Re: [PATCH 4/4] net/sfc: add configurable Rx CRC stripping

[Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>]

On 6/1/23 14:42, Denis Pryazhennikov wrote:
> Configurable Rx CRC stripping is allowed only if
> running firmware variant supports it and if NIC is
> configured with single PF per port and without VFs.

I'd like to double-check one thing. Doesn't it require fixes on
datapath to report correct length? If no, it would be good to
see notes about it here.

> 
> Signed-off-by: Roman Zhukov <roman.zhukov@arknetworks.am>
> Signed-off-by: Denis Pryazhennikov <denis.pryazhennikov@arknetworks.am>
> Reviewed-by: Andy Moreton <amoreton@xilinx.com>
> ---
>   doc/guides/nics/features/sfc.ini |  1 +
>   doc/guides/nics/sfc_efx.rst      |  6 ++++--
>   drivers/net/sfc/sfc.h            |  1 +
>   drivers/net/sfc/sfc_ef10_rx.c    |  3 ++-
>   drivers/net/sfc/sfc_port.c       | 12 ++++++++++++
>   drivers/net/sfc/sfc_rx.c         |  6 +++++-
>   6 files changed, 25 insertions(+), 4 deletions(-)
> 
> diff --git a/doc/guides/nics/features/sfc.ini b/doc/guides/nics/features/sfc.ini
> index f5ac644278ae..c41c47a63d49 100644
> --- a/doc/guides/nics/features/sfc.ini
> +++ b/doc/guides/nics/features/sfc.ini
> @@ -23,6 +23,7 @@ RSS key update       = Y
>   RSS reta update      = Y
>   SR-IOV               = Y
>   Flow control         = Y
> +CRC offload          = Y
>   VLAN offload         = P
>   L3 checksum offload  = Y
>   L4 checksum offload  = Y
> diff --git a/doc/guides/nics/sfc_efx.rst b/doc/guides/nics/sfc_efx.rst
> index de0656876b96..b3a44e7ddd92 100644
> --- a/doc/guides/nics/sfc_efx.rst
> +++ b/doc/guides/nics/sfc_efx.rst
> @@ -114,6 +114,10 @@ SFC EFX PMD has support for:
>   
>   - Loopback
>   
> +- Configurable Rx CRC stripping (if running firmware variant supports it and
> +  if NIC is configured with single PF per port and without VFs, otherwise
> +  always stripped)
> +
>   - SR-IOV PF
>   
>   - Port representors (see :ref: switch_representation)
> @@ -126,8 +130,6 @@ The features not yet supported include:
>   
>   - Priority-based flow control
>   
> -- Configurable RX CRC stripping (always stripped)
> -
>   - Header split on receive
>   
>   - VLAN filtering
> diff --git a/drivers/net/sfc/sfc.h b/drivers/net/sfc/sfc.h
> index 730d054aea74..5c97d5911eb2 100644
> --- a/drivers/net/sfc/sfc.h
> +++ b/drivers/net/sfc/sfc.h
> @@ -72,6 +72,7 @@ struct sfc_port {
>   	unsigned int			flow_ctrl;
>   	boolean_t			flow_ctrl_autoneg;
>   	size_t				pdu;
> +	boolean_t			include_fcs;

Please, put it after flow_ctrl_autoneg to use available hole.
There is no requirements to put it after pdu.

>   
>   	/*
>   	 * Flow API isolated mode overrides promisc and allmulti settings;
> diff --git a/drivers/net/sfc/sfc_ef10_rx.c b/drivers/net/sfc/sfc_ef10_rx.c
> index 7be224c9c412..08fe41fe5d94 100644
> --- a/drivers/net/sfc/sfc_ef10_rx.c
> +++ b/drivers/net/sfc/sfc_ef10_rx.c
> @@ -826,7 +826,8 @@ struct sfc_dp_rx sfc_ef10_rx = {
>   	.dev_offload_capa	= RTE_ETH_RX_OFFLOAD_CHECKSUM |
>   				  RTE_ETH_RX_OFFLOAD_OUTER_IPV4_CKSUM |
>   				  RTE_ETH_RX_OFFLOAD_RSS_HASH,
> -	.queue_offload_capa	= RTE_ETH_RX_OFFLOAD_SCATTER,
> +	.queue_offload_capa	= RTE_ETH_RX_OFFLOAD_SCATTER |
> +				  RTE_ETH_RX_OFFLOAD_KEEP_CRC,

Why is it queue level offload? It is configured per port. So,
it should be device level offload if I'm not mistaken.

>   	.get_dev_info		= sfc_ef10_rx_get_dev_info,
>   	.qsize_up_rings		= sfc_ef10_rx_qsize_up_rings,
>   	.qcreate		= sfc_ef10_rx_qcreate,
> diff --git a/drivers/net/sfc/sfc_port.c b/drivers/net/sfc/sfc_port.c
> index 5f312ab1ba83..24d2daf6282b 100644
> --- a/drivers/net/sfc/sfc_port.c
> +++ b/drivers/net/sfc/sfc_port.c
> @@ -250,6 +250,11 @@ sfc_port_start(struct sfc_adapter *sa)
>   	if (rc != 0)
>   		goto fail_mac_pdu_set;
>   
> +	sfc_log_init(sa, "set include FCS=%u", port->include_fcs);
> +	rc = efx_mac_include_fcs_set(sa->nic, port->include_fcs);
> +	if (rc != 0)
> +		goto fail_include_fcs_set;
> +
>   	if (!sfc_sa2shared(sa)->isolated) {
>   		struct rte_ether_addr *addr = &port->default_mac_addr;
>   
> @@ -337,6 +342,7 @@ sfc_port_start(struct sfc_adapter *sa)
>   	(void)efx_mac_drain(sa->nic, B_TRUE);
>   
>   fail_mac_drain:
> +fail_include_fcs_set:
>   fail_mac_stats_upload:
>   	(void)efx_mac_stats_periodic(sa->nic, &port->mac_stats_dma_mem,
>   				     0, B_FALSE);
> @@ -384,11 +390,17 @@ sfc_port_configure(struct sfc_adapter *sa)
>   {
>   	const struct rte_eth_dev_data *dev_data = sa->eth_dev->data;
>   	struct sfc_port *port = &sa->port;
> +	const struct rte_eth_rxmode *rxmode = &dev_data->dev_conf.rxmode;
>   
>   	sfc_log_init(sa, "entry");
>   
>   	port->pdu = EFX_MAC_PDU(dev_data->mtu);
>   
> +	if (rxmode->offloads & RTE_ETH_RX_OFFLOAD_KEEP_CRC)
> +		port->include_fcs = true;
> +	else
> +		port->include_fcs = false;
> +
>   	return 0;
>   }
>   
> diff --git a/drivers/net/sfc/sfc_rx.c b/drivers/net/sfc/sfc_rx.c
> index edd0f0c03842..f80771778c64 100644
> --- a/drivers/net/sfc/sfc_rx.c
> +++ b/drivers/net/sfc/sfc_rx.c
> @@ -655,7 +655,8 @@ struct sfc_dp_rx sfc_efx_rx = {
>   	.features		= SFC_DP_RX_FEAT_INTR,
>   	.dev_offload_capa	= RTE_ETH_RX_OFFLOAD_CHECKSUM |
>   				  RTE_ETH_RX_OFFLOAD_RSS_HASH,
> -	.queue_offload_capa	= RTE_ETH_RX_OFFLOAD_SCATTER,
> +	.queue_offload_capa	= RTE_ETH_RX_OFFLOAD_SCATTER |
> +				  RTE_ETH_RX_OFFLOAD_KEEP_CRC,

It seems it should be device level offload as above.

>   	.qsize_up_rings		= sfc_efx_rx_qsize_up_rings,
>   	.qcreate		= sfc_efx_rx_qcreate,
>   	.qdestroy		= sfc_efx_rx_qdestroy,
> @@ -938,6 +939,9 @@ sfc_rx_get_offload_mask(struct sfc_adapter *sa)
>   	if (encp->enc_tunnel_encapsulations_supported == 0)
>   		no_caps |= RTE_ETH_RX_OFFLOAD_OUTER_IPV4_CKSUM;
>   
> +	if (encp->enc_rx_include_fcs_supported == 0)
> +		no_caps |= RTE_ETH_RX_OFFLOAD_KEEP_CRC;
> +
>   	return ~no_caps;
>   }
>