Memory virtualization

• We saw

  physical address not available

• Memory is not virtualized for the guest
• When the guest translates VA to PA using the guest CR3
  • as-is
    • the translated PA is used to access physical memory
    • the guest could read and write any memory (including hypervisor's or other guests' memory)
    • In our case, a PA the guest attempted to access was not available
  • with memory virtualization:
    • the translated PA is again translated using hypervisor managed mapping
    • the hypervisor can prevent guest from accessing hypervisor's or other guests' memory