From 03e0868b4cd779e44ef5550fcfee603d3acd017a Mon Sep 17 00:00:00 2001 From: Yongseok Koh Date: Tue, 10 Oct 2017 07:04:02 -0700 Subject: [PATCH] net/mlx5: fix deadlock due to buffered slots in Rx SW ring When replenishing Rx ring, there're always buffered slots reserved between consumed entries and HW owned entries. These have to be filled with fake mbufs to protect from possible overflow rather than optimistically expecting successful replenishment which can cause deadlock with small-sized queue. Fixes: fc048bd52cb7 ("net/mlx5: fix overflow of Rx SW ring") Cc: stable@dpdk.org Reported-by: Martin Weiser Signed-off-by: Yongseok Koh Tested-by: Martin Weiser --- drivers/net/mlx5/mlx5_rxtx_vec.h | 6 +++++- drivers/net/mlx5/mlx5_rxtx_vec_neon.h | 13 ++----------- drivers/net/mlx5/mlx5_rxtx_vec_sse.h | 13 ++----------- 3 files changed, 9 insertions(+), 23 deletions(-) diff --git a/drivers/net/mlx5/mlx5_rxtx_vec.h b/drivers/net/mlx5/mlx5_rxtx_vec.h index 426169037c..1f08ed0b27 100644 --- a/drivers/net/mlx5/mlx5_rxtx_vec.h +++ b/drivers/net/mlx5/mlx5_rxtx_vec.h @@ -101,7 +101,7 @@ mlx5_rx_replenish_bulk_mbuf(struct mlx5_rxq_data *rxq, uint16_t n) { const uint16_t q_n = 1 << rxq->elts_n; const uint16_t q_mask = q_n - 1; - const uint16_t elts_idx = rxq->rq_ci & q_mask; + uint16_t elts_idx = rxq->rq_ci & q_mask; struct rte_mbuf **elts = &(*rxq->elts)[elts_idx]; volatile struct mlx5_wqe_data_seg *wq = &(*rxq->wqes)[elts_idx]; unsigned int i; @@ -119,6 +119,10 @@ mlx5_rx_replenish_bulk_mbuf(struct mlx5_rxq_data *rxq, uint16_t n) wq[i].addr = rte_cpu_to_be_64((uintptr_t)elts[i]->buf_addr + RTE_PKTMBUF_HEADROOM); rxq->rq_ci += n; + /* Prevent overflowing into consumed mbufs. */ + elts_idx = rxq->rq_ci & q_mask; + for (i = 0; i < MLX5_VPMD_DESCS_PER_LOOP; ++i) + (*rxq->elts)[elts_idx + i] = &rxq->fake_mbuf; rte_io_wmb(); *rxq->rq_db = rte_cpu_to_be_32(rxq->rq_ci); } diff --git a/drivers/net/mlx5/mlx5_rxtx_vec_neon.h b/drivers/net/mlx5/mlx5_rxtx_vec_neon.h index 6dd18b6195..86b37d5c6a 100644 --- a/drivers/net/mlx5/mlx5_rxtx_vec_neon.h +++ b/drivers/net/mlx5/mlx5_rxtx_vec_neon.h @@ -445,13 +445,6 @@ rxq_cq_decompress_v(struct mlx5_rxq_data *rxq, volatile struct mlx5_cqe *cq, 31, 30 /* 4th mCQE */ }; - /* - * Not to overflow elts array. Decompress next time after mbuf - * replenishment. - */ - if (unlikely(mcqe_n + MLX5_VPMD_DESCS_PER_LOOP > - (uint16_t)(rxq->rq_ci - rxq->cq_ci))) - return; /* * A. load mCQEs into a 128bit register. * B. store rearm data to mbuf. @@ -778,10 +771,8 @@ rxq_burst_v(struct mlx5_rxq_data *rxq, struct rte_mbuf **pkts, uint16_t pkts_n) } elts_idx = rxq->rq_pi & q_mask; elts = &(*rxq->elts)[elts_idx]; - pkts_n = RTE_MIN(pkts_n - rcvd_pkt, - (uint16_t)(rxq->rq_ci - rxq->cq_ci)); - /* Not to overflow pkts/elts array. */ - pkts_n = RTE_ALIGN_FLOOR(pkts_n, MLX5_VPMD_DESCS_PER_LOOP); + /* Not to overflow pkts array. */ + pkts_n = RTE_ALIGN_FLOOR(pkts_n - rcvd_pkt, MLX5_VPMD_DESCS_PER_LOOP); /* Not to cross queue end. */ pkts_n = RTE_MIN(pkts_n, q_n - elts_idx); if (!pkts_n) diff --git a/drivers/net/mlx5/mlx5_rxtx_vec_sse.h b/drivers/net/mlx5/mlx5_rxtx_vec_sse.h index 88c5d75fac..c2142d7ca2 100644 --- a/drivers/net/mlx5/mlx5_rxtx_vec_sse.h +++ b/drivers/net/mlx5/mlx5_rxtx_vec_sse.h @@ -436,13 +436,6 @@ rxq_cq_decompress_v(struct mlx5_rxq_data *rxq, volatile struct mlx5_cqe *cq, 10, 11, 2, 3); #endif - /* - * Not to overflow elts array. Decompress next time after mbuf - * replenishment. - */ - if (unlikely(mcqe_n + MLX5_VPMD_DESCS_PER_LOOP > - (uint16_t)(rxq->rq_ci - rxq->cq_ci))) - return; /* * A. load mCQEs into a 128bit register. * B. store rearm data to mbuf. @@ -764,10 +757,8 @@ rxq_burst_v(struct mlx5_rxq_data *rxq, struct rte_mbuf **pkts, uint16_t pkts_n) } elts_idx = rxq->rq_pi & q_mask; elts = &(*rxq->elts)[elts_idx]; - pkts_n = RTE_MIN(pkts_n - rcvd_pkt, - (uint16_t)(rxq->rq_ci - rxq->cq_ci)); - /* Not to overflow pkts/elts array. */ - pkts_n = RTE_ALIGN_FLOOR(pkts_n, MLX5_VPMD_DESCS_PER_LOOP); + /* Not to overflow pkts array. */ + pkts_n = RTE_ALIGN_FLOOR(pkts_n - rcvd_pkt, MLX5_VPMD_DESCS_PER_LOOP); /* Not to cross queue end. */ pkts_n = RTE_MIN(pkts_n, q_n - elts_idx); if (!pkts_n) -- 2.20.1