Re: [Qemu-devel] [PATCH 8/8] qom: Make CPU a child of DeviceState

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 12 Dec 2012 11:59:01 -0200
Eduardo Habkost <ehabkost@redhat.com> wrote:

> On Wed, Dec 12, 2012 at 02:34:08PM +0100, Andreas Färber wrote:
> > Am 05.12.2012 17:49, schrieb Eduardo Habkost:
> [...]
> > >  static TypeInfo cpu_type_info = {
> > >      .name = TYPE_CPU,
> > > -    .parent = TYPE_OBJECT,
> > > +    .parent = TYPE_DEVICE,
> > >      .instance_size = sizeof(CPUState),
> > >      .abstract = true,
> > >      .class_size = sizeof(CPUClass),
> > 
> > This patch makes the CPU a device and looks good so far but does not
> > initialize the devices in cpu_*_init() like Anthony did in his previous
> > patch. I am unsure whether you forgot to do so or whether you wanted to
> > help keep our new CPU code clean of old-style qdev_init_nofail() calls?
> > Since you don't add a qdev initfn here the main difference will be the
> > devices internally staying in "created" rather than "initialized" state.
> 
> I think I used a version without the qdev_init_nofail() as base for this
> series (we had multiple proposals being sent in parallel, in the
> beginning), and in the end I forgot that we had a version with those
> calls being added.
> 
> The CPU classes don't set any DeviceClass.init() method, so in theory
> the missing qdev_init() calls wouldn't make any difference by now. On
> the other hand, keeping the device in "created" state sounds bad... but
> maybe this acceptable while we are still converting the CPU realize()
> functions to fit inside the DeviceState initialization abstraction?
Testing shows that lack of qdev_create()/init() doesn't break anything so
far. I was planing to send hot-plug RFC after properties and subclasses for
x86 are done and temporally wrap x86_cpu_realize() inside DeviceClass.init()
so we could use qdev_create()/init() and device_add() for CPU.
It's still on my TODO list. Perhaps after I resubmit properties series (I
hope to do it this week), I'll redo hot-plug prototype using as a base my
experimental subclasses branch
https://github.com/imammedo/qemu/commits/x86-cpu-classes.WIP