On Fri, Feb 17, 2023 at 9:39 AM Martin KaFai Lau <martin.lau@xxxxxxxxx> wrote: > > On 2/17/23 9:32 AM, Stanislav Fomichev wrote: > > On 02/17, Jesper Dangaard Brouer wrote: > >> With our XDP-hints kfunc approach, where individual drivers overload the > >> default implementation, it can be hard for API users to determine > >> whether or not the current device driver have this kfunc available. > > > >> Change the default implementations to use an errno (ENODEV), that > >> drivers shouldn't return, to make it possible for BPF runtime to > >> determine if bpf kfunc for xdp metadata isn't implemented by driver. > > > >> This is intended to ease supporting and troubleshooting setups. E.g. > >> when users on mailing list report -19 (ENODEV) as an error, then we can > >> immediately tell them their device driver is too old. > > > > I agree with the v1 comments that I'm not sure how it helps. > > Why can't we update the doc in the same fashion and say that > > the drivers shouldn't return EOPNOTSUPP? > > > > I'm fine with the change if you think it makes your/users life > > easier. Although I don't really understand how. We can, as Toke > > mentioned, ask the users to provide jited program dump if it's > > mostly about user reports. > > and there is xdp-features also. Yeah, I was going to suggest it, but then I wasn't sure how to reconcile our 'kfunc is not a uapi' with xdp-features (that probably is a uapi)?
