1. An apparatus to manage virtual machines, the apparatus including: a graphics processor coupled to a virtual machine monitor (VMM) to present a virtual graphics processor to a first virtual machine; and a mediator for the virtual graphics processor to synchronously shadow modifications to a first guest graphics translation table (GTT) of a first virtual machine to a shadow GTT of the VMM, the mediator further to detect a frequency of modifications to at least a first portion of contiguous GTT entries of the first guest GTT exceeds a threshold and, in response to the detection, asynchronously shadow at least a portion of the first guest GTT associated with the first portion to the shadow GTT.