My computer is router to internet for my home wireless net. I want connect my guest to my homenet.

ppp0 -- Internet

ath0 -- 192.168.0.1 homenet router (I attempt connect to 192.168.0.0/24)

murat[.kvm]$ cat qemu-ifup
#!/bin/sh
set -x
 
switch=br0
 
if [ -n "$1" ];then
        /usr/bin/sudo /usr/sbin/tunctl -u `whoami` -t $1
        /usr/bin/sudo /sbin/ip link set $1 up
        sleep 0.5s
        /usr/bin/sudo /usr/sbin/brctl addif $switch $1
        exit 0
else
        echo "Error: no interface specified"
        exit 1
fi

sudo /usr/sbin/brctl addbr br0

sudo /usr/sbin/brctl addif br0 ath0                                                                                                                                                                                                           

sudo /usr/sbin/brctl showbridge name    bridge id        STP enabled    interfaces
br0        8000.00179a74282b    no        ath0

murat[.kvm]$ qemu-system-x86_64 windows.img -net nic,macaddr=DE:AD:BE:EF:36:18 -net tap,script=qemu-ifup
warning: could not configure /dev/net/tun: no virtual network emulation
Could not initialize device 'tap'

What's I am doing wrong? :/