Comment 10 for bug 1987567

Verification done on focal.
---

$ sudo apt update && sudo apt install -y xen-system-amd64 microcode-initrd

$ sudo add-apt-repository -y 'deb http://archive.ubuntu.com/ubuntu focal-proposed main'
sudo apt install -y grub-common microcode-initrd

$ apt policy grub2-common
grub2-common:
  Installed: 2.04-1ubuntu26.17
  Candidate: 2.04-1ubuntu26.17
  Version table:
 *** 2.04-1ubuntu26.17 500
        500 http://archive.ubuntu.com/ubuntu focal-proposed/main amd64 Packages
        100 /var/lib/dpkg/status
...

$ grep module2 /boot/grub/grub.cfg | grep -v vmlinuz
 module2 --nounzip /boot/initrd.img-5.4.0-137-generic
 module2 --nounzip /boot/microcode.cpio
   module2 --nounzip /boot/initrd.img-5.4.0-137-generic
   module2 --nounzip /boot/microcode.cpio
   module2 --nounzip /boot/initrd.img-5.4.0-137-generic
   module2 --nounzip /boot/microcode.cpio
   module2 --nounzip /boot/initrd.img-5.4.0-137-generic
   module2 --nounzip /boot/microcode.cpio
   module2 --nounzip /boot/initrd.img-5.4.0-137-generic
   module2 --nounzip /boot/microcode.cpio

$ sudo reboot

# it works!

$ dmesg | grep 'Hypervisor detected'
[ 0.000000] Hypervisor detected: Xen PV

$ dmesg | grep -i initrd
[ 2.441382] Freeing initrd memory: 32296K

$ du -k /boot/initrd.img-* /boot/microcode.cpio
32296 /boot/initrd.img-5.4.0-137-generic
4936 /boot/microcode.cpio