From b3556005c5f319285610e3eae88b4078e1a4d3bc Mon Sep 17 00:00:00 2001
From: Eli Cohen <eli@mellanox.com>
Date: Wed, 22 Jun 2016 17:27:24 +0300
Subject: IB/core: Fix false search of the IB_SA_WELL_KNOWN_GUID

When virtualziation is supported, VFs may send SA MADs to a GID formed
by the concatenation of the subnet prefix with the
IB_SA_WELL_KNOWN_GUID. When a response is required, the current code
will search the local HCA's port for the received GID to figure out the
GID index of the entry containing this GID. However, since this is not a
real GID it will not be found and error will be printed.

We change the logic to check if the destination GID is this special GID
and avoid lookup in this case and use GID index 0.

Fixes: a0c1b2a35087 ('IB/core: Support accessing SA in virtualized environment')
Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
---
 drivers/infiniband/core/verbs.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

(limited to 'drivers/infiniband/core/verbs.c')

diff --git a/drivers/infiniband/core/verbs.c b/drivers/infiniband/core/verbs.c
index 1d7d4cf442e3..6298f54b4137 100644
--- a/drivers/infiniband/core/verbs.c
+++ b/drivers/infiniband/core/verbs.c
@@ -511,12 +511,16 @@ int ib_init_ah_from_wc(struct ib_device *device, u8 port_num,
 		ah_attr->grh.dgid = sgid;
 
 		if (!rdma_cap_eth_ah(device, port_num)) {
-			ret = ib_find_cached_gid_by_port(device, &dgid,
-							 IB_GID_TYPE_IB,
-							 port_num, NULL,
-							 &gid_index);
-			if (ret)
-				return ret;
+			if (dgid.global.interface_id != cpu_to_be64(IB_SA_WELL_KNOWN_GUID)) {
+				ret = ib_find_cached_gid_by_port(device, &dgid,
+								 IB_GID_TYPE_IB,
+								 port_num, NULL,
+								 &gid_index);
+				if (ret)
+					return ret;
+			} else {
+				gid_index = 0;
+			}
 		}
 
 		ah_attr->grh.sgid_index = (u8) gid_index;
-- 
cgit