RDMA/hns: WARN_ON if get a reserved sl from users

According to the RoCE v1 specification, the sl (service level) 0-7 are
mapped directly to priorities 0-7 respectively, sl 8-15 are reserved. The
driver should verify whether the value of sl is larger than 7, if so, an
exception should be returned.

Link: https://lore.kernel.org/r/1607650657-35992-6-git-send-email-liweihang@huawei.comSigned-off-by: NWeihang Li <liweihang@huawei.com>
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/hns/hns_roce_hw_v2.c

@@ -433,6 +433,10 @@ static int fill_ud_av(struct hns_roce_v2_ud_send_wqe *ud_sq_wqe,
 		       V2_UD_SEND_WQE_BYTE_36_TCLASS_S, ah->av.tclass);
 	roce_set_field(ud_sq_wqe->byte_40, V2_UD_SEND_WQE_BYTE_40_FLOW_LABEL_M,
 		       V2_UD_SEND_WQE_BYTE_40_FLOW_LABEL_S, ah->av.flowlabel);
+
+	if (WARN_ON(ah->av.sl > MAX_SERVICE_LEVEL))
+		return -EINVAL;
+
 	roce_set_field(ud_sq_wqe->byte_40, V2_UD_SEND_WQE_BYTE_40_SL_M,
 		       V2_UD_SEND_WQE_BYTE_40_SL_S, ah->av.sl);