Re: [PATCH 4/5] RDMA/rxe: Use the standard method to produce udp source port

[Leon Romanovsky <leon@kernel.org>]

On Wed, Jan 05, 2022 at 04:27:38PM +0800, Zhu Yanjun wrote:
> On Wed, Jan 5, 2022 at 3:52 PM Leon Romanovsky <leon@kernel.org> wrote:
> >
> > On Wed, Jan 05, 2022 at 05:12:36PM -0500, yanjun.zhu@linux.dev wrote:
> > > From: Zhu Yanjun <yanjun.zhu@linux.dev>
> > >
> > > Use the standard method to produce udp source port.
> > >
> > > Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
> > > ---
> > >  drivers/infiniband/sw/rxe/rxe_verbs.c | 6 ++++++
> > >  1 file changed, 6 insertions(+)
> > >
> > > diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
> > > index 0aa0d7e52773..42fa81b455de 100644
> > > --- a/drivers/infiniband/sw/rxe/rxe_verbs.c
> > > +++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
> > > @@ -469,6 +469,12 @@ static int rxe_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
> > >       if (err)
> > >               goto err1;
> > >
> > > +     if ((mask & IB_QP_AV) && (attr->ah_attr.ah_flags & IB_AH_GRH))
> >
> > You are leaving src_port default and wired to same port as other QPs
> > without any randomization.
> 
> Hi,
> 
> I do not get you. Why do you think I am leaving src_pport default?

Because in original code, you randomized src_port without any relation
to mask flags. 

       qp->src_port = RXE_ROCE_V2_SPORT +
               (hash_32_generic(qp_num(qp), 14) & 0x3fff);

After patch #5, if user doesn't pass "proper" mask, you will leave
qp->src_port to be equal to RXE_ROCE_V2_SPORT, which is different from
the current behaviour.

Thanks


> Thanks.
> 
> Zhu Yanjun
> 
> >
> > Thanks
> >
> > > +             qp->src_port = rdma_get_udp_sport(attr->ah_attr.grh.flow_label,
> > > +                                               qp->ibqp.qp_num,
> > > +                                               qp->attr.dest_qp_num);
> > > +
> > > +
> > >       return 0;
> > >
> > >  err1:
> > > --
> > > 2.27.0
> > >