[dpdk-dev] Per-queue bandwidth limit on XL710 NICs?

[Paul Emmerich <emmericp@net.in.tum.de>]

Hi,

I'm using the per-queue rate control feature found in ixgbe-style NICs 
(rte_eth_set_queue_rate_limit) quite extensively in my packet generator 
MoonGen.

I've read some parts of the XL710 datasheet and I guess it should be 
possible to implement this for this chip. I think there are two ways to 
achieves this:

1) Limiting the main VSI and thus the whole port by calling 
i40e_aq_config_vsi_bw_limit() in the driver works fine. Thus, creating 
multiple VSIs for each rate-controlled queue would be a possible solution.
I'm not sure if that works without major modifications to the driver. I 
probably need a VEB for that which currently isn't supported in the driver.

2) Use multiple TCs for the used VSI. That would limit us to 8 rate 
limits but that would be okay. Probably the simpler solution.

Can anyone with more insight into the XL710 hardware give me some hints 
on implementing this?


  Paul