On 2025-07-24 16:40, Mikulas Patocka wrote:
On Tue, 22 Jul 2025, Harald Freudenberger wrote:
Support for ahashes in dm-integrity.
Changelog:
v1: First implementation. Tested with crc32, sha256, hmac-sha256 and
the s390 specific implementations for hmac-sha256 and protected
key phmac-sha256. Also ran with some instrumented code (in the
digest
implementation) to verify that in fact now the code runs
asynchronous.
v2: Support shash and ahash. Based on Mikulas' idea about implementing
ahash support similar to dm-verity this version now adds support
for ahash but does not replace the shash support. For more details
see the text of the patch header.
v3: The line to store the digestsize into the new internal variable
did not make it into the patch set which was sent out. So now
this important code piece is also there. Also rebuilded, sparse
checked and tested to make sure the patches are ok.
v4: Thanks to Mikulas a total new implementation of the ahash support
for the dm-integrity layer :-)
v5: Slight rework around the allocation and comparing of ahash and
shash algorithm.
V5 has been tested with the new introduced ahash phmac which is a
protected key ("hardware key") version of a hmac for s390. As of
now
phmac is only available in Herbert Xu's cryptodev-2.6 kernel tree
but will be merged into mainline with the next merge window for
the 6.17 development kernel.
Mikulas Patocka (2):
dm-integrity: use internal variable for digestsize
dm-integrity: introduce ahash support for the internal hash
drivers/md/dm-integrity.c | 370
+++++++++++++++++++++++++++-----------
1 file changed, 265 insertions(+), 105 deletions(-)
base-commit: 89be9a83ccf1f88522317ce02f854f30d6115c41
--
2.43.0
Hi
Eric Biggers recently removed ahash support from dm-verity - see this
commit:
https://kernel.googlesource.com/pub/scm/linux/kernel/git/device-mapper/linux-dm/+/f43309c6743257244f11f14d31c297ee6a410ded
Should I revert Eric's patch? - would you need dm-verity with
asynchronous
hashes on zseries too?
Is this patch series needed for performance (does it perform better
than
the in-cpu instructions)? Or is it need because of better security (the
keys are hidden in the hardware)?
Mikulas
I've seen this. Well as of now we don't need dm-verity. However, I'll
check
our plans and let you know within the next days.
Thanks
Harald Freudenberger
with
