From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45202) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cTXpH-0002ub-Ae for qemu-devel@nongnu.org; Tue, 17 Jan 2017 12:45:44 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cTXpE-00048w-3T for qemu-devel@nongnu.org; Tue, 17 Jan 2017 12:45:43 -0500 Received: from mx1.redhat.com ([209.132.183.28]:49172) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cTXpD-00048N-Nf for qemu-devel@nongnu.org; Tue, 17 Jan 2017 12:45:39 -0500 Date: Tue, 17 Jan 2017 19:45:32 +0200 From: "Michael S. Tsirkin" Message-ID: <20170117194321-mutt-send-email-mst@kernel.org> References: <20160916033402-mutt-send-email-mst@kernel.org> <20161006041949-mutt-send-email-mst@kernel.org> <20161211052355-mutt-send-email-mst@kernel.org> <20170116161857-mutt-send-email-mst@kernel.org> <85C3D50B-7AFD-41E7-AD1B-634A42D04BB2@skyportsystems.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <85C3D50B-7AFD-41E7-AD1B-634A42D04BB2@skyportsystems.com> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] Virtual Machine Generation ID List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Ben Warren Cc: Ed Swierk , qemu-devel@nongnu.org, Igor Mammedov , Laszlo Ersek On Mon, Jan 16, 2017 at 10:57:42AM -0800, Ben Warren wrote: > I think we have a misunderstanding here. I=E2=80=99m storing the VM > Generation ID __data__ (a GUID) in a fw_cfg blob, not the address. Yes, I think I gathered this much from the discussion. This is what I'm saying - don't. Have guest loader reserve guest memory and write the address into a fw cfg blob, and have qemu write the id at that address. This way you can update guest memory at any time. --=20 MST