[cap-talk] Virtualizability vs. Synergy

[Norman Hardy]

On Jul 12, 2006, at 6:38 PM, Jed at Webstart wrote:

> At 03:58 PM 7/12/2006, David Hopwood wrote:
>> Norman Hardy wrote:
>>> On Jul 12, 2006, at 11:46 AM, Eric Jacobs wrote:
>>>> David Hopwood <david.nospam.hopwood at blueyonder.co.uk> wrote:
>>>>
>>>>> # In each synergy pattern I rely on some other object that I did
>>>>> # not get from you to tell me whether I can safely use P. I pass P
>>>>> # to it and it replies yes or no.
>>>>
>>>> I don't really understand what the conflict between that and full
>>>> virtualizability is. The very definition of full virtualization  
>>>> in a
>>>> capability system would be that there are no "other objects"  
>>>> that come
>>>> from outside the virtualizing host, I'd think.
>>>
>>> David was quoting from my page at
>> <http://cap-lore.com/CapTheory/Patterns/CapParam.html>.
>>> By "full virtualizability" I meant that any old program that holds a
>>> capability X, is in a position to unilaterally virtualize X (and  
>>> only
>>> X) without coordination with anyone else.
>>> This is in marked contrast to virtual machines where most or at  
>>> least
>>> much of the system must be virtualized and then only the privileged
>>> code (in everyone's TCB is capable of virtualizing.
>>> Does this clarify my comments?
>>
>> It may be clearer to use a different term than "virtualize" here.
>>
>> At <http://www.cap-lore.com/CapTheory/KK/m/211.html>, "synthesize" is
>> used with this meaning -- i.e. a kernel abstraction can be  
>> "synthesizable",
>> and the resulting object is "synthetic". I prefer this terminology.
>
> I'd like to add my support to the above.  I believe the terms  
> "virtualize"
> and "virtual machine" are used way too often and in many different
> and therefore potentially confusing situations.  Just for example,  
> there is:

I agree and I changed the wording at <http://cap-lore.com/CapTheory/ 
Patterns/Synthetic.html>.