blob: 12909940ccded731e96b283d8fb5a65c40eb7be4 (
plain) (
tree)
|
|
QEMU<->ACPI BIOS memory hotplug interface
--------------------------------------
ACPI BIOS GPE.3 handler is dedicated for notifying OS about memory hot-add
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.
|
