Re: [Qemu-devel] [PATCH RFC V3 1/4] Use Aff1 with mpidr This is an improved and KVM-aware alternative to

[Peter Maydell]

On 8 June 2015 at 08:50, Pavel Fedin <address@hidden> wrote:
>> I think it would be less confusing to store the entire MPIDR
>> here, and then mask it out if there are places that only
>> want the affinity bits.
>
>  I thought about it when i developed this, but in my implementation
> affinity bits are assigned during CPU instantiation, while feature
> bits can be added later, during realize. I could tweak set_feature()
> to sync up MPIDR value but perhaps it isn't the best thing to do.

Can we not just assign the whole thing at realize?

>  Additionally, currently we support only ARM_FEATURE_V7MP, which is
> 32-bit only. I believe this would be a more complex modification
> which would touch more of 32-bit code.

It's only 32-bit in the sense that all 64-bit systems (indeed, all v8
systems) have the feature and so the bit is effectively RES1.

You need to fix the 32-bit side anyway.

>  So would it be acceptable to leave mpidr handling as it is?

I still think that having the whole mpidr in the struct will
be less confusing.

thanks
-- PMM