Re: [PATCH v5 08/11] intel_sgx: in-kernel launch enclave

From: Jarkko Sakkinen
Date: Tue Nov 21 2017 - 07:23:46 EST

On Tue, Nov 21, 2017 at 12:48:26AM +0100, Thomas Gleixner wrote:
> The launch enclave is part of the kernel, at least that's what the subject
> line claims. So why and how would it do a syscall? The kernel has it's
> internal crypto API.

It's part of the kernel in the way as lets say code arch/x86/realmode
is. It's hosted by kernel but it does not run in the same address space
as the kernel.

These constraints apply for enclaves:

1. They only run in ring-3.
2. They can only execute code inside their address range.