From 3e3f736e50fba910d1d484b9c763d884dff6688f Mon Sep 17 00:00:00 2001 From: Junxiao Shi Date: Thu, 9 Sep 2021 14:42:06 +0000 Subject: [PATCH] net/memif: fix chained mbuf determination Previously, TX functions call rte_pktmbuf_is_contiguous to determine whether an mbuf is chained. However, rte_pktmbuf_is_contiguous is designed to work on the first mbuf of a packet only. In case a packet contains three or more segment mbufs in a chain, it may cause truncated packets or rte_mbuf_sanity_check panics. This patch updates TX functions to determine chained mbufs using mbuf_head->nb_segs field, which works in all cases. Moreover, it maintains that the second cacheline is only accessed when chained mbuf is actually present. Fixes: 09c7e63a71f9 ("net/memif: introduce memory interface PMD") Fixes: 43b815d88188 ("net/memif: support zero-copy slave") Cc: stable@dpdk.org Signed-off-by: Junxiao Shi Reviewed-by: Jakub Grajciar --- drivers/net/memif/rte_eth_memif.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/net/memif/rte_eth_memif.c b/drivers/net/memif/rte_eth_memif.c index de6becd45e..fd9e877c3d 100644 --- a/drivers/net/memif/rte_eth_memif.c +++ b/drivers/net/memif/rte_eth_memif.c @@ -199,6 +199,7 @@ memif_dev_info(struct rte_eth_dev *dev __rte_unused, struct rte_eth_dev_info *de dev_info->max_rx_queues = ETH_MEMIF_MAX_NUM_Q_PAIRS; dev_info->max_tx_queues = ETH_MEMIF_MAX_NUM_Q_PAIRS; dev_info->min_rx_bufsize = 0; + dev_info->tx_offload_capa = DEV_TX_OFFLOAD_MULTI_SEGS; return 0; } @@ -567,7 +568,7 @@ eth_memif_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts) rte_eth_devices[mq->in_port].process_private; memif_ring_t *ring = memif_get_ring_from_queue(proc_private, mq); uint16_t slot, saved_slot, n_free, ring_size, mask, n_tx_pkts = 0; - uint16_t src_len, src_off, dst_len, dst_off, cp_len; + uint16_t src_len, src_off, dst_len, dst_off, cp_len, nb_segs; memif_ring_type_t type = mq->type; memif_desc_t *d0; struct rte_mbuf *mbuf; @@ -615,6 +616,7 @@ eth_memif_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts) while (n_tx_pkts < nb_pkts && n_free) { mbuf_head = *bufs++; + nb_segs = mbuf_head->nb_segs; mbuf = mbuf_head; saved_slot = slot; @@ -659,7 +661,7 @@ next_in_chain: d0->length = dst_off; } - if (rte_pktmbuf_is_contiguous(mbuf) == 0) { + if (--nb_segs > 0) { mbuf = mbuf->next; goto next_in_chain; } @@ -696,6 +698,7 @@ memif_tx_one_zc(struct pmd_process_private *proc_private, struct memif_queue *mq uint16_t slot, uint16_t n_free) { memif_desc_t *d0; + uint16_t nb_segs = mbuf->nb_segs; int used_slots = 1; next_in_chain: @@ -716,7 +719,7 @@ next_in_chain: d0->flags = 0; /* check if buffer is chained */ - if (rte_pktmbuf_is_contiguous(mbuf) == 0) { + if (--nb_segs > 0) { if (n_free < 2) return 0; /* mark buffer as chained */ -- 2.20.1