1. An apparatus comprising: a processor; a volatile memory configured to be accessible in an active memory sharing configuration; a machine-readable storage medium encoded with instructions executable by the processor, the instructions comprising, first virtual machine instructions configured to access the volatile memory with a first virtual machine; second virtual machine instructions configured to access the volatile memory with a second virtual machine; and virtual machine monitor instructions configured to page first data out from a shared memory to a reserved memory section in the volatile memory responsive to the first virtual machine or the second virtual machine paging second data out from the shared memory or paging the second data in to the shared memory, wherein the shared memory is shared across the first virtual machine and the second virtual machine and the volatile memory comprises the shared memory.