From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:58262) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TJfJP-0001zI-Ve for qemu-devel@nongnu.org; Thu, 04 Oct 2012 02:53:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TJfJO-0006FY-8p for qemu-devel@nongnu.org; Thu, 04 Oct 2012 02:53:35 -0400 Received: from mx1.redhat.com ([209.132.183.28]:17749) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TJfJO-0006EM-0e for qemu-devel@nongnu.org; Thu, 04 Oct 2012 02:53:34 -0400 Date: Thu, 4 Oct 2012 08:53:22 +0200 From: Igor Mammedov Message-ID: <20121004085322.599a19ab@nial.usersys.redhat.com> In-Reply-To: <20121003165434.GT15784@otherpad.lan.raisama.net> References: <1349192235-31895-8-git-send-email-imammedo@redhat.com> <20121002203845.GB4362@otherpad.lan.raisama.net> <20121003150339.GS15784@otherpad.lan.raisama.net> <506C57CE.9060002@redhat.com> <20121003182411.7075c0ef@nial.usersys.redhat.com> <20121003165434.GT15784@otherpad.lan.raisama.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 07/23] target-i386: convert cpuid features into properties List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost Cc: aliguori@us.ibm.com, akong@redhat.com, stefanha@linux.vnet.ibm.com, gleb@redhat.com, jan.kiszka@siemens.com, Don@cloudswitch.com, mtosatti@redhat.com, qemu-devel@nongnu.org, mdroth@linux.vnet.ibm.com, blauwirbel@gmail.com, avi@redhat.com, Paolo Bonzini , hpa@linux.intel.com, lersek@redhat.com, afaerber@suse.de On Wed, 3 Oct 2012 13:54:34 -0300 Eduardo Habkost wrote: > On Wed, Oct 03, 2012 at 06:24:11PM +0200, Igor Mammedov wrote: > > On Wed, 03 Oct 2012 17:20:46 +0200 > > Paolo Bonzini wrote: > > > > > Il 03/10/2012 17:03, Eduardo Habkost ha scritto: > > > > On Tue, Oct 02, 2012 at 05:38:45PM -0300, Eduardo Habkost wrote: > > > >> (Now replying on the right thread, to keep the discussion in the > > > >> right place. I don't know how I ended up replying to a pre-historic > > > >> version of the patch, sorry.) > > > >> > > > >> On Tue, Oct 02, 2012 at 05:36:59PM +0200, Igor Mammedov wrote: > > > >> [...] > > > >>> @@ -1938,6 +2043,12 @@ static void x86_cpu_initfn(Object *obj) > > > >>> object_property_add(obj, "tsc-frequency", "int", > > > >>> x86_cpuid_get_tsc_freq, > > > >>> x86_cpuid_set_tsc_freq, NULL, NULL, NULL); > > > >>> + x86_register_cpuid_properties(obj, feature_name); > > > >>> + x86_register_cpuid_properties(obj, ext_feature_name); > > > >>> + x86_register_cpuid_properties(obj, ext2_feature_name); > > > >>> + x86_register_cpuid_properties(obj, ext3_feature_name); > > > >>> + x86_register_cpuid_properties(obj, kvm_feature_name); > > > >>> + x86_register_cpuid_properties(obj, svm_feature_name); > > > >> > > > >> Stupid question about qdev: > > > >> > > > >> - qdev_prop_set_globals() is called from device_initfn() > > > >> - device_initfn() is called before the child class instance_init() > > > >> function (x86_cpu_initfn()) > > > >> - So, qdev_prop_set_globals() gets called before the CPU class > > > >> properties are registered. > > > >> > > > >> So this would defeat the whole point of all the work we're doing, > > > >> that is to allow compatibility bits to be set as machine-type global > > > >> properties. But I don't know what's the right solution here. > > > >> > > > >> Should the qdev_prop_set_globals() call be moved to qdev_init() > > > >> instead? Should the CPU properties be registered somewhere else? > > > > > > Properties should be registered (for all objects, not just CPUs) in the > > > instance_init function. This is device_initfn. > > > > > > I would add an instance_postinit function that is called at the end of > > > object_initialize_with_type, that is after instance_init, and in the > > > opposite order (i.e. from the leaf to the root). > > > > You've meant something like that? > > > > That's almost exactly the same code I wrote here. :-) > > The only difference is that I added post_init to the struct Object > documentation comments, and added a unit test. The unit test required > the qdev-core/qdev split, so we could compile it without bringing too > many dependencies. I will submit it soon. > After irc discussion, Anthony suggested to use static properties instead of dynamic ones that we use now. But qdev_prop_set_globals() in device_initfn() is still causes problems even with static properties. For x86 CPU classes we were going dynamically generate CPU classes and store pointer to appropriate cpudef from builtin_x86_defs in class field for each CPU class and then init default feature words values from this field int x86_cpu_initfn(). However with qdev_prop_set_globals() in device_initfn() that is called before x86_cpu_initfn() it won't work because defaults in x86_cpu_initfn() will overwrite whatever was set by qdev_prop_set_globals(). IMHO from general POV it's not correct to set properties before object is completely created. But Anthony wants to keep qdev_prop_set_globals() qdev only thing, so could we move it from device_initfn() to qdev_init() or some other place then?