On Fri, Jan 19, 2024 at 3:35 PM Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> wrote: > > On Fri, Jan 19, 2024 at 3:13 PM Vincent Li <vincent.mc.li@xxxxxxxxx> wrote: > > > > On Fri, Jan 19, 2024 at 2:26 PM Alexei Starovoitov > > <alexei.starovoitov@xxxxxxxxx> wrote: > > > > > > On Fri, Jan 19, 2024 at 7:00 AM Vincent Li <vincent.mc.li@xxxxxxxxx> wrote: > > > > > > > > On Fri, Jan 19, 2024 at 4:23 AM Eduard Zingerman <eddyz87@xxxxxxxxx> wrote: > > > > > > > > > > On Fri, 2024-01-19 at 16:04 +0800, Shung-Hsi Yu wrote: > > > > > > > > > > [...] > > > > > > > > > > > Final goal would be have BPF selftests compiled and test against our own > > > > > > kernel, without having to come up with a specific kernel flavor that is > > > > > > used to build and run the selftest. For v5.14 and v5.19-based kernel it > > > > > > works: compilation is successful and I was able to run the verifier > > > > > > tests. (Did not try running the other tests though) > > > > > > > > > > You mean ./test_verifier binary, right? > > > > > A lot of tests had been moved from ./test_verifier to ./test_progs since. > > > > > > > > > > > > As far as I understand, selftests are supposed to be built and run > > > > > > > using specific configuration, here is how config for x86 CI is prepared: > > > > > > > > > > > > > > ./scripts/kconfig/merge_config.sh \ > > > > > > > ./tools/testing/selftests/bpf/config \ > > > > > > > ./tools/testing/selftests/bpf/config.vm \ > > > > > > > ./tools/testing/selftests/bpf/config.x86_64 > > > > > > > > > > > > > > (root is kernel source). > > > > > > > I'm not sure if other configurations are supposed to be supported. > > > > > > > > > > > > Would it make sense to have makefile target that builds/runs a smaller > > > > > > subset of general, config-agnostic selftests that tests the core feature > > > > > > (e.g. verifier + instruction set)? > > > > > > > > > > In ideal world I'd say that ./test_progs should include/exclude tests > > > > > conditioned on current configuration, but I don't know how much work > > > > > would it be to adapt build system for this. > > > > > > > > > > > > > I would also suggest skipping building the specific bpf test code when > > > > a specific CONFIG is removed, sometimes > > > > I only want to test some bpf selftests code I am interested in :) > > > > > > I don't think we should be complicating bpf selftests to test > > > configurations with reduced kconfig. > > > bpf/config.* is what we target in bpf CI and we expect > > > developers do the same amount of testing before they send patches. > > > > Totally understand that from the kernel bpf developer perspective. I > > am a bpf user learning how to write a bpf program from selftests, but > > I guess there is another way to learn, selftests is not for teaching > > bpf users, no need to complicate. > > Try libbpf-bootstrap ([0]) as a simple setup to play with new BPF > features. minimal or bootstrap examples are usually good starting > points. > > [0] https://github.com/libbpf/libbpf-bootstrap Thanks! I am aware of libbpf-bootstrap, I am on an old centos 8 distro which often miss linux headers that some selftests happens to require, especially the ones that are not using vmlinux.h, when a bpf kernel developer submit patches and selftests that I am interested in, I want to run that selftests and learn the new feature, and then probably port the new useful selftests code to a real use case bpf program. I often run into other selftests compiling errors when I want to selftest the new feature I am interested in. Anyway, it is my build environment problem, not selftests.
