On Thu, Aug 20, 2020 at 09:48:02AM +0200, Ard Biesheuvel wrote:
>
> > Or are you saying on Ben's machine cbc-aesni would have worse
> > performance vs. aes-generic?
> >
>
> Yes, given the pathological overhead of FPU preserve/restore for every
> block of 16 bytes processed by the cbcmac wrapper.
I'm sceptical. Do we have numbers showing this? You can get them
from tcrypt with my patch:
https://patchwork.kernel.org/patch/11701343/
Just do
modprobe tcrypt mode=400 alg='cmac(aes-aesni)' klen=16
modprobe tcrypt mode=400 alg='cmac(aes-generic)' klen=16
> cmac() is not really relevant for performance, afaict. Only cbcmac()
> is used for bulk data.
Sure but it's trivial to extend my cmac patch to support cbcmac.
Cheers,
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
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