64-bit guest OS doesn't work

[przemoc]

I have 64-bit CPU (AMD Athlon 64 X2), Virtualization support turned on in BIOS (in KN9 that is: Advanced BIOS Features->CPU Feature->Virtualization: Enabled), 64-bit host OS (XP64 with SP1), VirtualBox 2.0 64-bit, Enable AMD-V/VT-x checked along with recommended IO APIC.

First I tried to start existing 64-bit ubuntu 8.04 from physical drive via vmdk. After "Starting up..." I got:

This kernel requires an x86-64 CPU, but only detected an i586 CPU.
Unable to boot - please use a kernel appropriate for your CPU.

Next I tried to boot from 64-bit ubuntu 7.10 cd and start installation, but when I've chosen option to install it showed me message:

Your CPU does not support long mode. Use a 32bit distribution.

I'm not sure yet that problem occurs only in xp64 host and only with ubuntu64 guest, so I didn't change host and guest types.

[przemoc]

Running Ubuntu 8.04 64-bit on physical drive

[Sander van Leeuwen]

AMD-V is disabled by your BIOS. Is there a newer BIOS that you can try? It wouldn't be the first time a buggy BIOS is unable to turn on this feature.

[przemoc]

Replying to sandervl73:

AMD-V is disabled by your BIOS. Is there a newer BIOS that you can try? It wouldn't be the first time a buggy BIOS is unable to turn on this feature.

I have Abit KN9, based on (IMHO very good) nForce 4 Ultra. My current BIOS ID is 12, but changelog (​http://www.abit.com.tw/page/en/download/download_bios_detail.php?pTITLE_ON_SCREEN=KN9) doesn't reveal anything about possible changes in virtualization support.

[przemoc]

Replying to sandervl73:

AMD-V is disabled by your BIOS.

Can you tell what line of log exactly states that? In that case what changes Advanced BIOS Features->CPU Feature->Virtualization setting? I thought that hardware virtualization works fine in my vmware server.

[Doug Roberts]

Log from Kubuntu 8.04 AMD 64 host trying to boot a Kubuntu 8.04 AMD 64-bit guest

[Doug Roberts]

I can verify this as well. Version 2.0 failed to install a 64-bit version of kubuntu-8.04.1-desktop-amd64.iso

Host: Kubuntu 8.04 Linux on AMD 64 Guest: ditto.

The error message at virtual boot time was "This kernel requires an x86-64 CPU, but only detected an i1586 CPU. Unable to boot - please use a kernel appropriate for your CPU."

The log is attached.

--Doug

[Frank Mehnert]

rober1s, same applies to your machine: The AMD-V mode is somewhere disabled, most probably in the system BIOS.

[Frank Mehnert]

Have a look at the log files. Search for lines containing HWACCM.

[Doug Roberts]

Frank,

You well may be correct, but I've been through the BIOS set up (Gigabyte S-Series MB) and see no settings for AMD-V mode.

Also, two stupid questions:

1) Why can I build a non-virtual Kubuntu 8.04 64-bit OS on top of this very same bios, and 2) Why can VMWare do the same virtually, and VirtualBox cannot?

--Doug

[Frank Mehnert]

Please try to update your BIOS. It is just a limitation of VirtualBox to depend on VT-x or AMD-V for the 64-bit mode. When VMware started to support the 64-bit guest mode, VT-x / AMD-V was not yet as common as it is now.

[faghutz]

Replying to frank:

Please try to update your BIOS. It is just a limitation of VirtualBox to depend on VT-x or AMD-V for the 64-bit mode. When VMware started to support the 64-bit guest mode, VT-x / AMD-V was not yet as common as it is now.

I'm trying to run 64 bit Ubuntu 8.04.1 as guest on my MacBook running Leopard (10.5.4) host. VMWare Fusion as well as Parallels manages to run this, but VirtualBox 2.0 does not. Parallels has the following to say about my running Ubuntu 64 bit VM: "Hardware Virtualization: Intel VT-x".

How come?

[Sander van Leeuwen]

Faghutz: VT-x support is not yet there for the Mac OS X version of VBox. We'll enable it in a future version. Might be the next maintenance release.

[faghutz]

Replying to sandervl73:

Faghutz: VT-x support is not yet there for the Mac OS X version of VBox. We'll enable it in a future version. Might be the next maintenance release.

Thanks for the reply. It seems a bit odd to me to claim 64-bit support while hiding the fact that it doesn't work for Mac OS X in a short sentence in chapter 13 in the manual. A note about this in the change log would have been expected.

But it's great news that it will be corrected in a future release. Let's hope for the next maintenance release then.

[Frank Mehnert]

You are absolutely right, this is a bug. Such an entry was just missed. I've added a not to our FAQ at ​http://www.virtualbox.org/wiki/User_FAQ

[Sander van Leeuwen]

Continue the AMD-V detection issues in defect #1933 please. Closing this one.