Install

KVM

Before Install Check

kvm-ok
INFO: /dev/kvm exists
KVM acceleration can be used

Install KVM Package

apt install qemu-kvm libvirt-daemon-system \
libvirt-clients virtinst bridge-utils -y

Check And Start libvirt

systemctl status libvirtd
systemctl start libvirtd

Change Host Network Setting

Old Conf

network:
  ethernets:
    enp2s0:
      addresses:
      - 172.19.0.7/24
      gateway4: 172.19.0.254
      nameservers:
        addresses:
        - 172.19.0.1
        search:
        - ngu.tw
  version: 2

New conf

network:
  ethernets:
    enp2s0:
      dhcp4: false
      dhcp6: false
  bridges:
    br0:
      interfaces: [ enp2s0 ]
      addresses: [172.19.0.7/24]
      gateway4: 172.19.0.254
      mtu: 1500
      nameservers:
        addresses: [172.19.0.2,172.19.0.1]
      parameters:
        stp: true
        forward-delay: 4
      dhcp4: no
      dhcp6: no
  version: 2

Apply Network Setting

netplan apply

Change KVM Network

destroy default network

virsh net-destroy default
virsh net-undefine default

add new network, create file call bridge-host.xml

<network>
  <name>bridge-host</name>
  <forward mode="bridge"/>
  <bridge name="br0"/>
</network>

setting KVM network and check it

virsh net-define bridge-host.xml
virsh net-start bridge-host
virsh net-autostart bridge-host
virsh net-list --all

Used

Create VM

Add HDD

qemu-img create -f qcow2 \
/your/images/path/ubuntu20.04.qcow2 25G

Create VM

virt-install --virt-type kvm --name temp20.04 \
--ram 2048 --disk /your/images/path/ubuntu20.04.qcow2\
,format=qcow2 --network network=bridge-host \
--graphics vnc,listen=0.0.0.0,\
password=YOUR_PASSWORD \
--cdrom=/data/kvm/iso/ubuntu-20.04.1-live-server-amd64.iso

Login To VM And Check IP Address Using ip a