Re: [PATCH v3 2/8] KVM: Integrate gfn_to_memslot_approx() into search_memslots()

[Maciej S. Szmigiero]

On 19.05.2021 23:24, Sean Christopherson wrote:
> On Sun, May 16, 2021, Maciej S. Szmigiero wrote:
> > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> > index 8895b95b6a22..3c40c7d32f7e 100644
> > --- a/include/linux/kvm_host.h
> > +++ b/include/linux/kvm_host.h
> > @@ -1091,10 +1091,14 @@ bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args);
> >    * gfn_to_memslot() itself isn't here as an inline because that would
> >    * bloat other code too much.
> >    *
> > + * With "approx" set returns the memslot also when the address falls
> > + * in a hole. In that case one of the memslots bordering the hole is
> > + * returned.
> > + *
> >    * IMPORTANT: Slots are sorted from highest GFN to lowest GFN!
> >    */
> >   static inline struct kvm_memory_slot *
> > -search_memslots(struct kvm_memslots *slots, gfn_t gfn)
> > +search_memslots(struct kvm_memslots *slots, gfn_t gfn, bool approx)
>
> An alternative to modifying the PPC code would be to make the existing
> search_memslots() a wrapper to __search_memslots(), with the latter taking
> @approx.

I guess you mean that if search_memslots() only does an exact search
(like the current code does) its 3 callers won't have to be modified.
Will do it then.

> We might also want to make this __always_inline to improve the likelihood of the
> compiler optimizing away @approx.  I doubt it matters in practice...

Sounds like a good idea, will do.

Thanks,
Maciej