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| author | fishsoupisgood <github@madingley.org> | 2019-04-29 01:17:54 +0100 |
|---|---|---|
| committer | fishsoupisgood <github@madingley.org> | 2019-05-27 03:43:43 +0100 |
| commit | 3f2546b2ef55b661fd8dd69682b38992225e86f6 (patch) | |
| tree | 65ca85f13617aee1dce474596800950f266a456c /docs/specs/acpi_cpu_hotplug.txt | |
| download | qemu-master.tar.gz qemu-master.tar.bz2 qemu-master.zip | |
Diffstat (limited to 'docs/specs/acpi_cpu_hotplug.txt')
| -rw-r--r-- | docs/specs/acpi_cpu_hotplug.txt | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/docs/specs/acpi_cpu_hotplug.txt b/docs/specs/acpi_cpu_hotplug.txt new file mode 100644 index 00000000..340b751a --- /dev/null +++ b/docs/specs/acpi_cpu_hotplug.txt @@ -0,0 +1,24 @@ +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 for: + ICH9-LPC (IO port 0x0cd8-0xcf7, 1-byte access) + PIIX-PM (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. |