From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=56857 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Q0D0o-0007zg-9l for qemu-devel@nongnu.org; Thu, 17 Mar 2011 09:13:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Q0D0a-0000dZ-AS for qemu-devel@nongnu.org; Thu, 17 Mar 2011 09:12:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35709) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Q0D0Z-0000dR-W9 for qemu-devel@nongnu.org; Thu, 17 Mar 2011 09:12:56 -0400 Message-ID: <4D820956.4080709@redhat.com> Date: Thu, 17 Mar 2011 14:15:02 +0100 From: Kevin Wolf MIME-Version: 1.0 Subject: Re: [Qemu-devel] Re: [PATCH 00/15] QAPI Round 1 (core code generator) (v2) References: <1299884745-521-1-git-send-email-aliguori@us.ibm.com> <20110316113428.21c599a3@doriath> <4D80DE65.5080800@codemonkey.ws> <4D81FCDA.6060601@redhat.com> <4D820293.6020002@codemonkey.ws> In-Reply-To: <4D820293.6020002@codemonkey.ws> Content-Type: text/plain; charset=ISO-8859-1 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, Luiz Capitulino , Adam Litke , Markus Armbruster , Avi Kivity Am 17.03.2011 13:46, schrieb Anthony Liguori: > On 03/17/2011 07:21 AM, Kevin Wolf wrote: >>> >>>> Another detail is that, event extension is more important than command >>>> extension, because it's probably going to happen. I think it would be very >>>> bad to add new events just because we wanted to add a new field. >>> The way this is typically handled is that signals tend to pass >>> structures instead of lots of fields. For instance, most of the GDK >>> events just pass a structure for the event (like GdkButtonEvent). >> Can we do that with existing events or would we break the external >> interface because we'd have to nest everything one level deeper? > > We have to introduce new versions of existing events anyway so we can > make sure to nest the structures appropriately. I think BLOCK_IO_ERROR > is the only one that isn't doing this today FWIW. But then we must always send both events in order to maintain compatibility, right? That sucks. If I understand right, the problem with the current events isn't even on the protocol level, which would be visible externally, but just that it doesn't map to the C interface in the way you like. Is there a reason to change the events from a wire protocol perspective? Kevin