1. A computer-implemented method comprising: receiving, by a virtual machine monitor (VMM) of a host virtual machine (VM) server device, a memory management unit (MMU) synchronization event issued from a VM that is virtualized by the VMM of the host server device; identifying, by the VMM, unsynchronized page tables (PTs) of a shadow PT hierarchy maintained by the VMM that are in a visible address space of a guest PT hierarchy that caused the synchronization event, wherein the visible address space of the guest PT hierarchy comprises PTs of the shadow PT hierarchy that are associated with a current CR3 register address of the guest PT hierarchy; and synchronizing, by the VMM, the identified unsynchronized with corresponding guest PTs of a guest PT hierarchy maintained by the VM that caused the synchronization event.