Adding relevant maintainers.
> -----Original Message-----
> From: Dekel Peled [mailto:dek...@mellanox.com]
> Sent: Monday, August 13, 2018 10:47 AM
> To: dev@dpdk.org
> Cc: Ori Kam <or...@mellanox.com>; Shahaf Shuler
> <shah...@mellanox.com>
> Subject: [RFC] ethdev: support metadata as flow rule criteria
>
> Current implementation of rte_flow allows match pattern of flow rule, based
> on packet data or header fields.
> This limits the application use of match patterns.
>
> For example, consider a vswitch application which controls a set of VMs,
> connected with virtio, in a fabric with overlay of VXLAN.
> Several VMs can have the same inner tuple, while the outer tuple is different
> and controlled by the vswitch (encap action).
> For the vswtich to be able to offload the rule to the NIC, it must use a
> unique
> match criteria, independent from the inner tuple, to perform the encap
> action.
>
> This RFC adds support for additional metadata to use as match pattern.
> The metadata is an opaque item, fully controlled by the application.
>
> The use of metadata is relevant for egress rules only.
> It can be set in the flow rule using the RTE_FLOW_ITEM_META.
>
> Application should set the packet metdata in the mbuf->metadata field, and
> set the PKT_TX_METADATA flag in the mbuf->ol_flags.
> The NIC will use the packet metadata as match criteria for relevant flow
> rules.
>
> For example, to do an encap action depending on the VM id, the application
> needs to configure 'match on metadata' rte_flow rule with VM id as
> metadata, along with desired encap action.
> When preparing an egress data packet, application will set VM id data in
> mbuf metadata field and set PKT_TX_METADATA flag.
>
> PMD will send data packets to NIC, with VM id as metadata.
> Egress flow on NIC will match metadata as done with other criteria.
> Upon match on metadata (VM id) the appropriate encap action will be
> performed.
>
> This RFC introduces metadata item type for rte_flow
> RTE_FLOW_ITEM_META, along with corresponding struct
> rte_flow_item_meta and ol_flag PKT_TX_METADATA.
> It also enhances struct rte_mbuf with new data item, uint64_t metadata.
>
> Comments are welcome.
>
> Signed-off-by: Dekel Peled <dek...@mellanox.com>
> ---
> doc/guides/prog_guide/rte_flow.rst | 21 +++++++++++++++++++++
> lib/librte_ethdev/rte_flow.c | 1 +
> lib/librte_ethdev/rte_flow.h | 25 +++++++++++++++++++++++++
> lib/librte_mbuf/rte_mbuf.h | 11 +++++++++++
> 4 files changed, 58 insertions(+)
>
> diff --git a/doc/guides/prog_guide/rte_flow.rst
> b/doc/guides/prog_guide/rte_flow.rst
> index b305a72..b6e35f1 100644
> --- a/doc/guides/prog_guide/rte_flow.rst
> +++ b/doc/guides/prog_guide/rte_flow.rst
> @@ -1191,6 +1191,27 @@ Normally preceded by any of:
> - `Item: ICMP6_ND_NS`_
> - `Item: ICMP6_ND_OPT`_
>
> +Item: ``META``
> +^^^^^^^^^^^^^^
> +
> +Matches an application specific 64 bit metadata item.
> +
> +- Default ``mask`` matches any 64 bit value.
> +
> +.. _table_rte_flow_item_meta:
> +
> +.. table:: META
> +
> + +----------+----------+---------------------------+
> + | Field | Subfield | Value |
> + +==========+==========+===========================+
> + | ``spec`` | ``data`` | 64 bit metadata value |
> + +----------+--------------------------------------+
> + | ``last`` | ``data`` | upper range value |
> + +----------+----------+---------------------------+
> + | ``mask`` | ``data`` | zeroed to match any value |
> + +----------+----------+---------------------------+
> +
> Actions
> ~~~~~~~
>
> diff --git a/lib/librte_ethdev/rte_flow.c b/lib/librte_ethdev/rte_flow.c index
> cff4b52..54e5ef8 100644
> --- a/lib/librte_ethdev/rte_flow.c
> +++ b/lib/librte_ethdev/rte_flow.c
> @@ -66,6 +66,7 @@ struct rte_flow_desc_data {
> sizeof(struct rte_flow_item_icmp6_nd_opt_sla_eth)),
> MK_FLOW_ITEM(ICMP6_ND_OPT_TLA_ETH,
> sizeof(struct rte_flow_item_icmp6_nd_opt_tla_eth)),
> + MK_FLOW_ITEM(META, sizeof(struct rte_flow_item_meta)),
> };
>
> /** Generate flow_action[] entry. */
> diff --git a/lib/librte_ethdev/rte_flow.h b/lib/librte_ethdev/rte_flow.h index
> f8ba71c..b81c816 100644
> --- a/lib/librte_ethdev/rte_flow.h
> +++ b/lib/librte_ethdev/rte_flow.h
> @@ -413,6 +413,15 @@ enum rte_flow_item_type {
> * See struct rte_flow_item_mark.
> */
> RTE_FLOW_ITEM_TYPE_MARK,
> +
> + /**
> + * [META]
> + *
> + * Matches a metadata value specified in mbuf metadata field.
> + *
> + * See struct rte_flow_item_meta.
> + */
> + RTE_FLOW_ITEM_TYPE_META,
> };
>
> /**
> @@ -849,6 +858,22 @@ struct rte_flow_item_gre { #endif
>
> /**
> + * RTE_FLOW_ITEM_TYPE_META.
> + *
> + * Matches a specified metadata value.
> + */
> +struct rte_flow_item_meta {
> + uint64_t data;
> +};
> +
> +/** Default mask for RTE_FLOW_ITEM_TYPE_META. */ #ifndef __cplusplus
> +static const struct rte_flow_item_meta rte_flow_item_meta_mask = {
> + .data = RTE_BE64(UINT64_MAX),
> +};
> +#endif
> +
> +/**
> * RTE_FLOW_ITEM_TYPE_FUZZY
> *
> * Fuzzy pattern match, expect faster than default.
> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h index
> 9ce5d76..8f06a78 100644
> --- a/lib/librte_mbuf/rte_mbuf.h
> +++ b/lib/librte_mbuf/rte_mbuf.h
> @@ -182,6 +182,11 @@
> /* add new TX flags here */
>
> /**
> + * This flag indicates that the metadata field in the mbuf is in use.
> + */
> +#define PKT_TX_METADATA (1ULL << 41)
> +
> +/**
> * UDP Fragmentation Offload flag. This flag is used for enabling UDP
> * fragmentation in SW or in HW. When use UFO, mbuf->tso_segsz is used
> * to store the MSS of UDP fragments.
> @@ -593,6 +598,12 @@ struct rte_mbuf {
> */
> struct rte_mbuf_ext_shared_info *shinfo;
>
> + /**
> + * Application specific metadata value for flow rule match.
> + * Valid if PKT_TX_METADATA is set.
> + */
> + uint64_t metadata;
> +
> } __rte_cache_aligned;
>
> /**
> --
> 1.8.3.1
