mirror of
https://github.com/xemu-project/xemu.git
synced 2024-11-24 03:59:52 +00:00
3ef77acab2
- implements QEMU hardware part of memory hotplug protocol described at "docs/specs/acpi_mem_hotplug.txt" - handles only memory add notification event for now Signed-off-by: Igor Mammedov <imammedo@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
45 lines
2.0 KiB
Plaintext
45 lines
2.0 KiB
Plaintext
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.
|