[net 06/11] net/mlx5e: Properly block LRO when XDP is enabled

From: Saeed Mahameed <saeed@kernel.org>
To: "David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org, Maxim Mikityanskiy <maximmi@nvidia.com>,
	Tariq Toukan <tariqt@nvidia.com>,
	Saeed Mahameed <saeedm@nvidia.com>
Subject: [net 06/11] net/mlx5e: Properly block LRO when XDP is enabled
Date: Tue, 17 May 2022 23:34:22 -0700	[thread overview]
Message-ID: <20220518063427.123758-7-saeed@kernel.org> (raw)
In-Reply-To: <20220518063427.123758-1-saeed@kernel.org>

From: Maxim Mikityanskiy <maximmi@nvidia.com>

LRO is incompatible and mutually exclusive with XDP. However, the needed
checks are only made when enabling XDP. If LRO is enabled when XDP is
already active, the command will succeed, and XDP will be skipped in the
data path, although still enabled.

This commit fixes the bug by checking the XDP status in
mlx5e_fix_features and disabling LRO if XDP is enabled.

Fixes: 86994156c736 ("net/mlx5e: XDP fast RX drop bpf programs support")
Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 999241961714..3969916cfafe 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -3900,6 +3900,13 @@ static netdev_features_t mlx5e_fix_features(struct net_device *netdev,
 		}
 	}
 
+	if (params->xdp_prog) {
+		if (features & NETIF_F_LRO) {
+			netdev_warn(netdev, "LRO is incompatible with XDP\n");
+			features &= ~NETIF_F_LRO;
+		}
+	}
+
 	if (MLX5E_GET_PFLAG(params, MLX5E_PFLAG_RX_CQE_COMPRESS)) {
 		features &= ~NETIF_F_RXHASH;
 		if (netdev->features & NETIF_F_RXHASH)
-- 
2.36.1

