[dpdk-dev] [PATCH V2 3/7] app/testpmd: fix a segment fault when DCB test

[Huisong Li]

After DCB mode is configured, if we decrease the number of RX and TX
queues, fwd_config_setup() will be called to setup the DCB forwarding
configuration. And forwarding streams are updated based on new queue
numbers in fwd_config_setup(), but the mapping between the TC and
queues obtained by rte_eth_dev_get_dcb_info() is still old queue
numbers (old queue numbers are greater than new queue numbers).
In this case, the segment fault happens. So rte_eth_dev_configure()
should be called again to update the mapping between the TC and
queues before rte_eth_dev_get_dcb_info().

Like:
set nbcore 4
port stop all
port config 0 dcb vt off 4 pfc on
port start all
port stop all
port config all rxq 8
port config all txq 8

Fixes: 900550de04a7 ("app/testpmd: add dcb support")
Cc: stable at dpdk.org

Signed-off-by: Huisong Li <lihuisong at huawei.com>
Signed-off-by: Lijun Ou <oulijun at huawei.com>
---
 app/test-pmd/config.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
index 03ee40c..18b197b 100644
--- a/app/test-pmd/config.c
+++ b/app/test-pmd/config.c
@@ -2996,7 +2996,33 @@ dcb_fwd_config_setup(void)
 	uint16_t nb_rx_queue, nb_tx_queue;
 	uint16_t i, j, k, sm_id = 0;
 	uint16_t total_tc_num;
+	struct rte_port *port;
 	uint8_t tc = 0;
+	portid_t pid;
+	int ret;
+
+	/*
+	 * The fwd_config_setup() is called when the port is RTE_PORT_STARTED
+	 * RTE_PORT_STOPPED. When a port is RTE_PORT_STARTED, dev_configure
+	 * cannot be called.
+	 *
+	 * re-configure the device after changing queue numbers of stopped
+	 * ports, so that the updated mapping between tc and queue can be
+	 * obtained.
+	 */
+	for (pid = 0; pid < nb_fwd_ports; pid++) {
+		if (port_is_started(pid) == 1)
+			continue;
+
+		port = &ports[pid];
+		ret = rte_eth_dev_configure(pid, nb_rxq, nb_txq,
+					    &port->dev_conf);
+		if (ret < 0) {
+			printf("Failed to re-configure port %d, ret = %d.\n",
+				pid, ret);
+			return;
+		}
+	}
 
 	cur_fwd_config.nb_fwd_lcores = (lcoreid_t) nb_fwd_lcores;
 	cur_fwd_config.nb_fwd_ports = nb_fwd_ports;
-- 
2.7.4