A hypervisor receives a request pertaining to a multi-function device managed by the hypervisor from a guest operating system of a virtual machine where the multi-function device comprises a main function and a plurality of sub-functions and the request identifies an address within a configuration space associated with one of the plurality of sub-functions of the multi-function device. The hypervisor determines the main function of the multi-function device in view of the address of the configuration space associated with the sub-function, accesses a data structure associated with the main function to obtain an indicator of availability of the main function to the guest operating system, and determines, view of the indicator of availability, whether the main function is available to the guest operating system. Responsive to determining that the main function is not available, the hypervisor rejects the request from the guest operating system to access the address within the configuration space associated with the sub-function.