Re: [dpdk-dev] [PATCH 1/3] mbuf: add Tx offloads for packet marking

[Jerin Jacob <jerinjacobk@gmail.com>]

On Fri, Apr 17, 2020 at 12:53 PM Nithin Dabilpuram
<nithind1988@gmail.com> wrote:
>
> From: Nithin Dabilpuram <ndabilpuram@marvell.com>
>
> Introduce PKT_TX_MARK_IP_DSCP, PKT_TX_MARK_IP_ECN
> and PKT_TX_MARK_VLAN_DEI Tx offload flags to support
> packet marking.
>
> When packet marking feature in Traffic manager is enabled,
> application has to the use the three new flags to indicate
> to PMD on whether packet marking needs to be enabled on the
> specific mbuf or not. By setting the three flags, it is
> assumed by PMD that application has already verified the
> applicability of marking on that specific packet and
> PMD need not perform further checks as per RFC.
>
> Signed-off-by: Krzysztof Kanas <kkanas@marvell.com>
> Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>

None of the ethdev TM driver implementations has supported packet
marking support.
rte_tm and rte_mbuf maintainers(Christian, Oliver), Could you review this patch?


> ---
>  doc/guides/nics/features.rst    | 14 ++++++++++++++
>  lib/librte_mbuf/rte_mbuf.c      |  6 ++++++
>  lib/librte_mbuf/rte_mbuf_core.h | 36 ++++++++++++++++++++++++++++++++++--
>  3 files changed, 54 insertions(+), 2 deletions(-)
>
> diff --git a/doc/guides/nics/features.rst b/doc/guides/nics/features.rst
> index edd21c4..bc978fb 100644
> --- a/doc/guides/nics/features.rst
> +++ b/doc/guides/nics/features.rst
> @@ -913,6 +913,20 @@ Supports to get Rx/Tx packet burst mode information.
>  * **[implements] eth_dev_ops**: ``rx_burst_mode_get``, ``tx_burst_mode_get``.
>  * **[related] API**: ``rte_eth_rx_burst_mode_get()``, ``rte_eth_tx_burst_mode_get()``.
>
> +.. _nic_features_traffic_manager_packet_marking_offload:
> +
> +Traffic Manager Packet marking offload
> +--------------------------------------
> +
> +Supports enabling a packet marking offload specific mbuf.
> +
> +* **[uses]     mbuf**: ``mbuf.ol_flags:PKT_TX_MARK_IP_DSCP``,
> +  ``mbuf.ol_flags:PKT_TX_MARK_IP_ECN``, ``mbuf.ol_flags:PKT_TX_MARK_VLAN_DEI``,
> +  ``mbuf.ol_flags:PKT_TX_IPV4``, ``mbuf.ol_flags:PKT_TX_IPV6``.
> +* **[uses]     mbuf**: ``mbuf.l2_len``.
> +* **[related] API**: ``rte_tm_mark_ip_dscp()``, ``rte_tm_mark_ip_ecn()``,
> +  ``rte_tm_mark_vlan_dei()``.
> +
>  .. _nic_features_other:
>
>  Other dev ops not represented by a Feature
> diff --git a/lib/librte_mbuf/rte_mbuf.c b/lib/librte_mbuf/rte_mbuf.c
> index cd5794d..5c6896d 100644
> --- a/lib/librte_mbuf/rte_mbuf.c
> +++ b/lib/librte_mbuf/rte_mbuf.c
> @@ -880,6 +880,9 @@ const char *rte_get_tx_ol_flag_name(uint64_t mask)
>         case PKT_TX_SEC_OFFLOAD: return "PKT_TX_SEC_OFFLOAD";
>         case PKT_TX_UDP_SEG: return "PKT_TX_UDP_SEG";
>         case PKT_TX_OUTER_UDP_CKSUM: return "PKT_TX_OUTER_UDP_CKSUM";
> +       case PKT_TX_MARK_VLAN_DEI: return "PKT_TX_MARK_VLAN_DEI";
> +       case PKT_TX_MARK_IP_DSCP: return "PKT_TX_MARK_IP_DSCP";
> +       case PKT_TX_MARK_IP_ECN: return "PKT_TX_MARK_IP_ECN";
>         default: return NULL;
>         }
>  }
> @@ -916,6 +919,9 @@ rte_get_tx_ol_flag_list(uint64_t mask, char *buf, size_t buflen)
>                 { PKT_TX_SEC_OFFLOAD, PKT_TX_SEC_OFFLOAD, NULL },
>                 { PKT_TX_UDP_SEG, PKT_TX_UDP_SEG, NULL },
>                 { PKT_TX_OUTER_UDP_CKSUM, PKT_TX_OUTER_UDP_CKSUM, NULL },
> +               { PKT_TX_MARK_VLAN_DEI, PKT_TX_MARK_VLAN_DEI, NULL },
> +               { PKT_TX_MARK_IP_DSCP, PKT_TX_MARK_IP_DSCP, NULL },
> +               { PKT_TX_MARK_IP_ECN, PKT_TX_MARK_IP_ECN, NULL },
>         };
>         const char *name;
>         unsigned int i;
> diff --git a/lib/librte_mbuf/rte_mbuf_core.h b/lib/librte_mbuf/rte_mbuf_core.h
> index b9a59c8..d9f1290 100644
> --- a/lib/librte_mbuf/rte_mbuf_core.h
> +++ b/lib/librte_mbuf/rte_mbuf_core.h
> @@ -187,11 +187,40 @@ extern "C" {
>  /* add new RX flags here, don't forget to update PKT_FIRST_FREE */
>
>  #define PKT_FIRST_FREE (1ULL << 23)
> -#define PKT_LAST_FREE (1ULL << 40)
> +#define PKT_LAST_FREE (1ULL << 37)
>
>  /* add new TX flags here, don't forget to update PKT_LAST_FREE  */
>
>  /**
> + * Packet marking offload flags. These flags indicated what kind
> + * of packet marking needs to be applied on a given mbuf when
> + * appropriate Traffic Manager configuration is in place.
> + * When user set's these flags on a mbuf, below assumptions are made
> + * 1) When PKT_TX_MARK_VLAN_DEI is set,
> + * a) PMD assumes pkt to be a 802.1q packet.
> + * b) Application should also set mbuf.l2_len where 802.1Q header is
> + *    at (mbuf.l2_len - 6) offset.
> + * 2) When PKT_TX_MARK_IP_DSCP is set,
> + * a) Application should also set either PKT_TX_IPV4 or PKT_TX_IPV6
> + *    to indicate whether if it is IPv4 packet or IPv6 packet
> + *    for DSCP marking. It should also set PKT_TX_IP_CKSUM if it is
> + *    IPv4 pkt.
> + * b) Application should also set mbuf.l2_len that indicates
> + *    start offset of L3 header.
> + * 3) When PKT_TX_MARK_IP_ECN is set,
> + * a) Application should also set either PKT_TX_IPV4 or PKT_TX_IPV6.
> + *    It should also set PKT_TX_IP_CKSUM if it is IPv4 pkt.
> + * b) PMD will assume pkt L4 protocol is either TCP or SCTP and
> + *    ECN is set to 2'b01 or 2'b10 as per RFC 3168 and hence HW
> + *    can mark the packet for a configured color.
> + * c) Application should also set mbuf.l2_len that indicates
> + *    start offset of L3 header.
> + */
> +#define PKT_TX_MARK_VLAN_DEI           (1ULL << 38)
> +#define PKT_TX_MARK_IP_DSCP            (1ULL << 39)
> +#define PKT_TX_MARK_IP_ECN             (1ULL << 40)
> +
> +/**
>   * Outer UDP checksum offload flag. This flag is used for enabling
>   * outer UDP checksum in PMD. To use outer UDP checksum, the user needs to
>   * 1) Enable the following in mbuf,
> @@ -384,7 +413,10 @@ extern "C" {
>                 PKT_TX_MACSEC |          \
>                 PKT_TX_SEC_OFFLOAD |     \
>                 PKT_TX_UDP_SEG |         \
> -               PKT_TX_OUTER_UDP_CKSUM)
> +               PKT_TX_OUTER_UDP_CKSUM | \
> +               PKT_TX_MARK_VLAN_DEI |   \
> +               PKT_TX_MARK_IP_DSCP |    \
> +               PKT_TX_MARK_IP_ECN)
>
>  /**
>   * Mbuf having an external buffer attached. shinfo in mbuf must be filled.
> --
> 2.8.4
>