From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:58789) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UfCCa-0005UT-SE for qemu-devel@nongnu.org; Wed, 22 May 2013 12:47:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UfCCY-00033G-RI for qemu-devel@nongnu.org; Wed, 22 May 2013 12:47:48 -0400 Date: Wed, 22 May 2013 17:46:38 +0100 From: "Richard W.M. Jones" Message-ID: <20130522164638.GB28893@redhat.com> References: <1369240371-21253-1-git-send-email-mdroth@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1369240371-21253-1-git-send-email-mdroth@linux.vnet.ibm.com> Subject: Re: [Qemu-devel] [PATCH v2] wdt_i6300esb: fix vmstate versioning List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Michael Roth Cc: peter.maydell@linaro.org, nick@bytemark.co.uk, lersek@redhat.com, qemu-devel@nongnu.org, qemu-stable@nongnu.org On Wed, May 22, 2013 at 11:32:51AM -0500, Michael Roth wrote: > When this VMSD was introduced it's version fields were set to > sizeof(I6300State), making them essentially random from build to build, > version to version. > > To fix this, we lock in a high version id and low minimum version id to > support old->new migration from all prior versions of this device's > state. This should work since the device state has not changed since > its introduction. > > The potentially breaks migration from 1.5+ to 1.5, but since the > versioning was essentially random prior to this patch, new->old > migration was not consistently functional to begin with. > > Reported-by: Nicholas Thomas > Suggested-by: Peter Maydell > Cc: qemu-stable@nongnu.org > Signed-off-by: Michael Roth ACK. I guess no one uses watchdog much, or they don't try to migrate those guests :-( Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones virt-p2v converts physical machines to virtual machines. Boot with a live CD or over the network (PXE) and turn machines into KVM guests. http://libguestfs.org/virt-v2v