From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Rybchenko <arybchenko@solarflare.com>
Subject: Re: Survey for final decision about per-port offload API
Date: Fri, 30 Mar 2018 18:13:11 +0300
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Cc: Ajit Khaparde <ajit.khaparde@broadcom.com>, Jerin Jacob
 <jerin.jacob@caviumnetworks.com>, Shijith Thotton
 <shijith.thotton@cavium.com>, Santosh Shukla
 <santosh.shukla@caviumnetworks.com>, Rahul Lakkireddy
 <rahul.lakkireddy@chelsio.com>, John Daley <johndale@cisco.com>, Wenzhuo Lu
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 Beilei Xing <beilei.xing@intel.com>, Qi Zhang <qi.z.zhang@intel.com>,
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 <adrien.mazarguil@6wind.com>, Nelio Laranjeiro <nelio.laranjeiro@6wind.com>,
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 Alejandro Lucero <alejandro.lucero@netronome.com>, Hemant Agrawal
 <hemant.agrawal@nxp.com>, Shreyansh Jain <shreyansh.jain@nxp.com>, "Harish
 Patil" <harish.patil@cavium.com>, Rasesh M
To: Thomas Monjalon <thomas@monjalon.net>, <dev@dpdk.org>
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On 03/30/2018 04:47 PM, Thomas Monjalon wrote:
> There are some discussions about a specific part of the offload API:
> 	"To enable per-port offload, the offload should be set on both
> 	device configuration and queue setup."
>
> It means the application must repeat the port offload flags
> in rte_eth_conf.[rt]xmode.offloads and rte_eth_[rt]xconf.offloads,
> when calling respectively rte_eth_dev_configure() and
> rte_eth_[rt]x_queue_setup for each queue.
>
> The PMD must check if there is mismatch, i.e. a port offload not
> repeated in queue setup.
> There is a proposal to do this check at ethdev level:
> 	http://dpdk.org/ml/archives/dev/2018-March/094023.html
>
> It was also proposed to relax the API and allow "forgetting" port
> offloads in queue offloads:
> 	http://dpdk.org/ml/archives/dev/2018-March/092978.html
>
> It would mean the offloads applied to a queue result of OR operation:
> 	rte_eth_conf.[rt]xmode.offloads | rte_eth_[rt]xconf.offloads
>
> 1/ Do you agree with above API change?

Yes

> If we agree with this change, we need to update the documentation
> and remove the checks in PMDs.
> Note: no matter what is decided here, 18.05-rc1 should have all PMDs
> switched to the API which was defined in 17.11.
> Given that API is new and not yet adopted by the applications,
> the sonner it is fixed, the better.
>
> 2/ Should we do this change in 18.05-rc2?

Yes

> At the same time, we want to make clear that an offload enabled at
> port level, cannot be disabled at queue level.
>
> 3/ Do you agree with above statement (to be added in the doc)?

Yes

> There is the same kind of confusion in the offload capabilities:
> 	rte_eth_dev_info.[rt]x_offload_capa
> 	rte_eth_dev_info.[rt]x_queue_offload_capa
> The queue capabilities must be a subset of port capabilities,
> i.e. every queue capabilities must be reported as port capabilities.
> But the port capabilities should be reported at queue level
> only if it can be applied to a specific queue.
>
> 4/ Do you agree with above statement (to be added in the doc)?

Yes, may be it would be good to be more precise what "can be applied" mean.
As I understand it is "can be enabled on queue when it is disabled on 
port level".

Andrew.