'The CPU flag for AMD-V is "svm". This may be checked in BSD derivatives via
dmesg or sysctl and in Linux via /proc/cpuinfo.'
Previously created 64-bit VBox machines on earlier H/W and VBox are no longer
"defined" as 64-bit machines. All machine type selections are now 32-bit only
(see 'FBSD-VBox-5.2.18_no_64_bit.png' screen shot).
Attempting to start a previously configured 64-bit VM now results in an error
message (see 'FBSD-VBox-5.2.18_no_VTx_AMD-V_HW.png' screen shot) which further
informs that CPU virtualization support is "missing".