Setextradata HOSTCPUID CPUM not working?

[FlatChad]

I have a Windows 7 x86 Guest that is powered off. I run:

Code: Select all

vboxmanage setextradata "Win7-x86-SP1" VBoxInternal/CPUM/HostCPUID/00000001/eax 0x000506E3
vboxmanage setextradata "Win7-x86-SP1" VBoxInternal/CPUM/HostCPUID/00000001/ebx 0x00040800
vboxmanage setextradata "Win7-x86-SP1" VBoxInternal/CPUM/HostCPUID/00000001/ecx 0x1ED82203
vboxmanage setextradata "Win7-x86-SP1" VBoxInternal/CPUM/HostCPUID/00000001/edx 0x178BFBBF

I can see the changes have all been applied successfully by viewing the .vbox file.

I start the VM, and immediately the .vbox is modified, removing the 4 settings I just applied.

As a result, the CPUID instruction does not return these values when executed.

What am I doing wrong?

[michaln]

What am I doing wrong?

You're using an undocumented internal interface. Why are you doing that, anyway?

Use 'VBoxManage modifyvm <vmname> -- cpuidset <leaf> <eax> <ebx> <ecx> <edx>' instead.

[brunis]

Amazing, love how this official interface breaks my vm's. At least the undocumented one didn't.

Any idea how to unbreak my vm's if i tried any of the cpuid's on the list?

--cpuidremoveall has no effect.. or maybe that's because it's entires wiped now?

[socratis]

I thought that repeating the command with no arguments:

• VBoxManage modifyvm <vmname> --cpuidset

would work, alas it doesn't. So the only way I can think of is to quit VirtualBox and make sure that there are no VirtualBox processes running (VBox*, VM*). Another way would be to reboot your host and avoid launching VirtualBox.

You then edit the .vbox file of the affected machine and you delete three lines:

<CpuIdTree>
  <CpuIdLeaf id="1" eax="198313" ebx="1050624" ecx="2140857279" edx="126614527"/>
</CpuIdTree>

The e*x numbers may be different in your case.

[michaln]

What *exactly* is the problem, and what are you trying to solve by modifying the CPUID? Chances are you're doing something wrong/unnecessary. Without knowing the details, the general advice is "don't do this".