Comment 12 for bug 2012763

For a start to rule out a real bug...
And to rule out any other smartness let us start a very very small qemu that does almost nothing. Does the following stumble over the 384 cpu error as well?

$ sudo qemu-system-x86_64 -smp cpus=1,maxcpus=1 -enable-kvm -net none -m 512M -nographic -kernel /boot/vmlinuz -initrd /boot/initrd.img -chardev stdio,mux=on,id=char0 -mon chardev=char0,mode=readline -serial chardev:char0 -append "console=ttyS0"

That will load a kernel from your host disk, after kernel load it will fail missing a root disk but that is fine. This way we would quickly know if really "everything fails" (bug) or if there might be just a argument needed in your way to spawn guests (configuration).

Pleas let us know if this works