From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48907) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZYuEg-0002Ei-Vb for qemu-devel@nongnu.org; Mon, 07 Sep 2015 07:05:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZYu9i-0002C2-Vi for qemu-devel@nongnu.org; Mon, 07 Sep 2015 07:00:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60108) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZYu9i-0002By-PT for qemu-devel@nongnu.org; Mon, 07 Sep 2015 07:00:10 -0400 Date: Mon, 7 Sep 2015 12:00:04 +0100 From: "Daniel P. Berrange" Message-ID: <20150907110004.GE29882@redhat.com> References: <1441098383-22585-1-git-send-email-yanghy@cn.fujitsu.com> <1441098383-22585-6-git-send-email-yanghy@cn.fujitsu.com> <20150901144308.GE2407@stefanha-thinkpad.redhat.com> <55E6559E.5060305@cn.fujitsu.com> <20150902130245.GI17873@stefanha-thinkpad.redhat.com> <55E7214A.20803@cn.fujitsu.com> <20150904103255.GB8683@stefanha-thinkpad.redhat.com> <55ED3EB0.1030902@cn.fujitsu.com> <20150907091117.GA8893@stefanha-thinkpad.redhat.com> <55ED6CBD.90602@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <55ED6CBD.90602@cn.fujitsu.com> Subject: Re: [Qemu-devel] [PATCH v9 05/10] move out net queue structs define Reply-To: "Daniel P. Berrange" List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Yang Hongyang Cc: thuth@redhat.com, zhang.zhanghailiang@huawei.com, lizhijian@cn.fujitsu.com, jasowang@redhat.com, qemu-devel@nongnu.org, mrhines@linux.vnet.ibm.com, Markus Armbruster , Stefan Hajnoczi , Andreas Faerber On Mon, Sep 07, 2015 at 06:53:49PM +0800, Yang Hongyang wrote: > On 09/07/2015 05:11 PM, Stefan Hajnoczi wrote: > [...] > >>Thanks very much for the suggestion, I've already implemented it and tested, > >>the code looks cleaner now. > >> > >>The last issue is the QOM thing, do Markus and Andreas have more input > >>about that? > > > >If you would like to see examples of QOM usage, take a look at > >iothread.c and/or backends/hostmem.c. > > > >The key things are: > > > >1. They use include/qom/object.h to register a type based on > > TYPE_OBJECT and their properties are registered using > > object_property_add_*(). > > > >2. They implement the TYPE_USER_CREATABLE interface so the -object > > command-line option can be used to instantiate them. See > > object_interfaces.h. > > > >As a result, a lot of code becomes unnecessary and iothread.c, in > >particular, is quite short. > > After looking into this, I have some questions on the implement, could you > please help me on this because I don't know much about the object mechanism: > > The netfilter need to be initialized after the net_init_clients, because we > need to attach the filter to the net client. But currently, net client is not > using QOM, and seems that it is initialized after objects been created. So here > comes the problem: how can I initialize a certain object later, is it possiable? It is currently a bit hacky - most objects are initialized very early, but we have a similar problem with rng-egd which must be created /after/ chardevs. To deal with this in vl.c main() we have two helper methods object_create_initial and object_create_delayed. The delayed method though still happens before the net clients are created. We could probably just move the objec_create_delayed method invokation to later on, after net clients are created, but if that doesn't work just add an extra helper object_create_very_delayed :-) Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|