On Mon, Nov 6, 2023 at 3:38 AM Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> wrote: > > On Sun, Nov 5, 2023 at 4:17 PM Will Hawkins <hawkinsw@xxxxxx> wrote: > > > > On Sun, Nov 5, 2023 at 4:51 AM Alexei Starovoitov > > <alexei.starovoitov@xxxxxxxxx> wrote: > > > > > > On Fri, Nov 3, 2023 at 2:20 PM Will Hawkins <hawkinsw@xxxxxx> wrote: > > > > + > > > > +The ABI is specified in two parts: a generic part and a processor-specific part. > > > > +A pairing of generic ABI with the processor-specific ABI for a certain > > > > +instantiation of a BPF machine represents a complete binary interface for BPF > > > > +programs executing on that machine. > > > > + > > > > +This document is the generic ABI and specifies the parameters and behavior > > > > +common to all instantiations of BPF machines. In addition, it defines the > > > > +details that must be specified by each processor-specific ABI. > > > > + > > > > +These psABIs are the second part of the ABI. Each instantiation of a BPF > > > > +machine must describe the mechanism through which binary interface > > > > +compatibility is maintained with respect to the issues highlighted by this > > > > +document. However, the details that must be defined by a psABI are a minimum -- > > > > +a psABI may specify additional requirements for binary interface compatibility > > > > +on a platform. > > > > > > I don't understand what you are trying to say in the above. > > > In my mind there is only one BPF psABI and it doesn't have > > > generic and processor parts. There is only one "processor". > > > BPF is such a processor. > > > > What I was trying to say was that the document here describes a > > generic ABI. In this document there will be areas that are specific to > > different implementations and those would be considered processor > > specific. In other words, the ubpf runtime could define those things > > differently than the rbpf runtime which, in turn, could define those > > things differently than the kernel's implementation. > > I see what you mean. There is only one BPF psABI. There cannot be two. > ubpf can decide not to follow it, but it could only mean that > it's non conformant and not compatible. Okay. That was not how I was structuring the ABI. I thought we had decided that, as the document said, an instantiation of a machine had to 1. meet the gABI 2. specify its requirements vis a vis the psABI 3. (optionally) describe other requirements. If that is not what we decided then we will have to restructure the document. Will
