Apple - Virtual Machine support for DirectX 11 (Windows 10) hosted on OS X

Answer: Not likely to happen.

After years of pestering, January 2018 Parallels posted a formal statement and explanation regarding DirectX 11:

Why isn’t DirectX 11 supported in Parallels Desktop?

One of the mandatory DX11 features is called “compute shaders.” The name “shaders” usually refers to graphical functions that calculate the appropriate color and brightness for an image, but “compute shaders” are quite different. Compute shaders help the programmer to more easily take full advantage of the many processors on today’s graphics cards, primarily by broadening shader capabilities beyond pure graphics to more general calculations, which can be done on a graphics chip.

Parallels implements DirectX emulation by translating it to the equivalent OpenGL function, since OpenGL is implemented in the macOS®. Unfortunately, the version of OpenGL in the macOS does not have compute shaders. There is nothing for Parallels Desktop to map DirectX shaders to in the OpenGL framework in the macOS.

The macOS does support another style of compute shaders in the OpenCL framework. (Don’t let the similarity in the names “OpenGL” and “OpenCL” make you think they’re similar. They aren’t. In fact, they are competing “standards.”) Unfortunately, however, OpenCL on Mac isn’t as robust and doesn’t cooperate well with OpenGL.

Besides compute shaders, there are other features missing in OpenGL on macOS, which means there are additional “feature parity holes” with DirectX. There’s simply not enough functionality to translate DX11 to in the functions available in the macOS.

Apple® started pushing its own Metal API recently, which is universal for Mac computers. Only time will tell if Metal will give the Parallels Desktop programmers what they need to support DirectX 11. Stay tuned, but don’t get your hopes up for any major change in the near future....

Parallels 15 has DirectX 11 support... finally.

(To be fair, none the competitors seem to have it yet, so I guess it wasn't a simple fix)