RDMA/mlx5: Block FDB rules when not in switchdev mode

stable inclusion
from stable-5.10.48
commit 4ab869e0289dbab0aeeedea5e5c4536e13af47b2
bugzilla: 173268 https://gitee.com/openeuler/kernel/issues/I4DD1K

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4ab869e0289dbab0aeeedea5e5c4536e13af47b2

--------------------------------

commit edc0b0bc upstream.

Allow creating FDB steering rules only when in switchdev mode.

The only software model where a userspace application can manipulate
FDB entries is when it manages the eswitch. This is only possible in
switchdev mode where we expose a single RDMA device with representors
for all the vports that are connected to the eswitch.

Fixes: 52438be4 ("RDMA/mlx5: Allow inserting a steering rule to the FDB")
Link: https://lore.kernel.org/r/e928ae7c58d07f104716a2a8d730963d1bd01204.1623052923.git.leonro@nvidia.comReviewed-by: NMaor Gottlieb <maorg@nvidia.com>
Signed-off-by: NMark Bloch <mbloch@nvidia.com>
Signed-off-by: NLeon Romanovsky <leonro@nvidia.com>
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>
[sudip: use old mlx5_eswitch_mode]
Signed-off-by: NSudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/infiniband/hw/mlx5/fs.c

@@ -2136,6 +2136,13 @@ static int UVERBS_HANDLER(MLX5_IB_METHOD_FLOW_MATCHER_CREATE)(
 	if (err)
 		goto end;
 
+	if (obj->ns_type == MLX5_FLOW_NAMESPACE_FDB &&
+	    mlx5_eswitch_mode(dev->mdev->priv.eswitch) !=
+			      MLX5_ESWITCH_OFFLOADS) {
+		err = -EINVAL;
+		goto end;
+	}
+
 	uobj->object = obj;
 	obj->mdev = dev->mdev;
 	atomic_set(&obj->usecnt, 0);