I used the following way to start the VM:
#!/bin/bash ifconfig -a|grep tap0 >/dev/null 2>&1 || qemu-ifup tap0
qemu-system-ppc64 -hda ppcrhel5.img -cpu POWER7 -machine type=pseries,usb=off -m 768 -nographic -net nic -net tap,ifname=tap0,script=no qemu-ifdown tap0
I used the following way to start the VM:
#!/bin/bash
ifconfig -a|grep tap0 >/dev/null 2>&1 || qemu-ifup tap0
qemu-system-ppc64 -hda ppcrhel5.img -cpu POWER7 -machine type=pseries, usb=off -m 768 -nographic -net nic -net tap,ifname= tap0,script= no
qemu-ifdown tap0