Cloud simulation studies are realized by the combination of different tools and services. Currently, these tools cannot be easily combined and designers do not have full control over the experiments. This paper introduces Cloud Simulation Mashups (CSM), a framework for creating mashups of simulation models, data, and algorithms that give the designer full control over the simulation studies. This research framework is currently being implemented in a domain-specific language (DSL) in Python and we have demonstrated its feasibility using two industrial-strength tools and the deployment in the cloud.