I’ve read some forum articles and blogs which suggest to remove mac address of wireless device to get wpa_supplicant working.
However, this is only true when the wireless device is the only network card you activate.
If you have more than one network cards, e.g. wire and wireless network card, then you need to keep the mac addresses, otherwise kernel might get confuse and assign an unexpected name (such as wlan0) to the wireless. Consequently, wpa_supplicant cannot find the correct device to activate.
I was looking for a solution to tame wpa_supplicant inside of xen. After some intensive Googling, finally I found a Red Hat Virturalization Guide that shows how to set xen network on a laptop.
So, if your are a RHEL coustomer, please install Virtualization-(your locale) to get the document. 🙂