Re: regression: nvme rdma with bnxt_re0 broken

[Selvin Xavier <selvin.xavier@xxxxxxxxxxxx>]

On Fri, Jul 12, 2019 at 9:10 PM Jason Gunthorpe <jgg@xxxxxxxx> wrote:
>
> On Fri, Jul 12, 2019 at 12:52:24PM +0000, Parav Pandit wrote:
> >
> >
> > > From: Yi Zhang <yi.zhang@xxxxxxxxxx>
> > > Sent: Friday, July 12, 2019 5:11 PM
> > > To: Parav Pandit <parav@xxxxxxxxxxxx>; Selvin Xavier
> > > <selvin.xavier@xxxxxxxxxxxx>
> > > Cc: Daniel Jurgens <danielj@xxxxxxxxxxxx>; linux-rdma@xxxxxxxxxxxxxxx;
> > > Devesh Sharma <devesh.sharma@xxxxxxxxxxxx>; linux-
> > > nvme@xxxxxxxxxxxxxxxxxxx
> > > Subject: Re: regression: nvme rdma with bnxt_re0 broken
> > >
> > > Hi Parav
> > > The nvme connect still failed[1], I've paste all the dmesg log to[2], pls check it.
> > >
> > >
> > > [1]
> > > [root@rdma-perf-07 ~]$ nvme connect -t rdma -a 172.31.40.125 -s 4420 -n
> > > testnqn
> > > Failed to write to /dev/nvme-fabrics: Connection reset by peer
> > > [2]
> > > https://pastebin.com/ipvak0Sp
> > >
> >
> > I think vlan_id is not initialized to 0xffff due to which ipv4 entry addition also failed with my patch.
> > This is probably solves it. Not sure. I am not much familiar with it.
> >
> > Selvin,
> > Can you please take a look?
> >
> > From 7b55e1d4500259cf7c02fb4d9fbbeb5ad1cfc623 Mon Sep 17 00:00:00 2001
> > From: Parav Pandit <parav@xxxxxxxxxxxx>
> > Date: Fri, 12 Jul 2019 04:34:52 -0500
> > Subject: [PATCH v1] IB/bnxt_re: Honor vlan_id in GID entry comparison
> >
> > GID entry consist of GID, vlan, netdev and smac.
> > Extend GID duplicate check companions to consider vlan_id as well
> > to support IPv6 VLAN based link local addresses.
> >
> > GID deletion based on only GID comparision is not correct.
> > It needs further fixes.
> >
> > Fixes: 823b23da7113 ("IB/core: Allow vlan link local address based RoCE GIDs")
> > Change-Id: I2e026ec8065c8425ba24fad8525323d112a2f4e4
> > Signed-off-by: Parav Pandit <parav@xxxxxxxxxxxx>
> >  drivers/infiniband/hw/bnxt_re/qplib_res.c | 5 +++++
> >  drivers/infiniband/hw/bnxt_re/qplib_sp.c  | 7 ++++++-
> >  drivers/infiniband/hw/bnxt_re/qplib_sp.h  | 1 +
> >  3 files changed, 12 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/infiniband/hw/bnxt_re/qplib_res.c b/drivers/infiniband/hw/bnxt_re/qplib_res.c
> > index 37928b1111df..216648b640ce 100644
> > +++ b/drivers/infiniband/hw/bnxt_re/qplib_res.c
> > @@ -488,6 +488,8 @@ static int bnxt_qplib_alloc_sgid_tbl(struct bnxt_qplib_res *res,
> >                                    struct bnxt_qplib_sgid_tbl *sgid_tbl,
> >                                    u16 max)
> >  {
> > +     u16 i;
> > +
> >       sgid_tbl->tbl = kcalloc(max, sizeof(struct bnxt_qplib_gid), GFP_KERNEL);
> >       if (!sgid_tbl->tbl)
> >               return -ENOMEM;
> > @@ -500,6 +502,9 @@ static int bnxt_qplib_alloc_sgid_tbl(struct bnxt_qplib_res *res,
> >       if (!sgid_tbl->ctx)
> >               goto out_free2;
> >
> > +     for (i = 0; i < max; i++)
> > +             sgid_tbl->tbl[i].vlan_id = 0xffff;
> > +
> >       sgid_tbl->vlan = kcalloc(max, sizeof(u8), GFP_KERNEL);
> >       if (!sgid_tbl->vlan)
> >               goto out_free3;
> > diff --git a/drivers/infiniband/hw/bnxt_re/qplib_sp.c b/drivers/infiniband/hw/bnxt_re/qplib_sp.c
> > index 48793d3512ac..0d90be88685f 100644
> > +++ b/drivers/infiniband/hw/bnxt_re/qplib_sp.c
> > @@ -236,6 +236,9 @@ int bnxt_qplib_del_sgid(struct bnxt_qplib_sgid_tbl *sgid_tbl,
> >               return -ENOMEM;
> >       }
> >       for (index = 0; index < sgid_tbl->max; index++) {
> > +             /* FIXME: GID delete should happen based on index
> > +              * and refcount
> > +              */
> >               if (!memcmp(&sgid_tbl->tbl[index], gid, sizeof(*gid)))
> >                       break;
> >       }
> > @@ -296,7 +299,8 @@ int bnxt_qplib_add_sgid(struct bnxt_qplib_sgid_tbl *sgid_tbl,
> >       }
> >       free_idx = sgid_tbl->max;
> >       for (i = 0; i < sgid_tbl->max; i++) {
> > -             if (!memcmp(&sgid_tbl->tbl[i], gid, sizeof(*gid))) {
> > +             if (!memcmp(&sgid_tbl->tbl[i], gid, sizeof(*gid)) &&
> > +                 sgid_tbl->tbl[i].vlan_id == vlan_id) {
> >                       dev_dbg(&res->pdev->dev,
> >                               "SGID entry already exist in entry %d!\n", i);
>
> bnxt guys: please just delete this duplicate detection code from the
> driver. Every GID provided from the core must be programmed into the
> given gid table index.

Jason,
 This check is required in bnxt_re because the HW need only one entry
in its table for RoCE V1 and RoCE v2 Gids.
Sending the second add_gid for RoCE V2 (with the same gid as RoCE v1)
to the HW returns failure. So
driver handles this using a ref count. During delete_gid, the entry in
the HW is deleted only if the refcount is zero.

Thanks,
Selvin

>
> Jason