net/mlx5e: Create IPsec table with tunnel support only when encap is disabled

Current hardware doesn't support double encapsulation which is
happening when IPsec packet offload tunnel mode is configured
together with eswitch encap option.

Any user attempt to add new SA/policy after he/she sets encap mode, will
generate the following FW syndrome:

 mlx5_core 0000:08:00.0: mlx5_cmd_out_err:803:(pid 1904): CREATE_FLOW_TABLE(0x930) op_mod(0x0) failed,
 status bad parameter(0x3), syndrome (0xa43321), err(-22)

Make sure that we block encap changes before creating flow steering tables.
This is applicable only for packet offload in tunnel mode, while packet
offload in transport mode and crypto offload, don't have such limitation
as they don't perform encapsulation.
Reviewed-by: Raed Salem <raeds@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c

@@ -668,6 +668,14 @@ static int mlx5e_xfrm_add_state(struct xfrm_state *x,
 	if (err)
 		goto err_hw_ctx;
 
+	if (x->props.mode == XFRM_MODE_TUNNEL &&
+	    x->xso.type == XFRM_DEV_OFFLOAD_PACKET &&
+	    !mlx5e_ipsec_fs_tunnel_enabled(sa_entry)) {
+		NL_SET_ERR_MSG_MOD(extack, "Packet offload tunnel mode is disabled due to encap settings");
+		err = -EINVAL;
+		goto err_add_rule;
+	}
+
 	/* We use *_bh() variant because xfrm_timer_handler(), which runs
 	 * in softirq context, can reach our state delete logic and we need
 	 * xa_erase_bh() there.

drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.h

@@ -251,6 +251,7 @@ void mlx5e_accel_ipsec_fs_del_rule(struct mlx5e_ipsec_sa_entry *sa_entry);
 int mlx5e_accel_ipsec_fs_add_pol(struct mlx5e_ipsec_pol_entry *pol_entry);
 void mlx5e_accel_ipsec_fs_del_pol(struct mlx5e_ipsec_pol_entry *pol_entry);
 void mlx5e_accel_ipsec_fs_modify(struct mlx5e_ipsec_sa_entry *sa_entry);
+bool mlx5e_ipsec_fs_tunnel_enabled(struct mlx5e_ipsec_sa_entry *sa_entry);
 
 int mlx5_ipsec_create_sa_ctx(struct mlx5e_ipsec_sa_entry *sa_entry);
 void mlx5_ipsec_free_sa_ctx(struct mlx5e_ipsec_sa_entry *sa_entry);

drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_fs.c

@@ -4,6 +4,7 @@
 #include <linux/netdevice.h>
 #include "en.h"
 #include "en/fs.h"
+#include "eswitch.h"
 #include "ipsec.h"
 #include "fs_core.h"
 #include "lib/ipsec_fs_roce.h"
@@ -38,6 +39,7 @@ struct mlx5e_ipsec_rx {
 	struct mlx5e_ipsec_rule status;
 	struct mlx5e_ipsec_fc *fc;
 	struct mlx5_fs_chains *chains;
+	u8 allow_tunnel_mode : 1;
 };
 
 struct mlx5e_ipsec_tx {
@@ -47,6 +49,7 @@ struct mlx5e_ipsec_tx {
 	struct mlx5_flow_namespace *ns;
 	struct mlx5e_ipsec_fc *fc;
 	struct mlx5_fs_chains *chains;
+	u8 allow_tunnel_mode : 1;
 };
 
 /* IPsec RX flow steering */
@@ -254,7 +257,8 @@ static void rx_destroy(struct mlx5_core_dev *mdev, struct mlx5e_ipsec *ipsec,
 	mlx5_del_flow_rules(rx->sa.rule);
 	mlx5_destroy_flow_group(rx->sa.group);
 	mlx5_destroy_flow_table(rx->ft.sa);
-
+	if (rx->allow_tunnel_mode)
+		mlx5_eswitch_unblock_encap(mdev);
 	mlx5_del_flow_rules(rx->status.rule);
 	mlx5_modify_header_dealloc(mdev, rx->status.modify_hdr);
 	mlx5_destroy_flow_table(rx->ft.status);
@@ -305,6 +309,8 @@ static int rx_create(struct mlx5_core_dev *mdev, struct mlx5e_ipsec *ipsec,
 
 	/* Create FT */
 	if (mlx5_ipsec_device_caps(mdev) & MLX5_IPSEC_CAP_TUNNEL)
+		rx->allow_tunnel_mode = mlx5_eswitch_block_encap(mdev);
+	if (rx->allow_tunnel_mode)
 		flags = MLX5_FLOW_TABLE_TUNNEL_EN_REFORMAT;
 	ft = ipsec_ft_create(ns, MLX5E_ACCEL_FS_ESP_FT_LEVEL, MLX5E_NIC_PRIO, 2,
 			     flags);
@@ -362,6 +368,8 @@ static int rx_create(struct mlx5_core_dev *mdev, struct mlx5e_ipsec *ipsec,
 err_fs:
 	mlx5_destroy_flow_table(rx->ft.sa);
 err_fs_ft:
+	if (rx->allow_tunnel_mode)
+		mlx5_eswitch_unblock_encap(mdev);
 	mlx5_del_flow_rules(rx->status.rule);
 	mlx5_modify_header_dealloc(mdev, rx->status.modify_hdr);
 err_add:
@@ -496,7 +504,8 @@ static int ipsec_counter_rule_tx(struct mlx5_core_dev *mdev, struct mlx5e_ipsec_
 }
 
 /* IPsec TX flow steering */
-static void tx_destroy(struct mlx5e_ipsec_tx *tx, struct mlx5_ipsec_fs *roce)
+static void tx_destroy(struct mlx5_core_dev *mdev, struct mlx5e_ipsec_tx *tx,
+		       struct mlx5_ipsec_fs *roce)
 {
 	mlx5_ipsec_fs_roce_tx_destroy(roce);
 	if (tx->chains) {
@@ -508,6 +517,8 @@ static void tx_destroy(struct mlx5e_ipsec_tx *tx, struct mlx5_ipsec_fs *roce)
 	}
 
 	mlx5_destroy_flow_table(tx->ft.sa);
+	if (tx->allow_tunnel_mode)
+		mlx5_eswitch_unblock_encap(mdev);
 	mlx5_del_flow_rules(tx->status.rule);
 	mlx5_destroy_flow_table(tx->ft.status);
 }
@@ -530,6 +541,8 @@ static int tx_create(struct mlx5_core_dev *mdev, struct mlx5e_ipsec_tx *tx,
 		goto err_status_rule;
 
 	if (mlx5_ipsec_device_caps(mdev) & MLX5_IPSEC_CAP_TUNNEL)
+		tx->allow_tunnel_mode = mlx5_eswitch_block_encap(mdev);
+	if (tx->allow_tunnel_mode)
 		flags = MLX5_FLOW_TABLE_TUNNEL_EN_REFORMAT;
 	ft = ipsec_ft_create(tx->ns, 1, 0, 4, flags);
 	if (IS_ERR(ft)) {
@@ -581,6 +594,8 @@ static int tx_create(struct mlx5_core_dev *mdev, struct mlx5e_ipsec_tx *tx,
 err_pol_ft:
 	mlx5_destroy_flow_table(tx->ft.sa);
 err_sa_ft:
+	if (tx->allow_tunnel_mode)
+		mlx5_eswitch_unblock_encap(mdev);
 	mlx5_del_flow_rules(tx->status.rule);
 err_status_rule:
 	mlx5_destroy_flow_table(tx->ft.status);
@@ -609,7 +624,7 @@ static void tx_put(struct mlx5e_ipsec *ipsec, struct mlx5e_ipsec_tx *tx)
 	if (--tx->ft.refcnt)
 		return;
 
-	tx_destroy(tx, ipsec->roce);
+	tx_destroy(ipsec->mdev, tx, ipsec->roce);
 }
 
 static struct mlx5_flow_table *tx_ft_get_policy(struct mlx5_core_dev *mdev,
@@ -1603,3 +1618,15 @@ void mlx5e_accel_ipsec_fs_modify(struct mlx5e_ipsec_sa_entry *sa_entry)
 	mlx5e_accel_ipsec_fs_del_rule(sa_entry);
 	memcpy(sa_entry, &sa_entry_shadow, sizeof(*sa_entry));
 }
+
+bool mlx5e_ipsec_fs_tunnel_enabled(struct mlx5e_ipsec_sa_entry *sa_entry)
+{
+	struct mlx5e_ipsec_rx *rx =
+		ipsec_rx(sa_entry->ipsec, sa_entry->attrs.family);
+	struct mlx5e_ipsec_tx *tx = sa_entry->ipsec->tx;
+
+	if (sa_entry->attrs.dir == XFRM_DEV_OFFLOAD_OUT)
+		return tx->allow_tunnel_mode;
+
+	return rx->allow_tunnel_mode;
+}