Method and apparatus for facilitating recognition of an open event window during operation of guest software in a virtual machine environment

A processor, comprising:

• an interrupt request pin to receive a hardware interrupt signal input;
• and
• a hardware reorder buffer (ROB) logic, connected with the hardware interrupt request pin, to receive an interrupt window state signal input, an interrupt control signal input and at least one of the hardware interrupt signal input or a pending interrupt signal input, wherein the interrupt window state signal input indicates whether an interrupt window of a VM is open, the interrupt control signal input indicates whether interrupts are controlled by a virtual machine (VM) or by a virtual machine monitor (VMM), the hardware interrupt signal input indicates that a hardware interrupt is pending, and the pending interrupt signal input indicates that a pending interrupt is ready to be delivered to the VM by the VMM;
• the ROB logic to assert a first signal output when the interrupt window state signal input indicates that the VM's interrupt window is open and the pending interrupt signal input is received, wherein the first signal output indicates that a VM exit is to be generated due to the open interrupt window.