From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.61]) by mx.groups.io with SMTP id smtpd.web10.13383.1583152347914375086 for ; Mon, 02 Mar 2020 04:32:28 -0800 Authentication-Results: mx.groups.io; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=Bf28i1pJ; spf=pass (domain: redhat.com, ip: 205.139.110.61, mailfrom: dgilbert@redhat.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1583152347; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=7ZYlFsjgZkWhr6ABExReOoPa5md/+qAKcLtQu3csC/w=; b=Bf28i1pJxGT9RS8C8/y1QTTHJQU9e3Pn7PX0G+0XIiiIpa9/ksaAPTLw2oDfRzof+wdGSo 9bvKrmwInhdwGVM5yS8P+fZerbPNqvoprXulzZudFEE2Gi2eQ9KsSM8rFGsIDRG0ZHZZ1L 0R9F6BMCkI7wlJtXqeAo6xVmqO1BIhI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-296-ZKdfylv9MG-_YRDxcWGe7A-1; Mon, 02 Mar 2020 07:32:25 -0500 X-MC-Unique: ZKdfylv9MG-_YRDxcWGe7A-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A1D35800D6C; Mon, 2 Mar 2020 12:32:23 +0000 (UTC) Received: from work-vm (unknown [10.36.118.97]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C128C91D6C; Mon, 2 Mar 2020 12:32:21 +0000 (UTC) Date: Mon, 2 Mar 2020 12:32:19 +0000 From: "Dr. David Alan Gilbert" To: Laszlo Ersek Cc: Andrew Fish , devel@edk2.groups.io, wuchenye1995 , zhoujianjay , Alex =?iso-8859-1?Q?Benn=E9e?= , berrange@redhat.com, qemu-devel@nongnu.org, discuss Subject: Re: [edk2-devel] A problem with live migration of UEFI virtual machines Message-ID: <20200302123219.GE2798@work-vm> References: <87sgjhxbtc.fsf@zen.linaroharston> <20200224152810.GX635661@redhat.com> <8b0ec286-9322-ee00-3729-6ec7ee8260a6@redhat.com> <3E8BB07B-8730-4AB8-BCB6-EA183FB589C5@apple.com> <465a5a84-cac4-de39-8956-e38771807450@redhat.com> <8F42F6F1-A65D-490D-9F2F-E12746870B29@apple.com> <6666a886-720d-1ead-8f7e-13e65dcaaeb4@redhat.com> MIME-Version: 1.0 In-Reply-To: <6666a886-720d-1ead-8f7e-13e65dcaaeb4@redhat.com> User-Agent: Mutt/1.13.3 (2020-01-12) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Content-Disposition: inline * Laszlo Ersek (lersek@redhat.com) wrote: > The interesting question is, what happens when you power down the VM on > the destination host (=3D post migration), and launch it again there, fro= m > zero. In that case, the firmware executable file comes from the > *destination host* (it was never persistently migrated from the source > host, i.e. never written out on the dst). It simply comes from the OVMF > package that had been installed on the destination host, by the > sysadmin. However, the varstore pflash does reflect the permanent result > of the previous migration. So this is where things can fall apart, if > both firmware binaries (on the src host and on the dst host) don't agree > about the internal structure of the varstore pflash. My guess is that overtime we're going to need to find a way to handle this, otherwise we're going to find people having to maintain old versions of OVMF just to keep variable store compatiiblity. Dave > Thanks > Laszlo -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK