From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:36362)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <mst@redhat.com>) id 1V2JBQ-0000Pv-Qz
	for qemu-devel@nongnu.org; Thu, 25 Jul 2013 06:54:11 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <mst@redhat.com>) id 1V2JBO-0008TI-HU
	for qemu-devel@nongnu.org; Thu, 25 Jul 2013 06:54:08 -0400
Received: from mx1.redhat.com ([209.132.183.28]:5603)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <mst@redhat.com>) id 1V2JBO-0008TB-9c
	for qemu-devel@nongnu.org; Thu, 25 Jul 2013 06:54:06 -0400
Received: from int-mx09.intmail.prod.int.phx2.redhat.com
	(int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22])
	by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r6PAs5vl000818
	(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK)
	for <qemu-devel@nongnu.org>; Thu, 25 Jul 2013 06:54:05 -0400
Date: Thu, 25 Jul 2013 13:55:26 +0300
From: "Michael S. Tsirkin" <mst@redhat.com>
Message-ID: <20130725105526.GA28819@redhat.com>
References: <1374681580-17439-1-git-send-email-mst@redhat.com>
	<1374681580-17439-13-git-send-email-mst@redhat.com>
	<51F0FE20.7050302@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <51F0FE20.7050302@redhat.com>
Subject: Re: [Qemu-devel] [PATCH v3 12/14] pvpanic: add API to access io port
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: Gerd Hoffmann <kraxel@redhat.com>
Cc: qemu-devel@nongnu.org

On Thu, Jul 25, 2013 at 12:29:52PM +0200, Gerd Hoffmann wrote:
> On 07/24/13 18:02, Michael S. Tsirkin wrote:
> > Add API to find pvpanic device and get its io port.
> > Will be used to fill in guest info structure.
> 
> > +uint16_t pvpanic_port(void)
> > +{
> > +    Object *o = object_resolve_path_type("", TYPE_ISA_PVPANIC_DEVICE, NULL);
> > +    PVPanicState *s;
> > +    if (!o) {
> > +        return 0;
> > +    }
> 
>        return object_property_get_int(o, "ioport");
> }
> 
> Then you don't need PVPanicState access and can place the code into
> acpi-build.c.
> 
> cheers,
>   Gerd

I can change the implementation but I don't think it's
a good idea to copy property names around:
it's too fragile, compiler won't warn us if we
change the name or value semantics, or make
a mistake in acpi-build.c
Same applies to TYPE_ISA_PVPANIC_DEVICE: better
to expose an API than expose the type externally.

-- 
MST