From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83604C433E0 for ; Wed, 22 Jul 2020 09:57:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4E5DE20729 for ; Wed, 22 Jul 2020 09:57:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595411875; bh=Ac2zSfnLK6EdjtxqVu1WgVKMMw2MnwHoF9j9QNHNO7g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=KMk0Cv5zpxS0wn9lxKkbMFI5T7Ui/uMVQXJ5RjWeKUIK5oxD9cfvhQENLzGhMf56R rZbEJfVc9bUoCRCqB2YWtG0aAG7zt/xDEzAAdU5S4vpniTaAu17SidCw1m1ytQZhiO fZe00tKZ+h5M6UMyorqlaDD59IRUgj4j2j1zqC4k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731575AbgGVJ5y (ORCPT ); Wed, 22 Jul 2020 05:57:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:52000 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726153AbgGVJ5x (ORCPT ); Wed, 22 Jul 2020 05:57:53 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 84C4220714; Wed, 22 Jul 2020 09:57:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595411873; bh=Ac2zSfnLK6EdjtxqVu1WgVKMMw2MnwHoF9j9QNHNO7g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=abKrNRxXeuctelcKVMQbIUVI1Fxcf2Kts4FdVgofW1X77fDquvE4r9eZGe7/KBJsb DotcyKDC//m8E2dWye8Sa6UoTEfBk+ehLisu8oOYbqRPDppbhrS835EBNvvSs5dfVa doYjLbY6XAMppyxD6z7vZ1B8qgDfDDKM4B3MMqRk= Date: Wed, 22 Jul 2020 11:57:59 +0200 From: Greg KH To: "Paraschiv, Andra-Irina" Cc: linux-kernel@vger.kernel.org, Anthony Liguori , Benjamin Herrenschmidt , Colm MacCarthaigh , David Duncan , Bjoern Doebel , David Woodhouse , Frank van der Linden , Alexander Graf , Karen Noel , Martin Pohlack , Matt Wilson , Paolo Bonzini , Balbir Singh , Stefano Garzarella , Stefan Hajnoczi , Stewart Smith , Uwe Dannowski , Vitaly Kuznetsov , kvm@vger.kernel.org, ne-devel-upstream@amazon.com, Alexander Graf Subject: Re: [PATCH v5 01/18] nitro_enclaves: Add ioctl interface definition Message-ID: <20200722095759.GA2817347@kroah.com> References: <20200715194540.45532-1-andraprs@amazon.com> <20200715194540.45532-2-andraprs@amazon.com> <20200721121225.GA1855212@kroah.com> <5dad638c-0ef3-9d16-818c-54e1556d8fc8@amazon.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5dad638c-0ef3-9d16-818c-54e1556d8fc8@amazon.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 22, 2020 at 11:27:29AM +0300, Paraschiv, Andra-Irina wrote: > > > +#ifndef _UAPI_LINUX_NITRO_ENCLAVES_H_ > > > +#define _UAPI_LINUX_NITRO_ENCLAVES_H_ > > > + > > > +#include > > > + > > > +/* Nitro Enclaves (NE) Kernel Driver Interface */ > > > + > > > +#define NE_API_VERSION (1) > > Why do you need this version? It shouldn't be needed, right? > > The version is used as a way for the user space tooling to sync on the > features set provided by the driver e.g. in case an older version of the > driver is available on the system and the user space tooling expects a set > of features that is not included in that driver version. That is guaranteed to get out of sync instantly with different distro kernels backporting random things, combined with stable kernel patch updates and the like. Just use the normal api interfaces instead, don't try to "version" anything, it will not work, trust us :) If an ioctl returns -ENOTTY then hey, it's not present and your userspace code can handle it that way. thanks, greg k-h