Re: [PATCH v2 net-next 0/4] sfc: encapsulated filters

[Tom Herbert <tom@herbertland.com>]

On Fri, Jan 27, 2017 at 7:00 AM, Edward Cree <ecree@solarflare.com> wrote:
> This series adds support for setting up filters for encapsulated traffic on
> SFC 8000-series adapters, which recognise VXLAN, GENEVE and NVGRE packets by
> parsing packet headers.  (VXLAN and GENEVE will only be recognised if the
> driver on the primary PF has notified the firmware of relevant UDP ports,
> which this driver does not yet do.)
> While the driver currently has no way of using these filters for flow
> steering, it is nonetheless necessary to insert catch-all (aka 'default')
> filters to direct this traffic, similar to the existing unencapsulated uni-
> and multi-cast catch-all filters, as otherwise the traffic will be dropped
> by the NIC - implementation details of the hardware filtering mean that the
> traffic will not get matched on outer MAC address to unencapsulated catch-
> all filters.  (Yes, this is a mess.)

I don't understand this. You seem to be saying that unless there is
filtering for VXLAN and GENEVE these packets will dropped. These are
_just_ UDP packets. Anything that the NIC does special for them is at
most an optimization, it can *NEVER* be a requirement for NICs to be
able to parse these protocols. Please elaborate...

Tom


> Although this is, therefore, fixing a bug in the existing driver, it's a bug
> which has existed since 8000 series support was added, and the fix involves
> quite a big patch with an 'adding features' flavour to it, hence why this is
> for net-next rather than net and stable.
>
> v2: move netif_cond_dbg into netdevice.h and its own patch
>
> ---
> Edward Cree (2):
>   net: implement netif_cond_dbg macro
>   sfc: insert catch-all filters for encapsulated traffic
>
> Jon Cooper (2):
>   sfc: fixes to filter restore handling
>   sfc: refactor debug-or-warnings printks
>
>  drivers/net/ethernet/sfc/ef10.c   | 582 ++++++++++++++++++++++++++++----------
>  drivers/net/ethernet/sfc/filter.h |  41 ++-
>  drivers/net/ethernet/sfc/mcdi.c   |  19 +-
>  include/linux/netdevice.h         |   9 +
>  4 files changed, 497 insertions(+), 154 deletions(-)
>