Re: [PATCH Part2 RFC v4 07/40] x86/sev: Split the physmap when adding the page in RMP table
From: Sean Christopherson <seanjc@google.com>
Date: 2021-07-15 18:39:23
Also in:
kvm, linux-crypto, linux-efi, linux-mm, lkml, platform-driver-x86
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.