Yonghong Song says:
====================
bpf: Support new insns from cpu v4
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.
The llvm patch ([2]) has been merged into llvm-project 'main' branch.
The patchset implements interpreter, jit and verifier support for these new
insns.
For this patch set, I tested cpu v2/v3/v4 and the selftests are all passed.
I also tested selftests introduced in this patch set with additional changes
beside normal jit testing (bpf_jit_enable = 1 and bpf_jit_harden = 0)
- bpf_jit_enable = 0
- bpf_jit_enable = 1 and bpf_jit_harden = 1
and both testing passed.
[1] https://lore.kernel.org/bpf/
4bfe98be-5333-1c7e-2f6d-
42486c8ec039@meta.com/
[2] https://reviews.llvm.org/D144829
Changelogs:
v4 -> v5:
. for v4, patch 8/17 missed in mailing list and patchwork, so resend.
. rebase on top of master
v3 -> v4:
. some minor asm syntax adjustment based on llvm change.
. add clang version and target arch guard for new tests
so they can still compile with old llvm compilers.
. some changes to the bpf doc.
v2 -> v3:
. add missed disasm change from v2.
. handle signed load of ctx fields properly.
. fix some interpreter sdiv/smod error when bpf_jit_enable = 0.
. fix some verifier range bounding errors.
. add more C tests.
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.
====================
Link: https://lore.kernel.org/r/20230728011143.3710005-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>