Messages in this thread | | | Date | Fri, 28 Jul 2023 12:44:37 -0700 | From | Dan Williams <> | Subject | Re: [PATCH 0/4] keys: Introduce a keys frontend for attestation reports |
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Jarkko Sakkinen wrote: > On Fri Jul 28, 2023 at 7:30 PM UTC, Dan Williams wrote: > > The bulk of the justification for this patch kit is in "[PATCH 1/4] > > /patch kit/patch set/ > > > keys: Introduce tsm keys". The short summary is that the current > > approach of adding new char devs and new ioctls, for what amounts to the > > same functionality with minor formatting differences across vendors, is > > untenable. Common concepts and the community benefit from common > > infrastructure. > > > > Use Keys to build common infrastructure for confidential computing > > /Keys/Linux keyring/ > > > attestation report blobs, convert sevguest to use it (leaving the > > deprecation question alone for now), and pave the way for tdx-guest and > > the eventual risc-v equivalent to use it in lieu of new ioctls. > > > > The sevguest conversion is only compile-tested. > > > > This submission is To:David since he needs to sign-off on the idea of a > > new Keys type, the rest is up to the confidential-computing driver > > maintainers to adopt. > > > > Changes from / credit for internal review: > > - highlight copy_{to,from}_sockptr() as a common way to mix > > copy_user() and memcpy() paths (Andy) > > - add MODULE_DESCRIPTION() (Andy) > > - clarify how the user-defined portion blob might be used (Elena) > > - clarify the key instantiation options (Sathya) > > - drop usage of a list for registering providers (Sathya) > > - drop list.h include from tsm.h (Andy) > > - add a comment for how TSM_DATA_MAX was derived (Andy) > > - stop open coding kmemdup_nul() (Andy) > > - add types.h to tsm.h (Andy) > > - fix punctuation in comment (Andy) > > - reorder security/keys/Makefile (Andy) > > - add some missing includes to tsm.c (Andy) > > - undo an 81 column clang-format line break (Andy) > > - manually reflow tsm_token indentation (Andy) > > - move allocations after input validation in tsm_instantiate() (Andy) > > - switch to bin2hex() in tsm_read() (Andy) > > - move init/exit declarations next to their functions (Andy) > > > > > > --- > > > > Dan Williams (4): > > keys: Introduce tsm keys > > virt: sevguest: Prep for kernel internal {get,get_ext}_report() > > mm/slab: Add __free() support for kvfree > > virt: sevguest: Add TSM key support for SNP_{GET,GET_EXT}_REPORT > > > > > > drivers/virt/coco/sev-guest/Kconfig | 2 > > drivers/virt/coco/sev-guest/sev-guest.c | 135 ++++++++++++++- > > include/keys/tsm.h | 71 ++++++++ > > include/linux/slab.h | 2 > > security/keys/Kconfig | 12 + > > security/keys/Makefile | 1 > > security/keys/tsm.c | 282 +++++++++++++++++++++++++++++++ > > 7 files changed, 494 insertions(+), 11 deletions(-) > > create mode 100644 include/keys/tsm.h > > create mode 100644 security/keys/tsm.c > > > > base-commit: 06c2afb862f9da8dc5efa4b6076a0e48c3fbaaa5 > > So how does this scale? Does it scale to TDX, SGX, TPM's or even TEE's > (ARM SM, RISC-V Keystone etc.). I'm not sure about the scope but we want > of course something that adapts to multiple use cases, right?
TPMs and TEEs are covered by trusted-keys. I do think a "TSM" flavor of trusted-keys is in scope for where some of these implementations are headed, but that comes later. I talk about that in the changelog that functionality like SNP_GET_DERIVED_KEY likely wants to have a trusted-keys frontend and not isolated behind a vendor-specific ioctl interface.
This facility is different, it is just aiming to unify this attestation report flow. It scales to any driver that can provide the ->auth_new() operation. I have the sev-guest conversion in this set, and Sathya has tested this with tdx-guest. I am hoping Samuel can evaluate it for cove-guest or whatever that driver ends up being called.
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