Interrupts

The purpose of this page is to document how Xen set up and uses interrupts. It is a work in progress, and to a certain extent dynamic as patches modify the code. However, the contents of it is accurate of 14/11/2011

IDT vector entries

Refer to xen/include/asm-x86/mach-default/irq_vectors.h

Vector Ranges

Section	Range	Use
Exceptions	0x00 - 0x1f	Architecturally reserved
Dynamic IRQs	0x20 - 0xdf	Free for assignment for devices
Legacy	0xe0 - 0xef	Reserved range for PIC before switching to APIC
High Priority	0xf0 - 0xff	For IPIs and serial interrupts

Specific Vectors

Vector	Symbol	Description
0x20	IRQ_MOVE_CLEANUP_VECTOR	Clean up references to IRQs in past PCPUs after they have been moved
0x80	LEGACY_SYSCALL_VECTOR
0x82	HYPERCALL_VECTOR
0xf7	CMCI_APIC_VECTOR
0xf8	PMU_APIC_VECTOR
0xf9	LOCAL_TIMER_VECTOR
0xfa	THERMAL_APIC_VECTOR
0xfb	CALL_FUNCTION_VECTOR
0xfc	EVENT_CHECK_VECTOR
0xfd	INVALIDATE_TLB_VECTOR
0xfe	ERROR_APIC_VECTOR
0xff	SPURIOUS_APIC_VECTOR