1. A method for providing secure access control to a graphics processing unit, the method comprising: defining a plurality of security zones for controlling access to a graphics processing unit; assigning each of the security zones to a corresponding one of a plurality of GPU programming interfaces provided by the GPU, each of the GPU programming interfaces for receiving work orders issued by one or more applications associated with the corresponding security zone, the work orders comprising instructions to be executed by the GPU; and controlling execution of the work orders received by the plurality of GPU programming interfaces using separate secure memory regions, each secure memory region allocated to one of the plurality of security zones.