[dpdk-stable] [PATCH 19.11 3/6] net/mlx5: fix switchdev mode recognition

[Bing Zhao]

From: Viacheslav Ovsiienko <viacheslavo at nvidia.com>

[ upstream commit 6b157f3bfa64b734a069772bdbb4a3d3a8d26b83 ]

The new kernels might add the switch_id attribute to the
Netlink replies and this caused the wrong recognition
of the E-Switch presence. The single uplink device was
erroneously recognized as master and it caused the
extending match for source vport index on all installed
flows, including the default ones, and adding extra hops
in the steering engine, that affected the maximal
throughput packet rate.

The extra check for the new device name format (it supposes
the new kernel) and the device is only one is added. If this
check succeeds the E-Switch presence is considered as wrongly
detected and overridden.

Fixes: 30a86157f6d5 ("net/mlx5: support PF representor")
Cc: stable at dpdk.org

Signed-off-by: Viacheslav Ovsiienko <viacheslavo at nvidia.com>
Acked-by: Matan Azrad <matan at nvidia.com>
Signed-off-by: Bing Zhao <bingz at nvidia.com>
---
 drivers/net/mlx5/mlx5.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c
index 3208b2eda7..3f14bd5419 100644
--- a/drivers/net/mlx5/mlx5.c
+++ b/drivers/net/mlx5/mlx5.c
@@ -3364,6 +3364,18 @@ mlx5_pci_probe(struct rte_pci_driver *pci_drv __rte_unused,
 			ret = -rte_errno;
 			goto exit;
 		}
+		/*
+		 * New kernels may add the switch_id attribute for the case
+		 * there is no E-Switch and we wrongly recognized the
+		 * only device as master. Override this if there is the
+		 * single device with single port and new device name
+		 * format present.
+		 */
+		if (nd == 1 &&
+		    list[0].info.name_type == MLX5_PHYS_PORT_NAME_TYPE_UPLINK) {
+			list[0].info.master = 0;
+			list[0].info.representor = 0;
+		}
 	}
 	assert(ns);
 	/*
-- 
2.21.0