1. A network interface controller (NIC) to couple to a host computing device, the NIC comprising: a host interface to couple to the host computing device; a hybrid software-defined networking (SDN) controller implemented in circuitry of the NIC and configured to perform at least one SDN control function to reduce SDN processing load on the host computing device, the hybrid SDN controller comprising: a service abstraction layer module (SAL); a network stack; and a southbound application programming interface (SB API); wherein: the SAL is configured, in response to a request including a change in configuration of a physical network, to provide a simulated representation of the physical network based at least in part on the network stack and the change in configuration included in the request, to execute testing utilizing the simulated representation of the physical network, and to expose the simulated representation of the physical network to the host computing device as an actual representation of the physical network.