Did you actually read what was said above?
The network inside QEMU is emulated... you cannot access the 10.0.2.0/24 range.. (
Without setting up a tun interface, read qemu faq..).
So, adding "-redir tcp:9000::22" to the QEMU evocation line allows you to connect to the SSH daemon "within" the emulated environment.
How do you connect? You connect via localhost...
$ ssh localhost -p 9000
Do you understand now?