Re: [PATCH v2] providers/rxe: Set the correct value of resid for inline data

[Zhu Yanjun <zyjzyj2000@gmail.com>]

On Mon, Aug 9, 2021 at 10:43 PM Xiao Yang <yangx.jy@fujitsu.com> wrote:
>
> Resid indicates the residual length of transmitted bytes but current
> rxe sets it to zero for inline data at the beginning.  In this case,
> request will transmit zero byte to responder wrongly.

What are the symptoms if resid is set to zero?

Thanks
Zhu Yanjun

>
> Resid should be set to the total length of transmitted bytes at the
> beginning.
>
> Note:
> Just remove the useless setting of resid in init_send_wqe().
>
> Fixes: 1a894ca10105 ("Providers/rxe: Implement ibv_create_qp_ex verb")
> Fixes: 8337db5df125 ("Providers/rxe: Implement memory windows")
> Signed-off-by: Xiao Yang <yangx.jy@fujitsu.com>
> ---
>  providers/rxe/rxe.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/providers/rxe/rxe.c b/providers/rxe/rxe.c
> index 3c3ea8bb..3533a325 100644
> --- a/providers/rxe/rxe.c
> +++ b/providers/rxe/rxe.c
> @@ -1004,7 +1004,7 @@ static void wr_set_inline_data(struct ibv_qp_ex *ibqp, void *addr,
>
>         memcpy(wqe->dma.inline_data, addr, length);
>         wqe->dma.length = length;
> -       wqe->dma.resid = 0;
> +       wqe->dma.resid = length;
>  }
>
>  static void wr_set_inline_data_list(struct ibv_qp_ex *ibqp, size_t num_buf,
> @@ -1035,6 +1035,7 @@ static void wr_set_inline_data_list(struct ibv_qp_ex *ibqp, size_t num_buf,
>         }
>
>         wqe->dma.length = tot_length;
> +       wqe->dma.resid = tot_length;
>  }
>
>  static void wr_set_sge(struct ibv_qp_ex *ibqp, uint32_t lkey, uint64_t addr,
> @@ -1473,8 +1474,6 @@ static int init_send_wqe(struct rxe_qp *qp, struct rxe_wq *sq,
>         if (ibwr->send_flags & IBV_SEND_INLINE) {
>                 uint8_t *inline_data = wqe->dma.inline_data;
>
> -               wqe->dma.resid = 0;
> -
>                 for (i = 0; i < num_sge; i++) {
>                         memcpy(inline_data,
>                                (uint8_t *)(long)ibwr->sg_list[i].addr,
> --
> 2.25.1
>
>
>