My System Config
- MB: Asus P8Z77 V-Pro
- CPU: Intel Core i7 – 3770 @ 3.4Ghz
- OS: Windows 8 Pro (64 bit)
I am trying to use Virtual Box to install Ubuntu 12.10. But the installer failed to launch and the log mentioned that it failed to detect Hardware Assisted Virtualization (HAV).
I checked with securAble from http://www.grc.com/securable.htm. And it also mentioned that HAV is not present.
A look into the BIOS showed the following:
Intel Virtualization Technology - Enabled
Execute Disable Bit (XD) - Enabled
To give it a try I "Disabled" XD. And Virtual Box detected that I have Virtualization enabled. And the install process went on. Further securAble confirmed HAV is now enabled.
Issue
I am now trying to do some Windows Phone 8 development and this requires Hyper-V enabled for the emulator to function. But a little Googling pointed out that Hyper-V requires XD to be enabled.
So I am in a bit of a messy situation since I can't seem to have both HAV and Hyper-V enabled together.
Thanks You for your guidance in advance.
Best Answer
CPUs support disabling virtual machine extensions permanently until next power cycle. This is how BIOSes disable/enable it.
Maybe a buggy BIOS? Like @fah q suggests, might try updating and see if that improves.
Also, you can't "nest" hardware virtualization without explicit support from the VM hypervisor. From what I gather by looking at this, attempt to "turn on" virtualization (using the VMXON instruction) when it is already on causes a "VM exit", meaning control is passed back to the hypervisor. The hypervisor could do what's needed to emulate it in the VM, but I'm betting no currently available VM software does this.