Get a KVM guest's IP address

virt-addr.sh

#!/bin/bash
# Returns the IP address of a running KVM guest VM
# Assumes a working KVM/libvirt environment
#
# Install:
#   Add this bash function to your ~/.bashrc and `source ~/.bashrc`.
# Usage: 
#   $ virt-addr vm-name
#   192.0.2.16
#
virt-addr() {
    VM="$1"
    arp -an | grep "`virsh dumpxml $VM | grep "mac address" | sed "s/.*'\(.*\)'.*/\1/g"`" | awk '{ gsub(/[\(\)]/,"",$2); print $2 }'
}

VM=fedora25;
sudo virsh domifaddr $VM|tail -2 | awk '{print $4}'| cut -d/ -f1

i am sure a bash expert can make that line even better but it works for me and "if its not broken don't fix it" is a good rule for me

@marafa and rest here is an awk only script:
virsh domifaddr $VM | awk -F'[ /]+' '{if (NR>2) print $5}'

virt-info() {
    echo "------------------------------------------------------------------------------------------------------------------------";
    printf "%-30s%-17s%-12s%-12s%-8s%-40s\n" "VM Name" "IP Address" "Memory" "Current" "VCPUs" "UUID";
    virsh -c qemu:///system list --all | grep -o '[0-9]* [a-z]*.*running' | while read -r line;
    do
        line_cropped=$(echo "$line" | sed 's/[0-9][ ]*\([-._0-9a-zA-Z]*\)[ ]*running/\1/' );
        printf "%-30s%-17s%-12s%-12s%-8s%-40s\n" "$line_cropped" $( virt-addr "$line_cropped" ) $( virt-mem $line ) $( virt-currmem $line ) $( virt-vcpu $line ) $( virt-uuid $line );
    done;
    echo "------------------------------------------------------------------------------------------------------------------------";
}

This breaks if the ID is higher than 9

Change this line

line_cropped=$(echo "$line" | sed 's/[0-9][ ]*\([-._0-9a-zA-Z]*\)[ ]*running/\1/' );

To

line_cropped=$(echo "$line" | sed 's/[0-9]*[ ]*\([-._0-9a-zA-Z]*\)[ ]*running/\1/' );

@mistofvongola and the others.
If you have qmeu-agent installed on the guest machine you can user virsh to fetch the details directly from the VM using virsh.
Example commad: virsh domifaddr Squid-4.1-CentOS-Testing --source agent --full (the --source agent flag is important)

[root@kvm4 ~]# virsh list
 Id    Name                           State
----------------------------------------------------
 1     KVM4-MANAGER                   running
 2     Fast-Windows-10                running
 3     CHR-LAB-CLIENT1                running
 4     CHR-LAB-PX3                    running
 5     CHR-LAB-SERVER1                running
 6     CHR-R1                         running
 7     Squid-4.1-CentOS-Testing       running

[root@kvm4 ~]# virsh domifaddr Squid-4.1-CentOS-Testing --source agent --full
Name       MAC address          Protocol     Address
-------------------------------------------------------------------------------
 lo         00:00:00:00:00:00    ipv4         127.0.0.1/8
 lo         00:00:00:00:00:00    ipv6         ::1/128
 eth0       52:54:00:7e:7f:29    ipv4         192.168.89.59/24
 eth0       52:54:00:7e:7f:29    ipv6         fe80::125d:b868:7bf7:11f0/64
 eth1       52:54:00:18:05:6b    N/A          N/A
 eth2       52:54:00:fd:79:85    N/A          N/A
 eth3       52:54:00:cc:ac:c8    N/A          N/A