Re: [dpdk-dev] [PATCH v8] net/ice: optimize protocol extraction by dynamic mbuf API

[Ye Xiaolong <xiaolong.ye@intel.com>]

Hi, Haiyue

On 11/07, Haiyue Wang wrote:
>The original design is to use rte_mbuf::udata64 to save the metadata of
>protocol extraction which has network protocol data fields and type, a
>private API is used to decode this metadata.
>
>Use the dynamic mbuf field and flags to register the needed fields in
>mbuf, to avoid overwriting 'rte_mbuf::udata64' if the application uses
>it. It only needs 4B size to save the protocol extraction data, and its
>type and validity is indicated by related bit in 'rte_mbuf::ol_flags'.
>
>Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
>---
>v8: - Cleanup the doxgen, rename the dynamic filed and flags with ice prefix.
>
>v7: - Change the log level from ERR to DEBUG for a successful registration,
>      ERR is used to develop firstly.
>
>v6: - Don't need to register all flags when if one dev_args is set, register
>      it as required.
>
>v5: - Remove the '_OL/_ol' in dynamic mbuf flag to make the variable clean.
>
>v4: - Include the 'rte_pmd_ice.h' header in ICE source as needed, reduce
>      its compile scope.
>
>v3: - Use the conventions name "rte_net_<pmd>_dynfield_<name>" since it
>      is defined in a in PMD.
>    - Add helpers API for easiy access.
>
>v2: - disable the protocol extraction if failed to register some ol_flags
>    - rewrite the commit message
>
> doc/api/doxy-api-index.md               |   1 +
> doc/api/doxy-api.conf.in                |   1 +
> doc/guides/nics/ice.rst                 |  14 +-
> drivers/net/ice/ice_ethdev.c            |  84 ++++++-
> drivers/net/ice/ice_ethdev.h            |   9 +
> drivers/net/ice/ice_rxtx.c              |  88 ++++---
> drivers/net/ice/ice_rxtx.h              |   1 -
> drivers/net/ice/rte_pmd_ice.h           | 312 +++++++++++++++---------
> drivers/net/ice/rte_pmd_ice_version.map |  12 +
> 9 files changed, 369 insertions(+), 153 deletions(-)
>

[snip]

> 
>-  The extraction will be copied into the lower 32 bit of ``rte_mbuf::udata64``.
>+  The extraction metadata will be copied into the registered dynamic mbuf field
>+  with, and the related dynamic mbuf flags is set.

Above 'with' is redundant?

> 
>   .. table:: Protocol extraction : ``vlan``
> 
>@@ -175,10 +176,11 @@ Runtime Config Options
> 
>   TCPHDR2 - Reserved
> 
>-  Use ``get_proto_xtr_flds(struct rte_mbuf *mb)`` to access the protocol
>-  extraction, do not use ``rte_mbuf::udata64`` directly.
>+  Use ``rte_net_ice_dynf_proto_xtr_metadata_get`` to access the protocol
>+  extraction metadata, and use ``PKT_RX_DYNF_PROTO_XTR_*`` to get the
>+  metadata type of ``struct rte_mbuf::ol_flags``.
> 
>-  The ``dump_proto_xtr_flds(struct rte_mbuf *mb)`` routine shows how to
>+  The ``rte_net_ice_dump_proto_xtr_metadata`` routine shows how to
>   access the protocol extraction result in ``struct rte_mbuf``.
> 

[snip]

>+
>+	PMD_DRV_LOG(DEBUG,
>+		    "Protocol extraction metadata offset in mbuf is : %d",
>+		    offset);
>+	rte_net_ice_dynfield_proto_xtr_metadata = offset;

Seems rte_net_ice_dump_proto_xtr_metadata_off is a better name judging from
its real meaning.

>+
>+	for (i = 0; i < RTE_DIM(ice_proto_xtr_ol_flag_params); i++) {
>+		ol_flag = &ice_proto_xtr_ol_flag_params[i];
>+
>+		if (!ol_flag->required)

[snip]

>+static void
>+ice_rxd_to_proto_xtr(struct rte_mbuf *mb,
>+		     volatile struct ice_32b_rx_flex_desc_comms *desc)
>+{
>+	uint16_t stat_err = rte_le_to_cpu_16(desc->status_error1);
>+	uint32_t metadata;
>+	uint64_t ol_flag;
>+
>+	if (unlikely(!(stat_err & ICE_RX_PROTO_XTR_VALID)))
>+		return;
>+
>+	ol_flag = ice_rxdid_to_proto_xtr_ol_flag(desc->rxdid);

ol_flag here is obtained through offset which is returned by
rte_mbuf_dynflag_register, will it have any chance to conflict with
existing offload flags such as PKT_RX_VLAN, PKT_RX_VLAN_STRIPPED, ...? 

>+	if (unlikely(!ol_flag))
>+		return;
>+
>+	mb->ol_flags |= ol_flag;
>+

[snip]

>--- a/drivers/net/ice/rte_pmd_ice_version.map
>+++ b/drivers/net/ice/rte_pmd_ice_version.map
>@@ -2,3 +2,15 @@ DPDK_19.02 {
> 
> 	local: *;
> };
>+
>+EXPERIMENTAL {
>+	global:
>+
>+	# added in 19.11
>+	rte_net_ice_dynfield_proto_xtr_metadata;
>+	rte_net_ice_dynflag_proto_xtr_vlan;
>+	rte_net_ice_dynflag_proto_xtr_ipv4;
>+	rte_net_ice_dynflag_proto_xtr_ipv6;
>+	rte_net_ice_dynflag_proto_xtr_ipv6_flow;
>+	rte_net_ice_dynflag_proto_xtr_tcp;

Why put the variable other than the experimental api in the map?

Thanks,
Xiaolong

>+};
>-- 
>2.17.1
>