Re: [Qemu-devel] [Bug 596106] Re: kvm to emulate 64 bit cpu on 32 bit host

[Natalia Portillo]

Paolo said:
> They do it like TCG does it, not like KVM.

You are wrong, and it's easy to check as the speed is almost native.
Having emulation would make it slow as hell.

Jamie said:
> 
>>   VirtualPC is unable to run 64 bit guests at all even on 64 bit
>>   hosts
> 
> Are you sure?  Microsoft provides numerous downloadable 64-bit guest
> Windows images, and VirtualPC is Microsoft's; they must be running on
> something.
> 

That may be in Windows Virtual PC (that requires VT and Windows 7 
Ultimate/Professional, and is a feature of that OSes not a separate product) or 
Hyper-V (again, requires VT and is a feature of Windows 2008 Server), but not 
on the standalone Microsoft Virtual PC 2007.


It is fully possible to run 64-bit code in a 32-bit kernel, Mac OS X Leopard 
does that all the way without problems, and VMWare found how to do the trick 
with the NT kernel.

The question is not "is it possible to make KVM run 64-bit code in a 32-bit 
kernel?" (it is), the question is, "the people in charge of KVM want to add 
this feature?".

Personally I don't believe so, neither I am on the "do it" side, I'm just 
saying it is technically possible.

Natalia Portillo