Re: [RFC PATCH v3 06/19] KVM: x86: mmu: add gfn_in_memslot helper

Maxim Levitsky
2022-05-22T12:13:19Z

On Thu, 2022-05-19 at 16:43 +0000, Sean Christopherson wrote:
> On Wed, Apr 27, 2022, Maxim Levitsky wrote:
> > This is a tiny refactoring, and can be useful to check
> > if a GPA/GFN is within a memslot a bit more cleanly.
>
> This doesn't explain the actual motivation, which is to use the new helper from
> arch code.
I'll add this in the next version
>
> > Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
> > ---
> > include/linux/kvm_host.h | 10 +++++++++-
> > 1 file changed, 9 insertions(+), 1 deletion(-)
> >
> > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> > index 252ee4a61b58b..12e261559070b 100644
> > --- a/include/linux/kvm_host.h
> > +++ b/include/linux/kvm_host.h
> > @@ -1580,6 +1580,13 @@ int kvm_request_irq_source_id(struct kvm *kvm);
> > void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id);
> > bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args);
> >
> > +
> > +static inline bool gfn_in_memslot(struct kvm_memory_slot *slot, gfn_t gfn)
> > +{
> > + return (gfn >= slot->base_gfn && gfn < slot->base_gfn + slot->npages);
> > +}
> > +
>
> Spurious newline.
>
> > +
> > /*
> > * Returns a pointer to the memslot if it contains gfn.
> > * Otherwise returns NULL.
> > @@ -1590,12 +1597,13 @@ try_get_memslot(struct kvm_memory_slot *slot, gfn_t gfn)
> > if (!slot)
> > return NULL;
> >
> > - if (gfn >= slot->base_gfn && gfn < slot->base_gfn + slot->npages)
> > + if (gfn_in_memslot(slot, gfn))
> > return slot;
> > else
> > return NULL;
>
> At this point, maybe:

No objections.

Thanks for the review.

Best regards,
Maxim Levitsky

>
> if (!slot || !gfn_in_memslot(slot, gfn))
> return NULL;
>
> return slot;
>
> > }
> >
> > +
> > /*
> > * Returns a pointer to the memslot that contains gfn. Otherwise returns NULL.
> > *
> > --
> > 2.26.3
> >