1. At a computer system including one or more processors and system memory, the computer system also including a physical graphics processing unit (“GPU”), a method for providing a programmable GPU pipeline to a guest application executing in a child partition of a para-virtualized execution environment, the method comprising: an act of instantiating a virtual machine session, including instantiating a hypervisor that provides (i) a root partition having access to the physical GPU, and (ii) the child partition which executes the guest application; an act of presenting a virtualized graphics processing unit (“vGPU”) to the guest application, the vGPU executing within the child partition, including presenting a plurality of device driver interfaces (“DDIs”) of a rendering framework to the guest application as part of a user-mode driver (“UMD”) of the vGPU, the plurality of DDIs providing an application programming interface that enables the guest application to send commands to the vGPU for programming a GPU pipeline of the physical GPU to utilize one or more features of the rendering framework, including utilizing at least one of: a domain shader, a hull shader, or a geometric shader; and an act of a render component executing within the root partition receiving at least one physical GPU-specific command from the vGPU for using one or more of a domain shader, a hull shader, or a geometric shader at the physical GPU; and an act of the render component scheduling the at least one physical GPU-specific command for execution at the physical GPU.