Re: [PATCH 1/3] crypto: s390 - Remove des and des3_ede code

Holger Dengler
2026-03-27T08:52:40Z

Hi Eric,

On 26/03/2026 21:12, Eric Biggers wrote:
> Since DES and Triple DES are obsolete, there is very little point in
> maintining architecture-optimized code for them. Remove it.
>
> Signed-off-by: Eric Biggers <ebiggers@kernel.org>

Are there plans to completely remove des/3des in-kernel crypto support from
the kernel or is it just the arch-specific code, that is removed?

In fact there are still customers using des/3des (unbelievable!), but the
valid question is, do they also using the in-kernel crypto for their
workloads. I'll try to figure that out. Unfortunately, Harald is a few days
off and I need to discuss the removal with him as well.

Regarding the testing: in our CI we're running all in-kernel crypto modules
every night, including des/3des. So there is some test coverage.

Regarding qemu: we're currently investigating if we can provide qemu-support
for the s390 crypto instructions, but, to be honest, des/3des was not on our
top-priority list until now... ;)

We'll come back to you in a week or so. I hope, that's ok...

--
Mit freundlichen Grüßen / Kind regards
Holger Dengler
--
IBM Systems, Linux on IBM Z Development
dengler@linux.ibm.com