2014-06-02 15:25:16 +02:00
|
|
|
|
QEMU<->ACPI BIOS memory hotplug interface
|
|
|
|
|
--------------------------------------
|
|
|
|
|
|
|
|
|
|
ACPI BIOS GPE.3 handler is dedicated for notifying OS about memory hot-add
|
2015-04-27 10:47:15 +02:00
|
|
|
|
and hot-remove events.
|
2014-06-02 15:25:16 +02:00
|
|
|
|
|
|
|
|
|
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:
|
2015-04-27 10:47:20 +02:00
|
|
|
|
0: reserved, OSPM must clear it before writing to register.
|
|
|
|
|
Due to BUG in versions prior 2.4 that field isn't cleared
|
|
|
|
|
when other fields are written. Keep it reserved and don't
|
|
|
|
|
try to reuse it.
|
2014-06-02 15:25:16 +02:00
|
|
|
|
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.
|
2015-04-27 10:47:15 +02:00
|
|
|
|
|
|
|
|
|
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 |
|
|
|
|
|
+------------------+ | |
|
|
|
|
|
+-------------------+
|