From: Jakub Kicinski Date: Fri, 5 Jun 2026 00:29:05 +0000 (-0700) Subject: net: ethtool: optionally skip rtnl_lock on Netlink path for SET ops X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f9a3e05114b85d63452e7f9c172b53d6a1736fe0;p=thirdparty%2Fkernel%2Flinux.git net: ethtool: optionally skip rtnl_lock on Netlink path for SET ops Make ethtool not take rtnl_lock for SET commands when operation is performed on an ops-locked driver. cfg/cfg_pending are now ops-locked, since only ethtool modifies them. Some SET driver callbacks will still need rtnl_lock, most notably those which may end up calling netdev_update_features() or the qdisc layer (via netif_set_real_num_tx_queues()). Let drivers selectively opt back into the rtnl_lock with a new bitfield in ops. We need two helpers since Netlink and ioctl cmds have different values. Keep the helpers side by side in common.h to make sure they get updated together, even tho they will only get called from ioctl.c and netlink.c. SET commands which don't use ethnl_default_set_doit() are converted by subsequent commits. Reviewed-by: Eric Dumazet Acked-by: Stanislav Fomichev Reviewed-by: Jacob Keller Link: https://patch.msgid.link/20260605002912.3456868-6-kuba@kernel.org Signed-off-by: Jakub Kicinski --- diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c index edafa79f636c7..56d74a3c24b7c 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c @@ -5729,6 +5729,10 @@ const struct ethtool_ops bnxt_ethtool_ops = { .rxfh_max_num_contexts = BNXT_MAX_ETH_RSS_CTX + 1, .rxfh_indir_space = BNXT_MAX_RSS_TABLE_ENTRIES_P5, .rxfh_priv_size = sizeof(struct bnxt_rss_ctx), + .op_needs_rtnl = ETHTOOL_OP_NEEDS_RTNL_SCHANNELS | + ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM | + ETHTOOL_OP_NEEDS_RTNL_SCOALESCE | + ETHTOOL_OP_NEEDS_RTNL_RSS, .supported_coalesce_params = ETHTOOL_COALESCE_USECS | ETHTOOL_COALESCE_MAX_FRAMES | ETHTOOL_COALESCE_USECS_IRQ | diff --git a/drivers/net/ethernet/google/gve/gve_ethtool.c b/drivers/net/ethernet/google/gve/gve_ethtool.c index 7cd43e082b2a4..7cc22916852fb 100644 --- a/drivers/net/ethernet/google/gve/gve_ethtool.c +++ b/drivers/net/ethernet/google/gve/gve_ethtool.c @@ -983,6 +983,8 @@ const struct ethtool_ops gve_ethtool_ops = { .supported_coalesce_params = ETHTOOL_COALESCE_USECS, .supported_ring_params = ETHTOOL_RING_USE_TCP_DATA_SPLIT | ETHTOOL_RING_USE_RX_BUF_LEN, + .op_needs_rtnl = ETHTOOL_OP_NEEDS_RTNL_SCHANNELS | + ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM, .get_drvinfo = gve_get_drvinfo, .get_strings = gve_get_strings, .get_sset_count = gve_get_sset_count, diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c index 61993485e4517..2f5b626ba33fe 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c @@ -2719,6 +2719,9 @@ const struct ethtool_ops mlx5e_ethtool_ops = { .rxfh_per_ctx_fields = true, .rxfh_per_ctx_key = true, .rxfh_max_num_contexts = MLX5E_MAX_NUM_RSS, + .op_needs_rtnl = ETHTOOL_OP_NEEDS_RTNL_SCHANNELS | + ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM | + ETHTOOL_OP_NEEDS_RTNL_SPFLAGS, .supported_coalesce_params = ETHTOOL_COALESCE_USECS | ETHTOOL_COALESCE_MAX_FRAMES | ETHTOOL_COALESCE_USE_ADAPTIVE | diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c index ba6c0f38cc738..1a8a19f980d33 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c @@ -418,6 +418,8 @@ static const struct ethtool_ops mlx5e_rep_ethtool_ops = { .supported_coalesce_params = ETHTOOL_COALESCE_USECS | ETHTOOL_COALESCE_MAX_FRAMES | ETHTOOL_COALESCE_USE_ADAPTIVE, + .op_needs_rtnl = ETHTOOL_OP_NEEDS_RTNL_SCHANNELS | + ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM, .get_drvinfo = mlx5e_rep_get_drvinfo, .get_link = ethtool_op_get_link, .get_strings = mlx5e_rep_get_strings, diff --git a/drivers/net/ethernet/mellanox/mlx5/core/ipoib/ethtool.c b/drivers/net/ethernet/mellanox/mlx5/core/ipoib/ethtool.c index 3b2f54ca30a80..9b3b32408c64b 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/ipoib/ethtool.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/ipoib/ethtool.c @@ -285,6 +285,8 @@ const struct ethtool_ops mlx5i_ethtool_ops = { .supported_coalesce_params = ETHTOOL_COALESCE_USECS | ETHTOOL_COALESCE_MAX_FRAMES | ETHTOOL_COALESCE_USE_ADAPTIVE, + .op_needs_rtnl = ETHTOOL_OP_NEEDS_RTNL_SCHANNELS | + ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM, .get_drvinfo = mlx5i_get_drvinfo, .get_strings = mlx5i_get_strings, .get_sset_count = mlx5i_get_sset_count, diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c index a2c16d5993897..cb34fc166ef96 100644 --- a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c +++ b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c @@ -2021,7 +2021,10 @@ static const struct ethtool_ops fbnic_ethtool_ops = { ETHTOOL_RING_USE_HDS_THRS, .rxfh_max_num_contexts = FBNIC_RPC_RSS_TBL_COUNT, .op_needs_rtnl = ETHTOOL_OP_NEEDS_RTNL_LINKSETTINGS | - ETHTOOL_OP_NEEDS_RTNL_GPAUSEPARAM, + ETHTOOL_OP_NEEDS_RTNL_GPAUSEPARAM | + ETHTOOL_OP_NEEDS_RTNL_SPAUSEPARAM | + ETHTOOL_OP_NEEDS_RTNL_SCHANNELS | + ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM, .get_drvinfo = fbnic_get_drvinfo, .get_regs_len = fbnic_get_regs_len, .get_regs = fbnic_get_regs, diff --git a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c index 04350973e19e3..55df44d728a0a 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c +++ b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c @@ -575,6 +575,8 @@ static int mana_get_link_ksettings(struct net_device *ndev, const struct ethtool_ops mana_ethtool_ops = { .supported_coalesce_params = ETHTOOL_COALESCE_RX_CQE_FRAMES, + .op_needs_rtnl = ETHTOOL_OP_NEEDS_RTNL_SCHANNELS | + ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM, .get_ethtool_stats = mana_get_ethtool_stats, .get_sset_count = mana_get_sset_count, .get_strings = mana_get_strings, diff --git a/drivers/net/netdevsim/ethtool.c b/drivers/net/netdevsim/ethtool.c index 36a201533aaea..9350ba48eb815 100644 --- a/drivers/net/netdevsim/ethtool.c +++ b/drivers/net/netdevsim/ethtool.c @@ -209,6 +209,7 @@ static const struct ethtool_ops nsim_ethtool_ops = { .supported_coalesce_params = ETHTOOL_COALESCE_ALL_PARAMS, .supported_ring_params = ETHTOOL_RING_USE_TCP_DATA_SPLIT | ETHTOOL_RING_USE_HDS_THRS, + .op_needs_rtnl = ETHTOOL_OP_NEEDS_RTNL_SCHANNELS, .get_pause_stats = nsim_get_pause_stats, .get_pauseparam = nsim_get_pauseparam, .set_pauseparam = nsim_set_pauseparam, diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h index 1da49161d36f1..74c8109b0cf31 100644 --- a/include/linux/ethtool.h +++ b/include/linux/ethtool.h @@ -935,7 +935,13 @@ struct kernel_ethtool_ts_info { * these bits separate, per GET and SET. GET is much easier to "unlock". */ #define ETHTOOL_OP_NEEDS_RTNL_LINKSETTINGS BIT(0) -#define ETHTOOL_OP_NEEDS_RTNL_GPAUSEPARAM BIT(1) +#define ETHTOOL_OP_NEEDS_RTNL_SPFLAGS BIT(1) +#define ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM BIT(2) +#define ETHTOOL_OP_NEEDS_RTNL_SCHANNELS BIT(3) +#define ETHTOOL_OP_NEEDS_RTNL_SCOALESCE BIT(4) +#define ETHTOOL_OP_NEEDS_RTNL_GPAUSEPARAM BIT(5) +#define ETHTOOL_OP_NEEDS_RTNL_SPAUSEPARAM BIT(6) +#define ETHTOOL_OP_NEEDS_RTNL_RSS BIT(7) /** * struct ethtool_ops - optional netdev operations @@ -970,6 +976,8 @@ struct kernel_ethtool_ts_info { * The following commonly used core APIs currently require rtnl_lock * (this list may not be exhaustive): * - phylink helpers (note that phydev is currently unsupported!) + * - netdev_update_features() + * - netif_set_real_num_tx_queues() * * @get_drvinfo: Report driver/device information. Modern drivers no * longer have to implement this callback. Most fields are diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index a8709d0cc8d47..403b6d1c67f8f 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2584,7 +2584,7 @@ struct net_device { * @up, @moving_ns, @nd_net, @xdp_features * * Ops protects: - * @hwprov + * @cfg, @cfg_pending, @hwprov * * Double ops protects: * @real_num_rx_queues, @real_num_tx_queues diff --git a/net/ethtool/common.h b/net/ethtool/common.h index 391c41ca56bee..e3052972f953b 100644 --- a/net/ethtool/common.h +++ b/net/ethtool/common.h @@ -95,10 +95,24 @@ ethtool_nl_msg_needs_rtnl(const struct net_device *dev, u8 cmd) switch (cmd) { case ETHTOOL_MSG_LINKINFO_GET: + case ETHTOOL_MSG_LINKINFO_SET: case ETHTOOL_MSG_LINKMODES_GET: + case ETHTOOL_MSG_LINKMODES_SET: return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_LINKSETTINGS; + case ETHTOOL_MSG_PRIVFLAGS_SET: + return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_SPFLAGS; + case ETHTOOL_MSG_RINGS_SET: + return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM; + case ETHTOOL_MSG_CHANNELS_SET: + return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_SCHANNELS; + case ETHTOOL_MSG_COALESCE_SET: + return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_SCOALESCE; case ETHTOOL_MSG_PAUSE_GET: return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_GPAUSEPARAM; + case ETHTOOL_MSG_PAUSE_SET: + return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_SPAUSEPARAM; + case ETHTOOL_MSG_RSS_SET: + return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_RSS; } return false; } @@ -119,9 +133,25 @@ ethtool_ioctl_needs_rtnl(const struct net_device *dev, u32 ethcmd) switch (ethcmd) { case ETHTOOL_GLINKSETTINGS: case ETHTOOL_GSET: + case ETHTOOL_SLINKSETTINGS: + case ETHTOOL_SSET: return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_LINKSETTINGS; + case ETHTOOL_SPFLAGS: + return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_SPFLAGS; + case ETHTOOL_SRINGPARAM: + return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_SRINGPARAM; + case ETHTOOL_SCHANNELS: + return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_SCHANNELS; + case ETHTOOL_SCOALESCE: + return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_SCOALESCE; case ETHTOOL_GPAUSEPARAM: return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_GPAUSEPARAM; + case ETHTOOL_SPAUSEPARAM: + return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_SPAUSEPARAM; + case ETHTOOL_SRSSH: + case ETHTOOL_SRXFH: + case ETHTOOL_SRXFHINDIR: + return ops->op_needs_rtnl & ETHTOOL_OP_NEEDS_RTNL_RSS; } return false; } diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c index 2c30eb1f46664..1af395b54330e 100644 --- a/net/ethtool/netlink.c +++ b/net/ethtool/netlink.c @@ -903,6 +903,7 @@ static int ethnl_default_set_doit(struct sk_buff *skb, struct genl_info *info) const u8 cmd = info->genlhdr->cmd; struct ethnl_req_info *req_info; struct net_device *dev; + bool need_rtnl; int ret; ops = ethnl_default_requests[cmd]; @@ -927,8 +928,11 @@ static int ethnl_default_set_doit(struct sk_buff *skb, struct genl_info *info) } dev = req_info->dev; + need_rtnl = !netdev_need_ops_lock(dev) || + ethtool_nl_msg_needs_rtnl(dev, cmd); - rtnl_lock(); + if (need_rtnl) + rtnl_lock(); netdev_lock_ops(dev); dev->cfg_pending = kmemdup(dev->cfg, sizeof(*dev->cfg), GFP_KERNEL_ACCOUNT); @@ -958,7 +962,8 @@ out_free_cfg: out_tie_cfg: dev->cfg_pending = dev->cfg; netdev_unlock_ops(dev); - rtnl_unlock(); + if (need_rtnl) + rtnl_unlock(); out_dev: ethnl_parse_header_dev_put(req_info); out_free_req: