perftest: support set flow_label in GRH

For RoCE, the udp sport is randomly selected when flow_label is 0.
This makes the traffic go through different path when trying to
run test.
Add flow_label option to let it use same udp sport to go through
same path when running test.

Signed-off-by: Liu, Changcheng <[email protected]>

Author: changchengx

src/perftest_parameters.c

@@ -544,6 +544,11 @@ static void usage(const char *argv0, VerbType verb, TestType tst, int connection
 		printf("      --tclass=<value> ");
 		printf(" Set the Traffic Class in GRH (if GRH is in use)\n");
 
+		if (connection_type != RawEth) {
+			printf("      --flow_label=<value> ");
+			printf(" Set the flow_label in GRH (if GRH is in use)\n");
+		}
+
 		if (cuda_memory_supported()) {
 			printf("      --use_cuda=<cuda device id>");
 			printf(" Use CUDA specific device for GPUDirect RDMA testing\n");
@@ -841,6 +846,7 @@ static void init_perftest_params(struct perftest_parameters *user_param)
 	user_param->mr_per_qp			= 0;
 	user_param->dlid			= 0;
 	user_param->traffic_class		= 0;
+	user_param->flow_label			= 0;
 	user_param->flows			= DEF_FLOWS;
 	user_param->flows_burst			= 1;
 	user_param->perform_warm_up		= 0;
@@ -2819,7 +2825,11 @@ int parser(struct perftest_parameters *user_param,char *argv[], int argc)
 					use_hl_flag = 0;
 				}
 				if (flow_label_flag) {
-					CHECK_VALUE_NON_NEGATIVE(user_param->flow_label,int,"flow label",not_int_ptr);
+					CHECK_VALUE(user_param->flow_label,int,"flow label",not_int_ptr);
+					if (user_param->connection_type == RawEth && user_param->flow_label < 0) {
+						fprintf(stderr," flow label must be non-negative for RawEth\n");
+						return FAILURE;
+					}
 					flow_label_flag = 0;
 				}
 				if (retry_count_flag) {

src/perftest_resources.c

@@ -2524,6 +2524,7 @@ static int ctx_modify_qp_to_rtr(struct ibv_qp *qp,
 			attr->ah_attr.grh.sgid_index = (attr->ah_attr.port_num == user_param->ib_port) ? user_param->gid_index : user_param->gid_index2;
 			attr->ah_attr.grh.hop_limit = 0xFF;
 			attr->ah_attr.grh.traffic_class = user_param->traffic_class;
+			attr->ah_attr.grh.flow_label = user_param->flow_label;
 		}
 		if (user_param->connection_type != UD && user_param->connection_type != SRD) {
 			if (user_param->connection_type == DC) {