virtual machine settings--processors--virtualization engine
For virtualization options, you will be able to :
Virtualize Intel VT-x/EPT or AMD-V/RVI :
virtualize the Intel VT-x/EPT or AMD-V/RVI virtualization instructions of the host PC processor so that they can also be available in the virtual machine.This will only be necessary in rare cases : when you want to install VirtualBox in a VMware virtual machine, virtualize a virtualization server (as VMware ESXi or Citrix XenServer), ...
虛擬化 Intel VT-x/EPT 或 AMD-V/RVI ：
虛擬化主機 PC 處理器的 Intel VT-x/EPT 或 AMD-V/RVI 虛擬化指令，以便它們也可以在虛擬機中使用。這僅在極少數情況下才有必要：當您想在 VMware 虛擬機中安裝 VirtualBox 時，虛擬化虛擬化服務器（如 VMware ESXi 或 Citrix XenServer），...
Virtualize CPU performance counters :
virtualize CPU performance counters to monitor CPU usage with applications running in the virtual machine, using OProfile (on Linux) or VTune (on Windows).
虛擬化 CPU 性能計數器：
使用 OProfile（在 Linux 上）或 VTune（在 Windows 上），虛擬化 CPU 性能計數器以監視在虛擬機中運行的應用程序的 CPU 使用率。
Virtualize IOMMU (IO memory management unit) :
allows you to virtualize the IOMMU (of AMD) or Intel VT-d and thus block the direct access to the memory from the virtual machine.This feature is required by the Citrix XenServer virtualization server when you want to test PCI passthrough with a Citrix VM on Windows.
Virtualize IOMMU（IO 內存管理單元）：
允許您虛擬化 IOMMU（來自 AMD）或 Intel VT-d，從而阻止從虛擬機直接訪問內存。當您要在 Windows 上使用 Citrix VM 測試 PCI 直通時，Citrix XenServer 虛擬化服務器需要此功能。