If unsure, say Y.
+config XFRM_USER_COMPAT
+ tristate "Compatible ABI support"
+ depends on XFRM_USER && COMPAT_FOR_U64_ALIGNMENT && \
+ HAVE_EFFICIENT_UNALIGNED_ACCESS
+ select WANT_COMPAT_NETLINK_MESSAGES
+ help
+ Transformation(XFRM) user configuration interface like IPsec
+ used by compatible Linux applications.
+
+ If unsure, say N.
+
config XFRM_INTERFACE
tristate "Transformation virtual interface"
depends on XFRM && IPV6