The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/third_party/autotest/+/8e75bab067119dfdaa086e934755f010159da127

commit 8e75bab067119dfdaa086e934755f010159da127
Author: Jeffrey Kardatzke <jkardatzke@google.com>
Date: Thu Oct 18 21:54:31 2018

autotest: Perform cold reboot on test device to enable VM

There's an issue where some devices need to undergo a cold reboot in
order to reset the EC so a bit can get flipped to enable the VM. This
checks if the device supports VM functionality by testing the existence
of /usr/bin/vm_concierge and then if the cold reboot is needed by the
lack of /dev/kvm. If both those are true it uses ectool to do a cold
reboot.

BUG= chromium:892782 
TEST=Manually verified on locked DUT

Change-Id: I5d1994d896814e874f6f5659263d90b63e08d970
Reviewed-on: https://chromium-review.googlesource.com/1262395
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Jeffrey Kardatzke <jkardatzke@google.com>
Reviewed-by: Jeffrey Kardatzke <jkardatzke@google.com>

[modify] https://crrev.com/8e75bab067119dfdaa086e934755f010159da127/server/hosts/cros_repair_unittest.py
[modify] https://crrev.com/8e75bab067119dfdaa086e934755f010159da127/server/hosts/cros_repair.py