Re: [PATCH 0/5] crypto: Implement cmac based on cbc skcipher

[Ben Greear]

On 8/20/20 1:10 PM, Herbert Xu wrote:

On Thu, Aug 20, 2020 at 06:54:58AM -0700, Ben Greear wrote:

Here's a run on an:  Intel(R) Core(TM) i7-7700T CPU @ 2.90GHz

                testing speed of async cmac(aes-aesni) (cmac(aes-aesni))

[  259.397910] tcrypt: test  8 ( 1024 byte blocks, 1024 bytes per update,   1 
updates):   8442 cycles/operation,    8 cycles/byte

                testing speed of async cmac(aes-generic) (cmac(aes-generic))

[  294.171530] tcrypt: test  8 ( 1024 byte blocks, 1024 bytes per update,   1 
updates):   9022 cycles/operation,    8 cycles/byte

On my slow apu2 board with processor: AMD GX-412TC SOC

               testing speed of async cmac(aes-aesni) (cmac(aes-aesni))

[   51.751810] tcrypt: test  8 ( 1024 byte blocks, 1024 bytes per update,   1 
updates):  18759 cycles/operation,   18 cycle

               testing speed of async cmac(aes-generic) (cmac(aes-generic))

[   97.837497] tcrypt: test  8 ( 1024 byte blocks, 1024 bytes per update,   1 
updates):  31365 cycles/operation,   30 cycle

So clearly aes-generic is slower than aes-aesni even with saving and
restoring for each block.  Therefore improving the performance of
the latter per se does not make sense.

I have always assumed that I need aesni instructions to have any chance at this 
performing well,
but there are certainly chips out there that don't have aesni, so possibly it 
is still worth improving
if it is relatively easy to do so.

I am currently using x86-64 CPUs with aesni, and also some AP platforms running 
QCA ARM chips.
I am not sure if ARM is using aesni or not...it is certainly not that fast, but 
maybe for other
reasons.

Thanks,
Ben

Cheers,

--
Ben Greear <gree...@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com