yuzu is the world's most popular, open-source, Nintendo Switch emulator — started by the creators of Citra. It is written in C++ with portability in mind,
Persistent buffer maps were already used by the texture cache, this extends their usage for the buffer cache.
In my testing, using the memory maps for uploads was slower than the existing "ImmediateUpload" path, so the memory map usage is limited to downloads for the time being.