Cyber–Physical–Social–System (CPSS) relies on cloud and edge computing for service deployment and acceleration. As an enabling technology of CPSS, network virtualization allows different services to be deployed on a single physical server and provides them with differentiated network performance based on service-level-agreement (SLA). Unfortunately, current virtual switches (vSwitches) cannot guarantee this functionality due to the common resource competition and unpredictable processing capacity. As a software process on the server, vSwitch is allocated limited dedicated CPU cores to implement traffic forwarding for all services. But the QoS strategy inheriting from the hardware switch, does not consider the forwarding tasks’ competition for CPU cores in terms of utilization and timing, thus cannot guarantee the SLA. To solve this critical issue, we propose a CPU-cycle based QoS (C2QoS) strategy to realize the isolation and guarantee of service network performance by managing the usage and scheduling of the IO-dedicated CPU cores in vSwitch. C2QoS includes a CPU-cycle based token bucket mechanism to strictly limit service’s network bandwidth and a hierarchical batch scheduling mechanism to achieve hierarchical latency. Experimental results show that, compared with existing strategies, C2QoS can strictly guarantee the network bandwidth of the services and reduce the service latency by up to 80%.