[vbox-dev] 64-bit guest on 64-bit host

Nikolay Igotti Nikolay.Igotti at Sun.COM
Tue Oct 27 17:08:24 GMT 2009


You don't have to hide code to have functional VMM, for example VBox 
patch code is visible to the guest, it's just being relocated if guest 
tries to use particular patch address.
And unfortunately Intel marketing decided to keep low end Core 2 Duo 
(such as mine E7400) without VT-x, so for some hardware it still makes 
sense, just pretty hard to do. Also, IIRC, VMWare can run 64-bit OSes in 
pure software mode.


Tom Birch пишет:
> I believe there was a paper by some vmware guys about this, but
> basically AMD64 doesn't support segment limits so there's no efficient
> way run the VMM inside the guest OS and still keep it hidden. It's an
> issue with the actual hardware, not VirtualBox - I don't know of any
> VMM today that supports 64bit guests without Intel-VT/AMD-V. This blog
> post summarizes it fairly well: http://www.pagetable.com/?p=25
> Except for a couple of CPU models at the start, almost every
> 64bit-capable x86 chip also has VT so it's not really worth trying to do it.
> Tom
> On Tue, Oct 27, 2009 at 8:35 AM,  <jakub007 at aster.pl> wrote:
>> Hello,
>> Why VirtualBox currently doesn't support running 64-bit guest OS on 64-bit
>> host on CPUs without Intel-VT/AMD-V?
>> What should be done to implement it and how big effort would it take to
>> complete? I've got some experience
>> in C/C++ and Unices and free weekends...
>> Regards,
>> Jakub Jozwicki
>> ________________________________
>> Wiadomość wysłana z ASTER - http://www.aster.pl/
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