In several embodiments, a graphics processor couples to a virtual machine monitor (VMM) to present a virtual graphics processor to one or more virtual machines. A mediator for the virtual graphics processor synchronously shadows modifications to a guest graphics translation table (GTT) of a virtual machine to a shadow GTT of the VMM using trap and emulate virtualization. If the mediator detects a frequency of modifications to the guest GTT that exceeds a threshold the mediator may then asynchronously shadow at least a portion of the guest GTT to the shadow GTT and rebuild the shadow GTT prior to submitting commands for the virtual graphics processor to the graphics processor.