METHODS AND APPARATUS FOR FAST CONTEXT SWITCHING IN A VIRTUALIZED SYSTEM

The present disclosure provides methods and apparatus for fast context switching in a virtualized system. In the disclosed system, a globally unique application-space identifier is associated with each guest application. No two applications share the same application-space identifier, even if the two applications reside in different virtual machines. Domain identifiers are used to ensure that a guest's mappings are only active when that guest is executing. A unique domain identifier is associated with each virtual machine, and all translation lookaside buffer entries thereby mapping the guest's kernel pages with that domain value. All other mappings are tagged with a predefined domain such as zero. In addition, a virtual memory management unit may be configured to support two virtual page table pointers and a configurable boundary between a virtual user page table and a virtual kernel page table. In such an instance, the two virtual page table pointers are presented to a guest operating system, and two physical page table pointers are associated with the two virtual page table pointers.