net/mlx5: Add net namespace support to devcom

Extend the devcom framework to support namespace-aware components.

The existing devcom matching logic was based solely on numeric keys,
limiting its use to the global (init_net) scope or requiring clients to
ignore namespaces altogether, both of which are incorrect in
multi-namespace environments.

This patch introduces namespace support by allowing devcom clients to
provide a namespace match attribute. The devcom pairing mechanism is
updated to compare the namespace, enabling proper isolation and
interaction of components across different net namespaces.

With this change, components that require namespace aware pairing, such
as SD groups or LAG, can now work correctly in multi-namespace
scenarios. In particular, this opens the way to support hardware LAG
within a net namespace.

Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/1757940070-618661-4-git-send-email-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

4 files changed, 24 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index 9874a15c6fba..09c3eecb836d 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -66,6 +66,7 @@
 #include "lib/devcom.h"
 #include "lib/geneve.h"
 #include "lib/fs_chains.h"
+#include "lib/mlx5.h"
 #include "diag/en_tc_tracepoint.h"
 #include <asm/div64.h>
 #include "lag/lag.h"
@@ -5450,6 +5451,8 @@ int mlx5e_tc_esw_init(struct mlx5_rep_uplink_priv *uplink_priv)
 	err = netif_get_port_parent_id(priv->netdev, &ppid, false);
 	if (!err) {
 		memcpy(&attr.key.val, &ppid.id, sizeof(attr.key.val));
+		attr.flags = MLX5_DEVCOM_MATCH_FLAGS_NS;
+		attr.net = mlx5_core_net(esw->dev);
 		mlx5_esw_offloads_devcom_init(esw, &attr);
 	}
 
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c b/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c
index 1ab9de316deb..faa2833602c8 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c
@@ -4,6 +4,7 @@
 #include <linux/mlx5/vport.h>
 #include <linux/list.h>
 #include "lib/devcom.h"
+#include "lib/mlx5.h"
 #include "mlx5_core.h"
 
 static LIST_HEAD(devcom_dev_list);
@@ -23,7 +24,9 @@ struct mlx5_devcom_dev {
 };
 
 struct mlx5_devcom_key {
+	u32 flags;
 	union mlx5_devcom_match_key key;
+	possible_net_t net;
 };
 
 struct mlx5_devcom_comp {
@@ -123,6 +126,9 @@ mlx5_devcom_comp_alloc(u64 id, const struct mlx5_devcom_match_attr *attr,
 
 	comp->id = id;
 	comp->key.key = attr->key;
+	comp->key.flags = attr->flags;
+	if (attr->flags & MLX5_DEVCOM_MATCH_FLAGS_NS)
+		write_pnet(&comp->key.net, attr->net);
 	comp->handler = handler;
 	init_rwsem(&comp->sem);
 	lockdep_register_key(&comp->lock_key);
@@ -190,9 +196,16 @@ devcom_component_equal(struct mlx5_devcom_comp *devcom,
 	if (devcom->id != id)
 		return false;
 
+	if (devcom->key.flags != attr->flags)
+		return false;
+
 	if (memcmp(&devcom->key.key, &attr->key, sizeof(devcom->key.key)))
 		return false;
 
+	if (devcom->key.flags & MLX5_DEVCOM_MATCH_FLAGS_NS &&
+	    !net_eq(read_pnet(&devcom->key.net), attr->net))
+		return false;
+
 	return true;
 }
 
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.h b/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.h
index f350d2395707..609c85f47917 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.h
@@ -6,12 +6,18 @@
 
 #include <linux/mlx5/driver.h>
 
+enum mlx5_devom_match_flags {
+	MLX5_DEVCOM_MATCH_FLAGS_NS = BIT(0),
+};
+
 union mlx5_devcom_match_key {
 	u64 val;
 };
 
 struct mlx5_devcom_match_attr {
+	u32 flags;
 	union mlx5_devcom_match_key key;
+	struct net *net;
 };
 
 enum mlx5_devcom_component {
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/sd.c b/drivers/net/ethernet/mellanox/mlx5/core/lib/sd.c
index d4015328ba65..f5c2701f6e87 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/lib/sd.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/sd.c
@@ -217,6 +217,8 @@ static int sd_register(struct mlx5_core_dev *dev)
 
 	sd = mlx5_get_sd(dev);
 	attr.key.val = sd->group_id;
+	attr.flags = MLX5_DEVCOM_MATCH_FLAGS_NS;
+	attr.net = mlx5_core_net(dev);
 	devcom = mlx5_devcom_register_component(dev->priv.devc, MLX5_DEVCOM_SD_GROUP,
 						&attr, NULL, dev);
 	if (IS_ERR(devcom))