From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:42260) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RLfqt-0006M3-7L for qemu-devel@nongnu.org; Wed, 02 Nov 2011 14:47:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RLfqq-0006PI-Nx for qemu-devel@nongnu.org; Wed, 02 Nov 2011 14:47:55 -0400 Received: from cantor2.suse.de ([195.135.220.15]:49213 helo=mx2.suse.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RLfqq-0006Ox-6L for qemu-devel@nongnu.org; Wed, 02 Nov 2011 14:47:52 -0400 Message-ID: <4EB19053.4050500@suse.de> Date: Wed, 02 Nov 2011 19:47:47 +0100 From: Alexander Graf MIME-Version: 1.0 References: <4639B135-B96A-43A0-B4FA-6DDCBE3FBA92@suse.de> <4EB18172.1020905@adacore.com> <4EB18952.4080403@siemens.com> <4EB18C13.2030704@codemonkey.ws> <4EB18D1C.4090000@suse.de> <4EB18FFF.7010603@siemens.com> In-Reply-To: <4EB18FFF.7010603@siemens.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] GSoC mentor summit QEMU users session List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: Peter Maydell , Fabien Chouteau , "qemu-devel@nongnu.org Developers" Jan Kiszka wrote: > On 2011-11-02 19:34, Alexander Graf wrote: > >> Anthony Liguori wrote: >> >>> On 11/02/2011 01:17 PM, Jan Kiszka wrote: >>> >>>> On 2011-11-02 18:44, Fabien Chouteau wrote: >>>> >>>>> On 31/10/2011 14:12, Peter Maydell wrote: >>>>> >>>>>> On 29 October 2011 14:52, Alexander Graf wrote: >>>>>> >>>>>>> A lot of people seem to also have code that doesn't make sense >>>>>>> upstream, for example implementing a one-off device that only >>>>>>> really matters for their own devboard which nobody else owns. >>>>>>> For such cases, having a plugin framework would be handy. I >>>>>>> interestingly enough got into the same discussion on LinuxCon >>>>>>> with some QEMU downstreams. >>>>>>> >>>>>> If we get the qdev rework done then I think we're probably in >>>>>> a better position to have a plugin framework for devices. (There >>>>>> are some issues about API and ABI stability guarantees, of course.) >>>>>> >>>>>> >>>>> Interesting, we have a "plug-in" implementation in our Qemu branch. It >>>>> >>>> We have a "plugin" model here as well. It's really simple: the plugin is >>>> loaded dynamically into the QEMU process and can access any global >>>> function and variable. Of course, this breaks regularly. >>>> >>> Yes, this is the Right Model. >>> >>> All of the work is in making the interfaces not break regularly. >>> Loading a shared object is easy enough. >>> >> I agree. In fact, we could even do it the same way as the kernel and >> build all our internal hw pieces as shared objects. >> >> Then users who want to cut down QEMU can just remove .so files instead >> of messing with the build system or code. >> > > We should also be able to establish an EXPORT_SYMBOL concept, ie. only > export those functions that are supposed to be part of a component API. > Will be some work initially, but should be off long term, both to QEMU > in maintaining stable APIs and to external components in using the > proper ones. > Yes. IOW, let's go down the same road as Linux. It works well for them, why not for us? Alex