Re: [PATCH v6 13/17] powerpc/pseries/vas: Setup IRQ and fault handling

[Nicholas Piggin <npiggin@gmail.com>]

Excerpts from Haren Myneni's message of June 18, 2021 12:09 pm:
> On Fri, 2021-06-18 at 09:34 +1000, Nicholas Piggin wrote:
>> Excerpts from Haren Myneni's message of June 18, 2021 6:37 am:
>> > NX generates an interrupt when sees a fault on the user space
>> > buffer and the hypervisor forwards that interrupt to OS. Then
>> > the kernel handles the interrupt by issuing H_GET_NX_FAULT hcall
>> > to retrieve the fault CRB information.
>> > 
>> > This patch also adds changes to setup and free IRQ per each
>> > window and also handles the fault by updating the CSB.
>> 
>> In as much as this pretty well corresponds to the PowerNV code
>> AFAIKS,
>> it looks okay to me.
>> 
>> Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
>> 
>> Could you have an irq handler in your ops vector and have 
>> the core code set up the irq and call your handler, so the Linux irq
>> handling is in one place? Not something for this series, I was just
>> wondering.
> 
> Not possible to have common core code for IRQ  setup. 
> 
> PowerNV: Every VAS instance will be having IRQ and this setup will be
> done during initialization (system boot). A fault FIFO will be assigned
> for each instance and registered to VAS so that VAS/NX writes fault CRB
> into this FIFO.  
> 
> PowerVM: Each window will have an IRQ and the setup will be done during
> window open. 

Yeah, I thought as much. Just wondering.

Thanks,
Nick