app/testpmd: fix segment number check

[ upstream commit 3f47c01 ]

The --txpkts command line parameter was silently ignored due to
application was unable to check the Tx queue ring sizes for non
configured ports.

The "set txpkts <len0[,len1]*>" was also rejected if there
was some stopped or /unconfigured port.

This provides the following:

  - If fails to get ring size from the port, this can be because port is
    not initialized yet, ignore the check and just be sure segment size
    won't cause an out of bound access. The port descriptor check will
    be done during Tx setup.

  - The capability to send single packet is supposed to be very basic
    and always supported, the setting segment number to 1 is always
    allowed, no check performed

  - At the moment of Tx queue setup the descriptor number is checked
    against configured segment number

Bugzilla ID: 584
Fixes: 8dae835 ("app/testpmd: remove restriction on Tx segments set")

Signed-off-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
Acked-by: Xiaoyun Li <xiaoyun.li@intel.com>

app/test-pmd/cmdline.c

@@ -2808,6 +2808,10 @@ cmd_setup_rxtx_queue_parsed(
 		if (!numa_support || socket_id == NUMA_NO_CONFIG)
 			socket_id = port->socket_id;
 
+		if (port->nb_tx_desc[res->qid] < tx_pkt_nb_segs) {
+			printf("Failed to setup TX queue: not enough descriptors\n");
+			return;
+		}
 		ret = rte_eth_tx_queue_setup(res->portid,
 					     res->qid,
 					     port->nb_tx_desc[res->qid],

app/test-pmd/config.c

@@ -3842,13 +3842,15 @@ nb_segs_is_invalid(unsigned int nb_segs)
 	RTE_ETH_FOREACH_DEV(port_id) {
 		for (queue_id = 0; queue_id < nb_txq; queue_id++) {
 			ret = get_tx_ring_size(port_id, queue_id, &ring_size);
-
-			if (ret)
-				return true;
-
+			if (ret) {
+				/* Port may not be initialized yet, can't say
+				 * the port is invalid in this stage.
+				 */
+				continue;
+			}
 			if (ring_size < nb_segs) {
-				printf("nb segments per TX packets=%u >= "
-				       "TX queue(%u) ring_size=%u - ignored\n",
+				printf("nb segments per TX packets=%u >= TX "
+				       "queue(%u) ring_size=%u - txpkts ignored\n",
 				       nb_segs, queue_id, ring_size);
 				return true;
 			}
@@ -3864,12 +3866,26 @@ set_tx_pkt_segments(unsigned int *seg_lengths, unsigned int nb_segs)
 	uint16_t tx_pkt_len;
 	unsigned int i;
 
-	if (nb_segs_is_invalid(nb_segs))
+	/*
+	 * For single segment settings failed check is ignored.
+	 * It is a very basic capability to send the single segment
+	 * packets, suppose it is always supported.
+	 */
+	if (nb_segs > 1 && nb_segs_is_invalid(nb_segs)) {
+		printf("Tx segment size(%u) is not supported - txpkts ignored\n",
+			nb_segs);
 		return;
+	}
+
+	if (nb_segs > RTE_MAX_SEGS_PER_PKT) {
+		printf("Tx segment size(%u) is bigger than max number of segment(%u)\n",
+			nb_segs, RTE_MAX_SEGS_PER_PKT);
+		return;
+	}
 
 	/*
 	 * Check that each segment length is greater or equal than
-	 * the mbuf data sise.
+	 * the mbuf data size.
 	 * Check also that the total packet length is greater or equal than the
 	 * size of an empty UDP/IP packet (sizeof(struct rte_ether_hdr) +
 	 * 20 + 8).