[root@remote-host ~]# ip addr
    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eno1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether making:this:anonymous brd making:this:anonymous
    inet 12.34.567.111/29 brd 12.34.567.8xx scope global eno1
       valid_lft forever preferred_lft forever
    inet6 making:this:anonymous scope global dynamic
       valid_lft 414553sec preferred_lft 414553sec
    inet6 making:this:anonymous scope global noprefixroute dynamic
       valid_lft 2419198sec preferred_lft 345598sec
    inet6 making:this:anonymous scope link
       valid_lft forever preferred_lft forever
3: wlp3s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
    link/ether making:this:anonymous brd making:this:anonymous
4: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN qlen 1000
    link/ether making:this:anonymous brd making:this:anonymous
5: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN qlen 1000
    link/ether making:this:anonymous brd making:this:anonymous
50: br1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP qlen 1000
    link/ether making:this:anonymous brd making:this:anonymous
    inet 12.34.567.111/29 brd 12.34.567.8xx scope global br1
       valid_lft forever preferred_lft forever
    inet6 making:this:anonymous scope link
       valid_lft forever preferred_lft forever
63: vnet0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br1 state UNKNOWN qlen 1000
    link/ether making:this:anonymous brd making:this:anonymous
    inet6 making:this:anonymous scope link
       valid_lft forever preferred_lft forever
[root@remote-host ~]#

# virsh iface-bridge eth0 br0

# virsh iface-unbridge br0

# cat > ifcfg-eth0 <<EOF
DEVICE=eth0
HWADDR=00:16:76:D6:C9:45
ONBOOT=yes
BRIDGE=br0
NM_CONTROLLED=no
EOF

# cat > ifcfg-br0 <<EOF
DEVICE=br0
TYPE=Bridge
BOOTPROTO=dhcp
ONBOOT=yes
DELAY=0
NM_CONTROLLED=no
EOF

# service network restart

# cat >> /etc/sysctl.conf <<EOF
 net.bridge.bridge-nf-call-ip6tables = 0
 net.bridge.bridge-nf-call-iptables = 0
 net.bridge.bridge-nf-call-arptables = 0
 EOF
 # sysctl -p /etc/sysctl.conf

# echo "-I FORWARD -m physdev --physdev-is-bridged -j ACCEPT" > /etc/sysconfig/iptables-forward-bridged
# lokkit --custom-rules=ipv4:filter:/etc/sysconfig/iptables-forward-bridged
# service libvirtd reload

# chkconfig NetworkManager off
# chkconfig network on
# service NetworkManager stop
# service network start

...
<devices>
  ...
  <interface type='bridge'>
    <source bridge='br0'/>
  </interface>
  <interface type='bridge'>
    <source bridge='br1'/>
    <target dev='vnet7'/>
    <mac address="00:11:22:33:44:55"/>
  </interface>
  ...
</devices>

virsh net-list
virsh net-edit $NETWORKNAME

<dhcp>
  <range start='192.168.122.100' end='192.168.122.254'/>
  <host mac='52:54:00:6c:3c:01' name='vm1' ip='192.168.122.11'/>
  <host mac='52:54:00:6c:3c:02' name='vm2' ip='192.168.122.12'/>
  <host mac='52:54:00:6c:3c:03' name='vm3' ip='192.168.122.12'/>
</dhcp>

nl /var/lib/libvirt/dnsmasq/myvirtnet.lan.hostsfile
     1  52:54:00:39:ae:1c,192.168.122.242,minirhel.myvirtnet
     2  52:54:00:9b:0a:42,192.168.122.133,rhel7.myvirtnet
     3  52:54:00:f9:1e:45,192.168.122.134,rhel7.myvirtnet
     4  52:54:00:b0:d5:38,192.168.122.205,redqcow.myvirtnet
     5  52:54:00:af:c4:9c,192.168.122.206,redqcow.myvirtnet