[Qemu-devel] Re: TCG flow vs dyngen

[Stefano Bonifazi <stefboombastic@gmail.com>]

On 01/16/2011 08:24 PM, Peter Maydell wrote:
> 2011/1/16 Stefano Bonifazi<stefboombastic@gmail.com>:
>> I need to make the different instances of qemu-user exchange data ..
>> obviously keeping all of them in the same address space would be the easiest
>> way (unless I have to change all qemu code ;) )
>
> The problem is that you're trying to break a fundamental
> assumption made by a lot of qemu code. That's a large
> job which involves understanding, checking and possibly
> changing lots of already written code. In contrast, the
> code you need to exchange data between the instances is
> going to be fairly small and self contained and you'll already
> understand it because you've written it/will write it. I think
> it's pretty clear which one is going to be easier.
>
>>> Running each qemu as its own
>>> process and using interprocess communication for whatever
>>> coordination you need between the various instances seems
>>> more likely to be workable to me.
>
>> Exactly, it was the easiest way also for me.. and I've already done it,
>> works smoothly .. the only big problem is that it is not good for my
>> teacher.. he says it should work the dynamic library way o.O
>
> I think he's wrong. (You might like to think about what happens
> if the program being emulated in qemu user-mode does a fork()).
>
> Basically you're trying to do things the hard way; maybe
> you can get something that sort of works in the subset of
> cases you care about, but why on earth put in that much
> time and effort on something irrelevant to the actual problem
> you're trying to work on?
>
> -- PMM
>
>
Well my teacher's answer was that it is useless doing that, as there are 
already plenty of solutions based on IPC .. they are interested in this 
other approach, testing it .. They are not interested on how difficult 
it can be for a student, how long it can take.. :(
Best regards,
Stefano B.