bug#22633: Provide a kvm-less qemu / guix system vm

[Jookia]

On Thu, Feb 11, 2016 at 09:26:12AM -0800, Christopher Allan Webber wrote:
> So on my Libreboot-enabled machine, KVM does not work.  In fact, even
> starting qemu with KVM enabled on it appears to crash my whole system.
> Not only does "guix system vm" not work, even "guix system vm-image" can
> take the whole machine down!

Currently the 'solution' I've found is to edit Guix to remove the two instances
of '--enable-kvm' which works somewhat, though it's slower as there's absolutely
no acceleration.

> It would be nice to have a --no-kvm switch, because I'd really like to
> make use of Guix's nice VM features!

We should probably also blacklist kvm on Libreboot machines too somehow, though
this could also break it on non-Libreboot machines. I wonder if there's a way to
query the BIOS to see if Libreboot is enabled?

> PS: Apparently in future revisions of Libreboot, this will be fixed.
>   For now though...

Oh really? I was under the impression this was broken due to microcode issues.

Jookia.