Energy Internet (EI) is a revolution of power systems due to its flexible energy control. The smart meters are the key components in EI which perform real-time monitoring and require high demands on quality of services (QoSs). Besides, due to the great performance on resolving device-interconnecting and realising overall network control, software-defined networks (SDNs) are considered as a trend for future EI. However, most existing software-defined EI have all the data processed at SDN controller which makes it difficult to realise fine-grained and deep edge computation and control. Meanwhile, most existing QoS provisioning cannot provide satisfying service for EI because various metering data from smart meters require different time-variant QoS guarantees. To address above challenges, the authors propose a software-defined dynamic QoS provisioning for smart metering in EI using fog computing and network calculus (NC). First, a software-defined EI architecture, where fogs are deployed on smart meters and base stations to realise edge services, is proposed to perform deep edge control in EI. Second, the software-defined dynamic QoS provisioning based on NC theory is proposed to guarantee QoS. Simulations of latency as well as bandwidth utilisation show the advantages of the proposed scheme.