From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1J26q4-0006YT-ID for qemu-devel@nongnu.org; Tue, 11 Dec 2007 10:16:04 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1J26q0-0006Wk-Ni for qemu-devel@nongnu.org; Tue, 11 Dec 2007 10:16:04 -0500 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1J26q0-0006Wh-Jp for qemu-devel@nongnu.org; Tue, 11 Dec 2007 10:16:00 -0500 Received: from wr-out-0506.google.com ([64.233.184.233]) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1J26q0-0002cg-BL for qemu-devel@nongnu.org; Tue, 11 Dec 2007 10:16:00 -0500 Received: by wr-out-0506.google.com with SMTP id c37so6434204wra for ; Tue, 11 Dec 2007 07:15:57 -0800 (PST) Message-ID: <475EA9AA.3020503@codemonkey.ws> Date: Tue, 11 Dec 2007 09:15:54 -0600 From: Anthony Liguori MIME-Version: 1.0 Subject: Re: [Qemu-devel] [RFC] QEMU Dbus support - a proposal management API References: <475E5403.2000705@bellard.org> <1197364997.4242.10.camel@frecb07144> <475E617D.6090702@qumranet.com> <475EA3F4.50802@codemonkey.ws> <20071211150228.GD17368@redhat.com> In-Reply-To: <20071211150228.GD17368@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" , qemu-devel@nongnu.org Daniel P. Berrange wrote: > On Tue, Dec 11, 2007 at 08:51:32AM -0600, Anthony Liguori wrote: > >> Dor Laor wrote: >> >>> Laurent Vivier wrote: >>> >>>> Le mardi 11 décembre 2007 à 10:10 +0100, Fabrice Bellard a écrit : >>>> >>>> >>>>> Hi, >>>>> >>>>> >>>> Hi, >>>> >>>> >>>> >>>>> At this point I am not interested in integrating it into QEMU as it is >>>>> one more API level to maintain in addition to the command line monitor. >>>>> However, I can change my mind if several projects insists to have a >>>>> similar interface. >>>>> >>>>> >>>> perhaps the DBUS interface can replace the command line monitor ? >>>> We have just to move the command line interface to a client speaking to >>>> qemu through the DBUS interface. >>>> >>>> >>>> >>> This is a valid option but the problem is that local user will have to >>> use another tool (client) to >>> send commands. Another option is to have a common backend with machine >>> & user interfaces. >>> For example, if we use dbus as the backend, monitor commands will just >>> be translated into dbus. >>> The opposite option is also valid. >>> >>> Anyway, the motivation behind a new interface is that the monitor >>> interface is not good enough for automation: >>> There are not return status for commands, no option for async >>> notifications, no option for parallel actions in case >>> a command takes long time to complete (like snapshot). >>> >> All of these are valid, and addressable. Return statuses can just be >> added to the beginning of the output of each command (similar to how >> POP3 works). Async notification can be made to work by add support to >> the monitor for a "select" command. Semantically, select would block >> the monitor and then output events. For this to work really well, you >> would have to support multiple simultaneous monitor sessions. The >> parallel options for long running commands is already address in KVM >> with the migration command. We just have to rework the snapshotting to >> be properly asynchronous. >> > > Or have 2 monitor interaction modes. One mode uses the command line style > suitable for people / scripting languages. The other umode ses a binary XDR > protocol for serializing the args & returns values for formal control > APIs to use in a easy manner. It ought to be reasonably straightforward to > add a binary serialization format for all existing commands > I don't think binary is inherently easier to parse than text provided that some thought is put into the format of the textual output. I think we just want to levels of verbosity. Regards, Anthony Liguori > Dan. >