kvm virtualization on a liberated X200, part 1
As the libreboot website warns: there are issues with virtualization on x200 without microcode updated.
Virtualization is something that I use, and I have a number of VMs on that laptop, managed with libvirt; since it has microcode version 1067a, I decided to try and see if I was being lucky and virtualization was working anyway.
The result is that the machines no longer start: the kernel loads, and then it crashes and reboots. I don't remember why, however, I tried to start a debian installer CD (iso) I had around, and that one worked.
So, I decided to investigate a bit more: apparently a new installation done from that iso (debian-8.3.0-amd64-i386-netinst.iso) boots and works with no problem, while my (older, I suspect) installations don't. I tried to boot one of the older VMs with that image in recovery mode, tried to chroot in the original root and got failed to run command '/bin/bash': Exec format error.
Since that shell was lacking even the file command, I tried then to start a live image, and choose the lightweight debian-live-8.0.0-amd64-standard.iso: that one didn't start in the same way as the existing images.
Another try with debian-live-8.5.0-i386-lxde-desktop.iso confirmed that apparently Debian > 8.3 works, Debian 8.0 doesn't (I don't have ISOs for versions 8.1 and 8.2 to bisect properly the issue).
I've skimmed the release notes for 8.3 and noticed that there was an update in the intel-microcode package, but AFAIK the installer doesn't have anything from non-free, and I'm sure that non-free wasn't enabled on the VMs.
My next attempt (thanks tosky on #debian-it for suggesting this obvious solution that I was missing :) ) was to run one of the VMs with plain qemu instead of kvm and bring it up-to-date: the upgrade was successful and included the packages in this screenshot, but on reboot it's still not working as before.
Right now, I think I will just recreate from scratch the images I need, but when I'll have time I'd like to investigate the issue a bit more, so hopefully there will be a part 2 to this article.