How to find how long the GPU is waiting after frame draw (sharpDX)

Question

I need to find out how long there is between the frame being drawn in my DirectX/SharpDX window and when the GPU refreshes/send the frame to the display. I thought checking the VSYNC intervals might be useful but I can't figure that one out. I just need to know how long there is between an input and when the GPU sends the results of that input. I've got the frame time/present time, but the app runs at 1000 FPS (specifically so it's faster than the display at all times) so I can't just use the frame time on it's own. Any ideas? I'm out of my league.

To clarify: the DirectX/SharpDX code I've got works fine as is and I am not replacing it. I just want to add this feature. It's also DirectX 11, not 12.