KVM + Nested 15.5 Workstation

[StopyZ]

I have been waiting since version 13 for Nested to appear.

I also run Workstation in KVM and Nested does not work. Does it make sense to wait for the 16th version?

[wila]

Hi,

Nested has been working fine in VMware Workstation for quite a few years.

If OTOH you want to run nesting in a host with VMware Workstation running under KVM then you need support from KVM for that nesting part!

--

Wil

[StopyZ]

Good. Let's assume.

I have a virtual machine, where KVM is released as a hypervisor. Windows Server 2008R2 guest + all updates.

The virtual machine is started with: cpu: host, flags = + hv-tlbflush; + hv-evmcs; + aes

i3 8350K processor

In this virtual machine, Workstation 15.5. And also Virtualbox, which works, but let's not talk about it, he shit.

When starting any nested virtual machine in Workstation, you can see the message:

Virtualized Intel VT-x / EPT is not supported on this platform.

Continue without virtualized Intel VT-x / EPT?

And also just terrible brakes.

[wila]

Hi,

Yes support for VT-x and EPT is required nowadays in VMware Workstation.

The problem is that KVM is not offering this to the guest.

Without that you have problems with certain (perhaps all?) workloads.

You can probably get this to work, but then you need a very old version of VMware Workstation, one that supported binary translation.

I'm trying to remember in what version of VMware Workstation that got axed, but not sure.. version 12 perhaps?

So you'll need a VMware Workstation version from before that time. Perhaps somebody else here remembers the details better.

--

Wil

[StopyZ]

Why are there problems with this in new versions?

The old version doesn't fit ...

[wila]

Later versions of Workstation require the available CPU features for virtualisation as that makes it all much more performant.

Almost all CPUs from the last 10 years have those features.

VMware got rid of their old legacy code base for the binary translation feature as it takes time & effort to maintain it, efforts that are better spent elsewhere.

--

Wil

[StopyZ · Accepted solution]

I understand what you are talking about.

I hope this will be helpful to others:

options kvm-intel nested=Y

options kvm-intel enable_shadow_vmcs=1

options kvm-intel enable_apicv=1

options kvm-intel ept=1

[wila]

Hi,

Does that mean you got it to work?

If so, great job and nice to see that KVM supports these features.

--

Wil

[freesco]

I was about to open a topic for this but rather continuing the discussion. In the past I had a setup (talking of Debian Wheezy times) where I used the same server for both KVM + Vmware Workstation hypervisor. The trick was:

modprobe kvm-intel
/etc/init.d/libvirt-bin start

Load KVM after Vmware. This worked for a while, the majority of the heavy load VMs were in vmware back then but once in a while the server started segfaulting, hanging up until the level it was only possible to remote reboot it to use the magicRQ via sys.

Now I planning to do the nested setup although the responses are quite negative here.

I have another Linux KVM host server running like 30 KVM machines. I want to duplicate this server but not on physical hardware, I want to reproduce this inside in a Vmware Workstation VM.

Anyone tried something like this before?

[freesco]

Actually, just tested it on my laptop it works

Debian 9 HOST -> Kali Linux  Vmware VM -> KVM Virtual Machine -> OpenBSD VM

kvm-ok
INFO: /dev/kvm exists
KVM acceleration can be used

With VT-X, IMMOU works nicely. It is just too bad that Vmware does not support PCI Passtrough. That is actually one of the huge advantage of doing this in the other way around and using KVM as the main hypervisor. I have tried that once and failed with it to run ESXi inside KVM VM.