Re: Hardware acceleration indication in af_alg

[Nikos Mavrogiannopoulos <nmav@gnutls.org>]

On 10/21/2011 03:23 PM, Herbert Xu wrote:
> Matthias-Christian Ott <ott@mirix.org> wrote:
>> I did some experiments with af_alg and noticed that to be really
>> useful, it should indicate whether a certain algorithm is hardware
>> accelerated. I guess this has to be inferred by the priority of the
>> algorithm could be made available via a read-only socket option. Any
>> thoughts on this?
>>
>> I can imagine, an alternative approach and perhaps better approach
>> would be to measure the speed of the kernel provided algorithm against
>> a software implementation, but there are many other factors that could
>> influence the results. Therefore, it is perhaps better to just make
>> the assumption that hardware acceleration is faster which is made in
>> the kernel anyhow.
> You have to be careful to distinguish between hardware acceleration
> that is directly available to user-space (such as AESNI) and those
> that aren't.

How can this be done? The only driver field that could be used for that
is cra_priority and it seems it typically set to 300 irrespective of
instruction based crypto or external device.

regards,
Nikos