From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=45305 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PyVZI-0005re-JP for qemu-devel@nongnu.org; Sat, 12 Mar 2011 15:37:45 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PyVZG-0000oM-KC for qemu-devel@nongnu.org; Sat, 12 Mar 2011 15:37:44 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56823) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PyVZG-0000o7-Bj for qemu-devel@nongnu.org; Sat, 12 Mar 2011 15:37:42 -0500 Message-ID: <4D7BD98E.50705@redhat.com> Date: Sat, 12 Mar 2011 22:37:34 +0200 From: Avi Kivity MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH 19/22] qapi: add QMP put-event command References: <1299460984-15849-1-git-send-email-aliguori@us.ibm.com> <1299460984-15849-20-git-send-email-aliguori@us.ibm.com> <4D778117.9060505@redhat.com> <4D778545.7040403@codemonkey.ws> <4D778797.9090602@redhat.com> <4D778E07.5070408@codemonkey.ws> <4D78C69F.6010003@redhat.com> <4D78DC5A.3000601@codemonkey.ws> <4D78DF3A.9000600@redhat.com> <4D78EEA3.9050401@redhat.com> <4D78F11B.4050402@codemonkey.ws> <4D78F2F2.9020007@redhat.com> <4D78FF59.5090809@codemonkey.ws> In-Reply-To: <4D78FF59.5090809@codemonkey.ws> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: qemu-devel@nongnu.org, Markus Armbruster , Luiz Capitulino On 03/10/2011 06:42 PM, Anthony Liguori wrote: >>> Maybe for QMPv2, but for QMPv1, this is going to introduce an >>> extremely incompatible change. >> >> Why? It's 100% backwards compatible. > > > It's a very significant change for clients. While technical > compatible, it would require a change to the client infrastructure to > support the new feature. Yes. That's generally a good thing, you implement something at the infrastructure level once instead of at a higher level N times. > I'm not saying we shouldn't make a change like this, but we should > minimize these type of changes. I agree, so we should design the protocol well, without planned obsolescence. We'll make some mistakes, but at least they'll be unplanned. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.