Re: [Qemu-devel] Re: TCG flow vs dyngen

[Lluís]

Stefano Bonifazi writes:

> Hi!
> Thank you for answering me!

>> If I understand this correctly, the execution of one of your PPC cores
>> is oblivious of the others (they share no guest physical memory).
>>
> No! They do share the same address space.. the way I am loading the different
> qemu-ppc instances divides their namespaces allowing them to coexist, but they
> share the same address space anyway (that is the same of the caller process
> too), that is what I want for a communication.

Sure, but each core runs a separate (guest) process. It's not that they
are (guest) threads of the same (guest) application.


> The problem is that they are at the same time oblivious of the others and each
> of them wants to map its target binary at the same unique virtual address 
> (again
> see my last post about relocating target code)..

Right. The important point here is that each qemu core runs a separate
(guest) process.


> I tried successfully the way of IPC (interprocess communication) having a
> different qemu-ppc spawned by systemc as a process, then using shared memory 
> and
> signals for communicating.. pretty easy and well working, but the specs of my
> project (university) do not let me using IPC..

That sounds silly, but there's no way out if this is in the rules of the
project.


>> [1] http://sites.google.com/site/hplabscotson/
> Thank you, I am a student of digital electronics, with not big knowledge about
> developing in linux but this project is very interesting for my field.. some
> sort of alternative to systemc if I understand fine! Thanks surely I'll have a
> look at that!

Well, if you don't know about avilable simulators, there's a plethora of
them. From the top of my head, I can give you these other names:

* SESC
  http://sesc.sourceforge.net/
* M5
  http://www.m5sim.org/wiki/index.php/Main_Page
* GEMS
  http://www.cs.wisc.edu/gems/
* SimpleScalar
  http://www.simplescalar.com/
* Graphite
  http://groups.csail.mit.edu/carbon/?page_id=111


Lluis

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