On Wed, Nov 13, 2024 at 12:13:09PM +0000, edward.cree@xxxxxxx wrote:
>
> From: Edward Cree <ecree.xilinx@xxxxxxxxx>
>
> Ethtool ntuple filters with FLOW_RSS were originally defined as adding
> the base queue ID (ring_cookie) to the value from the indirection table,
> so that the same table could distribute over more than one set of queues
> when used by different filters.
> However, some drivers / hardware ignore the ring_cookie, and simply use
> the indirection table entries as queue IDs directly. Thus, for drivers
> which have not opted in by setting ethtool_ops.cap_rss_rxnfc_adds to
> declare that they support the original (addition) semantics, reject in
> ethtool_set_rxnfc any filter which combines FLOW_RSS and a nonzero ring.
> (For a ring_cookie of zero, both behaviours are equivalent.)
> Set the cap bit in sfc, as it is known to support this feature.
>
> Signed-off-by: Edward Cree <ecree.xilinx@xxxxxxxxx>
Reviewed-by: Martin Habets <habetsm.xilinx@xxxxxxxxx>
> ---
> drivers/net/ethernet/sfc/ef100_ethtool.c | 1 +
> drivers/net/ethernet/sfc/ethtool.c | 1 +
> include/linux/ethtool.h | 4 ++++
> net/ethtool/ioctl.c | 5 +++++
> 4 files changed, 11 insertions(+)
>
> diff --git a/drivers/net/ethernet/sfc/ef100_ethtool.c b/drivers/net/ethernet/sfc/ef100_ethtool.c
> index 5c2551369812..6c3b74000d3b 100644
> --- a/drivers/net/ethernet/sfc/ef100_ethtool.c
> +++ b/drivers/net/ethernet/sfc/ef100_ethtool.c
> @@ -59,6 +59,7 @@ const struct ethtool_ops ef100_ethtool_ops = {
> .get_rxfh_indir_size = efx_ethtool_get_rxfh_indir_size,
> .get_rxfh_key_size = efx_ethtool_get_rxfh_key_size,
> .rxfh_per_ctx_key = true,
> + .cap_rss_rxnfc_adds = true,
> .rxfh_priv_size = sizeof(struct efx_rss_context_priv),
> .get_rxfh = efx_ethtool_get_rxfh,
> .set_rxfh = efx_ethtool_set_rxfh,
> diff --git a/drivers/net/ethernet/sfc/ethtool.c b/drivers/net/ethernet/sfc/ethtool.c
> index bb1930818beb..83d715544f7f 100644
> --- a/drivers/net/ethernet/sfc/ethtool.c
> +++ b/drivers/net/ethernet/sfc/ethtool.c
> @@ -263,6 +263,7 @@ const struct ethtool_ops efx_ethtool_ops = {
> .get_rxfh_indir_size = efx_ethtool_get_rxfh_indir_size,
> .get_rxfh_key_size = efx_ethtool_get_rxfh_key_size,
> .rxfh_per_ctx_key = true,
> + .cap_rss_rxnfc_adds = true,
> .rxfh_priv_size = sizeof(struct efx_rss_context_priv),
> .get_rxfh = efx_ethtool_get_rxfh,
> .set_rxfh = efx_ethtool_set_rxfh,
> diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
> index 1199e308c8dd..299280c94d07 100644
> --- a/include/linux/ethtool.h
> +++ b/include/linux/ethtool.h
> @@ -734,6 +734,9 @@ struct kernel_ethtool_ts_info {
> * @rxfh_per_ctx_key: device supports setting different RSS key for each
> * additional context. Netlink API should report hfunc, key, and input_xfrm
> * for every context, not just context 0.
> + * @cap_rss_rxnfc_adds: device supports nonzero ring_cookie in filters with
> + * %FLOW_RSS flag; the queue ID from the filter is added to the value from
> + * the indirection table to determine the delivery queue.
> * @rxfh_indir_space: max size of RSS indirection tables, if indirection table
> * size as returned by @get_rxfh_indir_size may change during lifetime
> * of the device. Leave as 0 if the table size is constant.
> @@ -956,6 +959,7 @@ struct ethtool_ops {
> u32 cap_rss_ctx_supported:1;
> u32 cap_rss_sym_xor_supported:1;
> u32 rxfh_per_ctx_key:1;
> + u32 cap_rss_rxnfc_adds:1;
> u32 rxfh_indir_space;
> u16 rxfh_key_space;
> u16 rxfh_priv_size;
> diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
> index 7da94e26ced6..d86399bcf223 100644
> --- a/net/ethtool/ioctl.c
> +++ b/net/ethtool/ioctl.c
> @@ -992,6 +992,11 @@ static noinline_for_stack int ethtool_set_rxnfc(struct net_device *dev,
> if (rc)
> return rc;
>
> + /* Nonzero ring with RSS only makes sense if NIC adds them together */
> + if (info.flow_type & FLOW_RSS && !ops->cap_rss_rxnfc_adds &&
> + ethtool_get_flow_spec_ring(info.fs.ring_cookie))
> + return -EINVAL;
> +
> if (ops->get_rxfh) {
> struct ethtool_rxfh_param rxfh = {};
>
