IB/mlx4: Fix use of flow-counters for process_mad

For IB links, reading HCA flow counters through iboe_process_mad() should
be used when mlx4_ib_process_mad() is invoked only for VFs PMA queries and
exactly nothing else.

Fixes: 7193a141eb74 ('IB/mlx4: Set VF to read from QP counters')
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 19 insertions, 10 deletions

diff --git a/drivers/infiniband/hw/mlx4/mad.c b/drivers/infiniband/hw/mlx4/mad.c
index 9a810e302f6b..68b3dfa922bf 100644
--- a/drivers/infiniband/hw/mlx4/mad.c
+++ b/drivers/infiniband/hw/mlx4/mad.c
@@ -860,22 +860,31 @@ int mlx4_ib_process_mad(struct ib_device *ibdev, int mad_flags, u8 port_num,
         struct mlx4_ib_dev *dev = to_mdev(ibdev);
         const struct ib_mad *in_mad = (const struct ib_mad *)in;
         struct ib_mad *out_mad = (struct ib_mad *)out;
+        enum rdma_link_layer link = rdma_port_get_link_layer(ibdev, port_num);
 
         if (WARN_ON_ONCE(in_mad_size != sizeof(*in_mad) ||
                          *out_mad_size != sizeof(*out_mad)))
                 return IB_MAD_RESULT_FAILURE;
 
-        switch (rdma_port_get_link_layer(ibdev, port_num)) {
-        case IB_LINK_LAYER_INFINIBAND:
-                if (!mlx4_is_slave(dev->dev))
-                        return ib_process_mad(ibdev, mad_flags, port_num, in_wc,
-                                              in_grh, in_mad, out_mad);
-        case IB_LINK_LAYER_ETHERNET:
-                return iboe_process_mad(ibdev, mad_flags, port_num, in_wc,
-                                          in_grh, in_mad, out_mad);
-        default:
-                return -EINVAL;
+        /* iboe_process_mad() which uses the HCA flow-counters to implement IB PMA
+         * queries, should be called only by VFs and for that specific purpose
+         */
+        if (link == IB_LINK_LAYER_INFINIBAND) {
+                if (mlx4_is_slave(dev->dev) &&
+                    in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_PERF_MGMT &&
+                    in_mad->mad_hdr.attr_id == IB_PMA_PORT_COUNTERS)
+                        return iboe_process_mad(ibdev, mad_flags, port_num, in_wc,
+                                                in_grh, in_mad, out_mad);
+
+                return ib_process_mad(ibdev, mad_flags, port_num, in_wc,
+                                      in_grh, in_mad, out_mad);
         }
+
+        if (link == IB_LINK_LAYER_ETHERNET)
+                return iboe_process_mad(ibdev, mad_flags, port_num, in_wc,
+                                        in_grh, in_mad, out_mad);
+
+        return -EINVAL;
 }
 
 static void send_handler(struct ib_mad_agent *agent,