selftests/net/test_bpf fails for linux-kvm due to lack of Kconfig

Kernel selftest "test_bpf" fails for B/linux-kvm due to lack of Kconfig:

grep -v "#" tools/testing/selftests/net/test_bpf.sh

if /sbin/modprobe -q test_bpf ; then
        /sbin/modprobe -q -r test_bpf;
        echo "test_bpf: ok";
else
        echo "test_bpf: [FAIL]";
        exit 1;
fi

Checking the config files, for example:

# grep -n "TEST_BPF" /boot/config-4.15.0-1089-kvm
2310:# CONFIG_TEST_BPF is not set

# grep -n "TEST_BPF" /boot/config-4.15.0-142-generic
9105:CONFIG_TEST_BPF=m