Magmarock: It's also pretty redundant. I mean what is the point. I like emulators myself since they add to your current libery of games. But what is the point of building a computer to run nothing but PS2 games? You might as well just get a PS2. Same for how people install Linux and go through all this trouble to get Windows stuff to work.
Well, for starters, you can run Windows on kvm with GPU passthrough on play games without having to reboot your Linux OS with dual-boot. With both CPU and GPU passthrough, you'll get pretty much native-like performance.
You can also emulate a different hardware architecture (ex: arm64) to test some stuff in it. It's slow as hell (wouldn't recommend running a full desktop in an emulated hardware architecture), but when you just want to run something in the background and get a result, it does the work (funnily enough recently, I tried running something for the Raspberry Pi in a vm and got an error and at first, I dismissed it as some inaccuracy with the emulated hardware, but then I encountered the same error later in an actual Raspberry Pi ;P).
Also, if I want to do some less safe stuff that might screw up my machine (or you know, go on some websites that I shouldn't), I prefer to do it in a vm (if it screws up my vm, I can scrap it).
And last, but not least, when you have a machine with 64GB RAM like me, you can actually run a small cluster of vms directly on your machine to so some quick experiments with some multi-machine prod-like scenarios.
