From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Vrabel Subject: [PATCH 6/6] xl: generate a new random VM generation ID if requested Date: Tue, 3 Jun 2014 14:15:40 +0100 Message-ID: <1401801340-6196-7-git-send-email-david.vrabel@citrix.com> References: <1401801340-6196-1-git-send-email-david.vrabel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1WroZH-0006Ck-9V for xen-devel@lists.xenproject.org; Tue, 03 Jun 2014 13:15:55 +0000 In-Reply-To: <1401801340-6196-1-git-send-email-david.vrabel@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xenproject.org Cc: David Vrabel , Ian Jackson , Ian Campbell , Stefano Stabellini List-Id: xen-devel@lists.xenproject.org If the "generation_id" option is set in the domain configuration, generate and set a new random VM generation ID every time a domain is created or restored. xl lacks the infrastructure to fully track the lifecycle of VM images as they are snapshotted and cloned (etc) so always using a new ID is the safe option and ensures that a new one will be used where it matters. Signed-off-by: David Vrabel --- docs/man/xl.cfg.pod.5 | 14 ++++++++++++++ tools/libxl/xl_cmdimpl.c | 4 ++++ 2 files changed, 18 insertions(+) diff --git a/docs/man/xl.cfg.pod.5 b/docs/man/xl.cfg.pod.5 index a94d037..b74064d 100644 --- a/docs/man/xl.cfg.pod.5 +++ b/docs/man/xl.cfg.pod.5 @@ -936,6 +936,20 @@ number of vendor defined SMBIOS structures (type 128 - 255). Since SMBIOS structures do not present their overall size, each entry in the file must be preceded by a 32b integer indicating the size of the next structure. +=item B + +Provide a VM generation ID to the guest. + +The VM generation ID as a 128-bit random number that a guest may use +to determine if the guest has been restored from an earlier snapshot, +or cloned. + +This is required for Microsoft Windows Server 2012 (and later) domain +controllers. + +See also "Virtual Machine Generation ID" by Microsoft +(http://www.microsoft.com/en-us/download/details.aspx?id=30707). + =back =head3 Guest Virtual Time Controls diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c index 5195914..a611095 100644 --- a/tools/libxl/xl_cmdimpl.c +++ b/tools/libxl/xl_cmdimpl.c @@ -1058,6 +1058,10 @@ static void parse_config_data(const char *config_source, &b_info->u.hvm.smbios_firmware, 0); xlu_cfg_replace_string(config, "acpi_firmware", &b_info->u.hvm.acpi_firmware, 0); + + /* Generate and set a new random VM Generation ID? */ + if (!xlu_cfg_get_long(config, "generation_id", &l, 0)) + libxl_uuid_generate(&b_info->u.hvm.generation_id); break; case LIBXL_DOMAIN_TYPE_PV: { -- 1.7.10.4