Re: [RFC PATCH 06/10] ppc: Add a core_index to CPUPPCState for SMT vCPUs

[Nicholas Piggin]

On Tue May 28, 2024 at 6:52 PM AEST, Harsh Prateek Bora wrote:
> corrected typo, it's bitwise.
>
> On 5/28/24 14:18, Harsh Prateek Bora wrote:
> >> -    (POWERPC_CPU(cs)->env.spr_cb[SPR_PIR].default_value & 
> >> ~(cs->nr_threads - 1))
> >> +    (POWERPC_CPU(cs)->env.core_index)
> > 
> > Dont we want to keep the bitwise & with ~(cs->nr_threads - 1) ?
> > How's it taken care ?

For these accessors it actually just wants to have something that
compares if a CPU belongs to the same core or not, so exact value
doesn't really matter.

Maybe the helpers should do that comparison. It could possibly even
be a class method to be really clean, although that's more costly
to call (but writing to a SMT shared register is pretty costly anyway
so maybe doesn't matter).

I'll think a bit more.

Thanks,
Nick