Running Windows as guest instead of as host OS has made my life significantly easier. The sole exception used to be games, but that's getting better, too.
honggfuzz (http://honggfuzz.com) will run under cygwin - it uses similar algorithms (feedback driven by code coverage metrics), and last time I checked it under CygWin it worked with clang's -fsanitize-coverage=trace-pc modes well.
why? the peformance hit on VM's isn't that big, if you really care why don't you just run one? 7 hours or 27 isn't that huge of a difference in the grand scope of things . . .