diff options
| author | Igor Mammedov <imammedo@redhat.com> | 2013-04-25 16:05:25 +0200 |
|---|---|---|
| committer | Andreas Färber <afaerber@suse.de> | 2013-05-01 13:04:18 +0200 |
| commit | b8622725cf0196f672f272922b0941dc8ba1c408 (patch) | |
| tree | f33cacb399cb67622dd53a98240ac7073ceb0ad4 /docs/specs | |
| parent | 69e5ff067ae724155fd7465119ee6db5721288b6 (diff) | |
acpi_piix4: Add infrastructure to send CPU hot-plug GPE to guest
* introduce processor status bitmask visible to guest at 0xaf00 addr,
where ACPI asl code expects it
* set bit corresponding to APIC ID in processor status bitmask on
receiving CPU hot-plug notification
* trigger CPU hot-plug SCI, to notify guest about CPU hot-plug event
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Diffstat (limited to 'docs/specs')
| -rw-r--r-- | docs/specs/acpi_cpu_hotplug.txt | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/docs/specs/acpi_cpu_hotplug.txt b/docs/specs/acpi_cpu_hotplug.txt new file mode 100644 index 0000000000..5dec0c5010 --- /dev/null +++ b/docs/specs/acpi_cpu_hotplug.txt @@ -0,0 +1,22 @@ +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 0xaf00-0xae1f, 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. |