Messages in this thread | | | Subject | Re: [PATCH v3 0/5] x86: Show in sysfs if a memory node is able to do encryption | From | Dave Hansen <> | Date | Tue, 7 Dec 2021 12:13:49 -0800 |
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On 12/7/21 12:06 PM, Mike Rapoport wrote: >> An ABI that says "everything is encrypted" is pretty meaningless and >> only useful for this one, special case. >> >> A per-node ABI is useful for this case and is also useful going forward >> if folks want to target allocations from applications to NUMA nodes >> which have encryption capabilities. The ABI in this set is useful for >> the immediate case and is useful to other folks. > I don't mind per-node ABI, I'm just concerned that having a small region > without the encryption flag set will render the entire node "not > encryptable". This may happen because a bug in firmware, a user that shoot > themself in a leg with weird memmap= or some hidden gem in interaction > between e820, EFI and memblock that we still didn't discover.
That's a good point. But, that seems more in the realm of a pr_{info,warn}_once() than something deserving of its own specific ABI.
If we have a 100GB of a node that supports encryption, and 4k that causes the whole thing to be considered un-encryptable, a warning is be appropriate and feasible.
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