From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55324) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YSqRG-0005rx-IB for qemu-devel@nongnu.org; Tue, 03 Mar 2015 12:17:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YSqR9-0001uY-HR for qemu-devel@nongnu.org; Tue, 03 Mar 2015 12:16:58 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38338) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YSqR9-0001u8-9w for qemu-devel@nongnu.org; Tue, 03 Mar 2015 12:16:51 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t23HGoTL022461 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Tue, 3 Mar 2015 12:16:50 -0500 From: Igor Mammedov Date: Tue, 3 Mar 2015 17:18:13 +0100 Message-Id: <1425399495-13664-2-git-send-email-imammedo@redhat.com> In-Reply-To: <1425399495-13664-1-git-send-email-imammedo@redhat.com> References: <1425399495-13664-1-git-send-email-imammedo@redhat.com> Subject: [Qemu-devel] [PATCH V14 1/3] docs: vm generation id device's description List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: ghammer@redhat.com, mst@redhat.com From: Gal Hammer Signed-off-by: Gal Hammer Signed-off-by: Igor Mammedov --- v2: - ammend doc since no more MMIO occupied by vmgenid device and device became PCIDevice --- docs/specs/vmgenid.txt | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 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..718850a --- /dev/null +++ b/docs/specs/vmgenid.txt @@ -0,0 +1,36 @@ +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 PCI device with the following ACPI ID: "QEMU0003". + +The device has a "vmgenid.uuid" property, which can be set using +the command line argument or the QMP interface. +For example: +QEMU -device vmgenid,id=FOO,uuid="324e6eaf-d1d1-4bf6-bf41-b9bb6c91fb87" + +Or to change uuid in runtime use: + qom-set "/machine/peripheral/FOO.uuid" "124e6eaf-d1d1-4bf6-bf41-b9bb6c91fb87" + +According to the specification, any change to the GUID executes an +ACPI notification. The vmgenid device triggers the \_GPE._E00 handler +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. -- 2.1.0