The host CR3 value contains a different PML4 (Page Mape Level 4) PFN (Page Frame Number) then the system address space. This new address space contains the same PML4E's as the
system address space except the lower 255 PML4E's are reserved for the hypervisor. PML4E 256 is a self referencing PML4E setup by the hypervisor in `drv_entry`.