DEVCMD_ARGS
ENIC_BUS_WRITE_REGION_4(devcmd, DEVCMD_ARGS(0), (void *)&vdev->args[0], VNIC_DEVCMD_NARGS * 2);
err = -(int)ENIC_BUS_READ_8(devcmd, DEVCMD_ARGS(0));
ENIC_BUS_READ_REGION_4(devcmd, bar, DEVCMD_ARGS(0), (void *)&vdev->args[0], VNIC_DEVCMD_NARGS * 2);