The buried lede in NEMESIS and FORESHADOW:

   For the “case of a fault or external interrupt, the processor executes
   an Asynchronous Enclave Exit (AEX) procedure that saves the execution
   context securely in a preallocated state save area inside the enclave,
   and replaces the CPU registers with a synthetic state to avoid di- rect
   information leakage to the untrusted ISR.”

   Seems. Odd.

   I dunno. Did anyone read x86 documentation?