On 7/29/20 12:09 PM, Ard Biesheuvel wrote:
On Wed, 29 Jul 2020 at 15:27, Ben Greear <greearb@xxxxxxxxxxxxxxx> wrote:
On 7/28/20 11:06 PM, Ard Biesheuvel wrote:
On Wed, 29 Jul 2020 at 01:03, Ben Greear <greearb@xxxxxxxxxxxxxxx> wrote:
Hello,
As part of my wifi test tool, I need to do decrypt AES on the CPU, and the only way this
performs well is to use aesni. I've been using a patch for years that does this, but
recently somewhere between 5.4 and 5.7, the API I've been using has been removed.
Would anyone be interested in getting this support upstream? I'd be happy to pay for
the effort.
Here is the patch in question:
https://github.com/greearb/linux-ct-5.7/blob/master/wip/0001-crypto-aesni-add-ccm-aes-algorithm-implementation.patch
Please keep me in CC, I'm not subscribed to this list.
Hi Ben,
Recently, the x86 FPU handling was improved to remove the overhead of
preserving/restoring of the register state, so the issue that this
patch fixes may no longer exist. Did you try?
In any case, according to the commit log on that patch, the problem is
in the MAC generation, so it might be better to add a cbcmac(aes)
implementation only, and not duplicate all the CCM boilerplate.
Hello,
I don't know all of the details, and do not understand the crypto subsystem,
but I am pretty sure that I need at least some of this patch.
Whether this is true is what I am trying to get clarified.
Your patch works around a performance bottleneck related to the use of
AES-NI instructions in the kernel, which has been addressed recently.
If the issue still exists, we can attempt to devise a fix for it,
which may or may not be based on this patch.
Ok, I can do the testing. Do you expect 5.7-stable has all the needed
performance improvements?
Thanks,
Ben
If you can suggest a patch to try I'll be happy to test it to see how it
performs.
Please share performance numbers of an old kernel with this patch
applied, and a recent one without. If that shows there is in fact an
issue, we will do something about it.
--
Ben Greear <greearb@xxxxxxxxxxxxxxx>
Candela Technologies Inc http://www.candelatech.com
--
Ben Greear <greearb@xxxxxxxxxxxxxxx>
Candela Technologies Inc http://www.candelatech.com
