add a pointer in the README about machyve#5/machyve#9 so that no one …

…gets surprised.

Signed-off-by: António Meireles <antonio.meireles@reformi.st>

README.md

@@ -150,6 +150,14 @@ xhyve shares most of the code with bhyve but is architecturally very different.
 
 *bhyvectl*, *bhyveload* and *grub2-bhyve* are incompatible with a single process model and are dropped. As a stop-gap solution until we have a proper firmware xhyve supports the Linux [kexec protocol](http://www.kernel.org/doc/Documentation/x86/boot.txt), a very simple and straightforward way to bootstrap a Linux kernel. It takes a bzImage and optionally initrd image and kernel parameter string as input.
 
+Issues
+------
+Righ now, if you have (any version of) VirtualBox running and attempt to run
+xhyve it will immediately crash your system as it triggers a kernel panic.
+This is not a xhyve issue *per se*, since it runs in userspace, but a
+VirtualBox one which just doesn't play nice with Hypervisor.framework.
+(see issues [#5](mist64/xhyve#5) and [#9](mist64/xhyve#9) for the full context)
+
 TODO
 ----