With migration disabled, one function becomes unused: virt/kvm/guest_memfd.c:262:12: error: 'kvm_gmem_migrate_folio' defined but not used [-Werror=unused-function] 262 | static int kvm_gmem_migrate_folio(struct address_space *mapping, | ^~~~~~~~~~~~~~~~~~~~~~ Remove the #ifdef around the reference so that fallback_migrate_folio() is never used. The gmem implementation of the hook is trivial; since the gmem mapping is unmovable, the pages should not be migrated anyway. Fixes: a7800aa80ea4 ("KVM: Add KVM_CREATE_GUEST_MEMFD ioctl() for guest-specific backing memory") Reported-by: Arnd Bergmann <arnd@xxxxxxxx> Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> --- virt/kvm/guest_memfd.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c index b99272396119..c2e2371720a9 100644 --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c @@ -300,9 +300,7 @@ static int kvm_gmem_error_page(struct address_space *mapping, struct page *page) static const struct address_space_operations kvm_gmem_aops = { .dirty_folio = noop_dirty_folio, -#ifdef CONFIG_MIGRATION .migrate_folio = kvm_gmem_migrate_folio, -#endif .error_remove_page = kvm_gmem_error_page, }; -- 2.39.1