On Wed, 2023-07-12 at 23:07 -0700, Yonghong Song wrote: > > In previous discussion ([1]), it is agreed that we should introduce > > cpu version 4 (llvm flag -mcpu=v4) which contains some instructions > > which can simplify code, make code easier to understand, fix the > > existing problem, or simply for feature completeness. More specifically, > > the following new insns are proposed: > > . sign extended load > > . sign extended mov > > . bswap > > . signed div/mod > > . ja with 32-bit offset > > > > This patch set added kernel support for insns proposed in [1] except > > BPF_ST which already has full kernel support. Beside the above proposed > > insns, LLVM will generate BPF_ST insn as well under -mcpu=v4 ([2]). > > > > The patchset implements interpreter and jit support for these new > > insns as well as necessary verifier support. Hi Yonghong, Sorry for delayed response, I'm still in the middle of the series. I've tested this patch-set using updated LLVM version and have a few notes: - kernel/bpf/disasm.c needs an update to handle new instructions; - test_verifier test 'invalid 64-bit BPF_END' from basic_instr.c is failing because '.code = BPF_ALU64 | BPF_END | BPF_TO_LE' is now valid; - I've looked through the usage of BPF_LDX and found that there is a function seccomp.c:seccomp_check_filter(), that directly checks possible CLASS / CODE combinations. Should this function be updated to handle new instructions? Thanks, Eduard > > > > To test this patch set, you need to have latest llvm from 'main' branch > > of llvm-project repo and apply [2] on top of it. > > > > [1] https://lore.kernel.org/bpf/4bfe98be-5333-1c7e-2f6d-42486c8ec039@xxxxxxxx/ > > [2] https://reviews.llvm.org/D144829 > > > > Changelogs: > > RFCv1 -> v2: > > . add more verifier supports for signed extend load and mov insns. > > . rename some insn names to be more consistent with intel practice. > > . add cpuv4 test runner for test progs. > > . add more unit and C tests. > > . add documentation. > > > > Yonghong Song (15): > > bpf: Support new sign-extension load insns > > bpf: Fix sign-extension ctx member accesses > > bpf: Support new sign-extension mov insns > > bpf: Support new unconditional bswap instruction > > bpf: Support new signed div/mod instructions. > > bpf: Fix jit blinding with new sdiv/smov insns > > bpf: Support new 32bit offset jmp instruction > > selftests/bpf: Add a cpuv4 test runner for cpu=v4 testing > > selftests/bpf: Add unit tests for new sign-extension load insns > > selftests/bpf: Add unit tests for new sign-extension mov insns > > selftests/bpf: Add unit tests for new bswap insns > > selftests/bpf: Add unit tests for new sdiv/smod insns > > selftests/bpf: Add unit tests for new gotol insn > > selftests/bpf: Test ldsx with more complex cases > > docs/bpf: Add documentation for new instructions > > > > Documentation/bpf/bpf_design_QA.rst | 5 - > > .../bpf/standardization/instruction-set.rst | 100 ++- > > arch/x86/net/bpf_jit_comp.c | 131 ++- > > include/linux/filter.h | 14 +- > > include/uapi/linux/bpf.h | 1 + > > kernel/bpf/cgroup.c | 14 +- > > kernel/bpf/core.c | 174 +++- > > kernel/bpf/verifier.c | 315 ++++++-- > > tools/include/uapi/linux/bpf.h | 1 + > > tools/testing/selftests/bpf/.gitignore | 2 + > > tools/testing/selftests/bpf/Makefile | 18 +- > > .../selftests/bpf/bpf_testmod/bpf_testmod.c | 9 +- > > .../selftests/bpf/prog_tests/test_ldsx_insn.c | 88 ++ > > .../selftests/bpf/prog_tests/verifier.c | 10 + > > .../selftests/bpf/progs/test_ldsx_insn.c | 75 ++ > > .../selftests/bpf/progs/verifier_bswap.c | 45 ++ > > .../selftests/bpf/progs/verifier_gotol.c | 30 + > > .../selftests/bpf/progs/verifier_ldsx.c | 115 +++ > > .../selftests/bpf/progs/verifier_movsx.c | 177 ++++ > > .../selftests/bpf/progs/verifier_sdiv.c | 763 ++++++++++++++++++ > > 20 files changed, 1929 insertions(+), 158 deletions(-) > > create mode 100644 tools/testing/selftests/bpf/prog_tests/test_ldsx_insn.c > > create mode 100644 tools/testing/selftests/bpf/progs/test_ldsx_insn.c > > create mode 100644 tools/testing/selftests/bpf/progs/verifier_bswap.c > > create mode 100644 tools/testing/selftests/bpf/progs/verifier_gotol.c > > create mode 100644 tools/testing/selftests/bpf/progs/verifier_ldsx.c > > create mode 100644 tools/testing/selftests/bpf/progs/verifier_movsx.c > > create mode 100644 tools/testing/selftests/bpf/progs/verifier_sdiv.c > >
