Re: [dpdk-dev] Survey for final decision about per-port offload API

["Zhang, Qi Z" <qi.z.zhang@intel.com>]

Hi Thomas:
> -----Original Message-----
> From: Thomas Monjalon [mailto:thomas@monjalon.net]
> Sent: Friday, March 30, 2018 9:48 PM
> To: dev@dpdk.org
> Cc: Ajit Khaparde <ajit.khaparde@broadcom.com>; Jerin Jacob
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> Subject: Survey for final decision about per-port offload API
> 
> 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?
> 
> 
> If we agree with this change, we need to update the documentation and
> remove the checks in PMDs.

Do you mean we will move offload check from PMD to ethdev, 
or just remove specific check in each PMD
or it is not in the scope of this vote?

Thanks
Qi

> 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?

> 
> 
> 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)?
> 
> 
> 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

> 
> 
> Please give your opinion on questions 1, 2, 3 and 4.
> Answering by yes/no may be sufficient in most cases :) Thank you
>