[PATCH v2 0/6] crypto: x86_64 optimized XChaCha and NHPoly1305 (for Adiantum)

Eric Biggers
2018-11-30T10:10:33Z

Hello,

This series optimizes the Adiantum encryption mode for x86_64 by adding
SSE2 and AVX2 accelerated implementations of NHPoly1305, specifically
the NH part; and by modifying the existing x86_64 SSSE3/AVX2/AVX-512VL
ChaCha20 implementation to support XChaCha20 and XChaCha12.

This greatly improves Adiantum performance on x86_64.

For example, encrypting 4096-byte messages (single-threaded) on a
Skylake-based processor (Intel Xeon, supports AVX-512VL and AVX2):

Before After
-------- ---------
adiantum(xchacha12,aes) 348 MB/s 1458 MB/s
adiantum(xchacha20,aes) 265 MB/s 1240 MB/s

And on a Zen-based processor (Threadripper 1950X, supports AVX2):

Before After
-------- ---------
adiantum(xchacha12,aes) 505 MB/s 1250 MB/s
adiantum(xchacha20,aes) 387 MB/s 989 MB/s

Decryption is almost exactly the same speed as encryption.

The biggest benefit comes from accelerating XChaCha. Accelerating NH
gives a somewhat smaller, but still significant benefit.

Performance on 512-byte inputs is also improved, though that is much
slower in the first place. When Adiantium is used with dm-crypt (or
cryptsetup), we recommend using a 4096-byte sector size.

For comparison, AES-256-XTS is 2699 MB/s on the Skylake CPU and
4140 MB/s on the Zen CPU. However, AES has the benefit of direct AES-NI
hardware support whereas Adiantum is implemented entirely with
general-purpose instructions (scalar and SIMD). Adiantum is also a
super-pseudorandom permutation over the entire sector, unlike XTS.

Note that XChaCha20 and XChaCha12 can be used for other purposes too.

Changed since v1:
- Rebase on top of latest cryptodev with the AVX-512VL accelerated
ChaCha20 from Martin Willi.

Eric Biggers (6):
crypto: x86/nhpoly1305 - add SSE2 accelerated NHPoly1305
crypto: x86/nhpoly1305 - add AVX2 accelerated NHPoly1305
crypto: x86/chacha20 - limit the preemption-disabled section
crypto: x86/chacha20 - add XChaCha20 support
crypto: x86/chacha20 - refactor to allow varying number of rounds
crypto: x86/chacha - add XChaCha12 support

arch/x86/crypto/Makefile | 15 +-
...a20-avx2-x86_64.S => chacha-avx2-x86_64.S} | 33 +--
...12vl-x86_64.S => chacha-avx512vl-x86_64.S} | 35 +--
...0-ssse3-x86_64.S => chacha-ssse3-x86_64.S} | 99 ++++---
arch/x86/crypto/chacha20_glue.c | 208 -------------
arch/x86/crypto/chacha_glue.c | 280 ++++++++++++++++++
arch/x86/crypto/nh-avx2-x86_64.S | 157 ++++++++++
arch/x86/crypto/nh-sse2-x86_64.S | 123 ++++++++
arch/x86/crypto/nhpoly1305-avx2-glue.c | 77 +++++
arch/x86/crypto/nhpoly1305-sse2-glue.c | 76 +++++
crypto/Kconfig | 28 +-
11 files changed, 839 insertions(+), 292 deletions(-)
rename arch/x86/crypto/{chacha20-avx2-x86_64.S => chacha-avx2-x86_64.S} (97%)
rename arch/x86/crypto/{chacha20-avx512vl-x86_64.S => chacha-avx512vl-x86_64.S} (97%)
rename arch/x86/crypto/{chacha20-ssse3-x86_64.S => chacha-ssse3-x86_64.S} (93%)
delete mode 100644 arch/x86/crypto/chacha20_glue.c
create mode 100644 arch/x86/crypto/chacha_glue.c
create mode 100644 arch/x86/crypto/nh-avx2-x86_64.S
create mode 100644 arch/x86/crypto/nh-sse2-x86_64.S
create mode 100644 arch/x86/crypto/nhpoly1305-avx2-glue.c
create mode 100644 arch/x86/crypto/nhpoly1305-sse2-glue.c

--
2.20.0.rc0.387.gc7a69e6b6c-goog