[net-next,v2,1/2] net/mlx5e: Update hw flows when encap source mac changed

From: Tonghao Zhang <xiangxia.m.yue@gmail.com>

When we offload tc filters to hardware, hardware flows can
be updated when mac of encap destination ip is changed.
But we ignore one case, that the mac of local encap ip can
be changed too, so we should also update them.

To fix it, add route_dev in mlx5e_encap_entry struct to save
the local encap netdevice, and when mac changed, kernel will
flush all the neighbour on the netdevice and send NETEVENT_NEIGH_UPDATE
event. The mlx5 driver will delete the flows and add them when neighbour
available again.

Fixes: 232c001398ae ("net/mlx5e: Add support to neighbour update flow")
Cc: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c | 1 +
 drivers/net/ethernet/mellanox/mlx5/core/en_rep.c    | 4 ++++
 drivers/net/ethernet/mellanox/mlx5/core/en_rep.h    | 1 +
 3 files changed, 6 insertions(+)

On Mon, Jan 21, 2019 at 1:20 PM <xiangxia.m.yue@gmail.com> wrote:
>
> From: Tonghao Zhang <xiangxia.m.yue@gmail.com>
>
> When we offload tc filters to hardware, hardware flows can
> be updated when mac of encap destination ip is changed.
> But we ignore one case, that the mac of local encap ip can
> be changed too, so we should also update them.
>
> To fix it, add route_dev in mlx5e_encap_entry struct to save
> the local encap netdevice, and when mac changed, kernel will
> flush all the neighbour on the netdevice and send NETEVENT_NEIGH_UPDATE
> event. The mlx5 driver will delete the flows and add them when neighbour
> available again.
>
> Fixes: 232c001398ae ("net/mlx5e: Add support to neighbour update flow")
> Cc: Hadar Hen Zion <hadarh@mellanox.com>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
> ---
>  drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c | 1 +
>  drivers/net/ethernet/mellanox/mlx5/core/en_rep.c    | 4 ++++
>  drivers/net/ethernet/mellanox/mlx5/core/en_rep.h    | 1 +
>  3 files changed, 6 insertions(+)
>
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c
> index 046948e..156b2b3 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c
> @@ -256,6 +256,7 @@ int mlx5e_tc_tun_create_header_ipv4(struct mlx5e_priv *priv,

please address the ipv6 tunnel path as well

>         e->m_neigh.family = n->ops->family;
>         memcpy(&e->m_neigh.dst_ip, n->primary_key, n->tbl->key_len);
>         e->out_dev = out_dev;
> +       e->route_dev = route_dev;



>
>         /* It's important to add the neigh to the hash table before checking
>          * the neigh validity state. So if we'll get a notification, in case the
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c
> index 96cc0c6..c4b9073 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c
> @@ -594,6 +594,10 @@ static void mlx5e_rep_update_flows(struct mlx5e_priv *priv,
>         if (neigh_connected && !(e->flags & MLX5_ENCAP_ENTRY_VALID)) {
>                 ether_addr_copy(e->h_dest, ha);
>                 ether_addr_copy(eth->h_dest, ha);
> +               /* Update the encap source mac, in case that we delete
> +                * the flows when encap source mac changed.
> +                */
> +               ether_addr_copy(eth->h_source, e->route_dev->dev_addr);

there's must be some other location in the code which currently sets
the source mac. I need to look deeper but I suspect it has to be removed
and only the one you added should stay