Re: [dpdk-dev] [RFC] ethdev: remove all offload API

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> -----Original Message-----
> From: Yigit, Ferruh
> Sent: Monday, June 11, 2018 12:18 PM
> To: Shahaf Shuler <shahafs@mellanox.com>; Andrew Rybchenko <arybchenko@solarflare.com>; Jerin Jacob
> <jerin.jacob@caviumnetworks.com>; Lu, Wenzhuo <wenzhuo.lu@intel.com>; Wu, Jingjing <jingjing.wu@intel.com>; Iremonger,
> Bernard <bernard.iremonger@intel.com>; Mcnamara, John <john.mcnamara@intel.com>; Kovacevic, Marko
> <marko.kovacevic@intel.com>; Neil Horman <nhorman@tuxdriver.com>; Horton, Remy <remy.horton@intel.com>; Ori Kam
> <orika@mellanox.com>; Richardson, Bruce <bruce.richardson@intel.com>; De Lara Guarch, Pablo
> <pablo.de.lara.guarch@intel.com>; Nicolau, Radu <radu.nicolau@intel.com>; Akhil Goyal <akhil.goyal@nxp.com>; Kantecki, Tomasz
> <tomasz.kantecki@intel.com>; Van Haaren, Harry <harry.van.haaren@intel.com>; Jijiang Liu <jijiang.liu@intel.com>; Ravi Kumar
> <ravi1.kumar@amd.com>; Ananyev, Konstantin <konstantin.ananyev@intel.com>; Maxime Coquelin
> <maxime.coquelin@redhat.com>; Bie, Tiwei <tiwei.bie@intel.com>; Yong Wang <yongwang@vmware.com>; Mokhtar, Amr
> <amr.mokhtar@intel.com>; Doherty, Declan <declan.doherty@intel.com>; Chas Williams <chas3@att.com>; Hunt, David
> <david.hunt@intel.com>; Dumitrescu, Cristian <cristian.dumitrescu@intel.com>; Burakov, Anatoly <anatoly.burakov@intel.com>;
> Pattan, Reshma <reshma.pattan@intel.com>; Marohn, Byron <byron.marohn@intel.com>; Thomas Monjalon
> <thomas@monjalon.net>
> Cc: dev@dpdk.org
> Subject: Re: [RFC] ethdev: remove all offload API
> 
> On 6/11/2018 12:00 PM, Shahaf Shuler wrote:
> > Hi Ferruh,
> >
> > Thanks for this patch.
> >
> > Monday, June 11, 2018 12:10 PM, Ferruh Yigit:
> >> Subject: Re: [RFC] ethdev: remove all offload API
> >>
> >> On 6/9/2018 9:04 AM, Andrew Rybchenko wrote:
> >>> On 06/09/2018 01:41 AM, Ferruh Yigit wrote:
> >>>> Cc: Shahaf Shuler <shahafs@mellanox.com>
> >>>>
> >>>> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
> >>>> ---
> >>>
> >>> <...>
> >>>
> >>>> diff --git a/app/test-eventdev/test_perf_common.c
> >>>> b/app/test-eventdev/test_perf_common.c
> >>>> index d00f91802..9fe042ffe 100644
> >>>> --- a/app/test-eventdev/test_perf_common.c
> >>>> +++ b/app/test-eventdev/test_perf_common.c
> >>>> @@ -680,13 +680,7 @@ perf_ethdev_setup(struct evt_test *test, struct
> >> evt_options *opt)
> >>>>  			.mq_mode = ETH_MQ_RX_RSS,
> >>>>  			.max_rx_pkt_len = ETHER_MAX_LEN,
> >>>>  			.split_hdr_size = 0,
> >>>> -			.header_split   = 0,
> >>>> -			.hw_ip_checksum = 0,
> >>>> -			.hw_vlan_filter = 0,
> >>>> -			.hw_vlan_strip  = 0,
> >>>> -			.hw_vlan_extend = 0,
> >>>>  			.jumbo_frame    = 0,
> >>>> -			.hw_strip_crc   = 1,
> >>>
> >>
> >> Hi Andrew,
> >>
> >>> I have 2 questions here:
> >>>  1. Why is jumbo_frame kept? There is
> >> DEV_RX_OFFLOAD_JUMBO_FRAME.
> >>
> >> Because there are still some usage of this flag in PMDs, they need to be
> >> clarified before removing the flag. I am for removing the flag in final version,
> >> but for this RFC I am not able to find enough time to work on PMDs for it.
> >
> > Can you elaborate?
> > Is this something more than just a replace of the jumbo_frame bit with its corresponding flag?
> 
> That was my concern that copy paste won't be enough because some drivers not
> just use the jumbo_frame but set it based on max_rx_pkt_len etc.., that is why
> left out .jumbo_frame in the RFC.

But max_rx_pkt_len need to be remained (and properly processed anyway) no?
BTW, I always wonder is there any reason to have jumbo_frame flag at all
(as we do have max_rx_pkt_len anyway)?
Konstantin

> 
> >
> >>
> >>>  2. Why is hw_strip_crc=1 discarded? Yes, I remember plans to make it
> >>>      default behaviour and introduce flag to keep CRC, but right now
> >>> the
> >>>      patch looks like mixture of two changes which is not good.
> >>
> >> Yes it is wrong, app should replace "".hw_strip_crc=1 with KEEP_CRC offload.
> >> Since both are RFC, kind of hard to maintain, but I think good to create a
> >> dependency from this patch to KEEP_CRC one.
> >>
> >>>
> >>> There are more cases in the patch where hw_strip_crc=1 is simply
> >> discarded.
> >>>
> >>> <...>
> >>>
> >>>> diff --git a/drivers/net/sfc/sfc_ethdev.c
> >>>> b/drivers/net/sfc/sfc_ethdev.c index 1b6499f85..ee8ae5b9f 100644
> >>>> --- a/drivers/net/sfc/sfc_ethdev.c
> >>>> +++ b/drivers/net/sfc/sfc_ethdev.c
> >>>> @@ -1089,7 +1089,6 @@ sfc_tx_queue_info_get(struct rte_eth_dev
> >> *dev,
> >>>> uint16_t tx_queue_id,
> >>>>
> >>>>  	memset(qinfo, 0, sizeof(*qinfo));
> >>>>
> >>>> -	qinfo->conf.txq_flags = txq_info->txq->flags;
> >>>>  	qinfo->conf.offloads = txq_info->txq->offloads;
> >>>>  	qinfo->conf.tx_free_thresh = txq_info->txq->free_thresh;
> >>>>  	qinfo->conf.tx_deferred_start = txq_info->deferred_start; diff
> >>>> --git a/drivers/net/sfc/sfc_rx.c b/drivers/net/sfc/sfc_rx.c index
> >>>> cc76a5b15..58a0df583 100644
> >>>> --- a/drivers/net/sfc/sfc_rx.c
> >>>> +++ b/drivers/net/sfc/sfc_rx.c
> >>>> @@ -1446,7 +1446,6 @@ sfc_rx_check_mode(struct sfc_adapter *sa,
> >> struct rte_eth_rxmode *rxmode)
> >>>>  	if (~rxmode->offloads & DEV_RX_OFFLOAD_CRC_STRIP) {
> >>>>  		sfc_warn(sa, "FCS stripping cannot be disabled - always on");
> >>>>  		rxmode->offloads |= DEV_RX_OFFLOAD_CRC_STRIP;
> >>>> -		rxmode->hw_strip_crc = 1;
> >>>>  	}
> >>>>
> >>>>  	return rc;
> >>>> diff --git a/drivers/net/sfc/sfc_tx.c b/drivers/net/sfc/sfc_tx.c
> >>>> index 1bcc2c697..6d42a1a65 100644
> >>>> --- a/drivers/net/sfc/sfc_tx.c
> >>>> +++ b/drivers/net/sfc/sfc_tx.c
> >>>> @@ -171,7 +171,6 @@ sfc_tx_qinit(struct sfc_adapter *sa, unsigned int
> >> sw_index,
> >>>>  	txq->free_thresh =
> >>>>  		(tx_conf->tx_free_thresh) ? tx_conf->tx_free_thresh :
> >>>>  		SFC_TX_DEFAULT_FREE_THRESH;
> >>>> -	txq->flags = tx_conf->txq_flags;
> >>>>  	txq->offloads = offloads;
> >>>>
> >>>>  	rc = sfc_dma_alloc(sa, "txq", sw_index,
> >>>> EFX_TXQ_SIZE(txq_info->entries), @@ -182,7 +181,6 @@
> >> sfc_tx_qinit(struct sfc_adapter *sa, unsigned int sw_index,
> >>>>  	memset(&info, 0, sizeof(info));
> >>>>  	info.max_fill_level = txq_max_fill_level;
> >>>>  	info.free_thresh = txq->free_thresh;
> >>>> -	info.flags = tx_conf->txq_flags;
> >>>>  	info.offloads = offloads;
> >>>>  	info.txq_entries = txq_info->entries;
> >>>>  	info.dma_desc_size_max = encp->enc_tx_dma_desc_size_max;
> >> @@ -431,18
> >>>> +429,10 @@ sfc_tx_qstart(struct sfc_adapter *sa, unsigned int sw_index)
> >>>>  	if (rc != 0)
> >>>>  		goto fail_ev_qstart;
> >>>>
> >>>> -	/*
> >>>> -	 * The absence of ETH_TXQ_FLAGS_IGNORE is associated with a
> >> legacy
> >>>> -	 * application which expects that IPv4 checksum offload is enabled
> >>>> -	 * all the time as there is no legacy flag to turn off the offload.
> >>>> -	 */
> >>>> -	if ((txq->offloads & DEV_TX_OFFLOAD_IPV4_CKSUM) ||
> >>>> -	    (~txq->flags & ETH_TXQ_FLAGS_IGNORE))
> >>>> +	if (txq->offloads & DEV_TX_OFFLOAD_IPV4_CKSUM)
> >>>>  		flags |= EFX_TXQ_CKSUM_IPV4;
> >>>>
> >>>> -	if ((txq->offloads & DEV_TX_OFFLOAD_OUTER_IPV4_CKSUM) ||
> >>>> -	    ((~txq->flags & ETH_TXQ_FLAGS_IGNORE) &&
> >>>> -	     (offloads_supported &
> >> DEV_TX_OFFLOAD_OUTER_IPV4_CKSUM)))
> >>>> +	if (txq->offloads & DEV_TX_OFFLOAD_OUTER_IPV4_CKSUM)
> >>>>  		flags |= EFX_TXQ_CKSUM_INNER_IPV4;
> >>>>
> >>>>  	if ((txq->offloads & DEV_TX_OFFLOAD_TCP_CKSUM) || @@ -453,16
> >> +443,7
> >>>> @@ sfc_tx_qstart(struct sfc_adapter *sa, unsigned int sw_index)
> >>>>  			flags |= EFX_TXQ_CKSUM_INNER_TCPUDP;
> >>>>  	}
> >>>>
> >>>> -	/*
> >>>> -	 * The absence of ETH_TXQ_FLAGS_IGNORE is associated with a
> >> legacy
> >>>> -	 * application. In turn, the absence of ETH_TXQ_FLAGS_NOXSUMTCP
> >> is
> >>>> -	 * associated specifically with a legacy application which expects
> >>>> -	 * both TCP checksum offload and TSO to be enabled because the
> >> legacy
> >>>> -	 * API does not provide a dedicated mechanism to control TSO.
> >>>> -	 */
> >>>> -	if ((txq->offloads & DEV_TX_OFFLOAD_TCP_TSO) ||
> >>>> -	    ((~txq->flags & ETH_TXQ_FLAGS_IGNORE) &&
> >>>> -	     (~txq->flags & ETH_TXQ_FLAGS_NOXSUMTCP)))
> >>>> +	if (txq->offloads & DEV_TX_OFFLOAD_TCP_TSO)
> >>>>  		flags |= EFX_TXQ_FATSOV2;
> >>>>
> >>>>  	rc = efx_tx_qcreate(sa->nic, sw_index, 0, &txq->mem,
> >>>
> >>> net/sfc changes looks good.
> >>> Plus 'struct sfc_txq -> flags' (drivers/net/sfc/sfc_tx.h) and 'struct
> >>> sfc_dp_tx_qcreate_info -> flags' (drivers/net/sfc/sfc_dp_tx.h) should
> >>> be removed since there are not used now.
> >>>
> >>> If finally rxmode.jumbo_frame is removed, it should removed from
> >>> net/sfc as well (but compiler will help to find it in any case).
> >>>
> >>> After applying the patch:
> >>> $ git grep ETH_TXQ_FLAGS
> >>> drivers/net/fm10k/fm10k.h:#define FM10K_SIMPLE_TX_FLAG
> >>> ((uint32_t)ETH_TXQ_FLAGS_NOMULTSEGS | \
> >>> drivers/net/fm10k/fm10k.h:
> >>> ETH_TXQ_FLAGS_NOOFFLOADS)
> >>
> >> Thanks, will remove this too.
> >>
> >>>
> >>> In general I think that we should do it ASAP. Also it will guarantee
> >>> that new PMDs do not use corresponding structure members etc.
> >>
> >> +1, +1
> >