Re: [Qemu-devel] [PATCH v3 1/4] cpus: Define NMI callback

[Alexander Graf <agraf@suse.de>]

On 11.06.14 06:59, Paolo Bonzini wrote:
> Il 11/06/2014 02:28, Alexander Graf ha scritto:
>>
>>
>>> Am 11.06.2014 um 02:23 schrieb Peter Maydell 
>>> <peter.maydell@linaro.org>:
>>>
>>>> On 10 June 2014 19:09, Alexander Graf <agraf@suse.de> wrote:
>>>> I agree. I see two different paths forward:
>>>>
>>>>  1) Use the patches as they are - they seem pretty sound and take the
>>>> existing x86/s390 only feature to spapr
>>>>  2) Model an "NMI" button. That button would get instantiated by the
>>>> machine model. That would allow the wiring to be defined by the board.
>>>> Monitor / QMP would only "press" that button (trigger an edge 
>>>> interrupt?
>>>> call a function? something).
>>>>
>>>>
>>>> I don't mind much either way - option 2 is the architecturally 
>>>> correct way
>>>> of doing this. Option 1 probably won't hurt us either.
>>>
>>> In an ideal world I'd like (2), ie actually model front panel switches
>>> per machine and with whatever the machine's behaviour actually
>>> is. However pragmatically speaking that's an awful lot of work
>>> (especially since it basically requires adding a lot of U/I which is
>>> always controversial and hard to drive through). I think pragmatism
>>> should probably win here.
>>
>> Could we just stick a new nmi function callback into the machine 
>> class with the nmi command calling it?
>>
>> That gets us on the right track to the right direction without 
>> putting too much work on Alexey's shoulders. Converting from there to 
>> an actual button object should become reasonably straight forward later.
>
> Personally, I don't see anything wrong in these patches, apart from 
> the typo that Cornelia pointed out.

If you wanted to inject an NMI on non-sPAPR machines, such as -M mac99 
or -M g3beige you would have to trigger an interrupt with the MPIC, not 
the CPU itself.


Alex