Nested paging exposed to the guest

[mhanor]

Is it possible to expose Nested Paging (EPT/NPT) to the guest?

[socratis]

"EPT" as in "Ept - Extended Page Tables"? If so, everything I've seen so far^[1] has the following entry in the VBox.log:

00:00:02.439949 Nested hardware virtualization - VMX features
00:00:02.439949   Mnemonic - Description                                  = guest (host)
...
00:00:02.439978   Ept - Extended Page Tables                              = 0 (1)

I have yet to see a "1 (1)" case, which means no, not at the moment at least...

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^[1]: I've been collecting an assortment of CPUs (since 6.1.0b1 came out) trying to see what capabilities each one has, and see if they're nested-virtualization capable.

[Technologov]

I think EPT/NPT is necessary requirement for some hypervisors, including Hyper-V.

[mhanor]

Correct, that's why I'm asking.

[socratis]

Seems to me that someone(s) want to run Hyper-V inside a VM...

As previously stated in these 6.1.0b1 forums, it's best if you stick on getting "VirtualBox on VirtualBox" running first, and then the other "exotic" (as I call them) scenarios will follow. When you start seeing:

00:00:02.439978   Ept - Extended Page Tables  = 1 (1)

in your logs, then you'll know that something might be ready for public testing...

[mhanor]

I'm only looking for a straight answer from a developer, so we can be sure. In the past, I know that you could enable some CPU features or instructions, that weren't enabled by default for the guest.

[socratis]

I'm only looking for a straight answer from a developer, so we can be sure

Most of the times, I do seek confirmation before posting an answer, that's how my posts get... "gravitas"!

 socratis: EPT/NPT is not something that's passed to the guest, right?
Developer: not yet.

For more details, join the IRC #vbox-dev channel...