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].
[0]: https://datatracker.ietf.org/doc/draft-ietf-ipsecme-multi-sa-performance/03/ [1]: https://github.com/danobi/xdp-tools/blob/e89a1c617aba3b50d990f779357d6ce2863...
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 (7): bpf: xfrm: Add bpf_xdp_get_xfrm_state() kfunc bpf: xfrm: Add bpf_xdp_xfrm_state_release() kfunc bpf: selftests: test_tunnel: Use ping -6 over ping6 bpf: selftests: test_tunnel: Mount bpffs if necessary bpf: selftests: test_tunnel: Use vmlinux.h declarations bpf: selftests: test_tunnel: Disable CO-RE relocations 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 | 127 ++++++++++++++++++ .../selftests/bpf/progs/bpf_tracing_net.h | 1 + .../selftests/bpf/progs/test_tunnel_kern.c | 98 ++++++++------ tools/testing/selftests/bpf/test_tunnel.sh | 43 ++++-- 7 files changed, 227 insertions(+), 54 deletions(-) create mode 100644 net/xfrm/xfrm_state_bpf.c