It is well expected that a collection of smart objects such as IoT devices dynamically form an edge cloud allowing acquiring, storing, communicating, and processing of information done at the edge of the network. Edge cloud workers (i.e. IoT devices) usually have service specific characteristics while legacy cloud workers are more computing oriented. However, existing cloudlet architectures continue to take their allocation policy centered around computation resource virtualization without considering such characteristics of edge IoT clouds. In order to provide service specific QoS driven virtualization of an edge IoT cloud, which we call semantic virtualization, a new approach is required. In this paper, we investigate research issues and directions for realizing semantic virtualization for an edge IoT cloud.