You need to make a backup by either using an LG drive that can dump Gamecube/Wii discs or Google guides on enabling your Wii for Homebrew and dumping the disc to your pc from your Wii using dvd dumping software.
PC-DVD drives can not read original Wii/Gamecube game discs directly, so you must dump the image to your pc from your game disc in order to use it with Dolphin.
PC-DVD drives can not read original Wii/Gamecube game discs directly, so you must dump the image to your pc from your game disc in order to use it with Dolphin.