VM unrestricted guest capability required

Peter Grehan grehan at freebsd.org
Fri Oct 3 04:00:27 UTC 2014


Hi,

> I'm trying to install Ubuntu Linux 14.10 as a guest in FreeBSD
> 11-CURRENT r272460 host. When I try to run grub-bhyve (version 0.23)
> I see in console message: VM unrestricted guest capability required
> Error in initializing VM
>
> I've read a thread with the similar problem. As far as I understood,
> this message happen when CPU doesn't have unrestricted guest
> capability support (EPT).

  'Unrestricted guest' is a different feature than EPT (Extended Page 
Tables). It allows the CPU to run in real mode and unpaged protected 
mode. This feature was introduced with the Westmere microarchitecture,
and isn't available in your core i7 780 (aka Lynnfield, a Nehalem-based 
model)

  grub boots Linux in unpaged 32-bit "flat" protected mode so requires 
unrestricted guest support.

  Although bhyveload boots FreeBSD directly into 64-bit paged protected 
mode, secondary processors require 16-bit real mode to be spun up. This 
limits FreeBSD to a single CPU on any Nehalem-derived system.

later,

PEter.


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