Re: [PATCH for-next v2 1/5] RDMA/rxe: Change user/kernel API to allow indexing AH

[Jason Gunthorpe <jgg@nvidia.com>]

On Sun, Jul 18, 2021 at 04:27:00PM -0500, Bob Pearson wrote:
> Make changes to rdma_user_rxe.h to allow indexing AH objects, passing
> the index in UD send WRs to the driver and returning the index to the rxe
> provider. This change will allow removing handling of the AV in the user
> space provider.
> 
> In order to preserve ABI compatibility for old kernel and/or rdma-core
> code keep the AV in the WQE at the same offset but move to the UD specific
> part of the work request since that is the only case that uses it.
> 
> Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
> v2:
>   Moved AV from rxe_send_wqe to rxe_wr.
> 
>  drivers/infiniband/sw/rxe/rxe_av.c    |  2 +-
>  drivers/infiniband/sw/rxe/rxe_verbs.c |  3 ++-
>  include/uapi/rdma/rdma_user_rxe.h     | 10 +++++++++-
>  3 files changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/infiniband/sw/rxe/rxe_av.c b/drivers/infiniband/sw/rxe/rxe_av.c
> index da2e867a1ed9..85580ea5eed0 100644
> +++ b/drivers/infiniband/sw/rxe/rxe_av.c
> @@ -107,5 +107,5 @@ struct rxe_av *rxe_get_av(struct rxe_pkt_info *pkt)
>  	if (qp_type(pkt->qp) == IB_QPT_RC || qp_type(pkt->qp) == IB_QPT_UC)
>  		return &pkt->qp->pri_av;
>  
> -	return (pkt->wqe) ? &pkt->wqe->av : NULL;
> +	return (pkt->wqe) ? &pkt->wqe->wr.wr.ud.av : NULL;
>  }
> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
> index c223959ac174..4176fffa7fdc 100644
> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
> @@ -605,7 +605,8 @@ static void init_send_wqe(struct rxe_qp *qp, const struct ib_send_wr *ibwr,
>  	if (qp_type(qp) == IB_QPT_UD ||
>  	    qp_type(qp) == IB_QPT_SMI ||
>  	    qp_type(qp) == IB_QPT_GSI)
> -		memcpy(&wqe->av, &to_rah(ud_wr(ibwr)->ah)->av, sizeof(wqe->av));
> +		memcpy(&wqe->wr.wr.ud.av, &to_rah(ud_wr(ibwr)->ah)->av,
> +		       sizeof(struct rxe_av));
>  
>  	if (unlikely(ibwr->send_flags & IB_SEND_INLINE))
>  		copy_inline_data_to_wqe(wqe, ibwr);
> diff --git a/include/uapi/rdma/rdma_user_rxe.h b/include/uapi/rdma/rdma_user_rxe.h
> index e283c2220aba..ad7da77dca04 100644
> +++ b/include/uapi/rdma/rdma_user_rxe.h
> @@ -98,6 +98,10 @@ struct rxe_send_wr {
>  			__u32	remote_qpn;
>  			__u32	remote_qkey;
>  			__u16	pkey_index;
> +			__u16	reserved;
> +			__u32	ah_num;

I'd leave this as pad[5] until the later patch when you can swap in
ah_hum/pad[4]

> @@ -168,6 +171,11 @@ struct rxe_recv_wqe {
>  	struct rxe_dma_info	dma;
>  };
>  
> +struct rxe_create_ah_resp {
> +	__u32 ah_num;
> +	__u32 reserved;
> +};

This hunk should be moved to the later patch

Jason