[PATCH 1/8] ethdev: introduce IP reassembly offload

[Ananyev, Konstantin]

> IP Reassembly is a costly operation if it is done in software.
> The operation becomes even more costlier if IP fragmants are encrypted.
> However, if it is offloaded to HW, it can considerably save application cycles.
> 
> Hence, a new offload RTE_ETH_RX_OFFLOAD_IP_REASSEMBLY is introduced in
> ethdev for devices which can attempt reassembly of packets in hardware.
> rte_eth_dev_info is updated with the reassembly capabilities which a device
> can support.
> 
> The resulting reassembled packet would be a typical segmented mbuf in
> case of success.
> 
> And if reassembly of fragments is failed or is incomplete (if fragments do
> not come before the reass_timeout), the mbuf ol_flags can be updated.
> This is updated in a subsequent patch.
> 
> Signed-off-by: Akhil Goyal <gakhil at marvell.com>
> ---
>  doc/guides/nics/features.rst | 12 ++++++++++++
>  lib/ethdev/rte_ethdev.c      |  1 +
>  lib/ethdev/rte_ethdev.h      | 32 +++++++++++++++++++++++++++++++-
>  3 files changed, 44 insertions(+), 1 deletion(-)
> 
> diff --git a/doc/guides/nics/features.rst b/doc/guides/nics/features.rst
> index 27be2d2576..1dfdee9602 100644
> --- a/doc/guides/nics/features.rst
> +++ b/doc/guides/nics/features.rst
> @@ -602,6 +602,18 @@ Supports inner packet L4 checksum.
>    ``tx_offload_capa,tx_queue_offload_capa:RTE_ETH_TX_OFFLOAD_OUTER_UDP_CKSUM``.
> 
> 
> +.. _nic_features_ip_reassembly:
> +
> +IP reassembly
> +-------------
> +
> +Supports IP reassembly in hardware.
> +
> +* **[uses]     rte_eth_rxconf,rte_eth_rxmode**: ``offloads:RTE_ETH_RX_OFFLOAD_IP_REASSEMBLY``.
> +* **[provides] mbuf**: ``mbuf.ol_flags:RTE_MBUF_F_RX_IP_REASSEMBLY_INCOMPLETE``.
> +* **[provides] rte_eth_dev_info**: ``reass_capa``.
> +
> +
>  .. _nic_features_shared_rx_queue:
> 
>  Shared Rx queue
> diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
> index a1d475a292..d9a03f12f9 100644
> --- a/lib/ethdev/rte_ethdev.c
> +++ b/lib/ethdev/rte_ethdev.c
> @@ -126,6 +126,7 @@ static const struct {
>  	RTE_RX_OFFLOAD_BIT2STR(OUTER_UDP_CKSUM),
>  	RTE_RX_OFFLOAD_BIT2STR(RSS_HASH),
>  	RTE_RX_OFFLOAD_BIT2STR(BUFFER_SPLIT),
> +	RTE_RX_OFFLOAD_BIT2STR(IP_REASSEMBLY),
>  };
> 
>  #undef RTE_RX_OFFLOAD_BIT2STR
> diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
> index fa299c8ad7..11427b2e4d 100644
> --- a/lib/ethdev/rte_ethdev.h
> +++ b/lib/ethdev/rte_ethdev.h
> @@ -1586,6 +1586,7 @@ struct rte_eth_conf {
>  #define RTE_ETH_RX_OFFLOAD_RSS_HASH         RTE_BIT64(19)
>  #define DEV_RX_OFFLOAD_RSS_HASH             RTE_ETH_RX_OFFLOAD_RSS_HASH
>  #define RTE_ETH_RX_OFFLOAD_BUFFER_SPLIT     RTE_BIT64(20)
> +#define RTE_ETH_RX_OFFLOAD_IP_REASSEMBLY    RTE_BIT64(21)
> 
>  #define RTE_ETH_RX_OFFLOAD_CHECKSUM (RTE_ETH_RX_OFFLOAD_IPV4_CKSUM | \
>  				 RTE_ETH_RX_OFFLOAD_UDP_CKSUM | \
> @@ -1781,6 +1782,33 @@ enum rte_eth_representor_type {
>  	RTE_ETH_REPRESENTOR_PF,   /**< representor of Physical Function. */
>  };
> 
> +/* Flag to offload IP reassembly for IPv4 packets. */
> +#define RTE_ETH_DEV_REASSEMBLY_F_IPV4 (RTE_BIT32(0))
> +/* Flag to offload IP reassembly for IPv6 packets. */
> +#define RTE_ETH_DEV_REASSEMBLY_F_IPV6 (RTE_BIT32(1))
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this structure may change without prior notice.
> + *
> + * A structure used to set IP reassembly configuration.
> + *
> + * If RTE_ETH_RX_OFFLOAD_IP_REASSEMBLY flag is set in offloads field,
> + * the PMD will attempt IP reassembly for the received packets as per
> + * properties defined in this structure:
> + *
> + */
> +struct rte_eth_ip_reass_params {
> +	/** Maximum time in ms which PMD can wait for other fragments. */
> +	uint32_t reass_timeout;
> +	/** Maximum number of fragments that can be reassembled. */
> +	uint16_t max_frags;
> +	/**
> +	 * Flags to enable reassembly of packet types -
> +	 * RTE_ETH_DEV_REASSEMBLY_F_xxx.
> +	 */
> +	uint16_t flags;
> +};
> +
>  /**
>   * A structure used to retrieve the contextual information of
>   * an Ethernet device, such as the controlling driver of the
> @@ -1841,8 +1869,10 @@ struct rte_eth_dev_info {
>  	 * embedded managed interconnect/switch.
>  	 */
>  	struct rte_eth_switch_info switch_info;
> +	/** IP reassembly offload capabilities that a device can support. */
> +	struct rte_eth_ip_reass_params reass_capa;
> 
> -	uint64_t reserved_64s[2]; /**< Reserved for future fields */
> +	uint64_t reserved_64s[1]; /**< Reserved for future fields */
>  	void *reserved_ptrs[2];   /**< Reserved for future fields */
>  };
> 
> --

Acked-by: Konstantin Ananyev <konstantin.ananyev at intel.com>

> 2.25.1