On Fri, Jul 21, 2023 at 7:13 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote: > On Fri, Jul 21, 2023, Paolo Bonzini wrote: > > On 7/19/23 01:44, Sean Christopherson wrote: > > > @@ -413,6 +454,9 @@ int kvm_gmem_create(struct kvm *kvm, struct kvm_create_guest_memfd *args) > > > u64 flags = args->flags; > > > u64 valid_flags = 0; > > > + if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) > > > + valid_flags |= KVM_GUEST_MEMFD_ALLOW_HUGEPAGE; > > > + > > > > I think it should be always allowed. The outcome would just be "never have > > a hugepage" if thp is not enabled in the kernel. > > I don't have a strong preference. My thinking was that userspace would probably > rather have an explicit error, as opposed to silently running with a misconfigured > setup. Considering that is how madvise(MADV_HUGEPAGE) behaves, your patch is good. I disagree but consistency is better. Paolo