Windows hangs with VT-x enabled

[ingenium]

I'm running Windows XP as a guest with Ubuntu 8.10 as the host. When I enable VT-x, the guest will hang as soon as, or shortly after, I login. Virtualbox (2.1.0) itself is responsive, but the guest is not. This is not a new problem, I've had it for close to a year now. Disabling VT-x fixes the problem. The same issue occurs if I use other guests as well, so I don't believe it's something with the guest OS itself.

I have a Core Duo T2400 processor. VT-x is enabled in the BIOS, and VMware has no problem using VT-x, so I believe it's a Virtualbox problem.

A copy of the log is available at the address below. It doesn't show anything that stands out of me as being useful. There isn't even anything relevant at the end when the machine hangs.

http://www.joshuajhill.com/Windows%20XP ... -34-05.log

[Sasquatch]

The log mentions that you have enabled VT-x, as per this line:

Code: Select all

00:00:01.157 [/HWVirtExt/] (level 1)
00:00:01.157   Enabled      <integer> = 0x0000000000000001 (1)

However, a bit more down, in the CPU dump, it's not on:

Code: Select all

00:00:01.163 Mnemonic - Description                 = guest (host)
00:00:01.163 VMX - Virtual Machine Technology       = 0 (1)

So there is something wrong there. Have you tried a BIOS update yet?

[ingenium]

The log mentions that you have enabled VT-x, as per this line:

Code: Select all

00:00:01.157 [/HWVirtExt/] (level 1)
00:00:01.157   Enabled      <integer> = 0x0000000000000001 (1)

However, a bit more down, in the CPU dump, it's not on:

Code: Select all

00:00:01.163 Mnemonic - Description                 = guest (host)
00:00:01.163 VMX - Virtual Machine Technology       = 0 (1)

So there is something wrong there. Have you tried a BIOS update yet?

Yeah, I'm running the latest BIOS released for my system. I just checked again, and VT-x is indeed enabled in the BIOS. When I still had Windows on this machine, I turned on VT-x in VMware and it had no problem using it.

/proc/cpuinfo shows that it's also enabled:

flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx constant_tsc arch_perfmon bts pni monitor vmx est tm2 xtpr

Is there something else I would need to do to turn it on?

[Sasquatch]

Only the Guest setting. Advanced tab on the top entry of the Settings, it says AMD-v/VT-x.

Did you upgrade from a previous version of VB, or is it a clean install of 2.1.0? If you used an older version, did it also happen there?

[ingenium]

I upgraded from a previous version. I was using it since 1.x, a few months before they were acquired by Sun. I've always had this problem.

With the upgrade to version 2.1, it somehow corrupted my virtual machine (said it was inaccessible), but the virtual disk was fine. I created a new VM with that virtual disk which works fine other than I still have this VT-x bug. So it's probably not something corrupt/wrong with the config for this VM.

[Sasquatch]

If you always had this issue, why didn't you report it before? There have been numerous fixes with hardware virtualisation, so most should have already been fixed. It's also possible that there is some hardware issue and VMWare just disables VT-x when it encouters something like this.

[ingenium]

Hi. I'm still having this issue in Virtualbox 2.2.0. However, I have verified that it's not a VT-x issue on my system. Kvm runs with hardware virtualization with absolutely no problem. I believe KVM actually requires VT-x. So why does Virtualbox see it as not being on?

I also noticed that the wikipedia entry on KVM (http://en.wikipedia.org/wiki/Kernel-bas ... al_Machine) implies that Virtualbox can somehow use kvm; is there any truth in this? I know I have to unload the kvm module for Virtualbox to start, so I'm thinking this is just an error on the wiki, but it never hurts to ask.

[arnuschky]

Hi,

I'm having exactly the same issue. I'm currently using VirtualBox 2.2.0 on Gentoo Linux, with a Windows XP guest. When I enable VT-x in the guests config, th guest hangs. Safe-mode hangs at "mup.sys".

I upgraded my virtual machine from 1.5-something. 1.6 was fine. If I remember right, the issue appeared afterwards. I never had the time to report this and was kind of hoping it's an early bug of version 2, which disappears at some point. Well, it didn't.

Anyone haveing a solution? Can I re-setup my guest somehow, without reinstalling everything?

Cheers
Arnuschky

[vbox4me2]

2.2 allowes mixed vt-x modes, if you don't need it switch it off. Some vt-x enabled Guests also need IOAPIC to be on.

[ingenium]

Turning on IO APIC didn't have any effect, it still hung.

What do you mean that 2.2 supports mixed VT-x modes?

[vbox4me2]

How many modes are there? on and off, thats all. with 2.2 you can use both for different running VM's.

[arnuschky]

with 2.2 you can use both for different running VM's.

I don't really see how this helps me. I have one VM. VT-x was working, now it does not anymore. IO-APIC, PAE and ACPI is on.

[vbox4me2]

Have you tried 2.2.2 ? if that does the same try the older 2.08

[arnuschky]

I tried several version after 1.6, including 2.0.*, 2.1.* and 2.2.*, each time with the same result. Usable, but slow, because VT-x can't be enabled.

[vbox4me2]

Check the BIOS, maybe it got turned off if it was working before, via QuickClic you can find vt-x testing tools.