On 12/17/18 11:55 AM, Andy Lutomirski wrote:
>> You're effectively rebuilding reverse-mapping infrastructure here. It's
>> a frequent thing for the core VM to need to go from 'struct page' back
>> to the page tables mapping it. For that we go (logically)
>> page->{anon_vma,mapping}->vma->vm_mm->pagetable.
> This is a bit outside my expertise here, but doesn't
> unmap_mapping_range() do exactly what SGX wants?
There's no 'struct page' for enclave memory as it stands. That means no
page cache, and that means there's no 'struct address_space *mapping' in
the first place.
Basically, the choice was made a long time ago to have SGX's memory
management live outside the core VM. I've waffled back and forth on it,
but I do still think this is the right way to do it.
