With the pervasion of cloud computing, virtual enterprises (VEs) are anticipated to increasingly rely on ecosystems of highly distributed, task-oriented, and collaborative cloud services for their operations. In order to manage the complexity inherent in such ecosystems, VEs are expected to increasingly depend upon policies that regulate the deployment and delivery of these services. Nevertheless, the heterogeneity inherent in cloud services hinders the formulation of effective and interoperable such policies. This calls for a policy validation mechanism that is able to automatically evaluate the correctness of these policies. This paper proposes such a validation mechanism, one which is underpinned by a generic representation of the knowledge that lurks behind policies and thus is orthogonal to any particular cloud service delivery platform.