Quote Whonix ™ for KVM chapter Debian in Whonix wiki (bold added):
For Debian bullseye+ on Intel / AMD you need to install:
sudo apt install --no-install-recommends qemu-kvm libvirt-daemon-system libvirt-clients virt-manager gir1.2-spiceclientgtk-3.0 dnsmasq qemu-utils
What’s the purpose of package dnsmasq in the installation list?
Is it optional?
Can KVM work without that package being installed?