This patch adds driver flag in vdev bus driver so that
vdev drivers can require VA IOVA mode to be used, which
for example the case of Virtio-user PMD.
The patch implements the .get_iommu_class() callback, that
is called before devices probing to determine the IOVA mode
to be used, and adds a check right before the device is
probed to ensure compatible IOVA mode has been selected.
It also adds a ABI exception rule to accommodate with an
update on the driver registration API
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: David Marchand <david.marchand@redhat.com>
Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>