KVM: guest_memfd: move kvm_gmem_get_index() and use in kvm_gmem_prepare_folio()

Move kvm_gmem_get_index() to the top of the file so that it can be used
in kvm_gmem_prepare_folio() to replace the open-coded calculation.

No functional change intended.

Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Shivank Garg <shivankg@amd.com>
Link: https://lore.kernel.org/r/20251012071607.17646-1-shivankg@amd.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
index fbca8c0972da6e64e4b3a8418dd22e822ad4dc04..22dacf49a04dd585a6dadfad90fc448c879b016f 100644 (file)
--- a/virt/kvm/guest_memfd.c
+++ b/virt/kvm/guest_memfd.c
@@ -25,6 +25,11 @@ static inline kvm_pfn_t folio_file_pfn(struct folio *folio, pgoff_t index)
        return folio_pfn(folio) + (index & (folio_nr_pages(folio) - 1));
 }
 
+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)
 {
@@ -78,7 +83,7 @@ static int kvm_gmem_prepare_folio(struct kvm *kvm, struct kvm_memory_slot *slot,
         * checked when creating memslots.
         */
        WARN_ON(!IS_ALIGNED(slot->gmem.pgoff, 1 << folio_order(folio)));
-       index = gfn - slot->base_gfn + slot->gmem.pgoff;
+       index = kvm_gmem_get_index(slot, gfn);
        index = ALIGN_DOWN(index, 1 << folio_order(folio));
        r = __kvm_gmem_prepare_folio(kvm, slot, index, folio);
        if (!r)
@@ -335,11 +340,6 @@ static inline struct file *kvm_gmem_get_file(struct kvm_memory_slot *slot)
        return get_file_active(&slot->gmem.file);
 }
 
-static pgoff_t kvm_gmem_get_index(struct kvm_memory_slot *slot, gfn_t gfn)
-{
-       return gfn - slot->base_gfn + slot->gmem.pgoff;
-}
-
 static bool kvm_gmem_supports_mmap(struct inode *inode)
 {
        const u64 flags = (u64)inode->i_private;