[dpdk-stable] [PATCH v2] app/testpmd: fix segment number check

[Ferruh Yigit]

From: Viacheslav Ovsiienko <viacheslavo at nvidia.com>

The --txpkts command line parameter was silently ignored due to
application was unable to check the Tx queue ring sizes for non
configured ports [1].

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: 8dae835d88b7 ("app/testpmd: remove restriction on Tx segments set")
Cc: stable at dpdk.org

Signed-off-by: Viacheslav Ovsiienko <viacheslavo at nvidia.com>
Signed-off-by: Ferruh Yigit <ferruh.yigit at intel.com>
---
Cc: Andrew Boyer <aboyer at pensando.io>

v2:
* Become more flexible for the '--txpkts' command line, if not able to
  get the descriptor size from port, ignore the check.

  ('nb_txd' check was proposed before, this will require '--txd'
  parameter, but also enforces a specific order on the parameters,
  instead going with the option to flex the checks for parameter.)
---
 app/test-pmd/cmdline.c |  4 ++++
 app/test-pmd/config.c  | 32 ++++++++++++++++++++++++--------
 2 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c
index 12efbc0cab46..7feba8337781 100644
--- a/app/test-pmd/cmdline.c
+++ b/app/test-pmd/cmdline.c
@@ -2910,6 +2910,10 @@ 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],
diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
index e189062efde8..a4445a73bfa5 100644
--- a/app/test-pmd/config.c
+++ b/app/test-pmd/config.c
@@ -3697,13 +3697,15 @@ 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;
 			}
@@ -3719,12 +3721,26 @@ 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).
-- 
2.30.2