Comment 1 for bug 1397860

kernel 4.0 implement this feature.
843e433 KVM: VMX: Add PML support in VMX
88178fd KVM: x86: Add new dirty logging kvm_x86_ops for PML
1c91cad KVM: x86: Change parameter of kvm_mmu_slot_remove_write_access
9b51a63 KVM: MMU: Explicitly set D-bit for writable spte.
f4b4b18 KVM: MMU: Add mmu help functions to support PML
3b0f1d0 KVM: Rename kvm_arch_mmu_write_protect_pt_masked to be more generic for
d91ffee Optimize TLB flush in kvm_mmu_slot_remove_write_access.
7e71a59 KVM: x86: flush TLB when D bit is manually changed.