From patchwork Thu Aug 19 16:33:36 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luiz Capitulino X-Patchwork-Id: 62200 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id C22E6B70A9 for ; Fri, 20 Aug 2010 02:41:00 +1000 (EST) Received: from localhost ([127.0.0.1]:38415 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Om8Ai-0005KF-NI for incoming@patchwork.ozlabs.org; Thu, 19 Aug 2010 12:40:56 -0400 Received: from [140.186.70.92] (port=34218 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Om84J-00038d-Hz for qemu-devel@nongnu.org; Thu, 19 Aug 2010 12:34:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1Om84I-0001hj-6F for qemu-devel@nongnu.org; Thu, 19 Aug 2010 12:34:19 -0400 Received: from mx1.redhat.com ([209.132.183.28]:23071) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1Om84H-0001hZ-T0 for qemu-devel@nongnu.org; Thu, 19 Aug 2010 12:34:18 -0400 Received: from int-mx08.intmail.prod.int.phx2.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o7JGYGeR032145 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 19 Aug 2010 12:34:17 -0400 Received: from localhost (ovpn-113-87.phx2.redhat.com [10.3.113.87]) by int-mx08.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o7JGYEH5028021; Thu, 19 Aug 2010 12:34:16 -0400 From: Luiz Capitulino To: qemu-devel@nongnu.org Date: Thu, 19 Aug 2010 13:33:36 -0300 Message-Id: <1282235616-20988-5-git-send-email-lcapitulino@redhat.com> In-Reply-To: <1282235616-20988-1-git-send-email-lcapitulino@redhat.com> References: <1282235616-20988-1-git-send-email-lcapitulino@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.21 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. Cc: aliguori@us.ibm.com, armbru@redhat.com Subject: [Qemu-devel] [PATCH 4/4] QMP: Update README file X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org A number of changes I prefer to do in one shot: - Fix example - Small clarifications - Add multiple monitors example - Add 'Development Process' section Signed-off-by: Luiz Capitulino --- QMP/README | 71 ++++++++++++++++++++++++++++++++++++++++------------------- 1 files changed, 48 insertions(+), 23 deletions(-) diff --git a/QMP/README b/QMP/README index 35a80c7..b23f186 100644 --- a/QMP/README +++ b/QMP/README @@ -7,60 +7,85 @@ Introduction The QEMU Monitor Protocol (QMP) allows applications to communicate with QEMU's Monitor. -QMP is JSON[1] based and has the following features: +QMP is JSON[1] based and currently has the following features: - Lightweight, text-based, easy to parse data format -- Asynchronous events support -- Stability +- Asynchronous messages support (ie. events) +- Capabilities Negotiation -For more information, please, refer to the following files: +For detailed information on QMP's usage, please, refer to the following files: o qmp-spec.txt QEMU Monitor Protocol current specification -o qmp-commands.txt QMP supported commands +o qmp-commands.txt QMP supported commands (auto-generated at build-time) o qmp-events.txt List of available asynchronous events There are also two simple Python scripts available: -o qmp-shell A shell -o vm-info Show some information about the Virtual Machine +o qmp-shell A shell +o vm-info Show some information about the Virtual Machine + +IMPORTANT: It's strongly recommended to read the 'Stability Considerations' +section in the qmp-commands.txt file before making any serious use of QMP. + [1] http://www.json.org Usage ----- -To enable QMP, QEMU has to be started in "control mode". There are -two ways of doing this, the simplest one is using the the '-qmp' -command-line option. +To enable QMP, you need a QEMU monitor instance in "control mode". There are +two ways of doing this. + +The simplest one is using the '-qmp' command-line option. The following +example makes QMP available on localhost port 4444: -For example: + $ qemu [...] -qmp tcp:localhost:4444,server -$ qemu [...] -qmp tcp:localhost:4444,server +However, in order to have more complex combinations, like multiple monitors, +the '-mon' command-line option should be used along with the '-chardev' one. +For instance, the following example creates one user monitor on stdio and one +QMP monitor on localhost port 4444. -Will start QEMU in control mode, waiting for a client TCP connection -on localhost port 4444. + $ qemu [...] -chardev stdio,id=mon0 -mon chardev=mon0,mode=readline \ + -chardev socket,id=mon1,host=localhost,port=4444,server \ + -mon chardev=mon1,mode=control -It is also possible to use the '-mon' command-line option to have -more complex combinations. Please, refer to the QEMU's manpage for -more information. +Please, refer to QEMU's manpage for more information. Simple Testing -------------- -To manually test QMP one can connect with telnet and issue commands: +To manually test QMP one can connect with telnet and issue commands by hand: $ telnet localhost 4444 Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. -{"QMP": {"version": {"qemu": "0.12.50", "package": ""}, "capabilities": []}} +{"QMP": {"version": {"qemu": {"micro": 50, "minor": 13, "major": 0}, "package": ""}, "capabilities": []}} { "execute": "qmp_capabilities" } {"return": {}} { "execute": "query-version" } -{"return": {"qemu": "0.12.50", "package": ""}} +{"return": {"qemu": {"micro": 50, "minor": 13, "major": 0}, "package": ""}} + +Development Process +------------------- + +When changing QMP's interface (by adding new commands, events or modifying +existing ones) it's mandatory to update the relevant documentation, which is +one (or more) of the files listed in the 'Introduction' section*. + +Also, it's strongly recommended to send the documentation patch first, before +doing any code change. This is so because: + + 1. Avoids the code dictating the interface + + 2. It's very likely that the interface will change during review, updating + the code at the same time might be a big waste of time + +* The qmp-commands.txt file is generated from the qemu-monitor.hx one, which + is the file that should be edited. -Contact -------- +Homepage +-------- http://www.linux-kvm.org/page/MonitorProtocol -Luiz Fernando N. Capitulino