Virtualization Engine in VM Settings

[GnVm]

Hi,

I have seen in Virtual Machine Settings > Processors > Virtualization engine

• Virtualize Intel VT-x/EPT or AMD-V/RVI
• Virtualize CPU performance counters
• Virtualize IOMMU (IO memory management unit)

By default, all above options remain un-checked.

Please let me know some scenarios when these options are used?

Regards

GnVm

[wila]

Hi,

Configuring Virtual Machine Processor Settings

To sum it up:

- Intel VT-x/EPT and AMD-V/RVI

you only enable that if you want to run a VM in your VM. (nested virtualisation)

- CPU performance counters

A special use case where you need to measure performance

- Virtual IOMMU

Needed if you want to enable VBS

IOW, leaving these options unchecked unless you have one of those specific needs is highly recommended.

It will not make your VM faster.

If it does then an application installed in your guest OS is doing something behind your back.

--

Wil

[GnVm]

As you said,

Intel VT-x/EPT and AMD-V/RVI is required in case of a VM in your VM (nested virtualisation). I got it.

CPU performance counters is required, if I want to measure performance.

If I enable it, where I can see the performance measured by VMware Workstation?

Virtual IOMMU is needed if you want to enable VBS.

Let me know about VBS.

[RDPetruska]

Did you read the section of the user manual which wila linked to in his reply to you?  I think it answers those questions... or at least gives enough info for you to google and investigate further on your own...

[rajivroorkee]

Hi ,

Yes it's by default unchecked, Use all these option as per your requirement .

Intel VT-x or AMD-V :- VMware uses the physical CPU hardware extensions to run and isolate guest OS and application code. ... Intel VT-x/EPT or AMD-V/RVI - VMware uses the physical CPU hardware extensions to run and isolate guest code. Guest memory mapping is handled by the physical host's hardware paging.

Virtual CPU Performance Counters :- You can use performance tuning tools in the guest operating system for software profiling. You can identify and improve processor performance problems. This capability is useful for software developers who optimize or debug software that runs in the virtual machine.

OMMU : is a system specific IO mapping mechanism and can be used with most devices. IOMMU sounds like a generic name for Intel VT-d and AMD IOV. In which case I don't think you can multiplex devices, it's a lot like PCI passthrough before all these fancy virtualization instructions existed

Rajiv Pandey

vthesis.wordpress.com