Re: [PATCH v8 3/6] KVM: PPC: Book3S HV: Add support for H_RPT_INVALIDATE

[Bharata B Rao <bharata@linux.ibm.com>]

On Mon, Jul 05, 2021 at 02:42:33PM +1000, David Gibson wrote:
> On Mon, Jun 21, 2021 at 02:20:00PM +0530, Bharata B Rao wrote:
> > diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
> > index 4bc45d3ed8b0..b44f291fc909 100644
> > --- a/arch/powerpc/include/asm/mmu_context.h
> > +++ b/arch/powerpc/include/asm/mmu_context.h
> > @@ -124,8 +124,17 @@ static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
> >  
> >  #if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU)
> >  extern void radix_kvm_prefetch_workaround(struct mm_struct *mm);
> > +void do_h_rpt_invalidate_prt(unsigned long pid, unsigned long lpid,
> > +			     unsigned long type, unsigned long pg_sizes,
> > +			     unsigned long start, unsigned long end);
> >  #else
> >  static inline void radix_kvm_prefetch_workaround(struct mm_struct *mm) { }
> > +static inline void do_h_rpt_invalidate_prt(unsigned long pid,
> > +					   unsigned long lpid,
> > +					   unsigned long type,
> > +					   unsigned long pg_sizes,
> > +					   unsigned long start,
> > +					   unsigned long end) { }
> 
> Since the only plausible caller is in KVM HV code, why do you need the
> #else clause.

The call to the above routine is prevented for non-radix guests
in KVM HV code at runtime using kvm_is_radix() check and not by
CONFIG_PPC_RADIX_MMU. Hence the #else version would be needed.

Regards,
Bharata.