How does bpf2c handle memory model differences?

[lmb]

I recently attended a talk by Paul McKenney on the work on a BPF memory model. This exists so that programs accessing memory concurrently have meaningful semantics.

If I understand bpf2c correctly it works by translating a BPF instruction into an equivalent C statement. All statements are then compiled via MSVC, resulting in x64 assembly in a native .sys file. In terms of memory models we get the following:

Source C (Clang memory model) -> BPF (BPF MM) -> Generated C (MSVC MM) -> assembly (hardware MM)

How do you ensure that this transformation of BPF to C preserves BPF memory model semantics in the final assembly?

See https://datatracker.ietf.org/meeting/118/materials/slides-118-bpf-bpf-memory-model-00 for some context.

[shankarseal]

Thanks for bringing this up @lmb. Someone from the eBPF maintainers group will look into the presentation and reply back to this discussion.