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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 02410C3A59E for ; Thu, 22 Aug 2019 00:29:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D0DB522DD3 for ; Thu, 22 Aug 2019 00:29:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728605AbfHVA3n (ORCPT ); Wed, 21 Aug 2019 20:29:43 -0400 Received: from mga01.intel.com ([192.55.52.88]:39269 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728511AbfHVA3n (ORCPT ); Wed, 21 Aug 2019 20:29:43 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 21 Aug 2019 17:29:42 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,414,1559545200"; d="scan'208";a="262665013" Received: from soegtrop-mobl1.ger.corp.intel.com (HELO localhost) ([10.252.52.79]) by orsmga001.jf.intel.com with ESMTP; 21 Aug 2019 17:29:41 -0700 Date: Thu, 22 Aug 2019 03:29:40 +0300 From: Jarkko Sakkinen To: Sean Christopherson Cc: linux-sgx@vger.kernel.org Subject: Re: [PATCH] x86/sgx: Return 0 when !CONFIG_INTEL_SGX_DRIVER Message-ID: <20190822002940.hb7xjbrdkxxx4zoe@linux.intel.com> References: <20190714143212.971-1-jarkko.sakkinen@linux.intel.com> <20190715135902.GA442@linux.intel.com> <20190801162219.fqmkxlp4mgm4gi3f@linux.intel.com> <20190801162931.GB6783@linux.intel.com> <20190802193321.llx4dcqhslh46toy@linux.intel.com> <20190813012227.GJ4996@linux.intel.com> <20190815215600.u3cz27y27nrldq3i@linux.intel.com> <20190821172400.GH29345@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190821172400.GH29345@linux.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: NeoMutt/20180716 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Wed, Aug 21, 2019 at 10:24:00AM -0700, Sean Christopherson wrote: > How does the current code not align with this approach? The core subsystem > should tear itself down if loading the driver fails, which includes failing > because it doesn't exist. I get now the real issue that you are trying to point out (did not earlier). Still, I think your approach to fix it needs some reconsideration. Something that *does not exist* can never fail. That should be dead obvious. If the SGX driver does not exit and KVM does not have SGX support compiled in, then the only logical conclusion that you can end up with is that neither the SGX core should exist in vmlinux in the first place. This all summarizes to that I have to remove the INTEL_SGX_DRIVER kconfig flag. Its existence can only be considered when there >= 2 in-kernel users for SGX. /Jarkko