Re: [RFC] ethdev: remove all offload API

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 6/11/2018 12:26 PM, Ananyev, Konstantin wrote:
> 
> 
>> -----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?

Yes, it will remain.

> BTW, I always wonder is there any reason to have jumbo_frame flag at all
> (as we do have max_rx_pkt_len anyway)?

agree that jumbo_frame flag, max_rx_pkt_len and mtu usage/relation can be
clarified more.

> 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
>>>
>