1. install i3 in vm
2. on host, start local x server
host$ sudo xinit /usr/bin/xterm -- :1 &
3. x server starts, now it's on xterm with root privilege. Switch to a user, then ssh to vm
// switch to a user account
host# su -l u
host$ ssh -fY remotevm /usr/bin/i3
4. i3 started, but still it shows host's prompt. Use i3 to start a new terminal. The new window will be inside the remote vm.
