Re: [dpdk-dev] [PATCH v8] net/iavf: support flex desc metadata extraction

["Guo, Jia" <jia.guo@intel.com>]

> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit@intel.com>
> Sent: Wednesday, October 14, 2020 8:32 PM
> To: Guo, Jia <jia.guo@intel.com>; Wu, Jingjing <jingjing.wu@intel.com>;
> Zhang, Qi Z <qi.z.zhang@intel.com>; Xing, Beilei <beilei.xing@intel.com>
> Cc: dev@dpdk.org; Wang, Haiyue <haiyue.wang@intel.com>; Richardson,
> Bruce <bruce.richardson@intel.com>; Olivier Matz <olivier.matz@6wind.com>
> Subject: Re: [PATCH v8] net/iavf: support flex desc metadata extraction
> 
> On 10/13/2020 9:17 AM, Jeff Guo wrote:
> > Enable metadata extraction for flexible descriptors in AVF, that would
> > allow network function directly get metadata without additional
> > parsing which would reduce the CPU cost for VFs. The enabling metadata
> > extractions involve the metadata of VLAN/IPv4/IPv6/IPv6-
> FLOW/TCP/MPLS
> > flexible descriptors, and the VF could negotiate the capability of the
> > flexible descriptor with PF and correspondingly configure the specific
> > offload at receiving queues.
> >
> > Signed-off-by: Jeff Guo <jia.guo@intel.com>
> > Acked-by: Haiyue Wang <haiyue.wang@intel.com>
> > ---
> > v8:
> > rebase patch for apply issue
> >
> > v7:
> > clean some useless and add doc
> >
> > v6:
> > rebase patch
> >
> > v5:
> > remove ovs configure since ovs is not protocol extraction
> >
> > v4:
> > add flex desc type in rx queue for handling vector path handle ovs
> > flex type
> >
> > v3:
> > export these global symbols into .map
> >
> > v2:
> > remove makefile change and modify the rxdid handling
> > ---
> >   config/rte_config.h                       |   3 +
> >   doc/guides/nics/intel_vf.rst              |  16 +
> >   doc/guides/rel_notes/release_20_11.rst    |   6 +
> >   drivers/net/iavf/iavf.h                   |  24 +-
> >   drivers/net/iavf/iavf_ethdev.c            | 394 ++++++++++++++++++++++
> >   drivers/net/iavf/iavf_rxtx.c              | 252 ++++++++++++--
> >   drivers/net/iavf/iavf_rxtx.h              | 168 +++++----
> >   drivers/net/iavf/iavf_rxtx_vec_common.h   |   3 +
> >   drivers/net/iavf/iavf_vchnl.c             |  22 +-
> >   drivers/net/iavf/meson.build              |   2 +
> >   drivers/net/iavf/rte_pmd_iavf.h           | 250 ++++++++++++++
> >   drivers/net/iavf/rte_pmd_iavf_version.map |  13 +
> >   12 files changed, 1039 insertions(+), 114 deletions(-)
> >   create mode 100644 drivers/net/iavf/rte_pmd_iavf.h
> >
> > diff --git a/config/rte_config.h b/config/rte_config.h index
> > 03d90d78bc..2c53072c3d 100644
> > --- a/config/rte_config.h
> > +++ b/config/rte_config.h
> > @@ -127,6 +127,9 @@
> >   #define RTE_LIBRTE_I40E_QUEUE_NUM_PER_VF 4
> >   #define RTE_LIBRTE_I40E_QUEUE_NUM_PER_VM 4
> >
> > +/* iavf defines */
> > +#undef RTE_LIBRTE_IAVF_16BYTE_RX_DESC
> > +
> 
> Hi Jeff,
> 
> The 'RTE_LIBRTE_IAVF_16BYTE_RX_DESC' was already there, not introduced
> with this patch, so I think better to add this change as different patch.
> 
> Also not sure if we want to add more config options to the 'rte_config.h',
> indeed otherway around and we are trying to get rid of as much as compile
> time optios.
> cc'ed Bruce too.
> 
> >   /* Ring net PMD settings */
> >   #define RTE_PMD_RING_MAX_RX_RINGS 16
> >   #define RTE_PMD_RING_MAX_TX_RINGS 16 diff --git
> > a/doc/guides/nics/intel_vf.rst b/doc/guides/nics/intel_vf.rst index
> > ade5152595..207f456143 100644
> > --- a/doc/guides/nics/intel_vf.rst
> > +++ b/doc/guides/nics/intel_vf.rst
> > @@ -615,3 +615,19 @@ which belongs to the destination VF on the VM.
> >   .. figure:: img/inter_vm_comms.*
> >
> >      Inter-VM Communication
> > +
> > +
> > +Pre-Installation Configuration
> > +------------------------------
> > +
> > +Config File Options
> > +~~~~~~~~~~~~~~~~~~~
> > +
> > +The following options can be modified in the ``config`` file.
> > +Please note that enabling debugging options may affect system
> performance.
> > +
> > +- ``CONFIG_RTE_LIBRTE_IAVF_16BYTE_RX_DESC`` (default ``n``)
> 
> There is no 'CONFIG_RTE_LIBRTE_IAVF_16BYTE_RX_DESC' anymore, this is
> from make days naming.
> 
> Instead, what do you think not adding the
> 'RTE_LIBRTE_IAVF_16BYTE_RX_DESC' to the 'rte_config.h', but document
> how this flag can be provided by meson during
> build:
> meson -Dc_args="-DRTE_LIBRTE_IAVF_16BYTE_RX_DESC"
> 
> And we should plan for long term to convert this compile time flag to runtime
> devargs.
> 
> What do you think?
> 

Sorry, I miss this comment. And, I agree on. Too more compile time flag is not friendly to use. Do you agree to do the runtime devargs on next separate patch set?

> > +
> > +  Toggle to use a 16-byte RX descriptor, by default the RX descriptor is 32
> byte.
> > +  Configure to 16-byte Rx descriptor may cause a negotiation failure
> > + during VF driver initialization  if the PF driver doesn't support.
> > diff --git a/doc/guides/rel_notes/release_20_11.rst
> > b/doc/guides/rel_notes/release_20_11.rst
> > index e7691ee732..93d3ccc60a 100644
> > --- a/doc/guides/rel_notes/release_20_11.rst
> > +++ b/doc/guides/rel_notes/release_20_11.rst
> > @@ -160,6 +160,12 @@ New Features
> >     packets with specified ratio, and apply with own set of actions with a fate
> >     action. When the ratio is set to 1 then the packets will be 100% mirrored.
> >
> > +* **Updated Intel iavf driver.**
> > +
> > +  Updated iavf PMD with new features and improvements, including:
> > +
> > +  * Added support for flexible descriptor metadata extraction.
> > +
> 
> Can you please move the update to the net drivers block, instead of very
> bottom.
> There is an order in the release notes (as commented in section header) like:
> - core libs
> - ethdev lib related changes
> - ethdev PMDS change
> - ...
> 

Sure, will update it in v10.

> <...>
> 
> > +
> > +EXPERIMENTAL {
> > +        global:
> > +
> > +        # added in 20.11
> > +        rte_net_iavf_dynfield_proto_xtr_metadata_offs;
> > +        rte_net_iavf_dynflag_proto_xtr_vlan_mask;
> > +        rte_net_iavf_dynflag_proto_xtr_ipv4_mask;
> > +        rte_net_iavf_dynflag_proto_xtr_ipv6_mask;
> > +        rte_net_iavf_dynflag_proto_xtr_ipv6_flow_mask;
> > +        rte_net_iavf_dynflag_proto_xtr_tcp_mask;
> > +        rte_net_iavf_dynflag_proto_xtr_ip_offset_mask;
> 
> As a namespace previously "rte_pmd_xxx" was used for PMD specific APIs,
> can you please switch to that?
> 'rte_net_' is used by the 'librte_net' library.
> 

Make sense.

> Above list is the dynfield values, what is the correct usage for dynfields,
> 1- Put dynfileds names in to the header, and application does a lookup
> ('rte_mbuf_dynfield_lookup()') to get the dynfield values.
> or
> 2- Expose dynfield values to be accessed directly from application, as done
> above.
> 
> @Oliver, can you please support.
> 
> I can see (1) has advantage of portability if more than one PMD supports
> same dynfield names, but that sees not a case for above ones.