[jason@sun ~]$: The Solaris junkie finds a home

It seems that VirtualBox does not yet support 64 bit guests on a Mac OS X host.  This is a bit of a drag because I have 64 bit Vista, and would love to run Solaris 10 and OpenSolaris in 64 bit mode.  (Both will perform better in 64 bit mode, or so I have read.  Solaris Internals is still on my to-read stack...)

In VirtualBox for Mac hosts, both v1.6.6 and v2.0.0, there is an option to enable VT-x/AMD-V. 

VT-x is Intel's hardware virtualization support.  In this case, VT stands for 'Virtualization Technology'.  It used to stand for 'Vanderpool Technology', but it looks like it's been re-branded.  I support this since the new brand name makes sense; there's no need to look it up on Wikipedia. 

AMD-V is AMD's hardware virtualization support.

VT-x is required for running 64-bit guests.  You can't use software virtualization to run 64-bit guests (see User Manual, p. 15).

Anyway, enabling VT-x for a guest on a Mac host does not work as expected.

From the VM:

bash-3.00# isainfo -v
32-bit i386 applications
        sse2 sse fxsr mmx cmov cx8 tsc fpu

No dice.  But there's hope.  There's talk in the VirtualBox forums that VT-x support for Mac hosts is being worked.

UPDATE:  This is what I get for not RTFM.  From VirtualBox v2.0.0 User Manual, p. 177 (emphasis and formatting mine):

• Mac OS X host. The following restrictions apply (all of which will be resolved in future versions):
• No support for audio input
• No support for VT-x/AMD-V (rarely required)
• The numlock emulation isn’t implemented yet
• No support for connecting a virtual serial port to a physical serial port on the host
• No ACPI information (battery status, power source) is reported to the guest
• The CPU frequency metric is not supported

I wonder why the documenters thought VT-x support is 'rarely required' for Mac hosts.  Oh well, I know what I'll be keeping an eye out for...