On 10/06/20 20:14, Sean Christopherson wrote: >> - /* setup delayed work */ >> + /* Arch specific code should not do async PF in this case */ >> + if (unlikely(kvm_is_error_hva(hva))) > This feels like it should be changed to a WARN_ON_ONCE in a follow-up. > With the WARN, the comment could probably be dropped. I think a race is possible in principle where the memslots are changed (for example) between s390's page fault handler and the gfn_to_hva call in kvm_arch_setup_async_pf. Queued both, thanks! Paolo