* Mike Rapoport: > On October 27, 2019 12:30:21 PM GMT+02:00, Florian Weimer > <fw@xxxxxxxxxxxxx> 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.
