Re: [PATCH bpf-next v5 0/3] bpf, riscv: add timed may_goto support

[Pu Lehui <pulehui@huawei.com>]

On 2026/7/23 13:41, Feng Jiang wrote:
> This series adds RISC-V JIT support for the timed may_goto loop bound.
> 
> Patch 1 implements arch_bpf_timed_may_goto() and enables
> bpf_jit_supports_timed_may_goto() so the verifier uses the timed
> expansion path.
> 
> Patch 2 adds a test that checks R0-R5 are preserved across
> arch_bpf_timed_may_goto() calls.
> 
> Patch 3 enables the verifier_may_goto_1, stream_cond_break, and
> may_goto_interaction fastcall tests on riscv64.
> 
> Tested on riscv64 QEMU (rva23s64): may_goto programs load and JIT
> correctly, and the 250ms timeout path works as expected.
> 
> Signed-off-by: Feng Jiang <jiangfeng@kylinos.cn>

For this series:

Tested-by: Pu Lehui <pulehui@huawei.com>

> ---
> Changes in v5:
> - Use REG_S/REG_L/SZREG in arch_bpf_timed_may_goto assembly. (Pu Lehui)
> - Add __arch_s390x to the timed_may_goto_preserves_regs test. (Pu Lehui)
> - Switch the preserves-regs test to SEC("syscall") to fix
>    bpf_prog_test_run() EINVAL.
> - Link to v4: https://lore.kernel.org/r/20260722-riscv-bpf-timed-may-goto-v4-0-e117e6337bc7@kylinos.cn
> 
> Changes in v4:
> - Add 'bpf-next' prefix to match the BPF kernel tree workflow.
> - Add a test checking that R0-R5 are preserved across
>    arch_bpf_timed_may_goto() calls. Use bpf_get_prandom_u32() to
>    prevent the verifier from removing the checks via DCE.
> - Rename may_goto_interaction_arm64() to may_goto_interaction().
> - Wrap the arch_bpf_timed_may_goto address check to a single line.
> - Link to v3: https://lore.kernel.org/r/20260715-riscv-bpf-timed-may-goto-v3-0-cf2a9c3d843f@kylinos.cn
> 
> Changes in v3:
> - Set up the frame pointer in arch_bpf_timed_may_goto() so the function
>    does not break stack unwinding under CONFIG_FRAME_POINTER.
> 
> Changes in v2:
> - Fix BPF_REG_0 being clobbered after arch_bpf_timed_may_goto() calls.
> - Enable the may_goto_interaction fastcall test on riscv64.
> 
> ---
> Feng Jiang (3):
>        bpf, riscv: add support for timed may_goto
>        selftests/bpf: test timed may_goto preserves R0-R5
>        selftests/bpf: enable timed may_goto tests for riscv64
> 
>   arch/riscv/net/Makefile                            |  2 +-
>   arch/riscv/net/bpf_jit_comp64.c                    | 12 ++++-
>   arch/riscv/net/bpf_timed_may_goto.S                | 47 ++++++++++++++++
>   tools/testing/selftests/bpf/progs/stream.c         |  1 +
>   .../selftests/bpf/progs/verifier_bpf_fastcall.c    |  3 +-
>   .../selftests/bpf/progs/verifier_may_goto_1.c      | 62 ++++++++++++++++++++++
>   6 files changed, 124 insertions(+), 3 deletions(-)
> ---
> base-commit: a23a71823352e2d792dcaae25f1ebb744acbfc0b
> change-id: 20260710-riscv-bpf-timed-may-goto-0dce564985af
> 
> Best regards,