Serial Console for nested XCP NG

How to enable serial console for nested XCP-NG HVM guest.

Sometimes for development purposes, you may want to have nested XCP-NG. Although its console works fine via XCP-NG Center or XOA, you may need serial access to troubleshoot hang/crash of VM. Same procedure might apply for generic HVM typed Linux guest.

The XCP-NG boot entry looks like

menuentry 'XCP-ng' {
        search --label --set root root-kbonvw
        multiboot2 /boot/xen.gz dom0_mem=752M,max:752M watchdog ucode=scan dom0_max_vcpus=1-4 crashkernel=192M,below=4G console=vga vga=mode-0x0311
        module2 /boot/vmlinuz-4.4-xen root=LABEL=root-kbonvw ro nolvm hpet=disable xencons=hvc console=hvc0 console=tty0 quiet vga=785 splash plymouth.ignore-serial-consoles
        module2 /boot/initrd-4.4-xen.img
}

To enable serial console - change the following from module2 vmlinuz kernel command line

console=tty0

to

console=ttyS0

Reboot. Now you can connect to the serial console from host using

# xl console <Domain>|<Name>