Providing VMM Access to Guest Virtual Memory

A virtual-machine-based system provides a mechanism for a virtual machine monitor (VMM) to process a hypercall received from an application running in the virtual machine (VM). A hypercall interface causes the virtual memory pages, needed by the VMM to process the hypercall, to be available to the VMM. In one embodiment, when virtual memory pages needed by the VMM to process the hypercall are not available to the VMM, the application is caused to access the needed pages, in response to which the required virtual memory becomes available to the VMM.