Re: [PATCH] KVM: use folio_nr_pages() instead of shift operation

David Hildenbrand
2025-10-22T19:40:51Z

On 04.10.25 05:02, Pedro Demarchi Gomes wrote:
> folio_nr_pages() is a faster helper function to get the number of pages when
> NR_PAGES_IN_LARGE_FOLIO is enabled.
>
> Signed-off-by: Pedro Demarchi Gomes <pedrodemargomes@gmail.com>
> ---
> virt/kvm/guest_memfd.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
> index 7d85cc33c0bb..5fc5475cf826 100644
> --- a/virt/kvm/guest_memfd.c
> +++ b/virt/kvm/guest_memfd.c
> @@ -77,9 +77,9 @@ static int kvm_gmem_prepare_folio(struct kvm *kvm, struct kvm_memory_slot *slot,
> * The order will be passed when creating the guest_memfd, and
> * checked when creating memslots.
> */
> - WARN_ON(!IS_ALIGNED(slot->gmem.pgoff, 1 << folio_order(folio)));
> + WARN_ON(!IS_ALIGNED(slot->gmem.pgoff, folio_nr_pages(folio)));
> index = gfn - slot->base_gfn + slot->gmem.pgoff;
> - index = ALIGN_DOWN(index, 1 << folio_order(folio));
> + index = ALIGN_DOWN(index, folio_nr_pages(folio));
> r = __kvm_gmem_prepare_folio(kvm, slot, index, folio);
> if (!r)
> kvm_gmem_mark_prepared(folio);

FWIW

Reviewed-by: David Hildenbrand <david@redhat.com>

--
Cheers

David / dhildenb