On Mon, Apr 27, 2015 at 02:19:47PM +0300, Gal Hammer wrote: > Signed-off-by: Gal Hammer <gham...@redhat.com> > --- > docs/specs/vmgenid.txt | 35 +++++++++++++++++++++++++++++++++++ > 1 file changed, 35 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..86ce6ab > --- /dev/null > +++ b/docs/specs/vmgenid.txt > @@ -0,0 +1,35 @@ > +VIRTUAL MACHINE GENERATION ID > +============================= > + > +Copyright (C) 2014 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 > +exposes a 128-bit, cryptographically random, integer value identifier. > +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 sysbus device with the following ACPI ID: > +"QEMU0002". > + > +The device adds a "vmgenid.uuid" property, which can be modified using > +the -global command line argument or the QMP interface. > + > +The device uses a fixed memory resource: 0xfedf0000-0xfedf000f to store > +the GUID's buffer. > + > +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. > + > +Although not specified in Microsoft's document, it is assumed that the > +device is expected to use the little-endian system.
host? guest? Please fix that. UUID is just a byte array, no need to assume endian-ness anywhere. > -- > 2.1.0
