1. A method comprising: determining, at an intermediary manager, whether a guest operating system located at the same virtual machine as the intermediary manager is operable with a particular hypervisor that is separate from the intermediary manager, wherein the intermediary manager is not the particular hypervisor; in response to determining that the guest operating system is not operable with the particular hypervisor: intercepting, at the intermediary manager from the guest operating system, a hypercall directed to the particular hypervisor that is separate from the intermediary manager; determining that a particular intermediary service is associated with the hypercall; causing execution of service instructions associated with the particular intermediary service; and providing a set of hypercall function definitions to the guest operating system, wherein at least one hypercall function definition causes a corresponding hypercall to be sent to the intermediary manager, wherein a particular hypercall function definition of the set of hypercall function definitions indicates that hypercalls corresponding to the particular hypercall function definition are to be sent to the intermediary manager, and wherein the method is performed by one or more computing devices.