[PATCH net-next 1/2] netdevsim: add link speed support
From: Hangbin Liu <hidden>
Date: 2026-08-31 03:28:31
Also in:
linux-kselftest, lkml
Subsystem:
netdevsim, networking drivers, the rest · Maintainers:
Jakub Kicinski, Andrew Lunn, "David S. Miller", Eric Dumazet, Paolo Abeni, Linus Torvalds
From: Hangbin Liu <redacted> Add ethtool get/set_link_ksettings callbacks to netdevsim so the simulated link speed and duplex can be queried and configured from userspace. Move NSIM_LINK_SPEED_MAX and NSIM_LINK_SPEED_UNIT from dev.c to netdevsim.h so they are available to both the devlink rate path and the new ethtool code. The set callback rejects speeds exceeding NSIM_LINK_SPEED_MAX. The default link speed is set to SPEED_5000 with DUPLEX_FULL, matching the existing NSIM_LINK_SPEED_MAX definition. Signed-off-by: Hangbin Liu <redacted> --- drivers/net/netdevsim/dev.c | 6 ------ drivers/net/netdevsim/ethtool.c | 30 ++++++++++++++++++++++++++++++ drivers/net/netdevsim/netdevsim.h | 8 ++++++++ 3 files changed, 38 insertions(+), 6 deletions(-)
diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
index feb88ccbbced..729ce80f6c83 100644
--- a/drivers/net/netdevsim/dev.c
+++ b/drivers/net/netdevsim/dev.c@@ -1138,12 +1138,6 @@ nsim_dev_devlink_trap_policer_counter_get(struct devlink *devlink, return 0; } -#define NSIM_LINK_SPEED_MAX 5000 /* Mbps */ -#define NSIM_LINK_SPEED_UNIT 125000 /* 1 Mbps given in bytes/sec to avoid - * u64 overflow during conversion from - * bytes to bits. - */ - static int nsim_rate_bytes_to_units(char *name, u64 *rate, struct netlink_ext_ack *extack) { u64 val;
diff --git a/drivers/net/netdevsim/ethtool.c b/drivers/net/netdevsim/ethtool.c
index 025ea79879f3..59768bd7b620 100644
--- a/drivers/net/netdevsim/ethtool.c
+++ b/drivers/net/netdevsim/ethtool.c@@ -205,6 +205,30 @@ static int nsim_get_ts_info(struct net_device *dev, return 0; } +static int nsim_get_link_ksettings(struct net_device *dev, + struct ethtool_link_ksettings *cmd) +{ + struct netdevsim *ns = netdev_priv(dev); + + cmd->base.speed = ns->ethtool.speed; + cmd->base.duplex = ns->ethtool.duplex; + cmd->base.port = PORT_OTHER; + cmd->base.autoneg = AUTONEG_DISABLE; + return 0; +} + +static int nsim_set_link_ksettings(struct net_device *dev, + const struct ethtool_link_ksettings *cmd) +{ + struct netdevsim *ns = netdev_priv(dev); + + if (cmd->base.speed > NSIM_LINK_SPEED_MAX) + return -EINVAL; + + return ethtool_virtdev_set_link_ksettings(dev, cmd, &ns->ethtool.speed, + &ns->ethtool.duplex); +} + static const struct ethtool_ops nsim_ethtool_ops = { .supported_coalesce_params = ETHTOOL_COALESCE_ALL_PARAMS, .supported_ring_params = ETHTOOL_RING_USE_TCP_DATA_SPLIT |
@@ -223,6 +247,8 @@ static const struct ethtool_ops nsim_ethtool_ops = { .set_fecparam = nsim_set_fecparam, .get_fec_stats = nsim_get_fec_stats, .get_ts_info = nsim_get_ts_info, + .get_link_ksettings = nsim_get_link_ksettings, + .set_link_ksettings = nsim_set_link_ksettings, }; static void nsim_ethtool_ring_init(struct netdevsim *ns)
@@ -250,12 +276,16 @@ void nsim_ethtool_init(struct netdevsim *ns) ns->ethtool.fec.active_fec = ETHTOOL_FEC_NONE; ns->ethtool.channels = ns->nsim_bus_dev->num_queues; + ns->ethtool.duplex = DUPLEX_FULL; + ns->ethtool.speed = SPEED_5000; ethtool = debugfs_create_dir("ethtool", ns->nsim_dev_port->ddir); ns->ethtool_ddir = ethtool; debugfs_create_u32("get_err", 0600, ethtool, &ns->ethtool.get_err); debugfs_create_u32("set_err", 0600, ethtool, &ns->ethtool.set_err); + debugfs_create_u32("speed", 0600, ethtool, &ns->ethtool.speed); + debugfs_create_u8("duplex", 0600, ethtool, &ns->ethtool.duplex); dir = debugfs_create_dir("pause", ethtool); debugfs_create_bool("report_stats_rx", 0600, dir,
diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h
index 55aec41237b9..ce0d0dea00fb 100644
--- a/drivers/net/netdevsim/netdevsim.h
+++ b/drivers/net/netdevsim/netdevsim.h@@ -39,6 +39,11 @@ #define NSIM_HDS_THRESHOLD_MAX 1024 +#define NSIM_LINK_SPEED_MAX 5000 /* Mbps */ +#define NSIM_LINK_SPEED_UNIT 125000 /* 1 Mbps given in bytes/sec to avoid + * u64 overflow during conversion from + * bytes to bits. + */ struct nsim_sa { struct xfrm_state *xs; __be32 ipaddr[4];
@@ -95,6 +100,9 @@ struct nsim_ethtool { struct ethtool_coalesce coalesce; struct ethtool_ringparam ring; struct ethtool_fecparam fec; + + u32 speed; + u8 duplex; }; struct nsim_rq {
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2.55.0