In FreeBSD 12.2-STABLE before r365767, 11.4-STABLE before r365769, 12.1-RELEASE before p10, 11.4-RELEASE before p4 and 11.3-RELEASE before p14 a number of AMD virtualization instructions operate on host physical addresses, are not subject to nested page table translation, and guest use of these instructions was not trapped.
https://security.FreeBSD.org/advisories/FreeBSD-SA-20:29.bhyve_svm.asc