Install virt-manager, qemu and all dependencies

From terminal:

user $  sudo pacman -S --needed virt-manager qemu-desktop libvirt edk2-ovmf dnsmasq iptables-nft COPY TO CLIPBOARD

For TPM support:

user $  sudo pacman -S --asdeps swtpm COPY TO CLIPBOARD

Enable and start service

user $  sudo systemctl enable libvirtd.service COPY TO CLIPBOARD

Add user to libvirt, libvirt-qemu and kvm groups to use the system-level virtual machines (qemu:///system).

user $  sudo usermod -a -G libvirt,libvirt-qemu,kvm $USER COPY TO CLIPBOARD

Note that you will need to restart userspace for the groups to become active. To restart userspace

user $  systemctl soft-reboot COPY TO CLIPBOARD

Note

You don't need this step to run system-level virtual machines. However, virt-manager will prompt for sudoer's password when launch if the user is not in the libvirt group
You can also create user-level virtual machines (qemu:///session) and use without sudoer's privelige. However, some features such as VirtioFS file sharing may be unavailable in qemu:///session