Messages in this thread | | | From | Florian Weimer <> | Subject | Re: [PATCH RFC] mm: add MAP_EXCLUSIVE to create exclusive user mappings | Date | Mon, 28 Oct 2019 21:23:17 +0100 |
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* Mike Rapoport:
> On October 27, 2019 12:30:21 PM GMT+02:00, Florian Weimer > <fw@deneb.enyo.de> wrote: >>* Mike Rapoport: >> >>> The patch below aims to allow applications to create mappins that >>have >>> pages visible only to the owning process. Such mappings could be used >>to >>> store secrets so that these secrets are not visible neither to other >>> processes nor to the kernel. >> >>How is this expected to interact with CRIU? > > CRIU dumps the memory contents using a parasite code from inside the > dumpee address space, so it would work the same way as for the other > mappings. Of course, at the restore time the exclusive mapping should > be recreated with the appropriate flags.
Hmm, so it would use a bounce buffer to perform the extraction?
>>> I've only tested the basic functionality, the changes should be >>verified >>> against THP/migration/compaction. Yet, I'd appreciate early feedback. >> >>What are the expected semantics for VM migration? Should it fail? > > I don't quite follow. If qemu would use such mappings it would be able > to transfer them during live migration.
I was wondering if the special state is supposed to bubble up to the host eventually.
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