This is just the mitigations at the kernel level, to protect the kernel from applications and applications from each other. Without this applications can't even

This is just the mitigations at the kernel level, to protect the kernel from applications and applications from each other. Without this applications can't even attempt to secure themselves from these issues. I think to allow applications a chance to opt into being secure from these attacks without applying the fixes system-wide you'd need a way to disable speculative memory reads per page which would nerf performance even harder for the applications that turned that option on.