[dpdk-dev] [PATCH] net/mlx5: add supported hash function check

[Xueming(Steven) Li]

Just remind, denying unsupported hash function in rte_eth_dev_configure() might
impact some user app using PMD that simply ignoring them silently.

Testpmd command "port config <port> rss all" should be updated as well 
to 'all' supported values from rte_eth_dev_info, I'll include this change in 
next version.

> -----Original Message-----
> From: Nélio Laranjeiro [mailto:nelio.laranjeiro at 6wind.com]
> Sent: Monday, March 19, 2018 4:30 PM
> To: Xueming(Steven) Li <xuemingl at mellanox.com>
> Cc: Adrien Mazarguil <adrien.mazarguil at 6wind.com>; Shahaf Shuler
> <shahafs at mellanox.com>; dev at dpdk.org
> Subject: Re: [PATCH] net/mlx5: add supported hash function check
> 
> On Sun, Mar 18, 2018 at 03:37:20PM +0800, Xueming Li wrote:
> > Add supported RSS hash function check in device configuration to have
> > better error verbosity for application developers.
> >
> > Signed-off-by: Xueming Li <xuemingl at mellanox.com>
> > ---
> >  drivers/net/mlx5/mlx5_ethdev.c | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> >
> > diff --git a/drivers/net/mlx5/mlx5_ethdev.c
> > b/drivers/net/mlx5/mlx5_ethdev.c index b73cb53..175a1ff 100644
> > --- a/drivers/net/mlx5/mlx5_ethdev.c
> > +++ b/drivers/net/mlx5/mlx5_ethdev.c
> > @@ -346,6 +346,14 @@ struct ethtool_link_settings {
> >  		      rx_offloads, supp_rx_offloads);
> >  		return ENOTSUP;
> >  	}
> > +	if (dev->data->dev_conf.rx_adv_conf.rss_conf.rss_hf &
> > +	    MLX5_RSS_HF_MASK) {
> > +		ERROR("Some RSS hash function not supported "
> > +		      "requested 0x%" PRIx64 " supported 0x%" PRIx64,
> > +		      dev->data->dev_conf.rx_adv_conf.rss_conf.rss_hf,
> > +		      (uint64_t)(~MLX5_RSS_HF_MASK));
> > +		return ENOTSUP;
> > +	}
> >  	if (use_app_rss_key &&
> >  	    (dev->data->dev_conf.rx_adv_conf.rss_conf.rss_key_len !=
> >  	     rss_hash_default_key_len)) {
> > --
> > 1.8.3.1
> >
> 
> I would answer than an application should not try to configure something
> not advertise by the device.
> This information is present in struct rte_eth_dev_info returned by
> mlx5_dev_infos_get() and thus the devops of the device.
> 
> Seems rte_eth_dev_configure() should be fixed to avoid configuring wrong
> values.
> 
> Regards,
> 
> --
> Nélio Laranjeiro
> 6WIND