Yes, you can use a mod for open-source virtual machine software VirtualBox to build a working virtual PC running Windows 95 inside of Minecraft to play Doom. "Within Minecraft you simply place a PC case block and then use it to create virtual hard drives to install operating systems from ISO files," writes Tom Warren at The Verge.
The natural next step was to use VirtualBox to run Minecraft inside of Minecraft, as demonstrated by "vm nerd" @Naku.
Of course, this all begs the question: Are we a simulation running on a virtual machine inside Minecraft that itself is running on a virtual machine inside Minecraft? And who is simulating the simulators?