Re: [PATCH rdma-rc 5/9] IB/mlx4: Handle well-known-gid in mad_demux processing

jackm
2016-11-07T14:42:28Z

On Sat, 5 Nov 2016 17:03:25 -0400
Hal Rosenstock <hal-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org> wrote:

> On 11/5/2016 3:57 PM, Leon Romanovsky wrote:
> > From: Jack Morgenstein <jackm-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>
> >
> > If OpenSM runs over ConnectX-3, and there are ConnectIB VFs active
> > on the network, the OpenSM will receive QP1 packets containing a GRH
> > where the destination GID is the "Well-Known GID" -- which is not a
> > GID in the HCA Port's GID Table.
> >
> > This GID must be tested-for separately -- and packets which contain
> > this destination GID should be routed to slave 0 (the PF).
> >
> > Fixes: 37bfc7c1e83f ('IB/mlx4: SR-IOV multiplex and demultiplex
> > MADs') Signed-off-by: Jack Morgenstein <jackm-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>
> > Signed-off-by: Daniel Jurgens <danielj-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> > Signed-off-by: Leon Romanovsky <leon-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> > Signed-off-by: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> > ---
> > drivers/infiniband/hw/mlx4/mad.c | 16 ++++++++++++----
> > include/rdma/ib_verbs.h | 1 +
> > 2 files changed, 13 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/infiniband/hw/mlx4/mad.c
> > b/drivers/infiniband/hw/mlx4/mad.c index b8e9013..f0b8272 100644
> > --- a/drivers/infiniband/hw/mlx4/mad.c
> > +++ b/drivers/infiniband/hw/mlx4/mad.c
> > @@ -729,10 +729,18 @@ static int mlx4_ib_demux_mad(struct ib_device
> > *ibdev, u8 port,
> > /* If a grh is present, we demux according to it */
> > if (wc->wc_flags & IB_WC_GRH) {
> > - slave = mlx4_ib_find_real_gid(ibdev, port,
> > grh->dgid.global.interface_id);
> > - if (slave < 0) {
> > - mlx4_ib_warn(ibdev, "failed matching
> > grh\n");
> > - return -ENOENT;
> > + if (grh->dgid.global.interface_id ==
> > + cpu_to_be64(IB_SA_WELL_KNOWN_GUID) &&
> > + grh->dgid.global.subnet_prefix ==
> > + cpu_to_be64(IB_SA_WELL_KNOWN_GID_PREFIX)) {
> > + slave = 0;
> > + } else {
> > + slave = mlx4_ib_find_real_gid(ibdev, port,
> > +
> > grh->dgid.global.interface_id);
> > + if (slave < 0) {
> > + mlx4_ib_warn(ibdev, "failed
> > matching grh\n");
> > + return -ENOENT;
> > + }
> > }
> > }
> > /* Class-specific handling */
> > diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
> > index 467a4b4..da5949f 100644
> > --- a/include/rdma/ib_verbs.h
> > +++ b/include/rdma/ib_verbs.h
> > @@ -100,6 +100,7 @@ enum rdma_node_type {
> >
> > enum {
> > /* set the local administered indication */
> > + IB_SA_WELL_KNOWN_GID_PREFIX = 0xfe80000000000000ull,
> > IB_SA_WELL_KNOWN_GUID = BIT_ULL(57) | 2,
>
> Isn't the SA well-known GID the concatenation of the subnet prefix
> (which isn't necessarily the default link local one) and the GUID
> 0x0200000000000002 ?
>
> -- Hal

PLEASE DO NOT APPLY THIS PATCH. Hal is correct, and the patch needs
to be fixed. We will submit an updated (i.e. fixed) version.

-Jack

>
> > };
> >
> >