mirror_zfs/lib/libspl/include
Attila Fülöp 31b160f0a6
ICP: Improve AES-GCM performance
Currently SIMD accelerated AES-GCM performance is limited by two
factors:

a. The need to disable preemption and interrupts and save the FPU
state before using it and to do the reverse when done. Due to the
way the code is organized (see (b) below) we have to pay this price
twice for each 16 byte GCM block processed.

b. Most processing is done in C, operating on single GCM blocks.
The use of SIMD instructions is limited to the AES encryption of the
counter block (AES-NI) and the Galois multiplication (PCLMULQDQ).
This leads to the FPU not being fully utilized for crypto
operations.

To solve (a) we do crypto processing in larger chunks while owning
the FPU. An `icp_gcm_avx_chunk_size` module parameter was introduced
to make this chunk size tweakable. It defaults to 32 KiB. This step
alone roughly doubles performance. (b) is tackled by porting and
using the highly optimized openssl AES-GCM assembler routines, which
do all the processing (CTR, AES, GMULT) in a single routine. Both
steps together result in up to 32x reduction of the time spend in
the en/decryption routines, leading up to approximately 12x
throughput increase for large (128 KiB) blocks.

Lastly, this commit changes the default encryption algorithm from
AES-CCM to AES-GCM when setting the `encryption=on` property.

Reviewed-By: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-By: Jason King <jason.king@joyent.com>
Reviewed-By: Tom Caputi <tcaputi@datto.com>
Reviewed-By: Richard Laager <rlaager@wiktel.com>
Signed-off-by: Attila Fülöp <attila@fueloep.org>
Closes #9749
2020-02-10 12:59:50 -08:00
..
ia32 Remove autotools products 2012-08-27 11:47:44 -07:00
os Refactor zfs_context.h to build on FreeBSD 2019-12-04 13:12:57 -08:00
rpc config: better libtirpc detection 2019-03-02 16:19:05 -08:00
sys ICP: Improve AES-GCM performance 2020-02-10 12:59:50 -08:00
util cstyle: Resolve C style issues 2013-12-18 16:46:35 -08:00
assert.h libspl: declare aok extern in header 2019-12-26 10:52:14 -08:00
atomic.h Fix typos in lib/ 2019-09-02 17:53:27 -07:00
libdevinfo.h cstyle: Resolve C style issues 2013-12-18 16:46:35 -08:00
libgen.h zpool import -d to specify device path 2018-01-26 10:49:46 -08:00
libshare.h cstyle: Resolve C style issues 2013-12-18 16:46:35 -08:00
limits.h cstyle: Resolve C style issues 2013-12-18 16:46:35 -08:00
locale.h cstyle: Resolve C style issues 2013-12-18 16:46:35 -08:00
Makefile.am OpenZFS restructuring - libspl 2019-10-02 10:39:48 -07:00
statcommon.h Add linux libspl support 2010-08-31 13:41:59 -07:00
stdio.h cstyle: Resolve C style issues 2013-12-18 16:46:35 -08:00
stdlib.h cstyle: Resolve C style issues 2013-12-18 16:46:35 -08:00
string.h Check for strlcat and strlcpy 2018-12-11 16:01:41 -08:00
stropts.h Add linux libspl support 2010-08-31 13:41:59 -07:00
thread.h cstyle: Resolve C style issues 2013-12-18 16:46:35 -08:00
tzfile.h cstyle: Resolve C style issues 2013-12-18 16:46:35 -08:00
ucred.h cstyle: Resolve C style issues 2013-12-18 16:46:35 -08:00
umem.h Update build system and packaging 2018-05-29 16:00:33 -07:00
unistd.h Retire HAVE_IOCTL_* configure checks 2014-08-28 07:45:54 -07:00
zone.h cstyle: Resolve C style issues 2013-12-18 16:46:35 -08:00