Re: [Qemu-devel] [PATCH v1 06/11] target/s390x: cleanup cpu number/address handling

[Cornelia Huck]

On Thu, 31 Aug 2017 16:41:47 +0200
David Hildenbrand <address@hidden> wrote:

> On 31.08.2017 16:35, Cornelia Huck wrote:
> > On Wed, 30 Aug 2017 19:05:56 +0200
> > David Hildenbrand <address@hidden> wrote:
> >   
> >> Some time ago we discussed that using "id" as property name is not the
> >> right thing to do, as it is a reserved property for other devices.
> >>
> >> Switch to the term "addr" instead, which matches the definition in the
> >> PoP called "CPU address". There is no such thing as cpu number, so
> >> rename env.cpu_num to env.cpu_addr.
> >>
> >> We can get rid of cpu->id now. Keep cpu->index and env->cpu_addr in sync.
> >> cpu->index was already implicitly used by e.g. cpu_exists(), so keeping
> >> both in sync seems to be the right thing to do.
> >>
> >> cpu->index will now no longer automatically get set via
> >> cpu_exec_realizefn(). For now, we were lucky that both implicitly stayed
> >> in sync.
> >>
> >> Our new cpu property "addr" can be a static property. Range checks can
> >> be avoided by using the correct type and the "setting after realized"
> >> check is done implicitly.
> >>
> >> AFAIK, s390x only supports cpu_add and not device_add for cpus. So we
> >> should be able to safely rename that property (no the "id" property
> >> could properly be used for device_add, which needs an artificial id for
> >> identification purposes).  
> > 
> > I cannot parse the sentence in the brackets...  
> 
> Me too :)
> 
> ...So we should be able to safely rename that property. device_add will
> later need the reserved "id" property. Hotplugging a CPU would then look
> like this: "device_add host-s390-cpu id=cpu2 addr=2".

Yup, that's understandable :)