On 31 October 2021 06:52:33 GMT, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote: >On 30/10/21 09:58, David Woodhouse wrote: >>> Absolutely! The fixed version of kvm_map_gfn should not do any >>> map/unmap, it should do it eagerly on MMU notifier operations. >> Staring at this some more... what*currently* protects a >> gfn_to_pfn_cache when the page tables change — either because userspace >> either mmaps something else over the same HVA, or the underlying page >> is just swapped out and restored? > >kvm_cache_gfn_to_pfn calls gfn_to_pfn_memslot, which pins the page. It pins the underlying page but that doesn't guarantee that the page remains mapped at the HVA corresponding to that GFN, does it? And I though the whole point of the repeated map/unmap was *not* to pin the page, anyway? -- Sent from my Android device with K-9 Mail. Please excuse my brevity.
