[PATCH v5 7/7] net/mlx4: fix fast-path ops setup in secondary process

Long Li
2026-02-27T02:00:29Z

The secondary process MLX4_MP_REQ_START_RXTX handler sets
dev->rx_pkt_burst and dev->tx_pkt_burst, but does not update
rte_eth_fp_ops[].rxq.data and txq.data. Since rte_eth_rx_burst()
uses rte_eth_fp_ops (which is process-local), the secondary
retains stale queue data pointers after VF hot-add, causing a
segfault.

Similarly, the MLX4_MP_REQ_STOP_RXTX handler sets dev burst
functions to dummy but does not update rte_eth_fp_ops burst
pointers, leaving the secondary calling into freed resources.

Fix by updating rte_eth_fp_ops rxq.data and txq.data in the
START_RXTX handler, and rte_eth_fp_ops burst function pointers
in the STOP_RXTX handler.

Fixes: 080d8bc15905 ("net/mlx4: sync stop/start with secondary process")
Cc: stable@dpdk.org
Signed-off-by: Long Li <longli@microsoft.com>
---
drivers/net/mlx4/mlx4_mp.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/net/mlx4/mlx4_mp.c b/drivers/net/mlx4/mlx4_mp.c
index 534cb31151..0784b2d59a 100644
--- a/drivers/net/mlx4/mlx4_mp.c
+++ b/drivers/net/mlx4/mlx4_mp.c
@@ -149,6 +149,10 @@ mp_secondary_handle(const struct rte_mp_msg *mp_msg, const void *peer)
}
#endif
close(mp_msg->fds[0]);
+ rte_eth_fp_ops[param->port_id].rx_pkt_burst = dev->rx_pkt_burst;
+ rte_eth_fp_ops[param->port_id].tx_pkt_burst = dev->tx_pkt_burst;
+ rte_eth_fp_ops[param->port_id].rxq.data = dev->data->rx_queues;
+ rte_eth_fp_ops[param->port_id].txq.data = dev->data->tx_queues;
rte_mb();
mp_init_msg(dev, &mp_res, param->type);
res->result = 0;
@@ -158,6 +162,8 @@ mp_secondary_handle(const struct rte_mp_msg *mp_msg, const void *peer)
INFO("port %u stopping datapath", dev->data->port_id);
dev->tx_pkt_burst = rte_eth_pkt_burst_dummy;
dev->rx_pkt_burst = rte_eth_pkt_burst_dummy;
+ rte_eth_fp_ops[param->port_id].rx_pkt_burst = rte_eth_pkt_burst_dummy;
+ rte_eth_fp_ops[param->port_id].tx_pkt_burst = rte_eth_pkt_burst_dummy;
rte_mb();
mp_init_msg(dev, &mp_res, param->type);
res->result = 0;
--
2.43.0