Re: [RFC PATCH 0/11] Rework gfn_to_pfn_cache

[Paolo Bonzini <pbonzini@redhat.com>]

On 11/15/21 20:11, David Woodhouse wrote:
>> Changing mn_memslots_update_rcuwait to a waitq (and renaming it to
>> mn_invalidate_waitq) is of course also a possibility.
> I suspect that's the answer.
> 
> I think the actual*invalidation*  of the cache still lives in the
> invalidate_range() callback where I have it at the moment. But making
> the req to the affected vCPUs can live in invalidate_range_start(). And
> then the code which*handles*  that req can wait for the
> mmu_notifier_count to reach zero before it proceeds. Atomic users of
> the cache (like the Xen event channel code) don't have to get involved
> with that.
> 
>> Also, for the small requests: since you are at it, can you add the code
>> in a new file under virt/kvm/?
>
> Hm... only if I can make hva_to_pfn() and probably a handful of other
> things non-static?

Yes, I think sooner or later we also want all pfn stuff in one file 
(together with MMU notifiers) and all hva stuff in another; so for now 
you can create virt/kvm/hva_to_pfn.h, or virt/kvm/mm.h, or whatever 
color of the bikeshed you prefer.

Paolo