$ sudo pidof dnsmasq
240165 240164 240049 240048
$ ls /var/lib/libvirt
boot  dnsmasq  images  qemu  sanlock
$ ls /var/lib/libvirt/dnsmasq
puppet-environment0.addnhosts  puppet-environment0.hostsfile  vagrant-libvirt.conf       virbr1.macs    virbr2.macs
puppet-environment0.conf       vagrant-libvirt.addnhosts      vagrant-libvirt.hostsfile  virbr1.status  virbr2.status
$ sudo cat /var/lib/libvirt/dnsmasq/vagrant-libvirt.conf
##WARNING:  THIS IS AN AUTO-GENERATED FILE. CHANGES TO IT ARE LIKELY TO BE
##OVERWRITTEN AND LOST.  Changes to this configuration should be made using:
##    virsh net-edit vagrant-libvirt
## or other application using the libvirt API.
##
## dnsmasq conf file created by libvirt
strict-order
pid-file=/run/libvirt/network/vagrant-libvirt.pid
except-interface=lo
bind-dynamic
interface=virbr1
dhcp-range=192.168.121.1,192.168.121.254,255.255.255.0
dhcp-no-override
dhcp-authoritative
dhcp-lease-max=254
dhcp-hostsfile=/var/lib/libvirt/dnsmasq/vagrant-libvirt.hostsfile
addn-hosts=/var/lib/libvirt/dnsmasq/vagrant-libvirt.addnhosts