Setting up LILO

In a nutshell

eventually rebuild your kernel, reduce boot-loader timeout to 3 seconds and eventually make linux fast again by disabling mitigations.

MWE

keep the old and good-looking menu

ls -lF /etc/lilo.conf_example
mv -i /etc/lilo.conf /etc/lilo.conf.dist
sed -r '/^[[:space:]]*(#|$)/d' /etc/lilo.conf.dist > /etc/lilo.conf
vi /etc/lilo.conf

change/add

lba32
timeout = 30

image = /vmlinuz
    label = xenreiser4
    read-only
    append = "mitigations=off"

re-write the boot code

lilo
shutdown -r now

and check after reboot

uname -r
cat /proc/cmdline

Booting XEN with LILO

see mbootpack