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

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

Le 07/11/2014 09:05, Artyom Tarasenko a écrit :
> On Thu, Nov 6, 2014 at 11:05 PM, Damien Hilloulin
> <damien.hilloulin@epfl.ch> wrote:
>> 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)?
> http://people.freebsd.org/~jake/docs/802-7220-02.pdf
>
> The cross-calls are described in chapter 7.12.
>
> The interrupt processing of the Ultrasparc IIi CPUs is described here:
>
> http://people.freebsd.org/~jake/docs/805-0087.pdf
>
> The other documents from http://people.freebsd.org/~jake/docs/ may be
> helpful as well.
>
> Artyom
>
>
Thanks a lot for your help!
I will look at that!

Damien.