net: rtnetlink: add pacing_offload attribute to net_device

Add a new flag to administratively control pacing offload.

The feature is disabled by default. That does not cause regressions, as no
driver advertises max_pacing_offload_horizon yet.

Also add NLA_REJECT for max_pacing_offload_horizon, in line with
other such read-only members of link-attrs.

Both fields can be read with

    ynl --family rt-link --do getlink \
        --json '{"ifname": "eth0"}' | grep pacing

And pacing offload enabled with

    ynl --family rt-link --do setlink \
        --json '{"ifname": "eth0", "pacing-offload": 1}'

Signed-off-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260910171131.2532487-2-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 707b2e51c2b9..1f0710eef185 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1840,6 +1840,7 @@ enum netdev_reg_state {
  *			drivers. Mainly used by logical interfaces, such as
  *			bonding and tunnels
  *	@netmem_tx:	device netmem TX mode
+ *	@pacing_offload: enable EDT pacing offload.
  *
  *	@name:	This is the first field of the "visible" part of this structure
  *		(i.e. as seen by users in the "Space.c" file).  It is the name
@@ -2170,6 +2171,7 @@ struct net_device {
 		unsigned long		priv_flags:32;
 		unsigned long		lltx:1;
 		unsigned long		netmem_tx:2;
+		unsigned long		pacing_offload:1;
 	);
 	const struct net_device_ops *netdev_ops;
 	const struct header_ops *header_ops;