Re: [PATCH] spapr/xive: Allocate IPIs from the vCPU contexts

[Cédric Le Goater]

On 8/16/20 6:30 AM, David Gibson wrote:
> On Fri, Aug 14, 2020 at 05:08:13PM +0200, Cédric Le Goater wrote:
>>
>> This works as expected with a 128 vCPUs guest with pinned vcpus. The
>> first 64 IPIs are allocated on the first chip and the remaining 64
>> on the second chip.
>>
>> Still, this is more an RFC. We have time before the end of the merge
>> window.
> 
> It looks reasonable to me.  AFAICT it makes things better than they
> were, and even if we can improve it further, that won't break
> migration or other interfaces we need to preserve.

Yeah. What I don't like is this test below. I am not sure that 
machine->smp.cpus is the correct way to test the number of currently
active vCPUs. 

>>> +    if (srcno < machine->smp.cpus) {
>>> +        return kvmppc_xive_reset_ipi(xive, srcno, errp);
>>> +    }
>>> +
>>>      if (xive_source_irq_is_lsi(xsrc, srcno)) {
>>>          state |= KVM_XIVE_LEVEL_SENSITIVE;
>>>          if (xsrc->status[srcno] & XIVE_STATUS_ASSERTED) {