Re: [Qemu-devel] Adding SMP support for Sparc Target

[Damien Hilloulin <damien.hilloulin@epfl.ch>]

Le 06/11/2014 19:23, Artyom Tarasenko a écrit :
> On Thu, Nov 6, 2014 at 6:36 PM, Damien Hilloulin
> <damien.hilloulin@epfl.ch> wrote:
>> Le 06/11/2014 16:27, Artyom Tarasenko a écrit :
>>> Hello Damien,
>>>
>>> On Thu, Nov 6, 2014 at 8:38 AM, Damien Hilloulin
>>> <damien.hilloulin@epfl.ch> wrote:
>>>> Hello everyone,
>>>>
>>>> I'm a newcomer in QEMU and my goal would be to port an existing system
>>>> simulator using another emulator to QEMU.
>>>> Some work has already been done, and Sparc has been the main target so
>>>> far
>>>> because of its simplicity (and because we have a very good support for
>>>> Sparc
>>>> with the other emulator).
>>>> QEMU is great, open-source (contrary to the other emulator we have been
>>>> using in the past), and that's why we are aiming at using it.
>>>>
>>>> However, it seems that the Sparc targets doesn't really support SMP/CMT
>>>> as
>>>> of now. So I am considering two possibilities:
>>>> - adding SMP support in QEMU for the Sparc targets (and contribute it to
>>>> QEMU :) )
>>> Do you mean a) emulating multiple guest cores on in a single host
>>> thread, or b) emulating multiple guest cores in multiple host threads?
>> a) Would be enough for us (but b) would be amazing) !
>>> The former (a) should be relative easy for a sun4m platform: just have
>>> to put the CPUs at the proper place in the system bus and fill the CPU
>>> Module Ids (MIDs) with the proper data.
>> Could you please explain it with some more details? I don't really know how
>> to do that (yet)...
>> We are really interested in such a support for Sparc64, so I think that it
>> would be for sun4u machines only.
>> Would the changes would be the same or would there be more work?
> Taking into account the overall status of sun4u emulation, it is a bit
> more work.
> AFAIR the SMP-related registers of Ultrasparc CPUs/chipsets are not implemented.
> Additionally there are currently no sun4u SMP boards emulated in QEMU,
> but I think this is a smaller issue.
>
> Also some support in OpenBIOS might be necessary. Mark can surely tell more.
>
> Artyom
>
Ok... Quite bad that's not as easy than for Sparc32, but I think that's 
still better for us than focusing on ARM direclty.
Would someone have a little bit of documentation about those topics 
(specific registers/interrupts/bios)?
Any help is welcome!

Damien.