Techniques for utilizing processor cores include sequestering processor cores for use independently from an operating system. In at least one embodiment of the invention, a method includes executing an operating system on a first subset of cores including one or more cores of a plurality of cores of a computer system. The operating system executes as a guest under control of a virtual machine monitor. The method includes executing work for an application on a second subset of cores including one or more cores of the plurality of cores. The first and second subsets of cores are mutually exclusive and the second subset of cores is not visible to the operating system. In at least one embodiment, the method includes sequestering the second subset of cores from the operating system.