Re: [RFC PATCH v2 4/4] x86/vdso: Add __vdso_sgx_enter_enclave() to wrap SGX enclave transitions

[Andy Lutomirski]

> On Dec 7, 2018, at 10:44 AM, Dave Hansen <dave.hansen@xxxxxxxxx> wrote:
> 
>> On 12/7/18 10:15 AM, Jethro Beekman wrote:
>> This is not sufficient to support the Fortanix SGX ABI calling
>> convention, which was designed to be mostly compatible with the SysV
>> 64-bit calling convention. The following registers need to be passed in
>> to an enclave from userspace: RDI, RSI, RDX, R8, R9, R10. The following
>> registers need to be passed out from an enclave to userspace: RDI, RSI,
>> RDX, R8, R9.
> 
> Are you asking nicely to change the new Linux ABI to be consistent with
> your existing ABI?  Or, are you saying that the new ABI *must* be
> compatible with this previous out-of-tree implementation?

I think that allowing the enclave to return at least a few registers is quite reasonable, but I donât have a strong opinion.