From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:33588)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <peterx@redhat.com>) id 1ab4S0-0001Ey-QS
	for qemu-devel@nongnu.org; Wed, 02 Mar 2016 05:56:17 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <peterx@redhat.com>) id 1ab4Rx-0000Vl-DR
	for qemu-devel@nongnu.org; Wed, 02 Mar 2016 05:56:16 -0500
Received: from mx1.redhat.com ([209.132.183.28]:48196)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <peterx@redhat.com>) id 1ab4Rx-0000Ve-7I
	for qemu-devel@nongnu.org; Wed, 02 Mar 2016 05:56:13 -0500
Date: Wed, 2 Mar 2016 18:55:58 +0800
From: Peter Xu <peterx@redhat.com>
Message-ID: <20160302105558.GD5730@pxdev.xzpeter.org>
References: <1456224728-28163-1-git-send-email-peterx@redhat.com>
	<1456224728-28163-2-git-send-email-peterx@redhat.com>
	<1456842059.3566.11.camel@redhat.com>
	<20160302033444.GA5730@pxdev.xzpeter.org>
	<20160302071540.GC5730@pxdev.xzpeter.org>
	<87fuw9p5xg.fsf@blackfin.pond.sub.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <87fuw9p5xg.fsf@blackfin.pond.sub.org>
Subject: Re: [Qemu-devel] [PATCH 1/3] arm: gic: add GICType
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: Markus Armbruster <armbru@redhat.com>
Cc: wei@redhat.com, peter.maydell@linaro.org, drjones@redhat.com, mdroth@linux.vnet.ibm.com, qemu-devel@nongnu.org, Andrea Bolognani <abologna@redhat.com>

On Wed, Mar 02, 2016 at 10:47:39AM +0100, Markus Armbruster wrote:
> Peter Xu <peterx@redhat.com> writes:
> > If temporarily not considering kernel_irqchip=split case:
> >
> > [{
> >     "version": 2,
> >     "emulated": true,
> >     "kernel": true
> > },
> > {
> >     "version": 3,
> >     "emulated": false,
> >     "kernel": true
> > }]
> >
> > To use array rather than dict so that we do not need to change qapi
> > schema again when GICv4 comes.
> 
> Drive-by shooting without sufficient context: we may *want* to change
> the QAPI schema, because that makes the change introspectable with
> query-schema.

Failed to catch the point. :(

What's "query-schema"? Is that a QMP command?

What I meant is that, we can define the following (for example):

{ 'struct': 'GICCapInfo',
  'data': [
    'version': 'int',
    'emulated': 'bool',
    'kernel': 'bool'] }

And:

{ 'command': 'query-gic-capability',
  'returns': ['GICCapInfo'] }

So we can keep this schema as it is when new versions arrive. We
can just push another element in.

Peter