blob: dcc480891862eb26f264ea5ffa77298fe00020cc (
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
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
|
QEMU<->ACPI BIOS memory hotplug interface
--------------------------------------
ACPI BIOS GPE.3 handler is dedicated for notifying OS about memory hot-add
and hot-remove events.
Memory hot-plug interface (IO port 0xa00-0xa17, 1-4 byte access):
---------------------------------------------------------------
0xa00:
read access:
[0x0-0x3] Lo part of memory device phys address
[0x4-0x7] Hi part of memory device phys address
[0x8-0xb] Lo part of memory device size in bytes
[0xc-0xf] Hi part of memory device size in bytes
[0x10-0x13] Memory device proximity domain
[0x14] Memory device status fields
bits:
0: Device is enabled and may be used by guest
1: Device insert event, used to distinguish device for which
no device check event to OSPM was issued.
It's valid only when bit 1 is set.
2-7: reserved and should be ignored by OSPM
[0x15-0x17] reserved
write access:
[0x0-0x3] Memory device slot selector, selects active memory device.
All following accesses to other registers in 0xa00-0xa17
region will read/store data from/to selected memory device.
[0x4-0x7] OST event code reported by OSPM
[0x8-0xb] OST status code reported by OSPM
[0xc-0x13] reserved, writes into it are ignored
[0x14] Memory device control fields
bits:
0: reserved, OSPM must clear it before writing to register
1: if set to 1 clears device insert event, set by OSPM
after it has emitted device check event for the
selected memory device
2-7: reserved, OSPM must clear them before writing to register
Selecting memory device slot beyond present range has no effect on platform:
- write accesses to memory hot-plug registers not documented above are
ignored
- read accesses to memory hot-plug registers not documented above return
all bits set to 1.
Memory hot remove process diagram:
----------------------------------
+-------------+ +-----------------------+ +------------------+
| 1. QEMU | | 2. QEMU | |3. QEMU |
| device_del +---->+ device unplug request +----->+Send SCI to guest,|
| | | cb | |return control to |
+-------------+ +-----------------------+ |management |
+------------------+
+---------------------------------------------------------------------+
+---------------------+ +-------------------------+
| OSPM: | remove event | OSPM: |
| send Eject Request, | | Scan memory devices |
| clear remove event +<-------------+ for event flags |
| | | |
+---------------------+ +-------------------------+
|
|
+---------v--------+ +-----------------------+
| Guest OS: | success | OSPM: |
| process Ejection +----------->+ Execute _EJ0 method, |
| request | | set eject bit in flags|
+------------------+ +-----------------------+
|failure |
v v
+------------------------+ +-----------------------+
| OSPM: | | QEMU: |
| set OST event & status | | call device unplug cb |
| fields | | |
+------------------------+ +-----------------------+
| |
v v
+------------------+ +-------------------+
|QEMU: | |QEMU: |
|Send OST QMP event| |Send device deleted|
| | |QMP event |
+------------------+ | |
+-------------------+
|
