Two things you should avoid when trying to install GNU/Linux or some other Free OS on a Sony Vaio SVS1511L3ES / SVS151A12M :
change the BIOS boot settings from 'UEFI' to 'Default'
boot from the the optical drive
Both probably will cause the keyboad to stop working. Sounds weird but: tested a few times.
[Workaround]
if the keyboard is stuck already there seems to be no other way than booting M$ Windos once again - somehow the keyboard is activated this way - to do so plug in an external usb keyboard
