Re: [Qemu-devel] [PATCH v2] wdt_i6300esb: fix vmstate versioning

["Richard W.M. Jones" <rjones@redhat.com>]

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 <nick@bytemark.co.uk>
> Suggested-by: Peter Maydell <peter.maydell@linaro.org>
> Cc: qemu-stable@nongnu.org
> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

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
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