Re: [dpdk-dev] i40e mbuf->rss indication

["Chilikin, Andrey" <andrey.chilikin@intel.com>]

Hi Hanoh,

Could you please explain what do you mean by *wrong hash value*?

i40e calculates hash value for TCP/UDP using 4-tuple: L3 source/destination addresses and L4 source/destination ports. It does not use IP protocol, as TCP and UDP already separated to different PCTYPEs at HW level. Could this be the root cause of the problem you are seeing?

Regards,
Andrey

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Bruce Richardson
> Sent: Thursday, March 22, 2018 2:22 PM
> To: Hanoch Haim (hhaim) <hhaim@cisco.com>
> Cc: Yigit, Ferruh <ferruh.yigit@intel.com>; dev@dpdk.org
> Subject: Re: [dpdk-dev] i40e mbuf->rss indication
> 
> On Thu, Mar 22, 2018 at 12:52:30PM +0000, Hanoch Haim (hhaim) wrote:
> > Hi,
> > I think this is not the vector driver because I'm user scatter/gather
> >
> 
> Vector driver has supported multi-buffer packets for a while now, so it
> should be used for packet RX in i40e in just about all cases.
> 
> If possible, could you check if adjusting the setting for 16B/32B
> descriptors in the build-time config makes a difference. For 16B
> descriptors the flow director ID and RSS hash share a field in the
> descriptor, while they don't with 32B versions (though the vector driver
> only ever reads the first 16B of each descriptor in any case).
> 
> /Bruce
> 
> > Thanks,
> > Hanoh
> >
> >
> > -----Original Message-----
> > From: Ferruh Yigit [mailto:ferruh.yigit@intel.com]
> > Sent: Thursday, March 22, 2018 2:18 PM
> > To: Hanoch Haim (hhaim); Bruce Richardson
> > Cc: dev@dpdk.org
> > Subject: Re: [dpdk-dev] i40e mbuf->rss indication
> >
> > On 3/22/2018 11:46 AM, Hanoch Haim (hhaim) wrote:
> > > Driver: i40e
> > >
> > > DPDK : 17.11
> > >
> > > Configuration :
> > >
> > > 1)     RSS configuration
> > >        rxmode.mq_mode = ETH_MQ_RX_RSS;
> > >        rss->rss_hf = ETH_RSS_UDP | ETH_RSS_TCP;
> > >        rss->rss_key = Microsoft key
> > >        rss->rss_key_len = 52
> > >
> > >        *configure RETA to some rx-queues
> > >
> > > 2)        Change hash to TOEPLITZ (only for i40e)
> > >
> > >           struct rte_eth_hash_filter_info info = {};
> > >           info.info_type = RTE_ETH_HASH_FILTER_GLOBAL_CONFIG;
> > >           info.info.global_conf.hash_func =
> RTE_ETH_HASH_FUNCTION_TOEPLITZ;
> > >           rte_eth_dev_filter_ctrl(m_repid,
> > >                                   RTE_ETH_FILTER_HASH,
> > >                                   RTE_ETH_FILTER_SET, &info);
> > >
> > > 3) Configure some flow-director rules
> > >
> > > 4) TCP/UDP packets are received to the *right* core (based on a SW
> Toeplitz calculation +reta table) however
> > >    The reported rss value is *wrong* in the mbuf
> > >   (m->hash.rss == *wrong value*)
> >
> > Are you getting same result with both scalar and vector driver?
> >
> > >   ((m->ol_flags&PKT_RX_RSS_HASH) == PKT_RX_RSS_HASH
> > >
> > > 5) The above works fine for mlx5 and ixgbe
> > >
> > > 6) I suspect the hash is something else, maybe flow-director id or xor
> hash ..
> > >
> > > Wanted to know if this is a known issue. I can provide a simple way to
> reproduce it using TRex
> > >
> > > Thanks,
> > > Hanoh
> > >
> > >
> > > -----Original Message-----
> > > From: Bruce Richardson [mailto:bruce.richardson@intel.com]
> > > Sent: Thursday, March 22, 2018 1:35 PM
> > > To: Hanoch Haim (hhaim)
> > > Cc: dev@dpdk.org
> > > Subject: Re: [dpdk-dev] i40e mbuf->rss indication
> > >
> > > On Wed, Mar 21, 2018 at 06:47:22PM +0000, Hanoch Haim (hhaim) wrote:
> > >> Hi All,
> > >> DPDK:17.11
> > >> When i40e is configured with RSS enabled and hash.type=toeplitz
> > >>
> > >> m->hash.rss = some weird number
> > >> ((m->ol_flags&PKT_RX_RSS_HASH) == PKT_RX_RSS_HASH
> > >>
> > >> The hash value is correct and match the MS Toeplitz standard.
> > >>
> > >> Is this expected?
> > >
> > > I'm sorry, but I don't quite follow the question, or the problem. Are you
> meaning to say that the hash value is incorrect, or that the flag is not being
> set or something else?
> > >
> > > /Bruce
> > >
> > >>
> > >> The above works fine with ixgbe/mlx5
> > >>
> > >> Thanks,
> > >> Hanoh
> > >>
> >