Enhance the SGX_IOC_ENCLAVE_ADD_PAGE{S} ioctl so that userspace can add
multiple pages to an enclave in a single syscall. Also provide a flag
that allows replicating a single source page to multiple target pages so
that userspace doesn't need to allocate a giant chunk of memory when
initializing things like the enlave's .bss, heap, etc...
People that actually develop runtimes, please weigh in. Jarkko also
suggested going with a fully flexible ioctl, e.g. essentially creating an
array of the existing struct so that mrmask and/or secinfo can be unique
per page. AFAICT that's overkill and more cumbersome to use as it forces
userspace to allocate the full array. My understanding is that the
majority of enclaves will have contiguous blocks of pages with identical
mrmask and secinfo, e.g. code segments, ro data, etc..., thus the less
flexible but easier-in-theory to use approach proposed here.
Sean Christopherson (7):
x86/sgx: Modify ADD_PAGE ioctl to take offset instead of full address
selftests/x86/sgx: Update test to account for ADD_PAGE change
x86/sgx: Tweak ADD_PAGE ioctl to allow adding multiple pages
selftests/x86/sgx: Update enclave build flow to do multi-page add
x86/sgx: Add a flag to ADD_PAGES to allow replicating the source page
selftests/x86/sgx: Update selftest to account for ADD_PAGES flag
selftests/x86/sgx: Add test coverage for reclaim and replicate
arch/x86/include/uapi/asm/sgx.h | 25 +++++---
arch/x86/kernel/cpu/sgx/ioctl.c | 77 +++++++++++++++++------
tools/testing/selftests/x86/sgx/defines.h | 28 +++++++++
tools/testing/selftests/x86/sgx/main.c | 40 ++++++------
tools/testing/selftests/x86/sgx/sgxsign.c | 20 +++++-
5 files changed, 140 insertions(+), 50 deletions(-)
--
2.22.0
