...
Notes
Spectre V1 has been demonstrated to bypass protections provided by Intel SGX. Intel has updated the SGX SDK to mitigate these vulnerabilities when the SGX enclaves are rebuilt.
https://software.intel.com/sites/default/files/managed/e1/ec/SGX_SDK_Developer_Guidance-CVE-2017-5753.pdf
Spectre V1 has also been demonstrated to access protections provided by the System Management Range Register (SMRR) to access protected System Management Mode (SMM) memory.
https://blog.eclypsium.com/2018/05/17/system-management-mode-speculative-execution-attacks/