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

[Nélio Laranjeiro]

On Thu, Mar 22, 2018 at 10:42:44AM +0000, Xueming(Steven) Li wrote:
> Just remind, denying unsupported hash function in rte_eth_dev_configure() might
> impact some user app using PMD that simply ignoring them silently.

If the default behavior from other devices is to use only possible
values, this device should to the same instead of refusing it.

> 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

-- 
Nélio Laranjeiro
6WIND