[PATCH] net/mlx5: fix miniCQEs number calculation

[Slava Ovsiienko]

Acked-by: Viacheslav Ovsiienko <viacheslavo at nvidia.com>

> -----Original Message-----
> From: Alexander Kozyrev <akozyrev at nvidia.com>
> Sent: Monday, October 28, 2024 6:43 PM
> To: dev at dpdk.org
> Cc: stable at dpdk.org; Raslan Darawsheh <rasland at nvidia.com>; Slava
> Ovsiienko <viacheslavo at nvidia.com>; Matan Azrad <matan at nvidia.com>;
> Dariusz Sosnowski <dsosnowski at nvidia.com>; Bing Zhao
> <bingz at nvidia.com>; Suanming Mou <suanmingm at nvidia.com>
> Subject: [PATCH] net/mlx5: fix miniCQEs number calculation
> 
> Use the information from the CQE, not from the title packet, for getting the
> number of miniCQEs in the compressed CQEs array.
> This way we can avoid segfaults in the rxq_cq_decompress_v() in case of
> mbuf corruption (due to double mbuf free, for example).
> 
> Fixes: 6cb559d67b ("net/mlx5: add vectorized Rx/Tx burst for x86")
> 
> Signed-off-by: Alexander Kozyrev <akozyrev at nvidia.com>
> ---
>  drivers/net/mlx5/mlx5_rxtx_vec_altivec.h | 3 +--
>  drivers/net/mlx5/mlx5_rxtx_vec_neon.h    | 3 +--
>  drivers/net/mlx5/mlx5_rxtx_vec_sse.h     | 3 +--
>  3 files changed, 3 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/mlx5/mlx5_rxtx_vec_altivec.h
> b/drivers/net/mlx5/mlx5_rxtx_vec_altivec.h
> index b2bbc4ba17..3c6a14670d 100644
> --- a/drivers/net/mlx5/mlx5_rxtx_vec_altivec.h
> +++ b/drivers/net/mlx5/mlx5_rxtx_vec_altivec.h
> @@ -98,8 +98,7 @@ rxq_cq_decompress_v(struct mlx5_rxq_data *rxq,
> volatile struct mlx5_cqe *cq,
>  			11, 10,  9,  8};  /* bswap32, rss */
>  	/* Restore the compressed count. Must be 16 bits. */
>  	uint16_t mcqe_n = (rxq->cqe_comp_layout) ?
> -		(MLX5_CQE_NUM_MINIS(cq->op_own) + 1) :
> -		t_pkt->data_len + (rxq->crc_present *
> RTE_ETHER_CRC_LEN);
> +		(MLX5_CQE_NUM_MINIS(cq->op_own) + 1) :
> +rte_be_to_cpu_32(cqe->byte_cnt)
>  	uint16_t pkts_n = mcqe_n;
>  	const __vector unsigned char rearm =
>  		(__vector unsigned char)vec_vsx_ld(0, diff --git
> a/drivers/net/mlx5/mlx5_rxtx_vec_neon.h
> b/drivers/net/mlx5/mlx5_rxtx_vec_neon.h
> index 510f60b25d..ba79b460a4 100644
> --- a/drivers/net/mlx5/mlx5_rxtx_vec_neon.h
> +++ b/drivers/net/mlx5/mlx5_rxtx_vec_neon.h
> @@ -97,8 +97,7 @@ rxq_cq_decompress_v(struct mlx5_rxq_data *rxq,
> volatile struct mlx5_cqe *cq,
>  	};
>  	/* Restore the compressed count. Must be 16 bits. */
>  	uint16_t mcqe_n = (rxq->cqe_comp_layout) ?
> -		(MLX5_CQE_NUM_MINIS(cq->op_own) + 1) :
> -		t_pkt->data_len + (rxq->crc_present *
> RTE_ETHER_CRC_LEN);
> +		(MLX5_CQE_NUM_MINIS(cq->op_own) + 1) :
> +rte_be_to_cpu_32(cq->byte_cnt);
>  	uint16_t pkts_n = mcqe_n;
>  	const uint64x2_t rearm =
>  		vld1q_u64((void *)&t_pkt->rearm_data); diff --git
> a/drivers/net/mlx5/mlx5_rxtx_vec_sse.h
> b/drivers/net/mlx5/mlx5_rxtx_vec_sse.h
> index e71d6c303f..bd4010f2fe 100644
> --- a/drivers/net/mlx5/mlx5_rxtx_vec_sse.h
> +++ b/drivers/net/mlx5/mlx5_rxtx_vec_sse.h
> @@ -96,8 +96,7 @@ rxq_cq_decompress_v(struct mlx5_rxq_data *rxq,
> volatile struct mlx5_cqe *cq,
>  			    -1, -1, -1, -1  /* skip packet_type */);
>  	/* Restore the compressed count. Must be 16 bits. */
>  	uint16_t mcqe_n = (rxq->cqe_comp_layout) ?
> -		(MLX5_CQE_NUM_MINIS(cq->op_own) + 1) :
> -		t_pkt->data_len + (rxq->crc_present *
> RTE_ETHER_CRC_LEN);
> +		(MLX5_CQE_NUM_MINIS(cq->op_own) + 1) :
> +rte_be_to_cpu_32(cq->byte_cnt);
>  	uint16_t pkts_n = mcqe_n;
>  	const __m128i rearm =
>  		_mm_loadu_si128((__m128i *)&t_pkt->rearm_data);
> --
> 2.43.5