From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:53321)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <paolo.bonzini@gmail.com>) id 1XUtJq-0001jC-T1
	for qemu-devel@nongnu.org; Fri, 19 Sep 2014 04:13:39 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <paolo.bonzini@gmail.com>) id 1XUtJh-0001o0-Nn
	for qemu-devel@nongnu.org; Fri, 19 Sep 2014 04:13:30 -0400
Received: from mail-we0-x231.google.com ([2a00:1450:400c:c03::231]:59382)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <paolo.bonzini@gmail.com>) id 1XUtJh-0001nS-Fh
	for qemu-devel@nongnu.org; Fri, 19 Sep 2014 04:13:21 -0400
Received: by mail-we0-f177.google.com with SMTP id u57so2072791wes.22
	for <qemu-devel@nongnu.org>; Fri, 19 Sep 2014 01:13:15 -0700 (PDT)
Sender: Paolo Bonzini <paolo.bonzini@gmail.com>
Message-ID: <541BE595.6090905@redhat.com>
Date: Fri, 19 Sep 2014 10:13:09 +0200
From: Paolo Bonzini <pbonzini@redhat.com>
MIME-Version: 1.0
References: <1408789147-18675-1-git-send-email-lersek@redhat.com>	<53FB1108.6050400@redhat.com>
	<541BD1BC.8090501@ozlabs.ru>
In-Reply-To: <541BD1BC.8090501@ozlabs.ru>
Content-Type: text/plain; charset=koi8-r
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH 0/2] pflash (UEFI varstore) migration
	shortcut for libvirt
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Alexey Kardashevskiy <aik@ozlabs.ru>, Laszlo Ersek <lersek@redhat.com>, Michal Privoznik <mprivozn@redhat.com>, Eric Blake <eblake@redhat.com>, "Daniel P. Berrange" <berrange@redhat.com>, Kevin Wolf <kwolf@redhat.com>, Stefan Hajnoczi <stefanha@redhat.com>, Juan Quintela <quintela@redhat.com>, David Gilbert <dgilbert@redhat.com>, qemu devel list <qemu-devel@nongnu.org>, David Gibson <david@gibson.dropbear.id.au>

Il 19/09/2014 08:48, Alexey Kardashevskiy ha scritto:
> Right now we use NVRAM on sPAPR as:
> -drive id=id3,if=none,file=qemu_nvram.img
> -global spapr-nvram.drive=id3
> 
> So the NVRAM file is BlockDriverState and HMP's "migrate -b" copies the
> content just fine.
> 
> What is missing here? Thanks.

"migrate -b" is a big hammer, because it transfers all disks.  In some
cases it is useful to have shared storage for disks and non-shared
storage for variable stores.

For UEFI, we are using RAM migration to transfer non-volatile RAM from
the source to the destination.  This is done by loading the whole
contents of nvram into a RAM MemoryRegion at VM startup, and storing it
at postload time.  The latter is done with this patch.

Paolo