> -----Original Message-----
> From: Min Hu (Connor) <humi...@huawei.com>
> Sent: Wednesday, June 30, 2021 7:22 PM
> To: Yigit, Ferruh <ferruh.yi...@intel.com>; dev@dpdk.org; Thomas Monjalon
> <tho...@monjalon.net>; Andrew Rybchenko
> <andrew.rybche...@oktetlabs.ru>
> Cc: Xing, Beilei <beilei.x...@intel.com>; Matan Azrad
> <ma...@mellanox.com>; shah...@nvidia.com; viachesl...@nvidia.com
> Subject: Re: Question about 'rxm->hash.rss' and 'mb->hash.fdir'
>
> Hi, Beilei, Matan, Shahaf, Viacheslav,
>
> how about your opinion?
Agree with Ferruh.
>
> 在 2021/6/30 17:34, Ferruh Yigit 写道:
> > On 6/30/2021 3:45 AM, Min Hu (Connor) wrote:
> >> Hi, all
> >> one question about 'rxm->hash.rss' and 'mb->hash.fdir'.
> >>
> >> In Rx recv packets function,
> >> 'rxm->hash.rss' will report rss hash result from Rx desc.
> >> 'rxm->hash.fdir' will report filter identifier from Rx desc.
> >>
> >> But function implementation differs from some PMDs. for example:
> >> i40e, MLX5 report the two at the same time if pkt_flags is set,like:
> >> ******************************************
> >> if (pkt_flags & PKT_RX_RSS_HASH) {
> >> rxm->hash.rss =
> >> rte_le_to_cpu_32(rxd.wb.qword0.hi_dword.rss);
> >> }
> >> if (pkt_flags & PKT_RX_FDIR) {
> >> mb->hash.fdir.hi =
> >> rte_le_to_cpu_32(rxdp->wb.qword3.hi_dword.fd_id);
> >> }
> >> ********************************************
> >>
> >> While, ixgbe only report one of the two. like:
> >> ******************************************
> >> if (likely(pkt_flags & PKT_RX_RSS_HASH))
> >> mb->hash.rss = rte_le_to_cpu_32(
> >> rxdp[j].wb.lower.hi_dword.rss);
> >> else if (pkt_flags & PKT_RX_FDIR) {
> >> mb->hash.fdir.hash = rte_le_to_cpu_16(
> >> rxdp[j].wb.lower.hi_dword.csum_ip.csum) &
> >> IXGBE_ATR_HASH_MASK;
> >> mb->hash.fdir.id = rte_le_to_cpu_16(
> >> rxdp[j].wb.lower.hi_dword.csum_ip.ip_id);
> >> }
> >> ********************************************
> >> So, what is application scenario for 'rxm->hash.rss' and
> >> 'mb->hash.fdir', that is, why the two should be reported? How about
> >> reporting the two at the same time?
> >> Thanks for your reply.
> >
> >
> > Hi Connor,
> >
> > mbuf->hash is union, so it is not possible to set both 'hash.rss' &
> > 'hash.fdir'.
> >
> > I assume for i40e & mlx5 case 'pkt_flags' indicate which one is valid
> > and only one is set in practice. Cc'ed driver mainteriners for more comment.
>
> Thanks Ferruh,
> another question, why does user need this information: rxm-
> >hash.rss or mb->hash.fdir.hi ? what is the function?
>
> > .
> >
