qemu/docs/specs/acpi_cpu_hotplug.txt
Anthony PERARD 314b5d4bb6 docs: Fix IO port number for CPU present bitmap.
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewd-By: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-09-20 20:09:24 +04:00

23 lines
836 B
Plaintext

QEMU<->ACPI BIOS CPU hotplug interface
--------------------------------------
QEMU supports CPU hotplug via ACPI. 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 2 (GPE.2) used to notify CPU
hot-add/remove event to ACPI BIOS, via SCI interrupt.
CPU present bitmap (IO port 0xaf00-0xaf1f, 1-byte access):
---------------------------------------------------------------
One bit per CPU. Bit position reflects corresponding CPU APIC ID.
Read-only.
CPU hot-add/remove notification:
-----------------------------------------------------
QEMU sets/clears corresponding CPU bit on hot-add/remove event.
CPU present map read by ACPI BIOS GPE.2 handler to notify OS of CPU
hot-(un)plug events.