Processor control register configuration support

A method comprising:

• determining, by a hypervisor, a fault resulting from a guest attempting to execute first code from a memory page designated as non-executable, wherein the first code is configured to cause a new operating system to boot from a currently-executing operating system;
• changing, by the hypervisor, a configuration of a control register associated with a processor from a locked configuration to an unlocked configuration based at least in part on the fault;
• changing, by the hypervisor, the memory page from non-executable to executable;
• receiving, by the hypervisor from the guest after execution of the first code, a hypercall indicating that the control register has been configured by the guest after booting the new operating system;
• changing, by the hypervisor, the configuration of the control register from the unlocked configuration to the locked configuration;
• and
• changing, by the hypervisor, the memory page from executable to non-executable.

A non-transitory machine readable medium storing a program, which when executed by a processor causes a hypervisor to:

• determine a fault resulting from a guest attempting to execute first code from a memory page designated as non-executable, wherein the first code is configured to cause a new operating system to boot from a currently-executing operating system;
• change a configuration of a control register associated with the processor from a locked configuration to an unlocked configuration based at least in part on the fault;
• change the memory page from non-executable to executable;
• receive a hypercall from the guest after execution of the first code, the hypercall indicating that the control register has been configured by the guest after booting the new operating system;
• change the configuration of the control register from the unlocked configuration to the locked configuration;
• and
• change the memory page from executable to non-executable.