Re: [RFC PATCH] RDMA/rxe: Export imm_data to WC when the related WR with imm_data finished on SQ

[Leon Romanovsky <leon@kernel.org>]

On Thu, Jan 28, 2021 at 02:29:43PM +0800, Xiao Yang wrote:
> On 2021/1/27 20:04, Leon Romanovsky wrote:
> > On Wed, Jan 27, 2021 at 04:24:31PM +0800, Xiao Yang wrote:
> > > Even if we enable sq_sig_all or IBV_SEND_SIGNALED, current rxe
> > > module cannot set imm_data in WC when the related WR with imm_data
> > > finished on SQ.
> > >
> > > Signed-off-by: Xiao Yang<yangx.jy@cn.fujitsu.com>
> > > ---
> > >
> > > Current rxe module and other rdma modules(e.g. mlx5) only set
> > > imm_data in WC when the related WR with imm_data finished on RQ.
> > > I am not sure if it is a expected behavior.
> > This is IBTA behavior.
> >
> > 5.2.11 IMMEDIATE DATA EXTENDED TRANSPORT HEADER (ImmDt) - 4 BYTES
> > "Immediate Data (ImmDt) contains data that is placed in the receive
> >   Completion Queue Element (CQE). The ImmDt is only allowed in SEND or
> >   RDMA WRITE packets with Immediate Data."
> >
> > If I understand the spec, you shouldn't set imm_data in SQ.
> Hi Leon,
>
> About the behavior, I have another question:
> For send operation with imm_data, we can verify if the delivered imm_data is
> correct by CQE on RQ.
> For rdma write operation with imm_data, how to verify if the delivered
> imm_data is correct? :-)

Probably that I didn't understand the question, but the RDMA WRITE is
marked with special opcode in the BTH that indicates imm_data.

Thanks

>
> Best Regards,
> Xiao Yang
> > Thanks
> >
> >
> > .
> >
>
>
>