AMD-V not working

[DejanM.]

Configuration>

AMD phenom II 1075T 3.0 Ghz
Motherboard> Asus M4A87TD (i have BIOS, not uefi)

My virtualization in BIOS is already ENABLED. I checked.

Using VirtualBox 4.3.26 on windows 8.1 64bit
I want to install Oracle Linux 6.6 64bit in virtualbox, and then install KVM virtualization.

But when i check this> egrep '(vmx|svm)' --color=always /proc/cpuinfo (nothing comes out, so it isnt enabled)

Yes, i turned on VirtualBox VT-x/AMD-V.

I have webroot antivirus, didnt disable. SELinux is disabled.

what could be the problem?

[loukingjr]

VirtualBox doesn't support nested virtualization.

[DejanM.]

Ok, then for what you use AMD-V? if we cant use virtualization inside VirtualBox?

[loukingjr]

for guests of course. for one you need it to run 64bit guests.

[DejanM.]

Thanks for reply.

One more question> is it normal for Vbox to show nothing when type > egrep '(vmx|svm)' --color=always /proc/cpuinfo ????

[loukingjr]

Welcome and I don't know the answer to your second question. Someone else might.

[scottgus1]

Just to make things clear:

Virtualbox uses the VT-x / AMD-V capabilities of the host to run multiprocessor and/or 64-bit guests, or guests which require that capability even if 32-bit-one-cpu, like Windows 8.

Virtualbox does not pass that capability into the guest, so if one installs Virtualbox in the guest one would not see VT-x/AMD-V available in the guest's install of Virtualbox.

One could install and run 32-bit-one-processor-earlier-than-Windows-8 guests in the guest's "nested" Virtualbox, but they'd be slow.

Such a setup would not get support on the forum because it isn't tested and approved by the developers, even though it may ostensibly run.

I have no idea myself if KVM would run in a Virtualbox guest.

The "egrep" command, which sounds like a Linux command, is likely not something Virtualbox would have any way of knowing when you run it in the guest. So Virtualbox would not control what response you get when the command is run. You would need to ask the Linux forums what to expect when running that command on a non-VT-x-AMD-V computer.

[DejanM.]

Thank you scottgus1 for reply, now things are more clear. Then Linux inside of VirtuaBox doesnt see AMD-V. I will try Vmware, they suport nested virtualization.

[scottgus1]

Okeedoke, hope it works out for you!

[loukingjr]

Thank you scottgus1 for reply, now things are more clear. Then Linux inside of VirtuaBox doesnt see AMD-V. I will try Vmware, they suport nested virtualization.

Just to make things re-clear. Linux guests inside VirtualBox certainly "see" VT-x/AMD-V. All 20 or so of my Linux guests spread over 4 machines are 64bit and they couldn't be if they had no access to VT-x/AMD-V.

The reason I didn't know the answer to the second question was I had never run the command and I didn't feel like opening a Linux guest at the time to check. Once ANY guest inside VirtualBox has used VT-x/AMD-V it is no longer available to anything running inside.

So to answer your question about egrep "(vmx|svm)" /proc/cpuinfo, yes it is normal for a guest to show nothing since VT-x/AMD-v doesn't "pass through" the guest.