Re: [Qemu-devel] [PATCH v2 00/18] qom: dynamic properties and composition tree (v2)

[Anthony Liguori]

On 12/03/2011 03:34 PM, Anthony Liguori wrote:
> On 12/03/2011 08:24 AM, Paolo Bonzini wrote:
> > On 12/03/2011 03:40 AM, Anthony Liguori wrote:
> > > That is still true. The next step, inheritance, will pull the properties
> > > into a base class. That base class can be used elsewhere outside of the
> > > device model.
> > >
> > > But this is already a 20 patch series. If you want all of that in one
> > > series, it's going to be 100 patches that are not terribly easy to
> > > review at once.
> >
> > Without a design document and a roadmap, however, it's impossible to try to
> > understand how the pieces will be together. 100 patches may require some time to
> > digest, but 20 patches require a crystal ball to figure out what's ahead.
>
> You can see a bit further by looking at:
>
> https://github.com/aliguori/qemu/commits/qom-next
>
> That fills out the composition tree pretty well for the pc. The next step is
> aggressive refactoring such that the qdev objects reflect the composition. IOW,
> we should create the rtc from within the piix3 initialization function.

I've begun the work of introducing proper inheritance.  There's a lot going on 
but the basic idea is:

1) introduce QOM base type (Object), make qdev inherit from it

2) create a dynamic typeinfo based DeviceInfo, make device class point to 
deviceinfo

3) model qdev hierarchy in QOM

4) starting from the bottom of the hierarchy, remove DeviceInfo subclass and 
push that functionality into QOM classes

5) once (4) is complete, remove DeviceInfo

6) refactor any use of multiple child busses into separate devices with one bus

7) refactor busstate as an interface

8) refactor device model to make more aggressive use of composition

9) refactor life cycle events into virtual methods

The tree I've posted is on step (4).

Regards,

Anthony Liguori