Microprocessor system for virtual machine execution

A processor, comprising:

• first control registers supporting a privileged root operating mode and an unprivileged root operating mode, where the first control registers form a root privileged context defining execution permissions, and are accessible only in the privileged root operating mode;
• and
• second control registers supporting a privileged guest operating mode and an unprivileged guest operating mode, where the second control registers form a guest privileged context defining execution permissions, and are accessible only in the privileged guest operating mode and the privileged root operating mode;
• and
• wherein both the guest privileged context and the root privileged context and associated execution permissions are simultaneously active during program execution in guest operating modes to support virtualization of hardware resources without a context switch to or from memory, such that multiple operating systems supporting multiple applications are executed by the hardware resources, and such that an interrupt or exception typically causing exits from a guest operating mode is handled using the guest privileged context without additional context switching.