From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54854) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z1zDf-0004ia-Ir for qemu-devel@nongnu.org; Mon, 08 Jun 2015 11:44:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z1zDX-0004Av-SY for qemu-devel@nongnu.org; Mon, 08 Jun 2015 11:44:11 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49270) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z1zDX-0004AG-NM for qemu-devel@nongnu.org; Mon, 08 Jun 2015 11:44:03 -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 4778C19F244 for ; Mon, 8 Jun 2015 15:44:03 +0000 (UTC) Message-ID: <5575B83F.8000903@redhat.com> Date: Mon, 08 Jun 2015 17:43:59 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <556F2D51.2000203@redhat.com> <55759BB8.3010604@redhat.com> <55759C1B.7000905@redhat.com> <55759E0A.3090102@redhat.com> <55759EC2.5090802@redhat.com> <20150608135854.GC19157@redhat.com> <20150608165951-mutt-send-email-mst@redhat.com> <5575B20B.9000502@redhat.com> <20150608171921-mutt-send-email-mst@redhat.com> <5575B5BF.40401@redhat.com> <20150608174021-mutt-send-email-mst@redhat.com> In-Reply-To: <20150608174021-mutt-send-email-mst@redhat.com> Content-Type: text/plain; charset=windows-1252 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: "Michael S. Tsirkin" Cc: Gal Hammer , imammedo@redhat.com, qemu-devel@nongnu.org On 08/06/2015 17:41, Michael S. Tsirkin wrote: > > > Adding it by default for everyone still seems too aggressive. > > > We had a ton of pain with pvpanic exactly because of a > > > similar "can't hurt" approach. > > > > The ton of pain was due to enabling it in ACPI unconditionally. We can > > leave it disabled in the UUID is all zeroes, for example. > > Not if libvirt insists on adding a non zero uuid to all VMs > unconditionally. This is what I was arguing against really. That would be a libvirt bug. The VM UUID in SMBIOS and is different from the vmgenid UUID. Paolo