Show for each node if every memory descriptor in that node has the EFI_MEMORY_CPU_CRYPTO attribute. fwupd project plans to use it as part of a check to see if the users have properly configured memory hardware encryption capabilities. fwupd's people have seen cases where it seems like there is memory encryption because all the hardware is capable of doing it, but on a closer look there is not, either because of system firmware or because some component requires updating to enable the feature. It's planned to make it part of a specification that can be passed to people purchasing hardware These checks will run at every boot. The specification is called Host Security ID: https://fwupd.github.io/libfwupdplugin/hsi.html. We choosed to do it a per-node basis because although an ABI that shows that the whole system memory is capable of encryption would be useful for the fwupd use case, doing it in a per-node basis gives also the capability to the user to target allocations from applications to NUMA nodes which have encryption capabilities. I did some tests for some of the functions introduced (and modified) in e820.c. Sadly KUnit is not able to test __init functions and data so I had some warnings during the linking. There is a KUnit patch already to fix that [1]. I wanted to wait for it to be merged but it is taking more time than I expected so I'm sending this without tests for now. I'm planning to add unit tests in the future to the e820 range update rework and e820_update_table. [1] https://lore.kernel.org/lkml/20220419040515.43693-1-brendanhiggins@xxxxxxxxxx/T/ Changes since v7: Less kerneldocs Less verbosity in the e820 code Changes since v6: Fixes in __e820__handle_range_update Const correctness in e820.c Correct alignment in memblock.h Rework memblock_overlaps_region Changes since v5: Refactor e820__range_{update, remove, set_crypto_capable} in order to avoid code duplication. Warn the user when a node has both encryptable and non-encryptable regions. Check that e820_table has enough size to store both current e820_table and EFI memmap. Changes since v4: Add enum to represent the cryptographic capabilities in e820: e820_crypto_capabilities. Revert __e820__range_update, only adding the new argument for __e820__range_add about crypto capabilities. Add a function __e820__range_update_crypto similar to __e820__range_update but to only update this new field. Changes since v3: Update date in Doc/ABI file. More information about the fwupd usecase and the rationale behind doing it in a per-NUMA-node. Changes since v2: e820__range_mark_crypto -> e820__range_mark_crypto_capable. In e820__range_remove: Create a region with crypto capabilities instead of creating one without it and then mark it. Changes since v1: Modify __e820__range_update to update the crypto capabilities of a range; now this function will change the crypto capability of a range if it's called with the same old_type and new_type. Rework efi_mark_e820_regions_as_crypto_capable based on this. Update do_add_efi_memmap to mark the regions as it creates them. Change the type of crypto_capable in e820_entry from bool to u8. Fix e820__update_table changes. Remove memblock_add_crypto_capable. Now you have to add the region and mark it then. Better place for crypto_capable in pglist_data. Martin Fernandez (8): mm/memblock: Tag memblocks with crypto capabilities mm/mmzone: Tag pg_data_t with crypto capabilities x86/e820: Add infrastructure to refactor e820__range_{update,remove} x86/e820: Refactor __e820__range_update x86/e820: Refactor e820__range_remove x86/e820: Tag e820_entry with crypto capabilities x86/efi: Mark e820_entries as crypto capable from EFI memmap drivers/node: Show in sysfs node's crypto capabilities Documentation/ABI/testing/sysfs-devices-node | 10 + arch/x86/include/asm/e820/api.h | 1 + arch/x86/include/asm/e820/types.h | 12 +- arch/x86/kernel/e820.c | 388 ++++++++++++++----- arch/x86/platform/efi/efi.c | 37 ++ drivers/base/node.c | 10 + include/linux/memblock.h | 5 + include/linux/mmzone.h | 3 + mm/memblock.c | 62 +++ mm/page_alloc.c | 1 + 10 files changed, 431 insertions(+), 98 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-devices-node -- 2.30.2
