IB/mlx4: Handle well-known-gid in mad_demux processing

If OpenSM runs over a ConnectX-3, and there are ConnectX-4 or Connect-IB
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@dev.mellanox.co.il>
Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/hw/mlx4/mad.c b/drivers/infiniband/hw/mlx4/mad.c
index b8e90130db37d8afebbb37001fc8aa58b91fc147..7bcae41154082404a8a623ae9f18ad45cb9a9339 100644 (file)
--- 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(
+                       atomic64_read(&dev->sriov.demux[port - 1].subnet_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 */