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Hallyn" , kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, Chao Peng , Fuad Tabba , Jarkko Sakkinen , Yu Zhang , Vishal Annapurve , Ackerley Tng , Maciej Szmigiero , Vlastimil Babka , David Hildenbrand , Quentin Perret , Michael Roth , Wang , Liam Merwick , Isaku Yamahata , "Kirill A . Shutemov" Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, Jul 21, 2023 at 7:13=E2=80=AFPM Sean Christopherson 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_c= reate_guest_memfd *args) > > > u64 flags =3D args->flags; > > > u64 valid_flags =3D 0; > > > + if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) > > > + valid_flags |=3D 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 p= robably > rather have an explicit error, as opposed to silently running with a misc= onfigured > setup. Considering that is how madvise(MADV_HUGEPAGE) behaves, your patch is good. I disagree but consistency is better. Paolo