Hi,
some time ago I lost the AES hardware support for LUKS.
I found out that for some reason the Intel AES support modules:
crypto_simd and
aesni_intel are not longer preloaded by Grub.
If you have a LUKS partition with AES cypher (the default) than check that crypto_simd and aesni_intel are listed in
lsmod | grep crypto_simd
If they are not listed,
than I had to list the two AES hardware support modules in
/etc/mkinitcpio.conf
MODULES=(crypto_simd aesni_intel)
and than:
sudo mkinitcpio --allpresets
sudo update-grub
And after a reboot, my Intel hardware AES support for LUKS is now working again (huge difference).