The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From edc0b0bccc9c80d9a44d3002dcca94984b25e7cf Mon Sep 17 00:00:00 2001

From: Mark Bloch mbloch@nvidia.com Date: Mon, 7 Jun 2021 11:03:12 +0300 Subject: [PATCH] RDMA/mlx5: Block FDB rules when not in switchdev mode

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: 52438be44112 ("RDMA/mlx5: Allow inserting a steering rule to the FDB") Link: https://lore.kernel.org/r/e928ae7c58d07f104716a2a8d730963d1bd01204.162305292... Reviewed-by: Maor Gottlieb maorg@nvidia.com Signed-off-by: Mark Bloch mbloch@nvidia.com Signed-off-by: Leon Romanovsky leonro@nvidia.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com

diff --git a/drivers/infiniband/hw/mlx5/fs.c b/drivers/infiniband/hw/mlx5/fs.c index 2fc6a60c4e77..f84441ff0c81 100644 --- a/drivers/infiniband/hw/mlx5/fs.c +++ b/drivers/infiniband/hw/mlx5/fs.c @@ -2134,6 +2134,12 @@ 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) != MLX5_ESWITCH_OFFLOADS) { + err = -EINVAL; + goto end; + } + uobj->object = obj; obj->mdev = dev->mdev; atomic_set(&obj->usecnt, 0);