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=-5.4 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 F222FC433DB for ; Thu, 4 Feb 2021 22:42:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AE39864F9C for ; Thu, 4 Feb 2021 22:42:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230209AbhBDWmW (ORCPT ); Thu, 4 Feb 2021 17:42:22 -0500 Received: from mga12.intel.com ([192.55.52.136]:38807 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229931AbhBDWmU (ORCPT ); Thu, 4 Feb 2021 17:42:20 -0500 IronPort-SDR: dNs4OngiAN9jjE+Jh3c7qT055tUKDo4KTg1sl+vYeLKi3KD6GSJt4efBILYIDlj+QmRKJFMyEZ QpAP39DZrQ0g== X-IronPort-AV: E=McAfee;i="6000,8403,9885"; a="160501409" X-IronPort-AV: E=Sophos;i="5.81,153,1610438400"; d="scan'208";a="160501409" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Feb 2021 14:41:58 -0800 IronPort-SDR: lKZEDHlqCzKlI9zbUS7sclC8xB+bR7Rv/oFV2mSTqjB6fHdgDi4ywoF7MHmta779XZ++kDj4/U S5YoL2dUQ3LA== X-IronPort-AV: E=Sophos;i="5.81,153,1610438400"; d="scan'208";a="483736555" Received: from mmjajodi-mobl1.amr.corp.intel.com (HELO [10.251.130.164]) ([10.251.130.164]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Feb 2021 14:41:58 -0800 Subject: Re: [RFC PATCH v3 08/27] x86/sgx: Initialize virtual EPC driver even when SGX driver is disabled To: Jarkko Sakkinen , Kai Huang Cc: Sean Christopherson , linux-sgx@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org, luto@kernel.org, haitao.huang@intel.com, pbonzini@redhat.com, bp@alien8.de, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com References: <20210203134906.78b5265502c65f13bacc5e68@intel.com> From: Dave Hansen Autocrypt: addr=dave.hansen@intel.com; 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Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On 2/4/21 6:51 AM, Jarkko Sakkinen wrote: >>> A: ret == -ENODEV >>> B: ret == 0 >>> C: ret != 0 && ret != -ENODEV >> Let me try again: >> >> Why A and C should be treated differently? What will behave incorrectly, in case of >> C? > So you don't know what different error codes mean? How about we just leave the check in place as Sean wrote it, and add a nice comment to explain what it is doing: /* * Always try to initialize the native *and* KVM drivers. * The KVM driver is less picky than the native one and * can function if the native one is not supported on the * current system or fails to initialize. * * Error out only if both fail to initialize. */ ret = !!sgx_drv_init() & !!sgx_vepc_init(); if (ret) goto err_kthread;