[Bug]: Unable to enable the 'Nested VT-x/AMD-V' System option

[eabase]

Version

7.2.6

Host OS Type

Windows

Host OS name + version

Windows-11 Pro

Host Architecture

x64 (Intel i9-13900H + nVidia)

Guest OS Type

Linux

Guest Architecture

x86

Guest OS name + version

Debian 13 Trixie

Component

VBoxManage CLI
GUI

What happened?

I'm trying to enable the Nested VT-x/AMD-V option in System section of GUI.

Reading related help pages only refers to an old CVE that have been patched a decade ago as the reason why this was disabled. Meanwhile possibly providing performance enhancement for the guest OS.

Unfortunately the GUI, nor the CLI (provided by VBoxManage.exe showvminfo) does not seem to be able to clearly explain and enable this.

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I would have expected that VBoxManage modifyvm "xxxx" --x86-vtx-vpid=on would have enabled it, but no change.

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In addition, on the other Tabs, you also show:

What does that do, and which CLI option controls it?

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Finally, the various HV options are also not fully documented, and with vague names.

• (a) Which is the default?
• (b) What are each doing? (E.g. "Legacy" and "Minimal"?)

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How can we reproduce this?

n/a

Did you upload all of your necessary log files, screenshots, etc.?

• Yes, I've uploaded all pertinent files to this issue.

[Kc2353]

Plesae check if Hyper-V on Host is fully disabled.
Run msinfo32 for more infomations.
You may see virtualization based security is on,and a green turtle v on VM status bar
,view UserManual sec 13.7.2 and 5.1.2.
Nested VT-x cannot be enabled on hosts running on Hyper-V
by the way ,Nested paging and Nested VT-x are different functions.

[Kc2353]

default Paravirtualization Interface is
KVM for Linux guests
Hyper-V for Windows Guests
This is Documented and linked in Acceleration Tab