On Fri, 2019-02-08 at 17:55 +0100, Toke Høiland-Jørgensen wrote:

Saeed Mahameed [off-list ref] writes:

quoted

But:
2) this won't totally solve our problem, since sometimes the driver
can
decide to recreate (change of configuration) hw resources on the
fly
while redirect/devmap is already happening, so we need some kind of
a
dev_map_notification or a flag with rcu synch, for when the driver
want
to make the xdp redirect resources unavailable.

Good point, I'll make a note of this. Do you have a pointer to where
the
mlx5 driver does this kind of change currently?

example:
ethtool -L to reduce/increase the number of rings
e.g. @mlx5e_ethtool_set_ringparam
or virtually anywhere mlx5e_switch_priv_channels is called when xdp
prog redirect is attached to mlx5.

-Toke