VIOSCSI_NEEDED_FEATURES
if (!virtio_features_present(vio, VIOSCSI_NEEDED_FEATURES)) {
VIOSCSI_NEEDED_FEATURES, VIOSCSI_FEATURE_FORMAT,
CTASSERT(((VIOSCSI_WANTED_FEATURES & VIOSCSI_NEEDED_FEATURES) ^
VIOSCSI_NEEDED_FEATURES) == 0);