Re: [PATCH v36 21/24] x86/vdso: Implement a vDSO for Intel SGX enclave call

From: Sean Christopherson
Date: Mon Aug 10 2020 - 19:48:41 EST


On Mon, Aug 10, 2020 at 04:08:46PM -0700, Andy Lutomirski wrote:
> What am I missing? I still don't really understand why we are
> supporting this mechanism at all. Just the asm code to invoke the
> callback seems to be about half of the entire function.

Because the Intel SDK (and other SDKs?) wants to use the host stack to pass
parameters out of the enclave.