Before we start tweaking and enhancing hardware, I think it makes sense to document what we currently have, to make sure we stay compatible. This documents the hotplug interface for piix. Stubs for cpu hotplug, PM.
Signed-off-by: Michael S. Tsirkin <m...@redhat.com> --- docs/acpi.txt | 32 ++++++++++++++++++++++++++++++++ 1 files changed, 32 insertions(+), 0 deletions(-) create mode 100644 docs/acpi.txt diff --git a/docs/acpi.txt b/docs/acpi.txt new file mode 100644 index 0000000..4938d48 --- /dev/null +++ b/docs/acpi.txt @@ -0,0 +1,32 @@ +QEMU exposes the following registers to guests, +intended primarily for use by the ACPI interface. + +PCI Hotplug +---- + +Events use the standard GPE register: +GPE 0xafe0 - an ACPI GPE register + +Hotplug events set GPE bit 1 (mask 0x2) + +The following registers are used for PCI hotplug. +Each register is 32 bit (4 bytes) long, and has little endian format. +Bits 0-31 in each register correspond to slots 0-31 on the root bus, +respectively. + +UP 0xae00 - RO - Bit set by host on device insertion (note:existing implementations + trigger device check event) +DOWN 0xae04 - RO - Bit set by host on user eject request +EJ0 0xae08 - WO - Bit set by guest removes all power to device +RMV 0xae0c - RO - Bit set by host if slot supports hotplug + (can not change while guest is up) + + +Power management +---- +TODO + + +CPU hotplug +---- +TODO -- 1.7.9.111.gf3fb0
