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The link you posted mentions "setting up offloads", and unifying the functionality of DSA and switchdev. To me, DSA (as a "convenient" means to access/name/tre

The link you posted mentions "setting up offloads", and unifying the functionality of DSA and switchdev. To me, DSA (as a "convenient" means to access/name/treat individual switch ports) is a prerequisite to enable usage of whatever Switch-Chip-Level-Offloads the switch chip supports. Without DSA, vendors had to use nasty hacks to make use of e.g. HWNAT, which is why there never was mainline support for these acceleration features. HWNAT is a routing function, and many/most? switches of the last decade support that. But, OK, true, most of them will probably not be able to HWNAT "with proper QoS". But newer devices are not "just" a switch-chip, they contain a "Network processing engine", which is not a "fixed-function" device, but rather a "programmable" accelerator, that you could perhaps even "teach" how to do PPP, Encrption/VPN wrapping, and/or "offloading NAT/routing with proper QoS". And now that DSA and eBPF are in mainline, using eBPF to generate a program/set_of_rules for the Ethernet acceleration device from your nftable-rules seems like the natural next step for me. Or where do you see my reasoning go off the rails?

scottlamb 5y ago
To paraphrase: you're saying that DSA doesn't support offloads, and most HW NATs don't do QoS, but newer hardware is capable of it, and you expect mainline Linux to make full use of it in the future with DSA. No, I don't know of any problem in your reasoning. I'll look forward to that happening! I wasn't aware newer hardware was so flexible.
- stragies 5y ago
  Yes, nearly: DSA currently only supports a few basic offloads, and all?/most of those only work on some of the supported DSA targets. I think, MT76xx devices are the most "advanced" in that respect right now. But nothing "advanced" like even pppoe-offloading (yet). I just hope, "flexible" doesn't come with a large "Difficult-to-audit-caveat" side-dish. NPEs "governing" traffic could potentially substantially reduce the trust the user can have towards the platform.

scottlamb 5y ago

To paraphrase: you're saying that DSA doesn't support offloads, and most HW NATs don't do QoS, but newer hardware is capable of it, and you expect mainline Linux to make full use of it in the future with DSA. No, I don't know of any problem in your reasoning. I'll look forward to that happening! I wasn't aware newer hardware was so flexible.

stragies 5y ago
Yes, nearly: DSA currently only supports a few basic offloads, and all?/most of those only work on some of the supported DSA targets. I think, MT76xx devices are the most "advanced" in that respect right now. But nothing "advanced" like even pppoe-offloading (yet). I just hope, "flexible" doesn't come with a large "Difficult-to-audit-caveat" side-dish. NPEs "governing" traffic could potentially substantially reduce the trust the user can have towards the platform.