On Thu, Jul 15, 2021, Brijesh Singh wrote: > The memfd_secrets uses the set_direct_map_{invalid,default}_noflush() and it > is designed to remove/add the present bit in the direct map. We can't use > them, because in our case the page may get accessed by the KVM (e.g > kvm_guest_write, kvm_guest_map etc). But KVM should never access a guest private page, i.e. the direct map should always be restored to PRESENT before KVM attempts to access the page.