Re: [dpdk-dev] [PATCH v3 4/4] ethdev: Add metadata flow and action items support

["Xueming(Steven) Li" <xuemingl@mellanox.com>]

Hi Declan,

Is there a mapping between maetadata and mbuf field(s), or the lifecycle of metadata supposed to 
be in middle of flows?

There might be another use case that set metadata to a constant, is this covered?

Thanks,
Xueming

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Declan Doherty
> Sent: Friday, April 6, 2018 8:24 PM
> To: dev@dpdk.org
> Cc: Declan Doherty <declan.doherty@intel.com>
> Subject: [dpdk-dev] [PATCH v3 4/4] ethdev: Add metadata flow and action items support
> 
> Introduces a new action type RTE_FLOW_ACTION_TYPE_METADATA which enables metadata extraction from a
> packet into a specified metadata container for consumption on further pipeline stages or for
> propagation to the host interface.
> 
> As complementary function to the new metadata action type this patch also introduces a new flow item
> type which enables flow patterns to specify a specific metadata container as a matching criteria for a
> flow rule.
> 
> Signed-off-by: Declan Doherty <declan.doherty@intel.com>
> ---
>  doc/guides/prog_guide/rte_flow.rst | 85 ++++++++++++++++++++++++++++++++++++++
>  lib/librte_ether/rte_flow.h        | 42 +++++++++++++++++++
>  2 files changed, 127 insertions(+)
> 
> diff --git a/doc/guides/prog_guide/rte_flow.rst b/doc/guides/prog_guide/rte_flow.rst
> index 2f0a47a..9b2b0e3 100644
> --- a/doc/guides/prog_guide/rte_flow.rst
> +++ b/doc/guides/prog_guide/rte_flow.rst
> @@ -1580,6 +1580,91 @@ group on that device.
>     +--------------+---------------------------------+
> 
> 
> +
> +Action: ``METADATA``
> +^^^^^^^^^^^^^^^^^^^^
> +
> +Action extracts data from packet into user specified metadata field in
> +pipeline for use in downstream processing stages or for propagation to host interface.
> +
> +The pattern mask is used to define the data which is to be extracted
> +from the packet. The mask pattern types defined in the action metadata
> +pattern must match the flow pattern definitions up to the last flow
> +item from which data is to be extracted.
> +
> +- Non-terminating by default.
> +
> +.. _table_rte_flow_action_metadata:
> +
> +.. table:: METADATA
> +
> +   +--------------+---------------------------+
> +   | Field        | Value                     |
> +   +==============+===========================+
> +   | ``id``       | Metadata field Identifier |
> +   +--------------+---------------------------+
> +   | ``pattern``  | Extraction mask pattern   |
> +   +--------------+---------------------------+
> +
> +The example below demonstrates how the extraction mask to extract the
> +source/ destination IPv4 address, the UDP destination port and and the
> +VxLAN VNI can be specified.
> +
> +.. _table_rte_flow_action_metadata_example:
> +
> +.. table:: IPv4 VxLAN metadata extraction
> +
> +   +-------+--------------------------+-----------------------------------+
> +   | Index | Flow Item Type           | Flow Mask                         |
> +   +=======+==========================+===================================+
> +   | 0     | RTE_FLOW_ITEM_TYPE_ETH   | .dst = "\x00\x00\x00\x00\x00\x00" |
> +   |       |                          +-----------------------------------+
> +   |       |                          | .src = "\x00\x00\x00\x00\x00\x00" |
> +   |       |                          +-----------------------------------+
> +   |       |                          | .type = RTE_BE16(0x0)             |
> +   +-------+--------------------------+-----------------------------------+
> +   | 1     | RTE_FLOW_ITEM_TYPE_IPV4  | .src_addr = RTE_BE32(0xffffffff)  |
> +   |       |                          +-----------------------------------+
> +   |       |                          | .dst_addr = RTE_BE32(0xffffffff)  |
> +   +-------+--------------------------+-----------------------------------+
> +   | 2     | RTE_FLOW_ITEM_TYPE_UDP   | .src_port = RTE_BE16(0x0)         |
> +   |       |                          +-----------------------------------+
> +   |       |                          | .dst_port = RTE_BE16(0xffff)      |
> +   +-------+--------------------------+-----------------------------------+
> +   | 3     | RTE_FLOW_ITEM_TYPE_VXLAN | .vni = "\xff\xff\xff"             |
> +   +-------+--------------------------+-----------------------------------+
> +   | 4     | RTE_FLOW_ITEM_TYPE_END   | NULL                              |
> +
> + +-------+--------------------------+----------------------------------
> + -+
> +
> +If only the VxLAN VNI extraction was required then the extraction mask
> +would be as follows.
> +
> +.. _table_rte_flow_action_metadata_example_2:
> +
> +.. table::  VxLAN VNI metadata extraction
> +
> +   +-------+--------------------------+-----------------------------------+
> +   | Index | Flow Item Type           | Flow Mask                         |
> +   +=======+==========================+===================================+
> +   | 0     | RTE_FLOW_ITEM_TYPE_ETH   | .dst = "\x00\x00\x00\x00\x00\x00" |
> +   |       |                          +-----------------------------------+
> +   |       |                          | .src = "\x00\x00\x00\x00\x00\x00" |
> +   |       |                          +-----------------------------------+
> +   |       |                          | .type = RTE_BE16(0x0)             |
> +   +-------+--------------------------+-----------------------------------+
> +   | 1     | RTE_FLOW_ITEM_TYPE_IPV4  | .src_addr = RTE_BE32(0x0)         |
> +   |       |                          +-----------------------------------+
> +   |       |                          | .dst_addr = RTE_BE32(0x0)         |
> +   +-------+--------------------------+-----------------------------------+
> +   | 2     | RTE_FLOW_ITEM_TYPE_UDP   | .src_port = RTE_BE16(0x0)         |
> +   |       |                          +-----------------------------------+
> +   |       |                          | .dst_port = RTE_BE16(0x0)         |
> +   +-------+--------------------------+-----------------------------------+
> +   | 3     | RTE_FLOW_ITEM_TYPE_VXLAN | .vni = "\xff\xff\xff"             |
> +   +-------+--------------------------+-----------------------------------+
> +   | 4     | RTE_FLOW_ITEM_TYPE_END   | NULL                              |
> +
> + +-------+--------------------------+----------------------------------
> + -+
> +
>  Negative types
>  ~~~~~~~~~~~~~~
> 
> diff --git a/lib/librte_ether/rte_flow.h b/lib/librte_ether/rte_flow.h index 968a23b..f75dee7 100644
> --- a/lib/librte_ether/rte_flow.h
> +++ b/lib/librte_ether/rte_flow.h
> @@ -323,6 +323,13 @@ enum rte_flow_item_type {
>  	 * See struct rte_flow_item_geneve.
>  	 */
>  	RTE_FLOW_ITEM_TYPE_GENEVE,
> +
> +	/**
> +	 * Matches specified pipeline metadata field.
> +	 *
> +	 * See struct rte_flow_item_metadata.
> +	 */
> +	RTE_FLOW_ITEM_TYPE_METADATA
>  };
> 
>  /**
> @@ -815,6 +822,17 @@ static const struct rte_flow_item_geneve rte_flow_item_geneve_mask = {  #endif
> 
>  /**
> + * RTE_FLOW_ITEM_TYPE_METADATA
> + *
> + * Allow arbitrary pipeline metadata to be used in specification flow
> +pattern  */ struct rte_flow_item_metadata {
> +	uint32_t id;		/**< field identifier */
> +	uint32_t size;		/**< field size */
> +	uint8_t *bytes;		/**< field value */
> +};
> +
> +/**
>   * Matching pattern item definition.
>   *
>   * A pattern is formed by stacking items starting from the lowest protocol @@ -1266,6 +1284,30 @@
> struct rte_flow_action_group {  };
> 
>  /**
> + * RTE_FLOW_ACTION_TYPE_METADATA
> + *
> + * Action extracts data from packet into specified metadata field in
> +pipeline
> + * for use in downstream processing stages or for propagation to host interface.
> + *
> + * Pattern mask is use to define the extraction data for packet. The
> +mask
> + * pattern types defined in the action metadata pattern must match the
> +flow
> + * pattern definitions up to the last item from which data is to be extracted.
> + *
> + * Non-terminating by default.
> + */
> +struct rte_flow_action_metadata {
> +	uint32_t id;		/**< field identifier */
> +
> +	struct rte_flow_action_mask_item {
> +		enum rte_flow_item_type type;
> +		/**< Flow item type. */
> +		const void *mask;
> +		/**< Flow item mask. */
> +	} *pattern;
> +	/** metadata extraction pattern mask specification */ };
> +
> +/**
>   * Definition of a single action.
>   *
>   * A list of actions is terminated by a END action.
> --
> 2.7.4