RE: [PATCH] common/mlx5: fix MR lookup for non-contiguous mempool

[Raslan Darawsheh <rasland@nvidia.com>]

Hi,

> -----Original Message-----
> From: Dmitry Kozlyuk <dkozlyuk@nvidia.com>
> Sent: Friday, January 14, 2022 12:52 PM
> To: dev@dpdk.org
> Cc: stable@dpdk.org; Wang Yunjian <wangyunjian@huawei.com>; Slava
> Ovsiienko <viacheslavo@nvidia.com>; Matan Azrad <matan@nvidia.com>
> Subject: [PATCH] common/mlx5: fix MR lookup for non-contiguous mempool
> 
> Memory region (MR) lookup by address inside mempool MRs was not
> accounting for the upper bound of an MR.
> For mempools covered by multiple MRs this could return a wrong MR LKey,
> typically resulting in an unrecoverable TxQ failure:
> 
>     mlx5_net: Cannot change Tx QP state to INIT Invalid argument
> 
> Corresponding message from /var/log/dpdk_mlx5_port_X_txq_Y_index_Z*:
> 
>     Unexpected CQE error syndrome 0x04 CQN = 128 SQN = 4848
>         wqe_counter = 0 wq_ci = 9 cq_ci = 122
> 
> This is likely to happen with --legacy-mem and IOVA-as-PA, because EAL
> intentionally maps pages at non-adjacent PA to non-adjacent VA in this
> mode, and MLX5 PMD works with VA.
> 
> Fixes: 690b2a88c2f7 ("common/mlx5: add mempool registration facilities")
> Cc: stable@dpdk.org
> 
> Reported-by: Wang Yunjian <wangyunjian@huawei.com>
> Signed-off-by: Dmitry Kozlyuk <dkozlyuk@nvidia.com>
> Reviewed-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>

Patch applied to next-net-mlx,

Kindest regards,
Raslan Darawsheh