On Mon, Nov 19, 2018 at 07:29:36AM -0800, Andy Lutomirski wrote: > 1. The kernel needs some way to know *when* to apply this fixup. > Decoding the instruction stream and doing it to all exceptions that > hit an ENCLU instruction seems like a poor design. I'm not sure why you would ever need to do any type of fixup as the idea is to just return to AEP i.e. from chosen exceptions (EPCM, #UD) the AEP would work the same way as for exceptions that the kernel can deal with except filling the exception information to registers. > 2. It starts exposing what looks like a more generic exception > handling mechanism to userspace, except that it's nonsensical for > anything other than ENCLU. Well, I see the user space and namely the run-time the host for the enclave i.e. middle-man to provide services for emulating instructions etc. /Jarkko