Fold __kvm_gmem_prepare_folio() into kvm_gmem_prepare_folio() and extend the #ifdef guard to cover all of the kvm_gmem_prepare_folio(). Take care to align the gfn _before_ computing the index, otherwise KVM would end up with a mismatched gfn+pfn pair for folios larger than order-0 (this detail was subtly handled by recomputing gfn in the helper using the aligned pfn). Providing a single-use, ~2 line tail-call helper adds no value. In fact, due to having to reconstitute the gfn, *and* effectively hiding the alignment adjustment for hugepages, the separate helper is very arguably a net negative. Opportunistically convert the existing WARN in the prepare flow to a only fire once, e.g. so that a guest_memfd bug doesn't unintentionally Dos the kernel by spamming the log. No functional change intended. Signed-off-by: Sean Christopherson --- virt/kvm/guest_memfd.c | 24 ++++++++---------------- 1 file changed, 8 insertions(+), 16 deletions(-) diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c index 62c2c157f0c1..f9a1d6d64f6c 100644 --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c @@ -60,19 +60,6 @@ static pgoff_t kvm_gmem_get_index(struct kvm_memory_slot *slot, gfn_t gfn) return gfn - slot->base_gfn + slot->gmem.pgoff; } -static int __kvm_gmem_prepare_folio(struct kvm *kvm, struct kvm_memory_slot *slot, - pgoff_t index, struct folio *folio) -{ -#ifdef CONFIG_HAVE_KVM_ARCH_GMEM_PREPARE - kvm_pfn_t pfn = folio_file_pfn(folio, index); - gfn_t gfn = slot->base_gfn + index - slot->gmem.pgoff; - - return kvm_arch_gmem_prepare(kvm, gfn, pfn, folio_order(folio)); -#else - return 0; -#endif -} - /* * Process @folio, which contains @gfn, so that the guest can use it. * The folio must be locked and the gfn must be contained in @slot. @@ -82,6 +69,7 @@ static int __kvm_gmem_prepare_folio(struct kvm *kvm, struct kvm_memory_slot *slo static int kvm_gmem_prepare_folio(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn, struct folio *folio) { +#ifdef CONFIG_HAVE_KVM_ARCH_GMEM_PREPARE pgoff_t index; /* @@ -97,11 +85,15 @@ 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, folio_nr_pages(folio))); + WARN_ON_ONCE(!IS_ALIGNED(slot->gmem.pgoff, folio_nr_pages(folio))); + gfn = ALIGN_DOWN(gfn, folio_nr_pages(folio)); index = kvm_gmem_get_index(slot, gfn); - index = ALIGN_DOWN(index, folio_nr_pages(folio)); - return __kvm_gmem_prepare_folio(kvm, slot, index, folio); + return kvm_arch_gmem_prepare(kvm, gfn, folio_file_pfn(folio, index), + folio_order(folio)); +#else + return 0; +#endif } /* -- 2.55.0.141.g00534a21ce-goog