This is a WIP patch that declares QEMU thread(s) as high-performance to the macOS QoS scheduler.
Apply this patch using git am 0001-util-qemu-thread-posix.c-Declare-QEMU-thread-s-as-hi.patch
.
This is most useful on Apple Silicon (arm64) machines, as this pins QEMU to the faster performance cores instead of the slower efficiency cores on those systems (which use a heterogeneous core architecture).
This may possibly also result in better performance on x86_64 macOS machines, as well.
TODO: Determine if there is a better place to put this function call, as this would effectively declare every QEMU thread as high-performance, which may not be desired behaviour if QEMU spawns threads for purposes other than guest OS emulation (which I am not certain about).