Adventures with Intel Virtualization Technology (VT)

A couple of weeks ago, David Saxon and I ran a Windows 7 Skills Update workshop for some of our colleagues, based on a course obtained from the Microsoft Partner Training and Readiness Resource Center.  My plan was to use David’s excellent training skills to deliver the course (which I recorded), before he left the organisation to take up a new challenge.  Ironically, working for an IT company means that it’s not always easy to get hold of kit for labs and David called in a number of favours in order to get hold of 8 brand new PCs and monitors for us to run the labs.  Each machine was supplied with a quad core CPU and 8GB of RAM but, when we tried to enable the Hyper-V role in Windows Server 2008 R2, it failed because these computers didn’t support Intel’s Virtualization Technology (VT).

“No VT?”, I said “But these are Intel Core2Quad processors… ah…” – I remembered seeing something about how some Core2Quads don’t provide Intel VT support, even though the Core2Duos do.  These were the Q8300 2.5GHz chips and, according to an Intel document, the specification was changed in June to correct this and enable the VT.

I should have known better – after all, I’m an MVP in Virtual Machine technology – but I put my hands up, I didn’t check the specifications of the machines that David had ordered (and anyway, I would have expected modern CPUs to include VT).  Mea Culpa.

As the PCs had been manufactured in August, I thought there was a chance that they used the new CPUs but did not have BIOS support for VT.  If that was the case, it may have been possible to enable it (more on that in a moment) but running both CPU-Z and Securable confirmed that these processors definitely didn’t support VT.

In this case, it really was a case of the CPU not providing the necessary features but there are also documented cases of PCs with VT not allowing it to be enabled in the BIOS.  Typically the OEM (most notably Sony) claims that they are consumer models and that VT is an enterprise feature but with Windows 7’s XP Mode relying on Virtual PC 7, which has a dependency on Intel VT or AMD-v, that argument no longer holds water (XP Mode is definitely a consumer feature – as it’s certainly not suitable for enterprise deployment, regardless of Microsoft’s Windows 7 marketing message around application compatibility).

However, with a little bit of perseverance, it may be possible to force VT support on PCs where the functionality is there but not exposed in the BIOS.  Another friend and colleague, Garry Martin, alerted me to a forum post he found where a utility was posted to enable VT on certain Fujitsu machines that have been restricted in this way.  I should say that if you try this, then you do so at your own risk and I will not accept any responsibility for the consequences.  Indeed, I decided not to try it on my problem machines because they were a different model and also, I didn’t fancy explaining to our Equipment Management team how the brand new PCs that we’d borrowed for a couple of days had been “bricked”.  In fact, I’d think it highly unlikely that this tool works on anything other than the model described in the forum post (and almost certainly not with a different OEM’s equipment or with a different BIOS).

Incidentally, Ed Bott has reasearched which Intel desktop and mobile CPUs support VT and which do not.  As far as I know, all recent server CPUs (i.e. Xeon processors) support VT.

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