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From: Raslan Darawsheh <rasland@mellanox.com>
To: Slava Ovsiienko <viacheslavo@mellanox.com>,
	"dev@dpdk.org" <dev@dpdk.org>
Cc: Matan Azrad <matan@mellanox.com>, Ori Kam <orika@mellanox.com>
Subject: Re: [dpdk-dev] [PATCH] net/mlx5: fix legacy multi-packet Tx descriptors
Date: Tue, 26 Nov 2019 15:07:03 +0000	[thread overview]
Message-ID: <DB3PR0502MB39645F3758B1B14240E36FDEC2450@DB3PR0502MB3964.eurprd05.prod.outlook.com> (raw)
In-Reply-To: <1574765103-24499-1-git-send-email-viacheslavo@mellanox.com>

Hi,

> -----Original Message-----
> From: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
> Sent: Tuesday, November 26, 2019 12:45 PM
> To: dev@dpdk.org
> Cc: Matan Azrad <matan@mellanox.com>; Raslan Darawsheh
> <rasland@mellanox.com>; Ori Kam <orika@mellanox.com>
> Subject: [PATCH] net/mlx5: fix legacy multi-packet Tx descriptors
> 
> ConnectX-4LX supports multiple packets within the single Tx
> descriptor. This feature is named as "Legacy Multi-Packet Write"
> and imposes a lot of limitations:
> 
>   - no ACLs, it means no NIC Tx Flows are supported and Tx metadata
>     become meaningless
>   - the required minimal inline data must be zero
>   - no SR-IOV, it means no support in E-Switch configurations,
>   - no priority and dscp forcing
>   - no VLAN insertion
>   - no TSO
>   - all packets within MPW session must have the same size
> 
> This legacy MPW feature is mainly intended for test purposes.
> To explicitly engage the feature on ConnectX-4LX the devargs
> should be specified:
> 
>   - txq_mpw_en=1
> 
> This feature was dropped in 19.08, this patch reverts it back.
> 
> Fixes: 18a1c20044c0 ("net/mlx5: implement Tx burst template")
> 
> Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
> Acked-by: Matan Azrad <matan@mellanox.com>
> ---
>  drivers/net/mlx5/mlx5.c      |  3 +-
>  drivers/net/mlx5/mlx5_rxtx.c | 98
> ++++++++++++++++++++++++++++++++++++++------
>  drivers/net/mlx5/mlx5_txq.c  |  2 +-
>  3 files changed, 89 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c
> index 59ae408..487c2be 100644
> --- a/drivers/net/mlx5/mlx5.c
> +++ b/drivers/net/mlx5/mlx5.c
> @@ -2479,7 +2479,8 @@ struct mlx5_flow_id_pool *
>  	else
>  		config.mps = config.mps ? mps : MLX5_MPW_DISABLED;
>  	DRV_LOG(INFO, "%sMPS is %s",
> -		config.mps == MLX5_MPW_ENHANCED ? "enhanced " : "",
> +		config.mps == MLX5_MPW_ENHANCED ? "enhanced " :
> +		config.mps == MLX5_MPW ? "legacy " : "",
>  		config.mps != MLX5_MPW_DISABLED ? "enabled" :
> "disabled");
>  	if (config.cqe_comp && !cqe_comp) {
>  		DRV_LOG(WARNING, "Rx CQE compression isn't
> supported");
> diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
> index 3762002..73c16de 100644
> --- a/drivers/net/mlx5/mlx5_rxtx.c
> +++ b/drivers/net/mlx5/mlx5_rxtx.c
> @@ -62,6 +62,7 @@ enum mlx5_txcmp_code {
>  #define MLX5_TXOFF_CONFIG_VLAN (1u << 5) /* VLAN insertion
> supported.*/
>  #define MLX5_TXOFF_CONFIG_METADATA (1u << 6) /* Flow metadata. */
>  #define MLX5_TXOFF_CONFIG_EMPW (1u << 8) /* Enhanced MPW
> supported.*/
> +#define MLX5_TXOFF_CONFIG_MPW (1u << 9) /* Legacy MPW
> supported.*/
> 
>  /* The most common offloads groups. */
>  #define MLX5_TXOFF_CONFIG_NONE 0
> @@ -2240,6 +2241,9 @@ enum mlx5_txcmp_code {
>  {
>  	struct mlx5_wqe_cseg *restrict cs = &wqe->cseg;
> 
> +	/* For legacy MPW replace the EMPW by TSO with modifier. */
> +	if (MLX5_TXOFF_CONFIG(MPW) && opcode ==
> MLX5_OPCODE_ENHANCED_MPSW)
> +		opcode = MLX5_OPCODE_TSO | MLX5_OPC_MOD_MPW <<
> 24;
>  	cs->opcode = rte_cpu_to_be_32((txq->wqe_ci << 8) | opcode);
>  	cs->sq_ds = rte_cpu_to_be_32(txq->qp_num_8s | ds);
>  	cs->flags = RTE_BE32(MLX5_COMP_ONLY_FIRST_ERR <<
> @@ -3669,6 +3673,7 @@ enum mlx5_txcmp_code {
> 
>  /**
>   * Check the next packet attributes to match with the eMPW batch ones.
> + * In addition, for legacy MPW the packet length is checked either.
>   *
>   * @param txq
>   *   Pointer to TX queue structure.
> @@ -3676,6 +3681,8 @@ enum mlx5_txcmp_code {
>   *   Pointer to Ethernet Segment of eMPW batch.
>   * @param loc
>   *   Pointer to burst routine local context.
> + * @param dlen
> + *   Length of previous packet in MPW descriptor.
>   * @param olx
>   *   Configured Tx offloads mask. It is fully defined at
>   *   compile time and may be used for optimization.
> @@ -3688,6 +3695,7 @@ enum mlx5_txcmp_code {
>  mlx5_tx_match_empw(struct mlx5_txq_data *restrict txq __rte_unused,
>  		   struct mlx5_wqe_eseg *restrict es,
>  		   struct mlx5_txq_local *restrict loc,
> +		   uint32_t dlen,
>  		   unsigned int olx)
>  {
>  	uint8_t swp_flags = 0;
> @@ -3706,6 +3714,10 @@ enum mlx5_txcmp_code {
>  		es->metadata != (loc->mbuf->ol_flags &
> PKT_TX_DYNF_METADATA ?
>  				 *RTE_FLOW_DYNF_METADATA(loc->mbuf) :
> 0))
>  		return false;
> +	/* Legacy MPW can send packets with the same lengt only. */
> +	if (MLX5_TXOFF_CONFIG(MPW) &&
> +	    dlen != rte_pktmbuf_data_len(loc->mbuf))
> +		return false;
>  	/* There must be no VLAN packets in eMPW loop. */
>  	if (MLX5_TXOFF_CONFIG(VLAN))
>  		assert(!(loc->mbuf->ol_flags & PKT_TX_VLAN_PKT));
> @@ -3906,6 +3918,10 @@ enum mlx5_txcmp_code {
>  		eseg = &loc->wqe_last->eseg;
>  		dseg = &loc->wqe_last->dseg[0];
>  		loop = part;
> +		/* Store the packet length for legacy MPW. */
> +		if (MLX5_TXOFF_CONFIG(MPW))
> +			eseg->mss = rte_cpu_to_be_16
> +					(rte_pktmbuf_data_len(loc->mbuf));
>  		for (;;) {
>  			uint32_t dlen = rte_pktmbuf_data_len(loc->mbuf);
>  #ifdef MLX5_PMD_SOFT_COUNTERS
> @@ -3964,8 +3980,9 @@ enum mlx5_txcmp_code {
>  			 * - check sum settings
>  			 * - metadata value
>  			 * - software parser settings
> +			 * - packets length (legacy MPW only)
>  			 */
> -			if (!mlx5_tx_match_empw(txq, eseg, loc, olx)) {
> +			if (!mlx5_tx_match_empw(txq, eseg, loc, dlen, olx)) {
>  				assert(loop);
>  				part -= loop;
>  				mlx5_tx_sdone_empw(txq, loc, part, slen,
> olx);
> @@ -4059,6 +4076,10 @@ enum mlx5_txcmp_code {
>  				  olx & ~MLX5_TXOFF_CONFIG_VLAN);
>  		eseg = &loc->wqe_last->eseg;
>  		dseg = &loc->wqe_last->dseg[0];
> +		/* Store the packet length for legacy MPW. */
> +		if (MLX5_TXOFF_CONFIG(MPW))
> +			eseg->mss = rte_cpu_to_be_16
> +					(rte_pktmbuf_data_len(loc->mbuf));
>  		room = RTE_MIN(MLX5_WQE_SIZE_MAX / MLX5_WQE_SIZE,
>  			       loc->wqe_free) * MLX5_WQE_SIZE -
>  					MLX5_WQE_CSEG_SIZE -
> @@ -4209,8 +4230,9 @@ enum mlx5_txcmp_code {
>  			 * - check sum settings
>  			 * - metadata value
>  			 * - software parser settings
> +			 * - packets length (legacy MPW only)
>  			 */
> -			if (!mlx5_tx_match_empw(txq, eseg, loc, olx))
> +			if (!mlx5_tx_match_empw(txq, eseg, loc, dlen, olx))
>  				break;
>  			/* Packet attributes match, continue the same
> eMPW. */
>  			if ((uintptr_t)dseg >= (uintptr_t)txq->wqes_end)
> @@ -4313,8 +4335,9 @@ enum mlx5_txcmp_code {
>  				 * free the packet immediately.
>  				 */
>  				rte_pktmbuf_free_seg(loc->mbuf);
> -			} else if (!MLX5_TXOFF_CONFIG(EMPW) &&
> -				   txq->inlen_mode) {
> +			} else if ((!MLX5_TXOFF_CONFIG(EMPW) ||
> +				     MLX5_TXOFF_CONFIG(MPW)) &&
> +					txq->inlen_mode) {
>  				/*
>  				 * If minimal inlining is requested the eMPW
>  				 * feature should be disabled due to data is
> @@ -4949,6 +4972,30 @@ enum mlx5_txcmp_code {
>  		MLX5_TXOFF_CONFIG_METADATA)
> 
>  /*
> + * Generate routines with Legacy Multi-Packet Write support.
> + * This mode is supported by ConnectX-4LX only and imposes
> + * offload limitations, not supported:
> + *   - ACL/Flows (metadata are becoming meaningless)
> + *   - WQE Inline headers
> + *   - SRIOV (E-Switch offloads)
> + *   - VLAN insertion
> + *   - tunnel encapsulation/decapsulation
> + *   - TSO
> + */
> +MLX5_TXOFF_DECL(none_mpw,
> +		MLX5_TXOFF_CONFIG_NONE |
> MLX5_TXOFF_CONFIG_EMPW |
> +		MLX5_TXOFF_CONFIG_MPW)
> +
> +MLX5_TXOFF_DECL(mci_mpw,
> +		MLX5_TXOFF_CONFIG_MULTI |
> MLX5_TXOFF_CONFIG_CSUM |
> +		MLX5_TXOFF_CONFIG_INLINE |
> MLX5_TXOFF_CONFIG_EMPW |
> +		MLX5_TXOFF_CONFIG_MPW)
> +
> +MLX5_TXOFF_DECL(i_mpw,
> +		MLX5_TXOFF_CONFIG_INLINE |
> MLX5_TXOFF_CONFIG_EMPW |
> +		MLX5_TXOFF_CONFIG_MPW)
> +
> +/*
>   * Array of declared and compiled Tx burst function and corresponding
>   * supported offloads set. The array is used to select the Tx burst
>   * function for specified offloads set at Tx queue configuration time.
> @@ -5050,7 +5097,6 @@ enum mlx5_txcmp_code {
>  		MLX5_TXOFF_CONFIG_INLINE |
>  		MLX5_TXOFF_CONFIG_METADATA)
> 
> -
>  MLX5_TXOFF_INFO(mtv,
>  		MLX5_TXOFF_CONFIG_MULTI | MLX5_TXOFF_CONFIG_TSO
> |
>  		MLX5_TXOFF_CONFIG_VLAN |
> @@ -5091,6 +5137,19 @@ enum mlx5_txcmp_code {
>  MLX5_TXOFF_INFO(iv,
>  		MLX5_TXOFF_CONFIG_INLINE |
> MLX5_TXOFF_CONFIG_VLAN |
>  		MLX5_TXOFF_CONFIG_METADATA)
> +
> +MLX5_TXOFF_INFO(none_mpw,
> +		MLX5_TXOFF_CONFIG_NONE |
> MLX5_TXOFF_CONFIG_EMPW |
> +		MLX5_TXOFF_CONFIG_MPW)
> +
> +MLX5_TXOFF_INFO(mci_mpw,
> +		MLX5_TXOFF_CONFIG_MULTI |
> MLX5_TXOFF_CONFIG_CSUM |
> +		MLX5_TXOFF_CONFIG_INLINE |
> MLX5_TXOFF_CONFIG_EMPW |
> +		MLX5_TXOFF_CONFIG_MPW)
> +
> +MLX5_TXOFF_INFO(i_mpw,
> +		MLX5_TXOFF_CONFIG_INLINE |
> MLX5_TXOFF_CONFIG_EMPW |
> +		MLX5_TXOFF_CONFIG_MPW)
>  };
> 
>  /**
> @@ -5173,11 +5232,8 @@ enum mlx5_txcmp_code {
>  	if (config->mps == MLX5_MPW_ENHANCED &&
>  	    config->txq_inline_min <= 0) {
>  		/*
> -		 * The NIC supports Enhanced Multi-Packet Write.
> -		 * We do not support legacy MPW due to its
> -		 * hardware related problems, so we just ignore
> -		 * legacy MLX5_MPW settings. There should be no
> -		 * minimal required inline data.
> +		 * The NIC supports Enhanced Multi-Packet Write
> +		 * and does not require minimal inline data.
>  		 */
>  		olx |= MLX5_TXOFF_CONFIG_EMPW;
>  	}
> @@ -5185,6 +5241,20 @@ enum mlx5_txcmp_code {
>  		/* We should support Flow metadata. */
>  		olx |= MLX5_TXOFF_CONFIG_METADATA;
>  	}
> +	if (config->mps == MLX5_MPW) {
> +		/*
> +		 * The NIC supports Legacy Multi-Packet Write.
> +		 * The MLX5_TXOFF_CONFIG_MPW controls the
> +		 * descriptor building method in combination
> +		 * with MLX5_TXOFF_CONFIG_EMPW.
> +		 */
> +		if (!(olx & (MLX5_TXOFF_CONFIG_TSO |
> +			     MLX5_TXOFF_CONFIG_SWP |
> +			     MLX5_TXOFF_CONFIG_VLAN |
> +			     MLX5_TXOFF_CONFIG_METADATA)))
> +			olx |= MLX5_TXOFF_CONFIG_EMPW |
> +			       MLX5_TXOFF_CONFIG_MPW;
> +	}
>  	/*
>  	 * Scan the routines table to find the minimal
>  	 * satisfying routine with requested offloads.
> @@ -5253,7 +5323,11 @@ enum mlx5_txcmp_code {
>  		DRV_LOG(DEBUG, "\tVLANI (VLAN insertion)");
>  	if (txoff_func[m].olx & MLX5_TXOFF_CONFIG_METADATA)
>  		DRV_LOG(DEBUG, "\tMETAD (tx Flow metadata)");
> -	if (txoff_func[m].olx & MLX5_TXOFF_CONFIG_EMPW)
> -		DRV_LOG(DEBUG, "\tEMPW  (Enhanced MPW)");
> +	if (txoff_func[m].olx & MLX5_TXOFF_CONFIG_EMPW) {
> +		if (txoff_func[m].olx & MLX5_TXOFF_CONFIG_MPW)
> +			DRV_LOG(DEBUG, "\tMPW   (Legacy MPW)");
> +		else
> +			DRV_LOG(DEBUG, "\tEMPW  (Enhanced MPW)");
> +	}
>  	return txoff_func[m].func;
>  }
> diff --git a/drivers/net/mlx5/mlx5_txq.c b/drivers/net/mlx5/mlx5_txq.c
> index 8160516..5e45748 100644
> --- a/drivers/net/mlx5/mlx5_txq.c
> +++ b/drivers/net/mlx5/mlx5_txq.c
> @@ -957,7 +957,7 @@ struct mlx5_txq_obj *
>  		     (unsigned int)config->txq_inline_mpw;
>  	inlen_mode = (config->txq_inline_min == MLX5_ARG_UNSET) ?
>  		     0 : (unsigned int)config->txq_inline_min;
> -	if (config->mps != MLX5_MPW_ENHANCED)
> +	if (config->mps != MLX5_MPW_ENHANCED && config->mps !=
> MLX5_MPW)
>  		inlen_empw = 0;
>  	/*
>  	 * If there is requested minimal amount of data to inline
> --
> 1.8.3.1


Patch applied to next-net-mlx,

Kindest regards,
Raslan Darawsheh

      reply	other threads:[~2019-11-26 15:07 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-26 10:45 Viacheslav Ovsiienko
2019-11-26 15:07 ` Raslan Darawsheh [this message]

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