Re: [PATCH v7 1/4] KVM: stats: Separate generic stats from architecture specific ones

Paolo Bonzini
2021-06-11T12:14:17Z

On 11/06/21 14:08, Christian Borntraeger wrote:
>>
>> I always interpreted it as "number of times the KVM page table
>> management code needed other CPUs to learn about new page tables".
>> Whether the broadcast is done in software or hardware shouldn't
>> matter; either way I suppose there is still some traffic on the bus
>> involved.
>
>
> My point is that KVM page table management on s390x completely
> piggy-backs on the qemu address space page table management from common
> code for the last level.
> And due to the way we handle page tables we also do not teach "other
> CPUs". We always teach the whole system with things like IPTE.

But that just means that you'll have fewer KVM-exclusive and thus nicer
numbers than x86 or ARM. :) It still makes sense to count
gmap_flush_tlb calls.

Paolo