Windows 11 update gives me a turtle

[Andrew@USOP]

Prior to today all was well.
I did the cumulative update to the host - I'm running Windows 11 Pro 22H2, latest update (10 Jan, 2024) as the host
VirtualBox is 7.0.12
Guest is Ubuntu 22.04.3 LTS

Before the update, no turtle.
After the update, turtle.

This theoretically indicates a hypervisor problem, which dmesg believes is the case
But Hyper-V isn't running/enabled on the host - task manager shows nothing

So, bafflement

[scottgus1]

If the turtle is present, host Hyper-V is present. The turtle doesn't lie.

See HMR3Init: Attempting fall back to NEM (Hyper-V is active), especially the part about Windows Features not showing the whole picture.

[Andrew@USOP]

Ok, I was looking for hyper-v
Being a bit cleverer with the search I find these lines

00:00:02.152012 HM: HMR3Init: Attempting fall back to NEM: AMD-V is not available
and more (see attached)

I've never heard of AMD-V before

[scottgus1]

I've never heard of AMD-V before

This is because you have an AMD processor. Intel calls it VT-x.

[Andrew@USOP]

Weird then that that has existed from the first time I fired up the PC
It's never complained about that before, or given me the magic turtle as a result

I guess as it all works, albeit with a turtle, maybe... sometime in the future, someone will work this out

[scottgus1]

It's just that the update turned on something that needed host Hyper-V. Windows Updates do that all the time.

Determine if your VMs are performing OK or bad, and turn Hyper-V off per the tutorial if needed. There's nothing to fix on the Virtualbox side.

[Andrew@USOP]

Well, it's not behaving terribly, but this box is pretty much limited to development, not production.

I'm not going to stress about it, but in the VirtualBox settings for this VM, it's got "Enable Nested VT-x/AMD-V" shaded out.

Which means... life goes on, Microsoft is epic... I might need an alibi witness etc

[scottgus1]

it's got "Enable Nested VT-x/AMD-V" shaded out.

It's probably shaded out because of Hyper-V being enabled. Hyper-V won't let Virtualbox pass VT-X/AMD-V into a VM, beacuse Hyper-V is using it already.

That setting is only for nested virtualization: another layer of Virtualbox running inside a Virtualbox VM. If you didn't have that setup, you probably weren't using the checkbox feature.

[Andrew@USOP]

Enabled it is.
Enabled it wasn't.
The 22H2 update seems to be what enabled it
It doesn't look wise to screw with what it did
Life etc...

[BillG]

The simplest solution is to use the bcdedit command to prevent the Windows hypervisor from loading (as described in the tutorial you were referred to earlier). This does not require making any changes to your Windows configuration and is easily reversible - you simply enable it again.

Many people have used this method for a long time without any problems. The point is that all you change is a parameter in the boot sequence of the host PC. When you reboot the PC, the Windows hypervisor will not load. This allows VirtualBox to function as it used to.

If you find that your host PC needs some feature in Windows which requires the Windows hypervisor, simply change the boot parameter back and reboot your host PC.

[fth0]

Many people have used this method for a long time without any problems.

Until the Memory Integrity feature was changed to use Hyper-V nonetheless.

But I described that in an additional post in the tutorial. Just like BillG, I'd suggest to start with the BCD command, and if it's not enough, take a look at my post in the tutorial for a second step.