net/mlx5e: IPsec: Add Connect-X IPsec Rx data path offload

On receive flow inspect received packets for IPsec offload indication
using the cqe, for IPsec offloaded packets propagate offload status
and stack handle to stack for further processing.

Supported statuses:
- Offload ok.
- Authentication failure.
- Bad trailer indication.

Connect-X IPsec does not use mlx5e_ipsec_handle_rx_cqe.

For RX only offload, we see the BW gain. Below is the iperf3
performance report on two server of 24 cores Intel(R) Xeon(R)
CPU E5-2620 v3 @ 2.40GHz with ConnectX6-DX.
We use one thread per IPsec tunnel.

---------------------------------------------------------------------
Mode          |  Num tunnel | BW     | Send CPU util | Recv CPU util
              |             | (Gbps) | (Average %)   | (Average %)
---------------------------------------------------------------------
Cryto offload | 1           | 4.6    | 4.2           | 14.5
---------------------------------------------------------------------
Cryto offload | 24          | 38     | 73            | 63
---------------------------------------------------------------------
Non-offload   | 1           | 4      | 4             | 13
---------------------------------------------------------------------
Non-offload   | 24          | 23     | 52            | 67

Signed-off-by: Raed Salem <raeds@mellanox.com>
Reviewed-by: Boris Pismenny <borisp@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

1 files changed, 56 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.c
index 824b87ac8f9e..93a8d68815ad 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.c
@@ -360,6 +360,62 @@ struct sk_buff *mlx5e_ipsec_handle_rx_skb(struct net_device *netdev,
 	return skb;
 }
 
+enum {
+	MLX5E_IPSEC_OFFLOAD_RX_SYNDROME_DECRYPTED,
+	MLX5E_IPSEC_OFFLOAD_RX_SYNDROME_AUTH_FAILED,
+	MLX5E_IPSEC_OFFLOAD_RX_SYNDROME_BAD_TRAILER,
+};
+
+void mlx5e_ipsec_offload_handle_rx_skb(struct net_device *netdev,
+				       struct sk_buff *skb,
+				       struct mlx5_cqe64 *cqe)
+{
+	u32 ipsec_meta_data = be32_to_cpu(cqe->ft_metadata);
+	u8 ipsec_syndrome = ipsec_meta_data & 0xFF;
+	struct mlx5e_priv *priv;
+	struct xfrm_offload *xo;
+	struct xfrm_state *xs;
+	struct sec_path *sp;
+	u32  sa_handle;
+
+	sa_handle = MLX5_IPSEC_METADATA_HANDLE(ipsec_meta_data);
+	priv = netdev_priv(netdev);
+	sp = secpath_set(skb);
+	if (unlikely(!sp)) {
+		atomic64_inc(&priv->ipsec->sw_stats.ipsec_rx_drop_sp_alloc);
+		return;
+	}
+
+	xs = mlx5e_ipsec_sadb_rx_lookup(priv->ipsec, sa_handle);
+	if (unlikely(!xs)) {
+		atomic64_inc(&priv->ipsec->sw_stats.ipsec_rx_drop_sadb_miss);
+		return;
+	}
+
+	sp = skb_sec_path(skb);
+	sp->xvec[sp->len++] = xs;
+	sp->olen++;
+
+	xo = xfrm_offload(skb);
+	xo->flags = CRYPTO_DONE;
+
+	switch (ipsec_syndrome & MLX5_IPSEC_METADATA_SYNDROM_MASK) {
+	case MLX5E_IPSEC_OFFLOAD_RX_SYNDROME_DECRYPTED:
+		xo->status = CRYPTO_SUCCESS;
+		if (WARN_ON_ONCE(priv->ipsec->no_trailer))
+			xo->flags |= XFRM_ESP_NO_TRAILER;
+		break;
+	case MLX5E_IPSEC_OFFLOAD_RX_SYNDROME_AUTH_FAILED:
+		xo->status = CRYPTO_TUNNEL_ESP_AUTH_FAILED;
+		break;
+	case MLX5E_IPSEC_OFFLOAD_RX_SYNDROME_BAD_TRAILER:
+		xo->status = CRYPTO_INVALID_PACKET_SYNTAX;
+		break;
+	default:
+		atomic64_inc(&priv->ipsec->sw_stats.ipsec_rx_drop_syndrome);
+	}
+}
+
 bool mlx5e_ipsec_feature_check(struct sk_buff *skb, struct net_device *netdev,
 			       netdev_features_t features)
 {