Re: [PATCH Part2 RFC v4 07/40] x86/sev: Split the physmap when adding the page in RMP table

[Sean Christopherson]

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.