Just checking Wikipedia https://en.wikipedia.org/wiki/Software_Guard_Extensions#cite_note-14 we see that
a) There was a Prime+Probe attack which used "certain CPU instructions in lieu of a fine-grained timer to exploit cache DRAM side-channels" and a coutermeasure was published
b) The LSDS group at Imperial College London showed a proof of concept that the Spectre speculative execution security vulnerability can be adapted to attack the secure enclave and the code is dated 2 months ago.
I wonder if the "compiler-based tool, DR.SGX" which was a coutermeasure for Prime+Probe could be extended to handle Spectre?