In the above example of FIG. 21, the GPA referred to by the VCPU on node_0 that stalled was also locally defined on node_0. In some cases, the referred-to GPA may be defined on a node that is remote with respect to the VCPU on which the stall occurred. In some embodiments, to collocate the ownership of the GPA and the VCPU, ownership of the GPA is transferred to the node with the stalled VCPU. In another embodiment, the stalled VCPU is migrated to the node that owns the GPA. With the VCPU and GPA collocated, the dormant GPA is then mapped to a real physical page of zeroes, as described above, and then written into by the now collocated VCPU. Further details regarding migration of dormant pages will be described below. The determination of what resources should be migrated may be based on cost functions. As one example, the strategy cost functions may evaluate conditions such as memory pressure. For example, if the node with the VCPU is under memory pressure, then ownership of the page is not transferred, unless, for example, there are other VCPUs on the first node that share a common working set with the VCPU on the first node that took the stall. The cost functions may, for example, decide to push pages out from the node with the VCPU (e.g., to free space and relieve memory pressure so that the dormant page may be migrated to the node with the VCPU), or migrate the VCPU.
