Re: [PATCH] net/mlx5: fix multi segment packet send

[Adrien Mazarguil <adrien.mazarguil@6wind.com>]

Hi Shahaf,

On Mon, Dec 26, 2016 at 05:28:36PM +0200, Shahaf Shuler wrote:
> Dseg pointer is not initialised when the first segment is inlined
> causing a segmentation fault in such situation.
> 
> Fixes: 2a66cf378954 ("net/mlx5: support inline send")
> 
> CC: stable@dpdk.org
> Signed-off-by: Shahaf Shuler <shahafs@mellanox.com>

Thanks for fixing this bug, a few comments below.

> ---
>  drivers/net/mlx5/mlx5_rxtx.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
> index 97810e8..d6688c6 100644
> --- a/drivers/net/mlx5/mlx5_rxtx.c
> +++ b/drivers/net/mlx5/mlx5_rxtx.c
> @@ -483,7 +483,7 @@
>  				assert(addr <= addr_end);
>  			}
>  			/*
> -			 * 2 DWORDs consumed by the WQE header + 1 DSEG +
> +			 * 2 DWORDs consumed by the WQE header + ETH segment +
>  			 * the size of the inline part of the packet.
>  			 */
>  			ds = 2 + MLX5_WQE_DS(pkt_inline_sz - 2);
> @@ -498,6 +498,10 @@
>  			} else if (!segs_n) {
>  				goto next_pkt;
>  			} else {
> +				/* dseg will be advance as part of next_seg*/

Nit-picking here, there is a missing space in the above comment.

> +				dseg = (volatile rte_v128u32_t *)

rte_v128u32_t does not exist (yet) in the tree, this patch therefore depends
on "eal: define generic vector types" [1]. Such dependencies should be
mentioned as a notes section of a patch (after a three-dash line).

Regarding stable@dpdk.org, un case the vector types patch is not applied on
the stable branch, you'll also have to provide your own definition.

> +					((uintptr_t)wqe +
> +					 ((ds - 1) * MLX5_WQE_DWORD_SIZE));
>  				goto next_seg;
>  			}
>  		} else {
> -- 
> 1.8.3.1
> 

Otherwise,

Acked-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>

[1] http://dpdk.org/ml/archives/dev/2016-November/050261.html

-- 
Adrien Mazarguil
6WIND