# Ensuring VT-X is "working?"

## forkbomb

Have a machine with a Core 2 Duo E6600:

```

processor   : 1

vendor_id   : GenuineIntel

cpu family   : 6

model      : 15

model name   : Intel(R) Core(TM)2 CPU          6600  @ 2.40GHz

```

The processor does support VT-x. I have no reason to believe it's not working. But, just a few questions:

1) I have VT-x related options enabled in VMware Workstation 6.5x (installed manually from an x86-64 .bundle I have rather than through an ebuild) as well as in my BIOS configuration. Do I need to enable anything specific in my kernel config to get VT-x working (similar to how you'd compile in Xen support)?

2) Is there any way to "confirm" that these virtualization extensions are being used?

3) Most of my guests I use do have the VMware tools installed. Is this strictly needed to ensure that guests are using VT-x?

I'm not really concerned about performance. I had been having performance issues with multiple distros using 64-bit VMware on a 64-bit host, but I just recompiled my kernel the other day with the low-latency desktop preemption model and it is much better now.  Still, just wondering if there's something I can do to make sure I'm squeezing out the VT-x functionality?

Sorry if these are really elementary questions. Still trying to get my head around how to really get virtualization screaming.

EDIT: Oh yeah. I should clarify. Gentoo x86_64 is the host machine.

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## Hu

 *forkbomb wrote:*   

> 1) I have VT-x related options enabled in VMware Workstation 6.5x (installed manually from an x86-64 .bundle I have rather than through an ebuild) as well as in my BIOS configuration. Do I need to enable anything specific in my kernel config to get VT-x working (similar to how you'd compile in Xen support)?

 

No kernel configuration is necessary to use VT-x, as far as I know.

 *forkbomb wrote:*   

> 2) Is there any way to "confirm" that these virtualization extensions are being used?

 

Load another hypervisor that is known to use VT-x, such as KVM.  If the machine hangs, VT-x was already in use by VMware.  If the module loads successfully, then VMware was not using VT-x.

 *forkbomb wrote:*   

> 3) Most of my guests I use do have the VMware tools installed. Is this strictly needed to ensure that guests are using VT-x?

 

In general, no guest support is required to benefit from VT-x, which is why it is considered full virtualization rather than paravirtualization.  I do not know if VMware would skip using VT-x if the guest lacked VMware tools, but I see no technical reason why they should.

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## forkbomb

 *Quote:*   

> In general, no guest support is required to benefit from VT-x, which is why it is considered full virtualization rather than paravirtualization.  I do not know if VMware would skip using VT-x if the guest lacked VMware tools, but I see no technical reason why they should.

 

OK. Thanks for the reply.

That was my inclination but I wasn't sure. The VMware tools are necessary for mouse integration, ACPI, full screen video, direct host-to-guest file sharing (as opposed to going through a network filing protocol of some sort), and other miscellaneous stuff. But I haven't read anything about it being necessary for VT-x.

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## Hu

 *forkbomb wrote:*   

> The VMware tools are necessary for [...] ACPI, full screen video

 

Are you sure about those?  I think I have seen Windows guests using ACPI without VMware tools, and I would expect that full screen video should work as well since windowed video works fine without the tools.  I could certainly believe that both features will work much better with the tools than without them, though.

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## forkbomb

 *Hu wrote:*   

> 
> 
> Are you sure about those?  I think I have seen Windows guests using ACPI without VMware tools, and I would expect that full screen video should work as well since windowed video works fine without the tools.  I could certainly believe that both features will work much better with the tools than without them, though.

 

Actually, come to think of it, now that you mention it, no. Got me second guessing myself.  :Razz:  I'm reasonably certain about the mouse integration and host-to-guest file sharing. But as for the full screen and ACPI, maybe I'm thinking of Virtualbox and the Guest Additions. Really shows you how long it's been since I have run a fresh install of a VMware machine. I just keep around 7zipped archives of my most-used VMs which already have the tools installed, and I just extract a new "clone" when I need a fresh hoss.

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