Proxmox nested virtualization aktivieren
// For Intel
# echo "options kvm-intel nested=Y" > /etc/modprobe.d/kvm-intel.conf
// For AMD
# echo "options kvm-amd nested=1" > /etc/modprobe.d/kvm-amd.conf
//Reboot or reload the kernel module
modprobe -r kvm_intel
modprobe kvm_intel