summaryrefslogtreecommitdiffstats
path: root/qemu/docs/specs/acpi_pci_hotplug.txt
blob: a839434f313d4320c0e94ba289f343b67797e9d2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
QEMU<->ACPI BIOS PCI hotplug interface
--------------------------------------

QEMU supports PCI hotplug via ACPI, for PCI bus 0. This document
describes the interface between QEMU and the ACPI BIOS.

ACPI GPE block (IO ports 0xafe0-0xafe3, byte access):
-----------------------------------------

Generic ACPI GPE block. Bit 1 (GPE.1) used to notify PCI hotplug/eject
event to ACPI BIOS, via SCI interrupt.

PCI slot injection notification pending (IO port 0xae00-0xae03, 4-byte access):
---------------------------------------------------------------
Slot injection notification pending. One bit per slot.

Read by ACPI BIOS GPE.1 handler to notify OS of injection
events.  Read-only.

PCI slot removal notification (IO port 0xae04-0xae07, 4-byte access):
-----------------------------------------------------
Slot removal notification pending. One bit per slot.

Read by ACPI BIOS GPE.1 handler to notify OS of removal
events.  Read-only.

PCI device eject (IO port 0xae08-0xae0b, 4-byte access):
----------------------------------------

Write: Used by ACPI BIOS _EJ0 method to request device removal.
One bit per slot.

Read: Hotplug features register.  Used by platform to identify features
available.  Current base feature set (no bits set):
 - Read-only "up" register @0xae00, 4-byte access, bit per slot
 - Read-only "down" register @0xae04, 4-byte access, bit per slot
 - Read/write "eject" register @0xae08, 4-byte access,
   write: bit per slot eject, read: hotplug feature set
 - Read-only hotplug capable register @0xae0c, 4-byte access, bit per slot

PCI removability status (IO port 0xae0c-0xae0f, 4-byte access):
-----------------------------------------------

Used by ACPI BIOS _RMV method to indicate removability status to OS. One
bit per slot.  Read-only