[dpdk-dev] [PATCH] doc: add Linux rawio capability requirement in mlx5 guide

[Thomas Monjalon]

01/04/2021 14:06, Eli Britstein:
> On 4/1/2021 2:39 PM, Thomas Monjalon wrote:
> > About the title: "rawio" is not a word.
> > "raw IO" would be better.
> 
> It was meant for cap_sys_rawio. As underscores are not allowed in the 
> title, I used "rawio".
> 
> I think "raw IO" misses that meaning. What do you think?

I think "raw IO capability" can be understood by everybody.
Otherwise "cap_sys_rawio" may be more explicit for those who know.

> > 01/04/2021 09:49, Eli Britstein:
> >> For an application to be able to create "transfer" rte_flows for mlx5
> > What is "tranfer" rule?
> 
> https://doc.dpdk.org/guides/prog_guide/rte_flow.html#attribute-transfer
> 
> How would you suggest to call it?

"transfer flow rule" is OK.
Or maybe more explicit: "flow rule with transfer attribute".

[...]
> >> +``cap_sys_rawio`` optional
> >> +   For the application to be able to apply rte_flow flows in transfer
> >> +   mode.
> > 
> > "For the application" looks useless.
> > We don't apply "rte_flow flows" but "flow rules".
> > What is "transfer mode"? It is not mentioned elsewhere in this doc.

You could add the link to the transfer attribute here.

> > How this capability is related to dv_esw_en?
> 
> I think FDB flows are applicable only if dv_esw_en=1. Do you think need 
> to mention it here?

Yes

> > Do we need it in case of trusted VF?
> 
> I think a VF, even if trusted cannot apply FDB flows. Only the ESW manager.

Please confirm, and document if it applies only to PF, etc.

When looking at the Linux driver, it seems cap_sys_rawio
is required for all these features:
	MLX5_UCTX_CAP_INTERNAL_DEV_RES
	MLX5_IB_UAPI_DM_TYPE_STEERING_SW_ICM
	MLX5_IB_UAPI_DM_TYPE_HEADER_MODIFY_SW_ICM
	IB_WQ_FLAGS_DELAY_DROP
What does apply to the DPDK driver?