest that has an IDE driver, but not an AHCI one can be started with
'qemu -hda foo.img' today. After changing the default to a q35 machine
type which uses AHCI by default, this guest wouldn't boot any more with
the same command line.

Kevin