On Wed, 2020-05-06 at 09:39 -0700, Jordan Hand wrote: > On 4/21/20 2:52 PM, Jarkko Sakkinen wrote: > > Intel(R) SGX is a set of CPU instructions that can be used by applications > > to set aside private regions of code and data. The code outside the enclave > > is disallowed to access the memory inside the enclave by the CPU access > > control. > > > > There is a new hardware unit in the processor called Memory Encryption > > Engine (MEE) starting from the Skylake microacrhitecture. BIOS can define > > one or many MEE regions that can hold enclave data by configuring them with > > PRMRR registers. > > > > The MEE automatically encrypts the data leaving the processor package to > > the MEE regions. The data is encrypted using a random key whose life-time > > is exactly one power cycle. > > > > The current implementation requires that the firmware sets > > IA32_SGXLEPUBKEYHASH* MSRs as writable so that ultimately the kernel can > > decide what enclaves it wants run. The implementation does not create > > any bottlenecks to support read-only MSRs later on. > > > > You can tell if your CPU supports SGX by looking into /proc/cpuinfo: > > > > cat /proc/cpuinfo | grep sgx > > > > v29: > > * The selftest has been moved to selftests/sgx. Because SGX is an execution > > environment of its own, it really isn't a great fit with more "standard" > > x86 tests. > > > > The RSA key is now generated on fly and the whole signing process has > > been made as part of the enclave loader instead of signing the enclave > > during the compilation time. > > > > Finally, the enclave loader loads now the test enclave directly from its > > ELF file, which means that ELF file does not need to be coverted as raw > > binary during the build process. > > * Version the mm_list instead of using on synchronize_mm() when adding new > > entries. We hold the write lock for the mm_struct, and dup_mm() can thus > > deadlock with the page reclaimer, which could hold the lock for the old > > mm_struct. > > * Disallow mmap(PROT_NONE) from /dev/sgx. Any mapping (e.g. anonymous) can > > be used to reserve the address range. Now /dev/sgx supports only opaque > > mappings to the (initialized) enclave data. > > * Make the vDSO callable directly from C by preserving RBX and taking leaf > > from RCX. > > > > Tested with the Open Enclave SDK on top of Intel PSW. Specifically built > the Intel PSW with changes to support /dev/sgx mapping[1] new in v29. > > Tested-by: Jordan Hand <jorhand@xxxxxxxxxxxxxxxxxxx> > > [1] https://github.com/intel/linux-sgx/pull/530 Thank you! /Jarkko
