Dynamic virtual machine function enabling

A method performed by a computing system, the method comprising:

• while in a context of a guest managed by a hypervisor of the computing system, requesting execution of a first VMFUNC instruction;
• determining that VMFUNC ability is in a disabled state;
• exiting the context of the guest in response to detecting the requesting execution of the first VMFUNC instruction while the VMFUNC ability is in the disabled state;
• while out of the context of the guest, validating a page table that maps guest virtual addresses to guest physical addresses;
• and
• after validating the page table, switching the VMFUNC ability to an enabled state.

A system comprising:

• a processor;
• and
• memory comprising machine readable instructions that comprise a hypervisor configured to manage a number of guests, wherein a guest of the number of guests is configured to:
• request execution of a virtual machine function instruction, the virtual machine function instruction allowing the guest to access a protected portion of memory without exiting a context of the guest;
• determine that virtual machine function ability is in a disabled state;
• exiting a context of the guest in response to detecting the request for execution of the first virtual machine function instruction while the virtual machine function ability is in the disabled state;
• after a page table that maps guest virtual addresses to guest physical addresses has been validated, determining that the virtual machine function ability is enabled;
• and
• in response to determining that the virtual machine function ability is in an enabled state, executing a virtual machine function instruction.