[dpdk-dev] [PATCH v2] ixgbe: don't override mbuf buffer length

[Jean-Mickael Guerin <jean-mickael.guerin@6wind.com>]

The template mbuf_initializer is hard coded with a buflen which
might have been set differently by the application at the time of
mbuf pool creation.

Switch to a mbuf allocation, to fetch the correct default values.
There is no performance impact because this is not a data-plane API.

Signed-off-by: Jean-Mickael Guerin <jean-mickael.guerin@6wind.com>
Acked-by: David Marchand <david.marchand@6wind.com>
Fixes: 0ff3324da2 ("ixgbe: rework vector pmd following mbuf changes")
---

 v2: check returned value of ixgbe_rxq_vec_setup

 lib/librte_pmd_ixgbe/ixgbe_rxtx.c     |  5 ++++-
 lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c | 19 ++++++++++++-------
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
index 5c36bff..7994da1 100644
--- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
+++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
@@ -2244,7 +2244,10 @@ ixgbe_dev_rx_queue_setup(struct rte_eth_dev *dev,
 	use_def_burst_func = check_rx_burst_bulk_alloc_preconditions(rxq);
 
 #ifdef RTE_IXGBE_INC_VECTOR
-	ixgbe_rxq_vec_setup(rxq);
+	if (ixgbe_rxq_vec_setup(rxq) < 0) {
+		ixgbe_rx_queue_release(rxq);
+		return (-ENOMEM);
+	}
 #endif
 	/* Check if pre-conditions are satisfied, and no Scattered Rx */
 	if (!use_def_burst_func && !dev->data->scattered_rx) {
diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c b/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c
index c1b5a78..f7b02f5 100644
--- a/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c
+++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c
@@ -732,17 +732,22 @@ static struct ixgbe_txq_ops vec_txq_ops = {
 int
 ixgbe_rxq_vec_setup(struct igb_rx_queue *rxq)
 {
-	struct rte_mbuf mb_def = { .buf_addr = 0 }; /* zeroed mbuf */
+	struct rte_mbuf *mb_def;
 
-	mb_def.nb_segs = 1;
-	mb_def.data_off = RTE_PKTMBUF_HEADROOM;
-	mb_def.buf_len = rxq->mb_pool->elt_size - sizeof(struct rte_mbuf);
-	mb_def.port = rxq->port_id;
-	rte_mbuf_refcnt_set(&mb_def, 1);
+	mb_def = rte_pktmbuf_alloc(rxq->mb_pool);
+	if (mb_def == NULL) {
+		PMD_INIT_LOG(ERR, "ixgbe_rxq_vec_setup: could not allocate one mbuf");
+		return -1;
+	}
+	/* nb_segs, refcnt, data_off and buf_len are already set */
+	mb_def->port = rxq->port_id;
 
 	/* prevent compiler reordering: rearm_data covers previous fields */
 	rte_compiler_barrier();
-	rxq->mbuf_initializer = *((uint64_t *)&mb_def.rearm_data);
+	rxq->mbuf_initializer = *((uint64_t *)&mb_def->rearm_data);
+
+	rte_pktmbuf_free(mb_def);
+
 	return 0;
 }
 
-- 
2.1.3