Re: [Qemu-devel] [PATCH v3 1/6] hw/misc/dyn_sysbus_binding: helpers for sysbus device dynamic binding

[Alexander Graf <agraf@suse.de>]

On 10.09.14 12:21, Paolo Bonzini wrote:
> Il 10/09/2014 12:09, Alexander Graf ha scritto:
>> Fair enough.
>>
>> As far as moving "platform bus" logic into sysbus, I'd really like to
>> hold back and see what this whole thing ends up getting used for first.
>>
>> So for now, I'd definitely prefer to keep "platform bus" logic and
>> "sysbus" logic separate. If we realize that every user only ever uses
>> the dynamic sysbus creation in conjunction with our "platform bus"
>> implementation, we can merge them.
> 
> I agree.  As you pointed out, we have two usecases:
> 
> 1) arbitrary dynamic sysbus devices, because you're playing with board
> design or because you're working on a virtualized platform
> 
> 2) pluggable components in a fixed board design (e.g. CCSR)
> 
> The only thing they share is FDT creation.  The other part, which is
> assigning the interrupts and memory regions, is different: case (1) has
> it driven by command line or simply bottom-to-top; case (2) has it
> driven by an implementation of a spec.
> 
> It's not even clear to me that E500 CCSR devices should be sysbus, in
> fact...

The problem if you continue that thought process is that we'd end up
with 500 different buses and 500 different uart boilerplate devices just
to fit into the respective buses ;).

Otherwise I agree.


Alex