ffac39deae
The VM generation counter is a 128-bit value exposed by the BIOS via ACPI. The value changes to another unique identifier whenever a VM is duplicated. Additionally, ACPI provides notification events when such events occur. The driver decodes the pointer to the UUID, exports the value to userspace via OPAQUE sysctl blob, and forwards the ACPI notifications in the form of an EVENTHANDLER invocation as well as userspace devctl events. See design paper: https://go.microsoft.com/fwlink/p/?LinkID=260709
48 lines
2.1 KiB
C
48 lines
2.1 KiB
C
/*-
|
|
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
|
|
*
|
|
* Copyright (c) 2019 Conrad Meyer <cem@FreeBSD.org>. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* $FreeBSD$
|
|
*/
|
|
#include <sys/_eventhandler.h>
|
|
|
|
/*
|
|
* VM Generation Counter driver
|
|
*
|
|
* This driver has two functions: first, it provides a system event (both in
|
|
* the kernel EVENTHANDLER framework as well as a userspace devctl event)
|
|
* whenever a VM has been (HyperV doc, for example):
|
|
* - Snapped and the snapshot is executing
|
|
* - Recovered from backup
|
|
* - Failed over in a HA setup
|
|
* - Imported, copied, or cloned
|
|
* - And unspecified if VM configuration changes might cause a changed
|
|
* generation counter
|
|
*
|
|
* Second, it can read the current VM generation counter, a 128-bit GUID.
|
|
*/
|
|
typedef void (*vmgenc_handler)(void *);
|
|
EVENTHANDLER_DECLARE(acpi_vmgenc_event, vmgenc_handler);
|