[ovs-dev] [PATCH v2 8/8] netdev-dpdk: set FDIR config

[Chandran, Sugesh]

Regards
_Sugesh

> -----Original Message-----
> From: Yuanhan Liu [mailto:yliu at fridaylinux.org]
> Sent: Thursday, September 14, 2017 4:19 AM
> To: Darrell Ball <dball at vmware.com>
> Cc: Finn Christensen <fc at napatech.com>; Chandran, Sugesh
> <sugesh.chandran at intel.com>; dev at openvswitch.org
> Subject: Re: [ovs-dev] [PATCH v2 8/8] netdev-dpdk: set FDIR config
> 
> On Wed, Sep 13, 2017 at 01:57:22AM +0000, Darrell Ball wrote:
> >
> >
> > On 9/11/17, 1:14 AM, "ovs-dev-bounces at openvswitch.org on behalf of
> Finn Christensen" <ovs-dev-bounces at openvswitch.org on behalf of
> fc at napatech.com> wrote:
> >
> >     -----Original Message-----
> >     From: ovs-dev-bounces at openvswitch.org [mailto:ovs-dev-
> bounces at openvswitch.org] On Behalf Of Yuanhan Liu
> >     Sent: 11. september 2017 09:55
> >     To: Chandran, Sugesh <sugesh.chandran at intel.com>
> >     Cc: dev at openvswitch.org
> >     Subject: Re: [ovs-dev] [PATCH v2 8/8] netdev-dpdk: set FDIR config
> >
> >     On Mon, Sep 11, 2017 at 07:42:57AM +0000, Chandran, Sugesh wrote:
> >     >
> >     >
> >     > Regards
> >     > _Sugesh
> >     >
> >     >
> >     > > -----Original Message-----
> >     > > From: ovs-dev-bounces at openvswitch.org [mailto:ovs-dev-
> >     > > bounces at openvswitch.org] On Behalf Of Yuanhan Liu
> >     > > Sent: Tuesday, September 5, 2017 10:23 AM
> >     > > To: dev at openvswitch.org
> >     > > Subject: [ovs-dev] [PATCH v2 8/8] netdev-dpdk: set FDIR config
> >     > >
> >     > > From: Finn Christensen <fc at napatech.com>
> >     > >
> >     > > The Intel i40e PMD driver requires the fdir mode set to
> >     > > RTE_FDIR_MODE_PERFECT, otherwise, the flow creation would be
> failed.
> >     > [Sugesh] this means it doesn't honor the flow masks which passed onto
> rte_flow_*?
> >
> >     IIRC, that's what I found after divig the code. It's an issue reported/fixed
> by Finn. I also don't have the nic for testing.
> >
> >     [Finn] Yes, this was needed to make our test setup using an XL710 work,
> with the rte_flow implementation.
> >     It's a while ago so I don't exactly remember how we ended up with this
> solution. However, we are definitely not
> >     Intel XL710 experts, so there might be other ways to achieve the
> rte_flow functionality.
> >     This issue, and problem raised about the overall change in configuration
> impact on NICs using this setting (Napatech
> >     does not use it), I think should be reviewed/verified by NIC vendors
> using it.
> >
> >
> > [Darrell] We need to confirm the masking in the flow (but from what I see,
> it is ignored as Sugesh mentioned),
> >                 which would be a significant difference.
> >                 I guess we need input from Intel flow director folks to be sure and
> check if this can be done otherwise.
> >                 What about the 82599 as another example ?
> 
> 
> I will leave this to Intel folks.
[Sugesh] From the 82599 datasheet 

=======
The 82599 support two types of filtering modes (static setting by the FDIRCTRL.PerfectMatch
bit):
* Perfect match filters - The hardware checks a match between the masked fields of
the received packets and the programmed filters. Masked fields should be
programmed as zeros in the filter context. The 82599 support up to 8 K - 2 perfect
match filters.
* Signature filters - The hardware checks a match between a hash-based signature of
the masked fields of the received packet. The 82599 supports up to 32 K - 2
signature filters.
* Notation - The Perfect Match fields and Signature field are denoted as Flow ID fields.
The 82599 supports masking / range for the previously described fields. These masks are
defined globally for all filters in the FDIR...M register.
=======
So my understanding is even if it can support masking, the mask is global and not per flow.

Again I will confirm this and provide more details.

> 
> 	--yliu