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

[Artyom Tarasenko]

On Thu, Nov 6, 2014 at 11:05 PM, Damien Hilloulin
<address@hidden> wrote:
> Le 06/11/2014 19:23, Artyom Tarasenko a écrit :
>
>> On Thu, Nov 6, 2014 at 6:36 PM, Damien Hilloulin
>> <address@hidden> wrote:
>>>
>>> Le 06/11/2014 16:27, Artyom Tarasenko a écrit :
>>>>
>>>> Hello Damien,
>>>>
>>>> On Thu, Nov 6, 2014 at 8:38 AM, Damien Hilloulin
>>>> <address@hidden> 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


-- 
Regards,
Artyom Tarasenko

SPARC and PPC PReP under qemu blog: http://tyom.blogspot.com/search/label/qemu