In Libgcrypt 1.8.4, the C implementation of AES is vulnerable to a flush-and-reload side-channel attack because physical addresses are available to other processes. (The C implementation is used on platforms where an assembly-language implementation is unavailable.)
Created libgcrypt tracking bugs for this issue:
Affects: fedora-all [bug 1730321]
This seems more a theoretical attack possibility than and practical one. This seems to be the same opinion from upstream maintainers at https://dev.gnupg.org/T4541.
Given that, the patches looks like much more a hardening. I'm closing this bug as WONTFIX for now.
Created mingw-libgcrypt tracking bugs for this issue:
Affects: epel-7 [bug 1752913]