Re: [Qemu-devel] Multi heterogenous CPU archs for SoC sim?

[Blue Swirl]

On Thu, May 26, 2011 at 11:07 PM, Lluís <address@hidden> wrote:
> Blue Swirl writes:
>
>> On Wed, May 25, 2011 at 10:20 PM, Peter Maydell
>> <address@hidden> wrote:
>>> On 25 May 2011 19:44, Greg McGary <address@hidden> wrote:
>>>> I would like to create a QEMU model of an SoC that has several
>>>> CPU cores having different architectures.  I'm guessing this
>>>> can be done.
>>>
>>> It's not supported currently as far as I'm aware. There was
>>> at least one paper at the QEMU Forum earlier this year describing
>>> an approach to multi-CPU environments (embedding QEMU into a
>>> SystemC world) that basically saved and restored all QEMU's
>>> global variables every time it switched cores...
>>>
>>> It would be good if it was supported in QEMU proper, but I
>>> suspect you may be in for some large-scale restructuring work.
>
>> One of the long standing goals for QEMU has been to be able to use a
>> single executable to emulate multiple architectures. I think for
>> example the lines like
>> #define cpu_init cpu_sparc_init
>> #define cpu_exec cpu_sparc_exec
>> etc. stand for this purpose, so there has been some consideration for this.
>
> Nicely handling per-arch functions would be one of the benefits of using
> C++ in QEMU (I know, it's sufficient but not necessary). What were the
> conclusions regarding such a change?

I don't think the discussions gave enough motivation for the change.
There's resistance to qdevification already and that is far from a
real object model.