From: Huisong Li <lihuisong@huawei.com>

Currently, 'nb_fwd_lcores' value are both adjusted based on
'nb_fwd_streams' in rss/simple/icmp_echo_fwd_config_setup. But the
operation is lack for dcb_fwd_config_setup, which may lead to a
bad events where multiple polling threads operate on the same
queue. As a result, various possible exceptions will occur. The
procedure is as follows:

startup testpmd app as follows:
testpmd> port stop all
testpmd> set nbcore 8
testpmd> port config 0 dcb vt off 4 pfc on
testpmd> port config all rxq 16
testpmd> port config all txq 16
testpmd> port start all
testpmd> set fwd mac
Logical Core 1 (socket 0) forwards packets on 4 streams:
RX P=0/Q=0 (socket 0) -> TX P=0/Q=0 (socket 0) peer=02:00:00:00:00:00
RX P=0/Q=1 (socket 0) -> TX P=0/Q=1 (socket 0) peer=02:00:00:00:00:00
RX P=0/Q=2 (socket 0) -> TX P=0/Q=2 (socket 0) peer=02:00:00:00:00:00
RX P=0/Q=3 (socket 0) -> TX P=0/Q=3 (socket 0) peer=02:00:00:00:00:00
Logical Core 2 (socket 0) forwards packets on 4 streams:
RX P=0/Q=4 (socket 0) -> TX P=0/Q=4 (socket 0) peer=02:00:00:00:00:00
RX P=0/Q=5 (socket 0) -> TX P=0/Q=5 (socket 0) peer=02:00:00:00:00:00
RX P=0/Q=6 (socket 0) -> TX P=0/Q=6 (socket 0) peer=02:00:00:00:00:00
RX P=0/Q=7 (socket 0) -> TX P=0/Q=7 (socket 0) peer=02:00:00:00:00:00
Logical Core 3 (socket 0) forwards packets on 4 streams:
RX P=0/Q=8 (socket 0) -> TX P=0/Q=8 (socket 0) peer=02:00:00:00:00:00
RX P=0/Q=9 (socket 0) -> TX P=0/Q=9 (socket 0) peer=02:00:00:00:00:00
RX P=0/Q=10 (socket 0) -> TX P=0/Q=10 (socket 0) peer=02:00:00:00:00:00
RX P=0/Q=11 (socket 0) -> TX P=0/Q=11 (socket 0) peer=02:00:00:00:00:00
Logical Core 4 (socket 0) forwards packets on 4 streams:
RX P=0/Q=12 (socket 0) -> TX P=0/Q=12 (socket 0) peer=02:00:00:00:00:00
RX P=0/Q=13 (socket 0) -> TX P=0/Q=13 (socket 0) peer=02:00:00:00:00:00
RX P=0/Q=14 (socket 0) -> TX P=0/Q=14 (socket 0) peer=02:00:00:00:00:00
RX P=0/Q=15 (socket 0) -> TX P=0/Q=15 (socket 0) peer=02:00:00:00:00:00
Logical Core 5 (socket 0) forwards packets on 1 streams:
RX P=0/Q=4 (socket 0) -> TX P=0/Q=4 (socket 0) peer=02:00:00:00:00:00
Logical Core 6 (socket 0) forwards packets on 1 streams:
RX P=0/Q=5 (socket 0) -> TX P=0/Q=5 (socket 0) peer=02:00:00:00:00:00
Logical Core 7 (socket 0) forwards packets on 1 streams:
RX P=0/Q=6 (socket 0) -> TX P=0/Q=6 (socket 0) peer=02:00:00:00:00:00
Logical Core 8 (socket 0) forwards packets on 1 streams:
RX P=0/Q=7 (socket 0) -> TX P=0/Q=7 (socket 0) peer=02:00:00:00:00:00

Notice: number of rxq and txq in running cmdline are greater than
used nb_tc.

For the DCB forwarding test, each core is assigned on each traffic class
and each core is assigned a multi-stream. Therefore, 'nb_fwd_lcores'
value can be adjusted based on 'total_tc_num' in all forwarding ports.

In addition, after operation of port stop/port start, forwarding
configuration is changed by rss_fwd_config_setup. In "start_port"
function, dcb_test is set to 1 based on dcb_config. So it also
should be cleared when dcb_config is 0.

Fixes: 900550de04a7 ("app/testpmd: add dcb support")
Fixes: ce8d561418d4 ("app/testpmd: add port configuration settings")
Cc: stable@dpdk.org

Signed-off-by: Huisong Li <lihuisong@huawei.com>
Signed-off-by: Lijun Ou <redacted>
---
 app/test-pmd/config.c  | 19 +++++++++++++++++++
 app/test-pmd/testpmd.c | 12 +++++++-----
 2 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
index 576d5ac..c89f8cd 100644
--- a/app/test-pmd/config.c
+++ b/app/test-pmd/config.c

@@ -2864,6 +2864,21 @@ rss_fwd_config_setup(void)
 	}
 }
 
+static uint16_t
+get_fwd_port_total_tc_num(void)
+{
+	struct rte_eth_dcb_info dcb_info;
+	uint16_t total_tc_num = 0;
+	unsigned int i;
+
+	for (i = 0; i < nb_fwd_ports; i++) {
+		(void)rte_eth_dev_get_dcb_info(fwd_ports_ids[i], &dcb_info);
+		total_tc_num += dcb_info.nb_tcs;
+	}
+
+	return total_tc_num;
+}
+
 /**
  * For the DCB forwarding test, each core is assigned on each traffic class.
  *

@@ -2883,12 +2898,16 @@ dcb_fwd_config_setup(void)
 	lcoreid_t  lc_id;
 	uint16_t nb_rx_queue, nb_tx_queue;
 	uint16_t i, j, k, sm_id = 0;
+	uint16_t total_tc_num = 0;
 	uint8_t tc = 0;
 
 	cur_fwd_config.nb_fwd_lcores = (lcoreid_t) nb_fwd_lcores;
 	cur_fwd_config.nb_fwd_ports = nb_fwd_ports;
 	cur_fwd_config.nb_fwd_streams =
 		(streamid_t) (nb_rxq * cur_fwd_config.nb_fwd_ports);
+	total_tc_num = get_fwd_port_total_tc_num();
+	if (cur_fwd_config.nb_fwd_lcores > total_tc_num)
+		cur_fwd_config.nb_fwd_lcores = total_tc_num;
 
 	/* reinitialize forwarding streams */
 	init_fwd_streams();

diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index 1a57324..7eb810b 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c

@@ -2707,14 +2707,16 @@ stop_port(portid_t pid)
 	portid_t peer_pl[RTE_MAX_ETHPORTS];
 	int peer_pi;
 
-	if (dcb_test) {
-		dcb_test = 0;
-		dcb_config = 0;
-	}
-
 	if (port_id_is_invalid(pid, ENABLED_WARN))
 		return;
 
+	/*
+	 * In "start_port" function, dcb_test is set to 1 based on dcb_config.
+	 * So it should be cleared when dcb_config is 0.
+	 */
+	if (dcb_config == 0)
+		dcb_test = 0;
+
 	printf("Stopping ports...\n");
 
 	RTE_ETH_FOREACH_DEV(pi) {

-- 
2.7.4