Vol. 3C 30-13

VMX INSTRUCTION REFERENCE

VMFUNC—Invoke VM function

Description

This instruction allows software in VMX non-root operation to invoke a VM function, which is processor functionality 
enabled and configured by software in VMX root operation. The value of EAX selects the specific VM function being 
invoked.
The behavior of each VM function (including any additional fault checking) is specified in Section 25.5.5, 
“VM Functions”.

Operation

Perform functionality of the VM function specified in EAX;

Flags Affected

Depends on the VM function specified in EAX. See Section 25.5.5, “VM Functions”.

Protected Mode Exceptions (not including those defined by specific VM functions)

#UD

If executed outside VMX non-root operation.
If “enable VM functions” VM-execution control is 0.
If EAX ≥ 64.

Real-Address Mode Exceptions

Same exceptions as in protected mode.

Virtual-8086 Exceptions

Same exceptions as in protected mode.

Compatibility Mode Exceptions

Same exceptions as in protected mode.

64-Bit Mode Exceptions

Same exceptions as in protected mode.

Opcode

Instruction

Description

0F 01 D4

VMFUNC

Invoke VM function specified in EAX.