It's unclear to me if it's important, but it's obviously causing my
technical colleages some headaches and I'd hate such imprecision to
slow virtio adoption.

I've emailed this to all non-trivial contributors for approval, too.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NRyan Harper <ryanh@us.ibm.com>
Acked-by: NAnthony Liguori <aliguori@us.ibm.com>
Acked-by: NEric Van Hensbergen <ericvh@gmail.com>
Acked-by: Njohn cooper <john.cooper@redhat.com>
Acked-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NFernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>