Re: [Qemu-devel] [PATCH] scripts: Add qom-tree script as modern equivalent of info qtree

[Paolo Bonzini]

Il 07/02/2014 13:49, Andreas Färber ha scritto:
> qdev is a framework from Paul Brook with a bus-tree-oriented graph.
> QOM by comparison uses an arbitrary composition tree of child<> nodes.
>
> qdev as such no longer exists since late 2011 / early 2012.

Let me be blunt: to me, this is a huge, huge delusion.  And I guess this 
difference in views is why we keep talking past each other.

First, having to kill qdev is a dogma at best.  QOM allows more 
expressive relationships than just bus-children, but real hardware does 
have buses.  A bus is not just a n:1 relationship between a controller 
and a controlled device.  Buses, not composition, describe the path that 
signals actually follow while the system runs.  Composition lets you 
understand how a system is built.  Buses lets you run it.

Second, if anyone killed qdev, I didn't notice.  At best, qdev is now 
implemented on top of QOM.  And in fact, the "fake" buses that qdev 
introduced are all still there, so whoever "killed" qdev left quite a 
few traces behind him.

Paolo