From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47087) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YTFPz-0006Hm-Fk for qemu-devel@nongnu.org; Wed, 04 Mar 2015 14:57:21 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YTFPw-00009J-A5 for qemu-devel@nongnu.org; Wed, 04 Mar 2015 14:57:19 -0500 Received: from mx1.redhat.com ([209.132.183.28]:50312) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YTFPw-000099-2J for qemu-devel@nongnu.org; Wed, 04 Mar 2015 14:57:16 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t24JvFFa032676 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Wed, 4 Mar 2015 14:57:15 -0500 Message-ID: <54F7639A.7000203@redhat.com> Date: Wed, 04 Mar 2015 12:57:14 -0700 From: Eric Blake MIME-Version: 1.0 References: <1425399495-13664-1-git-send-email-imammedo@redhat.com> <1425399495-13664-2-git-send-email-imammedo@redhat.com> In-Reply-To: <1425399495-13664-2-git-send-email-imammedo@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="BCo7lHu2sWVAvvEfTGpF1lh2nfuPADAbr" Subject: Re: [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: Igor Mammedov , qemu-devel@nongnu.org Cc: ghammer@redhat.com, mst@redhat.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --BCo7lHu2sWVAvvEfTGpF1lh2nfuPADAbr Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 03/03/2015 09:18 AM, Igor Mammedov wrote: > From: Gal Hammer >=20 > Signed-off-by: Gal Hammer > Signed-off-by: Igor Mammedov > --- > v2: > - ammend doc since no more MMIO occupied by vmgenid s/ammend/amend/ (but this isn't part of the commit message) > device and device became PCIDevice > --- > docs/specs/vmgenid.txt | 36 ++++++++++++++++++++++++++++++++++++ > 1 file changed, 36 insertions(+) > create mode 100644 docs/specs/vmgenid.txt >=20 > 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 > +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D > + > +Copyright (C) 2014 Red Hat, Inc. Might also want to claim 2015, as you have redesigned this since 2014. > + > +This work is licensed under the terms of the GNU GPL, version 2 or lat= er. > +See the COPYING file in the top-level directory. > + > +=3D=3D=3D > + > +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). It sounds like management applications (and not qemu) is responsible for populating the 128 bits with cryptographically random data. That is, if libvirt fails to put truly random data in the memory via qom-set, the bug would be in libvirt and not qemu. Correct? If so, should this doc make it explicit that qemu is leaving it up to management to write correct data into the memory? > + > +This is specified on the web at: http://go.microsoft.com/fwlink/?LinkI= d=3D260709 How sure are we that this link won't go stale in the future? Should we archive a copy of it somewhere on a site we control? > + > +--- > + > +The vmgenid device is a PCI device with the following ACPI ID: "QEMU00= 03". > + > +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=3DFOO,uuid=3D"324e6eaf-d1d1-4bf6-bf41-b9bb6c9= 1fb87" > + > +Or to change uuid in runtime use: > + qom-set "/machine/peripheral/FOO.uuid" "124e6eaf-d1d1-4bf6-bf41-b9bb6= c91fb87" > + > +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. >=20 --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --BCo7lHu2sWVAvvEfTGpF1lh2nfuPADAbr Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBCAAGBQJU92OaAAoJEKeha0olJ0Nqpg4H/1yFGWUNYiQHdJG6KVKf8PMn jru/RD0v9e/ghm+Rz5XpOOCj1Gg4PIUM/vMEktP0yog0eBcl9mZp04J5nnYL4Xz5 fQHgCO4LX9EQkf48BxGM+C98JIyWF5IBmS5qlH46Phg30+adfxvliIYFXBpgI+7T ygf2sfAK9fru1TIb60tvZTNCPeMDLlWZtwVrswWRyJ/9MAKmqiSVOm0ges/qxxPL hY+jjHeRbngjwt6qgfCPgPajOZTBQ7ro3Be4juoivM9q8SW3BEprRzVF05Ymh8k5 3UpNmZI370ItFQikYGgOVwGThTDhp9iit6ISk81iR2oZPPaP85W8YrpzQqX6MoM= =jn1V -----END PGP SIGNATURE----- --BCo7lHu2sWVAvvEfTGpF1lh2nfuPADAbr--