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

[Alexey Kardashevskiy]

On 06/11/2014 04:09 AM, Alexander Graf wrote:
> On 06/10/2014 06:29 PM, Paolo Bonzini wrote:
>> Il 10/06/2014 16:48, Luiz Capitulino ha scritto:
>>> > The s390 restart interrupt is a per-vcpu interrupt, which we really
>>> > don't want to inject on _all_ vcpus. OTOH, we want to inject that
>>> > interrupt on any vcpu - we don't care which one it is. So I'd really
>>> > like an "inject nmi on default cpu" option.
>>>
>>> We could define a default CPU for the command. What isn't going to work
>>> is to use the human monitor's "current CPU" concept (set with the cpu
>>> command).
>>
>> It isn't going to work, but to me it seems like a bug.  Why was the NMI
>> command even converted to QAPI if it cannot work?  Let's just use
>> monitor_set_cpu from qmp_cpu and call it a day.
>>
>> The amount of churn that Alexey is going through for this feature is
>> unreasonable.
> 
> 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).


Ufff... A button? Any good existing example? A device like hw/input/ps2.c?
And HMP's do_mouse_button()? There are queues, I'll need to fight against
them...


> 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.



-- 
Alexey