IRQ_VECTOR
vm_install_exception_handler(vm, IRQ_VECTOR, guest_irq_handler);
APIC_DM_FIXED | IRQ_VECTOR);
static_assert(IRQ_VECTOR >= 16, "invalid IRQ vector number");
tpr = IRQ_VECTOR / 16;
vm_install_exception_handler(vm, IRQ_VECTOR,
vm_install_exception_handler(vm, IRQ_VECTOR,
x2apic_write_reg(APIC_SELF_IPI, IRQ_VECTOR);
IRQ_VECTOR;