On 11/7/22 10:24, Jakub Kicinski wrote: [snip]
Yeah, it's a balancing act. Please explore the metadata option, I think most people jump to the skb extension because they don't know about metadata. If you still want skb extension after, I'll look away.
It seems to me like we are trying too hard to have a generic out of band solution to provide tagger information coming from a DMA descriptor as opposed to just introducing a DSA tagger variant specific to the format being used and specific to the switch + integrated MAC. Something like DSA_TAG_IPQDMA or whatever the name chosen would be, may be fine.
The only value I see at this point in just in telling me that the tagger format is coming from a DMA descriptor, but other than that, it is just a middle layer that requires marshalling of data on both sides, so sure the idea behind DSA was to be able to mix and match any Ethernet MAC with any discrete switch, but integrating both into the same ASIC does nullify the design goal.
-- Florian
