From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58741) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZYuq4-00058V-GS for qemu-devel@nongnu.org; Mon, 07 Sep 2015 07:43:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZYuq0-0000af-O5 for qemu-devel@nongnu.org; Mon, 07 Sep 2015 07:43:56 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57732) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZYuq0-0000aV-Gp for qemu-devel@nongnu.org; Mon, 07 Sep 2015 07:43:52 -0400 Date: Mon, 7 Sep 2015 12:43:46 +0100 From: "Daniel P. Berrange" Message-ID: <20150907114346.GH29882@redhat.com> References: <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> <20150907110004.GE29882@redhat.com> <55ED77E6.3030003@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <55ED77E6.3030003@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 07:41:26PM +0800, Yang Hongyang wrote: > > > On 09/07/2015 07:00 PM, Daniel P. Berrange wrote: > >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 :-) > > If it's ok to move creation of "rng-egd" later, then "move the > objec_create_delayed method invokation after net clients are created" should > solve the problem. I think it should be ok, because IIRC, the only requirement from rng-egd was that it be created /after/ -device is processed, so moving it even later shouldn't hurt it 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 :|