64 bit guests on 32 bit vista host don't work

[w3seek]

I attempted to install two different 64 bit guests on my 32 bit vista running on a x86-64 bit capable core2duo CPU in VBox 2.1.2:

Debian lenny 64 bit: As soon as I boot from the ISO, I see that the CD is read for a couple of seconds and then the guest just hangs. The screen remains black without any text. Host+Del doesn't work.

Windows 7 Beta 64 bit: As soon as it boots from the ISO image, the VirtualBox.exe process crashes.

Any ideas what could be wrong?

[Karl Viklund]

Well. Instead of filing a "Bug" report wasting peoples time. First make a post in the forums. Anyway. Have you tried any of this, taken from the Manual:

1.6 64-bit guests

Starting with Version 2.0, VirtualBox also supports 64-bit guest operating systems. Starting with Version 2.1, you can even run 64-bit guests on a 32-bit host operating system, so long as you have sufficient hardware. In detail, 64-bit guests are supported under the following conditions:

1. You need a 64-bit processor with hardware virtualization support (see chapter

1.2, Software vs. hardware virtualization (VT-x and AMD-V), page 10).

2. You must enable hardware virtualization for the particular VM for which you

want 64-bit support; software virtualization is not supported for 64-bit VMs.

Note: On most systems, the hardware virtualization features first need to be enabled in the BIOS before VirtualBox can use them.

3. If you want to use 64-bit guest support on a 32-bit host operating system, you

must also select a 64-bit operating system for the particular VM. Since supporting 64 bits on 32-bit hosts incurs additional overhead, VirtualBox only enables this support upon explicit request. On 64-bit hosts, 64-bit guest support is always enabled, so you can simply install a 64-bit operating system in the guest.

Warning: On any host, you should enable the I/O APIC for virtual machines that you intend to use in 64-bit mode. This is especially true for 64-bit Windows VMs. See chapter 3.7.1.2, “Advanced” tab, page 46. In addition, for 64-bit Windows guests, you should make sure that the VM uses the Intel networking device, since there is no 64-bit driver support for the AMD PCnet card; see chapter 6.1, Virtual networking hardware, page 77.

Read the manual here: ​http://download.virtualbox.org/virtualbox/2.1.2/UserManual.pdf

[w3seek]

VT-X is definitely turned on in the VM's settings. However, I pressed F12 during boot and peeked into the session information dialog, and it says VT-x is disabled. As far as I recall Vbox had a global setting to enable/disable VT-x in an earlier version, and I had it disabled there because of the BSOD bug after waking up the host from standby why VMs were running. Now I suspect that VT-x is still globally disabled, but I can't enable it because the setting no longer exists in the global preferences dialog.

[w3seek]

OK, turns out that VT-x was disabled in the BIOS for some reason. It would be nice if VBox could warn the user that VT-x could not be enabled for 64 bit guests if it is running on a 32 bit host.

[Frank Mehnert]

w3seek, please attach the VBox.log file of such a VM session. And no, VT-x is not globally disabled. The VT-x setting is per-VM only (in the current release).

[Frank Mehnert]

Oh, didn't read your last comment. So this works now?

[w3seek]

Yes it's working now. Apparently VT-x got disabled in the BIOS due to a bad battery on the motherboard. I would've expected VBox to warn me if my CPU supports VT-x but it cannot enable it. Or if that's not possible, then at least don't allow me to start a 64 bit guest on a 32 bit host resulting in a crash.

[Karl Viklund]

A happy ending after all.

[Sander van Leeuwen]

We'll include a warning in the next version. Closing this one.