On Fri, Dec 1, 2023 at 12:23 PM Daniel Xu dxu@dxuuu.xyz wrote:
This patchset adds two kfunc helpers, bpf_xdp_get_xfrm_state() and bpf_xdp_xfrm_state_release() that wrap xfrm_state_lookup() and xfrm_state_put(). The intent is to support software RSS (via XDP) for the ongoing/upcoming ipsec pcpu work [0]. Recent experiments performed on (hopefully) reproducible AWS testbeds indicate that single tunnel pcpu ipsec can reach line rate on 100G ENA nics.
Note this patchset only tests/shows generic xfrm_state access. The "secret sauce" (if you can really even call it that) involves accessing a soon-to-be-upstreamed pcpu_num field in xfrm_state. Early example is available here [1].
Changes from v2:
- Fix/simplify BPF_CORE_WRITE_BITFIELD() algorithm
- Added verifier tests for bitfield writes
- Fix state leakage across test_tunnel subtests
Changes from v1:
- Move xfrm tunnel tests to test_progs
- Fix writing to opts->error when opts is invalid
- Use __bpf_kfunc_start_defs()
- Remove unused vxlanhdr definition
- Add and use BPF_CORE_WRITE_BITFIELD() macro
- Make series bisect clean
Changes from RFCv2:
- Rebased to ipsec-next
- Fix netns leak
Changes from RFCv1:
- Add Antony's commit tags
- Add KF_ACQUIRE and KF_RELEASE semantics
Daniel Xu (9): bpf: xfrm: Add bpf_xdp_get_xfrm_state() kfunc bpf: xfrm: Add bpf_xdp_xfrm_state_release() kfunc libbpf: Add BPF_CORE_WRITE_BITFIELD() macro bpf: selftests: test_loader: Support __btf_path() annotation libbpf: selftests: Add verifier tests for CO-RE bitfield writes bpf: selftests: test_tunnel: Setup fresh topology for each subtest bpf: selftests: test_tunnel: Use vmlinux.h declarations bpf: selftests: Move xfrm tunnel test to test_progs bpf: xfrm: Add selftest for bpf_xdp_get_xfrm_state()
include/net/xfrm.h | 9 + net/xfrm/Makefile | 1 + net/xfrm/xfrm_policy.c | 2 + net/xfrm/xfrm_state_bpf.c | 128 ++++++++++++++ tools/lib/bpf/bpf_core_read.h | 34 ++++ .../selftests/bpf/prog_tests/test_tunnel.c | 162 +++++++++++++++++- .../selftests/bpf/prog_tests/verifier.c | 2 + tools/testing/selftests/bpf/progs/bpf_misc.h | 1 + .../selftests/bpf/progs/bpf_tracing_net.h | 1 + .../selftests/bpf/progs/test_tunnel_kern.c | 138 ++++++++------- .../bpf/progs/verifier_bitfield_write.c | 100 +++++++++++ tools/testing/selftests/bpf/test_loader.c | 7 + tools/testing/selftests/bpf/test_tunnel.sh | 92 ---------- 13 files changed, 522 insertions(+), 155 deletions(-)
I really think this should go via bpf-next tree. The bpf changes are much bigger than ipsec.