[PATCH v2] mbuf: dump Tx offload metadata

[David Marchand <david.marchand@redhat.com>]

When debugging TSO and other checksum offloads, dumping the various
l*_len fields and TSO segmentation size can be helpful.

Example in OVS that dumps a mbuf on rte_eth_tx_prepare failure:

Before:
netdev_dpdk(pmd-c30/id:11)|DBG|dpdk0: First invalid packet:
dump mbuf at 0x2201a916c0, iova=0x2200800580, buf_len=6864
  pkt_len=6804, ol_flags=0x3114800000000102, nb_segs=1, port=65535, ptype=0
  segment at 0x2201a916c0, data=0x22008005b2, len=6804, off=50, refcnt=1
  Dump data at [0x22008005b2], len=6804
...

After:
netdev_dpdk(pmd-c30/id:11)|DBG|dpdk0: First invalid packet:
dump mbuf at 0x2201a916c0, iova=0x2200800580, buf_len=6864, pkt_len=6804
  outer_l2_len=14, outer_l3_len=40, l2_len=38, l3_len=40, l4_len=32
  ol_flags=0x3114800000000102, nb_segs=1, port=65535, ptype=0
  segment at 0x2201a916c0, data=0x22008005b2, len=6804, off=50, refcnt=1
  Dump data at [0x22008005b2], len=6804
...

Signed-off-by: David Marchand <david.marchand@redhat.com>
---
 lib/mbuf/rte_mbuf.c | 41 +++++++++++++++++++++++++++++++++++++----
 1 file changed, 37 insertions(+), 4 deletions(-)

diff --git a/lib/mbuf/rte_mbuf.c b/lib/mbuf/rte_mbuf.c
index 0d931c7a15..12710a59df 100644
--- a/lib/mbuf/rte_mbuf.c
+++ b/lib/mbuf/rte_mbuf.c
@@ -750,10 +750,43 @@ rte_pktmbuf_dump(FILE *f, const struct rte_mbuf *m, unsigned dump_len)
 
 	__rte_mbuf_sanity_check(m, 1);
 
-	fprintf(f, "dump mbuf at %p, iova=%#" PRIx64 ", buf_len=%u\n", m, rte_mbuf_iova_get(m),
-		m->buf_len);
-	fprintf(f, "  pkt_len=%u, ol_flags=%#"PRIx64", nb_segs=%u, port=%u",
-		m->pkt_len, m->ol_flags, m->nb_segs, m->port);
+	fprintf(f, "dump mbuf at %p, iova=%#" PRIx64 ", buf_len=%u, pkt_len=%u\n",
+		m, rte_mbuf_iova_get(m), m->buf_len, m->pkt_len);
+	if (m->ol_flags & RTE_MBUF_F_TX_OFFLOAD_MASK) {
+		const char *sep = "";
+
+		fprintf(f, "  ");
+		if (m->outer_l2_len != 0) {
+			fprintf(f, "%souter_l2_len=%u", sep, m->outer_l2_len);
+			sep = ", ";
+		}
+		if (m->outer_l3_len != 0) {
+			fprintf(f, "%souter_l3_len=%u", sep, m->outer_l3_len);
+			sep = ", ";
+		}
+		if (m->l2_len != 0) {
+			fprintf(f, "%sl2_len=%u", sep, m->l2_len);
+			sep = ", ";
+		}
+		if (m->l3_len != 0) {
+			fprintf(f, "%sl3_len=%u", sep, m->l3_len);
+			sep = ", ";
+		}
+		if (m->l4_len != 0) {
+			fprintf(f, "%sl4_len=%u", sep, m->l4_len);
+			sep = ", ";
+		}
+		if (m->tso_segsz != 0) {
+			fprintf(f, "%stso_segsz=%u", sep, m->tso_segsz);
+			sep = ", ";
+		}
+
+		if (sep[0] == '\0')
+			fprintf(f, "no tx offload length set");
+		fprintf(f, "\n");
+	}
+	fprintf(f, "  ol_flags=%#"PRIx64", nb_segs=%u, port=%u",
+		m->ol_flags, m->nb_segs, m->port);
 
 	if (m->ol_flags & (RTE_MBUF_F_RX_QINQ | RTE_MBUF_F_TX_QINQ))
 		fprintf(f, ", vlan_tci_outer=%u", m->vlan_tci_outer);
-- 
2.51.0