Re: [PATCH v5 04/13] KVM: Introduce a new guest mapping API

From: Raslan, KarimAllah
Date: Fri Jan 25 2019 - 13:09:41 EST


On Wed, 2019-01-23 at 12:50 -0500, Konrad Rzeszutek Wilk wrote:
> >
> > + if (dirty)
> > + kvm_release_pfn_dirty(map->pfn);
> > + else
> > + kvm_release_pfn_clean(map->pfn);
> > + map->hva = NULL;
>
> I keep on having this gnawing feeling that we MUST set map->page to
> NULL.
>
> That is I can see how it is not needed if you are using 'map' and
> 'unmap' together - for that we are good. But what I am worried is that
> some one unmaps it .. and instead of checking map->hva they end up
> checking map->page and think the page is mapped.
>
> Would you be OK adding that extra statement just as a fail-safe
> mechanism in case someones misues the APIs?

Good point, will do.



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