Hello,

Starting with Mac OS X version 10.10.3, Apple provides a system-level hypervisor framework (similar to KVM's kernel driver functionality on Linux).

a good write-up here:
 http://www.pagetable.com/?p=764
 http://www.pagetable.com/?p=831

a working hypervisor (forked from BSD's bhyve) is here:
  https://github.com/mist64/xhyve

This attached patch attempts to provide the infrastructure glue for qemu to use this framework (when compiled on Mac OS X). It is not yet functional, but enables the following:

  ./configure --enable-hvf --target-list=x86_64-softmmu
  qemu-system-x86_64 -machine accel=hvf [...]

Please advise as to whether this is the right approach, and whether it's worth pursuing.
Comments welcomed,
 - assaf