Hello. I found out that VT-x/AMD-V boxes are unchecked by default in VirtualBox machines menu for both Gateway and Workstation VMs. Should I check this option or only leave PAE/NX checked?
Another question. Is it safe to update VirtualBox to version 7? Are Whonix VMs ok with new version of VirtualBox or users should stay on version 6?
Pointless exercise (no need) to show a point: Try to enable the VT-X/AMD-V box. It’s grayed out right? Meaning, you cannot make any changes there anyhow.
VT-X/AMD-V is already enabled. No changes required. To see that VT-X/AMD-V is already enabled, here are some commands that work out of the box on Linux based operating systems such as Debian or Kicksecure.
vboxmanage showvminfo Whonix-Gateway-XFCE
vboxmanage showvminfo Whonix-Gateway-XFCE | grep -i vt
vboxmanage showvminfo Whonix-Gateway-XFCE --machinereadable | grep -i vt
(For Windows, generally speaking (not specifically about this topic) running vboxmanage could be a bit more cumbersome due to how PATH works on Windows but that’s unspecific to this topic and unspecific to Whonix.)
No, it is not grayed out, it is just unchecked. But in both GW and WS I can type lscpu and it shows my physical processor. Can it be a bug? Should I check VT-X/AMD-V in VirtualBox machine settings ?
Define bug. 
Well, it’s not related to this forum thread. You could call it an issue / bug but it’s expected. I.e. a “known issue”.
It’s documented here:
This chapter specifically:
Protocol Leak and Fingerprinting Protection‎ chapter Hardware Identifiers in Whonix wiki
Not so fast. Please try above commands including grep first and post the output here.
That’s weird.
Also please post the output of this:
vboxmanage showvminfo Whonix-Gateway-XFCE --machinereadable | grep -i hwvirt
And.
vboxmanage showvminfo Whonix-Gateway-XFCE --machinereadable | grep -i paravirt
Also the exact wording of that box is Enable Nested VT-x/AMD-V?
The keyword here is Nested.
Clearly, no. Do not enable this. There’s no need for it. You can completely ignore this.
Why would it be grayed out for some? See this.
Exception: That is unless you are interested in nested virtualization. If so, see:
VBoxManage modifyvm Whonix-Workstation --cpuidremoveall
After this is running, when I enter lscpu in the virtual machine, it still displays the CPU name on my physical host
Off-topic.
Expected.
Plenty of search results.