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[bpf-next,v2,0/3] arm64 BPF JIT Optimizations

Message ID 20200508181547.24783-1-luke.r.nels@gmail.com (mailing list archive)
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Series arm64 BPF JIT Optimizations | expand

Message

Luke Nelson May 8, 2020, 6:15 p.m. UTC 
This patch series introduces several optimizations to the arm64 BPF JIT.
The optimizations make use of arm64 immediate instructions to avoid
loading BPF immediates to temporary registers, when possible.

In the process, we discovered two bugs in the logical immediate encoding
function in arch/arm64/kernel/insn.c using Serval. The series also fixes
the two bugs before introducing the optimizations.

Tested on aarch64 QEMU virt machine using test_bpf and test_verifier.

v2:
 - Cleaned up patch to insn.c.
   (Marc Zyngier, Will Deacon) 

Luke Nelson (3):
  arm64: insn: Fix two bugs in encoding 32-bit logical immediates
  bpf, arm64: Optimize AND,OR,XOR,JSET BPF_K using arm64 logical
    immediates
  bpf, arm64: Optimize ADD,SUB,JMP BPF_K using arm64 add/sub immediates

 arch/arm64/kernel/insn.c      | 14 +++----
 arch/arm64/net/bpf_jit.h      | 22 +++++++++++
 arch/arm64/net/bpf_jit_comp.c | 73 ++++++++++++++++++++++++++++-------
 3 files changed, 88 insertions(+), 21 deletions(-)

Cc: Xi Wang <xi.wang@gmail.com>

Comments

Will Deacon May 11, 2020, 12:55 p.m. UTC | #1 
On Fri, 8 May 2020 11:15:43 -0700, Luke Nelson wrote:
> This patch series introduces several optimizations to the arm64 BPF JIT.
> The optimizations make use of arm64 immediate instructions to avoid
> loading BPF immediates to temporary registers, when possible.
> 
> In the process, we discovered two bugs in the logical immediate encoding
> function in arch/arm64/kernel/insn.c using Serval. The series also fixes
> the two bugs before introducing the optimizations.
> 
> [...]

Applied to arm64 (for-next/bpf), thanks!

[1/3] arm64: insn: Fix two bugs in encoding 32-bit logical immediates
      https://git.kernel.org/arm64/c/579d1b3faa37
[2/3] bpf, arm64: Optimize AND,OR,XOR,JSET BPF_K using arm64 logical immediates
      https://git.kernel.org/arm64/c/fd49591cb49b
[3/3] bpf, arm64: Optimize ADD,SUB,JMP BPF_K using arm64 add/sub immediates
      https://git.kernel.org/arm64/c/fd868f148189

Cheers,