Signed-off-by: Gal Hammer <gham...@redhat.com> --- docs/specs/vmgenid.txt | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 docs/specs/vmgenid.txt
diff --git a/docs/specs/vmgenid.txt b/docs/specs/vmgenid.txt new file mode 100644 index 0000000..d06977a --- /dev/null +++ b/docs/specs/vmgenid.txt @@ -0,0 +1,33 @@ +VIRTUAL MACHINE GENERATION ID +============================= + +Copyright (C) 2015 Red Hat, Inc. + +This work is licensed under the terms of the GNU GPL, version 2 or later. +See the COPYING file in the top-level directory. + +=== + +The VM generation ID (vmgenid) device is an emulated device which +is expected to exposes a 128-bit, cryptographically random, integer value +identifier, provided by a management system (It is NOT in the device's +responsibilty to ensure that the value is cryptographically random). + +This allows management applications (e.g. libvirt) to notify the guest +operating system when the virtual machine is executed with a different +configuration (e.g. snapshot execution or creation from a template). + +This is specified on the web at: http://go.microsoft.com/fwlink/?LinkId=260709 + +--- + +The vmgenid device is a device with the following ACPI ID: "QEMU0002". + +It has two properties: + +uuid - The virtual machine generation ID (A required UUID string) +addr - The uuid memory location (A 64-bit address, defaults to 0xfedf0000) + +According to the specification, any change to the GUID executes an +ACPI notification. The vmgenid device triggers the GPE._E00 which +executes the ACPI Notify operation. -- 2.1.0
