Comment 1 for bug 375937

Also a problem for me on both AMD X2 and Intel Core2 CPU machines after I upgraded kvm to 1:62+dfsg-0ubuntu8.1

Starting via libvirt:
$ virsh start ubuntu804-wiki
Connecting to uri: qemu:///system
libvir: QEMU error : QEMU quit during console startup
qemu: unknowm parameter 'boot' in 'file=/home/VM/qemu/ubuntu804-wiki/root.qcow2,if=ide,boot=on'
error: Failed to start domain ubuntu804-wiki

Starting directly using kvm:
$ sudo /usr/bin/kvm -M pc -m 256 -smp 1 -monitor pty -drive file=/home/VM/qemu/ubuntu804-wiki/root.qcow2,if=ide,boot=on -net nic,macaddr=00:16:36:1a:ee:82,vlan=0 -net tap,fd=7,script=,vlan=0 -usb -vnc 127.0.0.1:82
qemu: unknowm parameter 'boot' in 'file=/home/VM/qemu/ubuntu804-wiki/root.qcow2,if=ide,boot=on'

I also tried removing and reloading the kvm and kvm_intel module.

After reading the kvm and kvm-qemu manpages I noticed that there was a new "-boot" option.

So I removed the "boot=on" option and added "-boot c" to boot from the virtual hard drive:
$ sudo /usr/bin/kvm -M pc -m 256 -smp 1 -monitor pty -drive file=/home/VM/qemu/ubuntu804-wiki/root.qcow2,if=ide -net nic,macaddr=00:16:36:1a:ee:82,vlan=0 -net tap,fd=7,script=,vlan=0 -usb -vnc 127.0.0.1:82 -boot c
char device redirected to /dev/pts/0

The machine starts up, and is available via VNC but not the network. May be the networking options have changed as well?

The "--help" output from kvm still lists "boot=on" as a valid option, which is no longer true.