Re: [PATCH rdma-next v1 6/7] RDMA/cm: Set flow label of recv_wc based on primary flow label

[Leon Romanovsky <leon@kernel.org>]

On Fri, Mar 27, 2020 at 09:37:33AM -0300, Jason Gunthorpe wrote:
> On Sun, Mar 22, 2020 at 11:30:30AM +0200, Leon Romanovsky wrote:
> > From: Mark Zhang <markz@mellanox.com>
> >
> > In the request handler of the response side, Set flow label of the
> > recv_wc if it is not net. It will be used for all messages sent
> > by the responder.
> >
> > Signed-off-by: Mark Zhang <markz@mellanox.com>
> > Reviewed-by: Maor Gottlieb <maorg@mellanox.com>
> > Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
> >  drivers/infiniband/core/cm.c | 7 +++++++
> >  1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
> > index bbbfa77dbce7..4ab2f71da522 100644
> > +++ b/drivers/infiniband/core/cm.c
> > @@ -2039,6 +2039,7 @@ static int cm_req_handler(struct cm_work *work)
> >  	struct cm_req_msg *req_msg;
> >  	const struct ib_global_route *grh;
> >  	const struct ib_gid_attr *gid_attr;
> > +	struct ib_grh *ibgrh;
> >  	int ret;
> >
> >  	req_msg = (struct cm_req_msg *)work->mad_recv_wc->recv_buf.mad;
> > @@ -2048,6 +2049,12 @@ static int cm_req_handler(struct cm_work *work)
> >  	if (IS_ERR(cm_id_priv))
> >  		return PTR_ERR(cm_id_priv);
> >
> > +	ibgrh = work->mad_recv_wc->recv_buf.grh;
> > +	if (!(be32_to_cpu(ibgrh->version_tclass_flow) & IB_GRH_FLOWLABEL_MASK))
> > +		ibgrh->version_tclass_flow |=
> > +			cpu_to_be32(IBA_GET(CM_REQ_PRIMARY_FLOW_LABEL,
> > +					    req_msg));
>
> This doesn't seem right.

I will check, this part looks strange while reading IBTA sections
"13.5.4.3 CONSTRUCTING A RESPONSE WITHOUT A GRH" and
"13.5.4.4 CONSTRUCTING A RESPONSE WITH A GRH"

Thanks