Re: [PATCH net-next v7 11/13] net: mana: keep a user-configured RSS table across a queue rebuild

[Wei Hu <weh@linux.microsoft.com>]

Hi,

> Does this silent reset desynchronize the driver from the ethtool core?

I will leave the ordinary allocation path unchanged in v8. The stale
user-indirection metadata is a real gap, but both upstream bases already
reinitialize the RSS table in mana_alloc_queues() without clearing the
ethtool core's user-table state. It is not introduced by this series.

A hardware queue-limit reduction during reattach can make a saved user
table invalid. Rebuilding a default table without reporting the loss can
then leave the core describing a user configuration that no longer
exists. I am treating this as an independent baseline issue, not claiming
that documenting the silent reset makes it correct.

The specific later-growth scenario also needs qualification because the
inspected reattach path monotonically clamps apc->max_queues. The stale
metadata and missing loss notification are the more direct issues.

> Can we safely call ethtool_rxfh_indir_lost() here to keep the states
> synchronized?

Not solely on the basis of its initial RTNL assertion. The notification
call chain also reaches netdev_assert_locked_ops_compat(). MANA registers
net_shaper_ops, so that check requires the netdev operations lock. The
reset worker holds RTNL but not that lock.

A separate correction needs to account for the notification context and
locking of every ordinary allocation caller; an unconditional helper
call at this location is not sufficient. That broader baseline fix is
outside this queue-set revision.

Thanks,
Wei