O Manual do VirtualBox , na seção intitulada Provedores de paravirtualização explica muito claramente quando cada um deve ser usado (ênfase adicionada):
Minimal: Announces the presence of a virtualized environment. Additionally, reports the TSC and APIC frequency to the guest operating system. This provider is mandatory for running any Mac OS X guests.
KVM: Presents a Linux KVM hypervisor interface which is recognized by Linux kernels starting with version 2.6.25. VirtualBox's implementation currently supports paravirtualized clocks and SMP spinlocks. This provider is recommended for Linux guests.
Hyper-V: Presents a Microsoft Hyper-V hypervisor interface which is recognized by Windows 7 and newer operating systems. VirtualBox's implementation currently supports paravirtualized clocks, APIC frequency reporting, guest debugging, guest crash reporting and relaxed timer checks. This provider is recommended for Windows guests.
As outras opções na lista suspensa fazem o seguinte, conforme explicado na vboxmanage
docs :
None: Specifying
none
explicitly turns off exposing any paravirtualization interface.Default: The option
default
, will pick an appropriate interface depending on the guest OS type while starting the VM. This is the default option chosen while creating new VMs.Legacy: The
legacy
option is chosen for VMs which were created with older VirtualBox versions and will pick a paravirtualization interface while starting the VM with VirtualBox 5.0 and newer.