It looks like a KVM bug, which I can cover on a span of commits. This are commits form the Linux stable repository. gitk bb3dd056ed1af9b186f0d9fe849eab78c51d14ce..813ae37e6aed72cc457094b6066aa38efd66c9e9
What is certainly safe in any case, it will affect all KVM hosted OpenBSD with a kernel which is newer than 4.9.
