From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:38341) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RbBOY-0003QF-Hg for qemu-devel@nongnu.org; Thu, 15 Dec 2011 08:30:47 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RbBOQ-0004ih-GB for qemu-devel@nongnu.org; Thu, 15 Dec 2011 08:30:46 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57398) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RbBOQ-0004ib-8S for qemu-devel@nongnu.org; Thu, 15 Dec 2011 08:30:38 -0500 Message-ID: <4EE9F734.7050305@redhat.com> Date: Thu, 15 Dec 2011 14:33:40 +0100 From: Kevin Wolf MIME-Version: 1.0 References: <4EE9F3B8.6000407@siemens.com> In-Reply-To: <4EE9F3B8.6000407@siemens.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] Transitioning from HMP to QMP for QEMU List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: Anthony Liguori , libvir-list@redhat.com, Stefan Hajnoczi , qemu-devel , Luiz Capitulino , Adam Litke Am 15.12.2011 14:18, schrieb Jan Kiszka: > On 2011-12-15 14:02, Stefan Hajnoczi wrote: >> What is the status of QEMU's transition from HMP to the QMP interface? >> >> My current understanding is that QEMU provides new HMP commands for >> humans, but HMP is being phased out as an API. Management tools >> should rely only on QMP for new commands. That would mean new HMP >> commands are not guaranteed to produce backwards-compatible output >> because tools are not supposed to parse the output. >> >> On the libvirt side, new QEMU features should only be supported via >> the json monitor in the future (i.e. human monitor patches should not >> be sent/merged)? Existing HMP commands will still need the human >> monitor support in order to handle old QEMU versions gracefully, but >> I'm thinking about new commands only. >> >> Does everyone agree on this? I think this is an important discussion >> if we want our management interface to get better and more consistent >> in the future. > > To phase out the classic HMP implementation, we need an internal > HMP-over-JSON wrapper (with tab expansion etc.) so that virtual console > and gdbstub monitors continue to benefit from new commands. Those > interfaces will stay for a long time, I'm sure. I think we're not talking about dropping HMP here, only about how long to support it as a stable API for management tools. I believe that we have been in a transitional phase for long enough now that we can start changing the output format of HMP commands without considering it an API breakage. Kevin