Real hardware is finicky and complex. It would be very slow to virtualize every hardware device in a system to a level not distinguishable to software. If you do shoot for complete accuracy (e.g. projects like 86Box), you take at least a ~100x performance hit, and also lose out on useful features like dragging files into/out of the VM.
ethbr0|4 years ago
Specifically, look for examples of bugs they've fixed, and why they were triggered.
At this point, they're essentially all of the "X software depended on a quirk of Y feature, to do (whatever), because the developers chose to do it that way." For that one specific piece of software, and nowhere else.
And that's for a game console with highly standardized hardware and libraries. The general purpose computer has a bit larger mutation surface. :-)
Or, to crib from another sibling poster,
"You have a million places to make sure your virtualization looks like the actual artifact. Of those, 100 are used by everything, 1,000 are used by many things, and 10,000 are used by a few things. The remainder may be used by some piece of software out there, somewhere."
"You have a year to build a working product. Are you going to implement and equally test all million things?"
[0] https://dolphin-emu.org/blog/