From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42676) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z1xeh-00046o-EW for qemu-devel@nongnu.org; Mon, 08 Jun 2015 10:04:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z1xec-0004Ey-Mf for qemu-devel@nongnu.org; Mon, 08 Jun 2015 10:03:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39815) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z1xec-0004Es-Hl for qemu-devel@nongnu.org; Mon, 08 Jun 2015 10:03:54 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (Postfix) with ESMTPS id 35D7619CF8E for ; Mon, 8 Jun 2015 14:03:54 +0000 (UTC) Message-ID: <5575A10D.1050806@redhat.com> Date: Mon, 08 Jun 2015 17:05:01 +0300 From: Gal Hammer MIME-Version: 1.0 References: <1430133591-6197-1-git-send-email-ghammer@redhat.com> <1430133591-6197-5-git-send-email-ghammer@redhat.com> <556F2D51.2000203@redhat.com> <55759BB8.3010604@redhat.com> <55759C1B.7000905@redhat.com> <55759E0A.3090102@redhat.com> <55759EC2.5090802@redhat.com> <20150608135854.GC19157@redhat.com> In-Reply-To: <20150608135854.GC19157@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH V15 4/5] i386: add a Virtual Machine Generation ID device List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" , Paolo Bonzini Cc: imammedo@redhat.com, qemu-devel@nongnu.org, mst@redhat.com On 08/06/2015 16:58, Daniel P. Berrange wrote: > On Mon, Jun 08, 2015 at 03:55:14PM +0200, Paolo Bonzini wrote: >> >> >> On 08/06/2015 15:52, Gal Hammer wrote: >>>>> 2. Is it possible to create a sysbus device using the "-device" command >>>>> line argument? I vaguely recall that it is not possible to do it and >>>>> that's the reason that I specifically add the device in the pc init. >>>> >>>> It's now possible, but it is somewhat complicated. I think it's simpler >>>> to initialize this unconditionally and hide it (via ACPI _STA) if the >>>> vmgenid is all zeros. >>> >>> I didn't understand. I need the device to be a sysbus device so it won't >>> be found as an ISA or a PCI device by Windows. So I need to know what >>> ever or not it is possible to create a sysbus device using "-device". In >>> either way it won't be created if vmgenid is not given so no need to >>> hide it using _STA. >> >> Windows doesn't enumerate ISA devices when you create them with -device. >> It just enumerates devices from the ACPI DSDT/SSDT. So it's okay to >> make it an ISADevice, or to make it a part of another device (e.g. the >> ISA bridge or the power management device). It's still ugly though. >> >> If you make it a sysbus device, you can just add it unconditionally, and >> define _STA so that Windows only sees it under the appropriate >> circumstances: for example, return 0 from _STA if the vmgenid (from the >> command line) is all zeroes. >> >> What is the command line option like? Is it "-global vmgenid.uuid=foo"? > > FWIW, although the spec for this feature comes from Windows/Microsoft, > I'd expect that when we enable it in libvirt, we'll want to make it > unconditionally available to all VMs, since its a generically useful > information source for guest OS'. Once qemu part will be completed it will be possible to add a module to Linux as well (and maybe use it as a RNG generator source too). Gal. > Regards, > Daniel >