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GITS_UMSIR

GITS_UMSIR, ITS Unmapped MSI register

The GITS_UMSIR characteristics are:

Purpose

Provides the DeviceID and EventID of the unmapped MSI that set GITS_STATUSR.UMSI.

Configuration

This register is present only when GITS_TYPER.UMSI == 1. Otherwise, direct accesses to GITS_UMSIR are RES0.

Attributes

GITS_UMSIR is a 64-bit register.

Field descriptions

63	62	61	60	59	58	57	56	55	54	53	52	51	50	49	48	47	46	45	44	43	42	41	40	39	38	37	36	35	34	33	32
31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
DeviceID
EventID

DeviceID, bits [63:32]

DeviceID of MSI that set GITS_STATUSR.UMSI to 1.

If GITS_STATUSR.UMSI is 0, this field is UNKNOWN.

EventID, bits [31:0]

EventID of MSI that set GITS_STATUSR.UMSI to 1.

If GITS_STATUSR.UMSI is 0, this field is UNKNOWN.

Accessing GITS_UMSIR

GITS_UMSIR can be accessed through the memory-mapped interfaces:

Component	Offset	Instance
GIC ITS control	0x0048	GITS_UMSIR

Accesses to this register are RO.

2026-03-12 12:23:09, 2025-09_rel_asl1