Re: communicating from the user space

[Nikos Mavrogiannopoulos <nmav@gnutls.org>]

On Sun, 2015-02-22 at 16:04 +0100, Stephan Mueller wrote:
> Am Sonntag, 22. Februar 2015, 18:32:34 schrieb sri sowj:
> 
> Hi sri,
> 
> > Hi Stephen,
> > 
> > It was a great information with respective PF_ALG , I have explored a
> > bit on openssl and algorithms prospect , Please let me know if
> > anything to add to it.
> > 
> > openssl crypto engine:
> > 
> > below are the steps to enable openssl to communicate using pf/af_alg.
> > 
> > #1:git clone http://src.carnivore.it/users/common/af_alg/
> Yes, that is it. But it is not fully efficient as it does not use vmsplice 
> where appropriate. So, libkcapi should be faster in several use cases.

When would vmsplice be appropriate? As far as I understand vmsplice adds
a cost on operations for small data, which is the majority of use cases
in crypto. In the measurements I did for cryptodev-linux [0] vmsplice
did improve performance only for more than 64k packets which is never
the case with real world crypto (TLS has a maximum of 14k for example).

regards,
Nikos

[0]. http://cryptodev-linux.org/comparison.html