The settings relevant to Spectre are:
CONFIG_BPF_JIT - this being set to y is enough to make Intel
processors vulnerable to variant 1/2. This being set to y is
necessary, but not sufficient, for making AMD vulnerable to variant 1.
net.core.bpf_jit_enable - this being set to 1 along with the config
option being set is sufficient to make AMD vulnerable to variant 1.
This setting has no effect on making Intel vulnerable to variant 1 or
2. I suspect this sysctl item won't appear unless it is loaded into
the kernel in the first place.

Thanks for the clarification. I checked my three systemd systems and all are;

# CONFIG_BPF_JIT is not set

systemd ebuild is looking for;

$ grep -i bpf /usr/portage/sys-apps/systemd/systemd-2*
/usr/portage/sys-apps/systemd/systemd-235-r1.ebuild: kernel_is -ge 4 10 && CONFIG_CHECK+=" ~CGROUP_BPF"
/usr/portage/sys-apps/systemd/systemd-236-r4.ebuild: kernel_is -ge 4 10 && CONFIG_CHECK+=" ~CGROUP_BPF"