Re: [PATCH v4 0/5] Support trampoline for LoongArch

[Daniel Borkmann]

On 7/25/25 12:18 PM, Chenghao Duan wrote:
> On Thu, Jul 24, 2025 at 08:30:35AM -0700, Vincent Li wrote:
> > On Thu, Jul 24, 2025 at 7:19 AM Chenghao Duan <duanchenghao@xxxxxxxxxx> wrote:
> > > v4:
> > > 1. Delete the #3 patch of version V3.
> > >
> > > 2. Add 5 NOP instructions in build_prologue().
> > >     Reserve space for the move_imm + jirl instruction.
> > >
> > > 3. Differentiate between direct jumps and ftrace jumps of trampoline:
> > >     direct jumps skip 5 instructions.
> > >     ftrace jumps skip 2 instructions.
> > >
> > > 4. Remove the generation of BL jump instructions in emit_jump_and_link().
> > >     After the trampoline ends, it will jump to the specified register.
> > >     The BL instruction writes PC+4 to r1 instead of allowing the
> > >     specification of rd.
> > >
> > > -----------------------------------------------------------------------
> > > Historical Version:
> > > v3:
> > > 1. Patch 0003 adds EXECMEM_BPF memory type to the execmem subsystem.
> > >
> > > 2. Align the size calculated by arch_bpf_trampoline_size to page
> > > boundaries.
> > >
> > > 3. Add the flush icache operation to larch_insn_text_copy.
> > >
> > > 4. Unify the implementation of bpf_arch_xxx into the patch
> > > "0004-LoongArch-BPF-Add-bpf_arch_xxxxx-support-for-Loong.patch".
> > >
> > > 5. Change the patch order. Move the patch
> > > "0002-LoongArch-BPF-Update-the-code-to-rename-validate_.patch" before
> > > "0005-LoongArch-BPF-Add-bpf-trampoline-support-for-Loon.patch".
> > >
> > > URL for version v3:
> > > https://lore.kernel.org/all/20250709055029.723243-1-duanchenghao@xxxxxxxxxx/
> > > ---------
> > > v2:
> > > 1. Change the fixmap in the instruction copy function to set_memory_xxx.
> > >
> > > 2. Change the implementation method of the following code.
> > >          - arch_alloc_bpf_trampoline
> > >          - arch_free_bpf_trampoline
> > >          Use the BPF core's allocation and free functions.
> > >
> > >          - bpf_arch_text_invalidate
> > >          Operate with the function larch_insn_text_copy that carries
> > >          memory attribute modifications.
> > >
> > > 3. Correct the incorrect code formatting.
> > >
> > > URL for version v2:
> > > https://lore.kernel.org/all/20250618105048.1510560-1-duanchenghao@xxxxxxxxxx/
> > > ---------
> > > v1:
> > > Support trampoline for LoongArch. The following feature tests have been
> > > completed:
> > >          1. fentry
> > >          2. fexit
> > >          3. fmod_ret
> > >
> > > TODO: The support for the struct_ops feature will be provided in
> > > subsequent patches.
> > >
> > > URL for version v1:
> > > https://lore.kernel.org/all/20250611035952.111182-1-duanchenghao@xxxxxxxxxx/
> > > -----------------------------------------------------------------------
> > >
> > > Chenghao Duan (4):
> > >    LoongArch: Add larch_insn_gen_{beq,bne} helpers
> > >    LoongArch: BPF: Update the code to rename validate_code to
> > >      validate_ctx
> > >    LoongArch: BPF: Add bpf_arch_xxxxx support for Loongarch
> > >    LoongArch: BPF: Add bpf trampoline support for Loongarch
> > >
> > > Tiezhu Yang (1):
> > >    LoongArch: BPF: Add struct ops support for trampoline
> > >
> > >   arch/loongarch/include/asm/inst.h |   3 +
> > >   arch/loongarch/kernel/inst.c      |  60 ++++
> > >   arch/loongarch/net/bpf_jit.c      | 521 +++++++++++++++++++++++++++++-
> > >   arch/loongarch/net/bpf_jit.h      |   6 +
> > >   4 files changed, 589 insertions(+), 1 deletion(-)
> > >
> > > --
> > > 2.25.1
> >
> > Tested the whole patch series and it resolved the xdp-tool xdp-filter issue
> >
> > [root@fedora ~]# xdp-loader status
> > CURRENT XDP PROGRAM STATUS:
> >
> > Interface        Prio  Program name      Mode     ID   Tag
> >    Chain actions
> > --------------------------------------------------------------------------------------
> > lo                     xdp_dispatcher    skb      53   4d7e87c0d30db711
> >   =>              10     xdpfilt_alw_all           62
> > 320c53c06933a8fa  XDP_PASS
> > dummy0                 <No XDP program loaded!>
> > sit0                   <No XDP program loaded!>
> > enp0s3f0               <No XDP program loaded!>
> > wlp3s0                 <No XDP program loaded!>
> >
> > you can add Tested-by: Vincent Li <vincent.mc.li@xxxxxxxxx>
>
> Hi Vincent,
>
> Okay, thank you very much for your support. The existing patch has
> included "Tested-by: Vincent Li vincent.mc.li@xxxxxxxxx".

Huacai, I presume you'll route this series to Linus, correct?

Thanks,
Daniel