Re: [PATCH v7 04/11] KVM: pfncache: base offset check on khva rather than gpa

[Sean Christopherson]

On Mon, Oct 02, 2023, Paul Durrant wrote:
> From: Paul Durrant <pdurrant@xxxxxxxxxx>
> 
> After a subsequent patch, the gpa may not always be set whereas khva will
> (as long as the cache valid flag is also set).

This holds true only because there are no users of KVM_GUEST_USES_PFN, and
because hva_to_pfn_retry() rather oddly adds the offset to a NULL khva.

I think it's time to admit using this to map PFNs into the guest is a bad idea
and rip out KVM_GUEST_USES_PFN before fully relying on khva.

https://lore.kernel.org/all/ZQiR8IpqOZrOpzHC@xxxxxxxxxx