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=-13.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 724A4C433B4 for ; Fri, 2 Apr 2021 19:30:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 43C846115B for ; Fri, 2 Apr 2021 19:30:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236424AbhDBTae (ORCPT ); Fri, 2 Apr 2021 15:30:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54948 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229553AbhDBTaa (ORCPT ); Fri, 2 Apr 2021 15:30:30 -0400 Received: from mail-pg1-x52b.google.com (mail-pg1-x52b.google.com [IPv6:2607:f8b0:4864:20::52b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D6037C0613E6 for ; Fri, 2 Apr 2021 12:30:28 -0700 (PDT) Received: by mail-pg1-x52b.google.com with SMTP id k8so4120034pgf.4 for ; Fri, 02 Apr 2021 12:30:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=mI2VwoucIGtwJkYw4jcbD6VsEjZ7aBO9iaogKVD4nI4=; b=KK2Kxxc4pkTexwVVGgJh/v3IhjphLvlaQKCImf4D6lAGS/OdKWcPPWAI+eTtnLJTeh nvX2apmNv/KMyLksk6sFFf2ztsd60zapv+9zdIcqjg1Z1Aa/fXESufNKsqtjIke5WQHt M0aG3TYe5f329OkBh/5aRwpQxCZRm57zZCvNnVVD/5SLohli1J+RMMmFCKU/pw3iLYAQ eHlZZjHe6dIwkHctw7SAmhSLbimCLbQgXdw9D0j+vDyLgO0zRXqUWTxLjE6wGz5k5GGV RGVxOAen6cBUcfr72E2gb1xq0kxs41Oio01KmGwmrzqQyIw0Ycu+FzgY/iJOTTSRrHFU fAZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=mI2VwoucIGtwJkYw4jcbD6VsEjZ7aBO9iaogKVD4nI4=; b=Kz4PDcxKHQ+qON68RUCEDvXoZVXUg3RkQpI1yX+DXUxPogqIDPJwMrnp2K0T7ujQiz qclNA07nd1Uw9jvCDs+eGHg6G9ZZuYuR6uBmBCamjqzOc1Xq0MGzM2rGBv7LHp1lk5U1 +bUOSw9I5TVU9a7ceq/fPqHXRdyXrVYwYlI9sxi+OjfUf9VP6d4f0F1IQSfTzGv7b1kK AUS0VP6h0xgkUeXxYuIB3s0+/PkQ9bQId+9rSD9qFRTCoEpZ1yII8U9tQ3CfG3sEFLQc 7zr0eagbfC4dPwPyXSg3e4A8CYgpEnaBzZJDJDhtr4pR8D9er52jBTKxeiCxSIGE1jCJ BCXw== X-Gm-Message-State: AOAM530oms36SNX6E2vWH6vPjM13BTWFg4ouUOR8VeYDfbFhH4aTVTWU WR/s2lNpBo6BoWQ9RvcuMiDkQw== X-Google-Smtp-Source: ABdhPJz+IwEe6kNxDW16gUdkP1UiHKndPYJHb24Xo12t7nWY35muI9rAeFyqM0+2dx4Uv3yTO8KcnA== X-Received: by 2002:aa7:8d8a:0:b029:1f8:aa27:7203 with SMTP id i10-20020aa78d8a0000b02901f8aa277203mr13370981pfr.64.1617391828115; Fri, 02 Apr 2021 12:30:28 -0700 (PDT) Received: from google.com (240.111.247.35.bc.googleusercontent.com. [35.247.111.240]) by smtp.gmail.com with ESMTPSA id s8sm8799796pjg.29.2021.04.02.12.30.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 02 Apr 2021 12:30:27 -0700 (PDT) Date: Fri, 2 Apr 2021 19:30:23 +0000 From: Sean Christopherson To: Borislav Petkov Cc: Kai Huang , kvm@vger.kernel.org, linux-sgx@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, jarkko@kernel.org, luto@kernel.org, dave.hansen@intel.com, rick.p.edgecombe@intel.com, haitao.huang@intel.com, pbonzini@redhat.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com Subject: Re: [PATCH v3 07/25] x86/sgx: Initialize virtual EPC driver even when SGX driver is disabled Message-ID: References: <20210402094816.GC28499@zn.tnic> <20210402191946.GL28499@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210402191946.GL28499@zn.tnic> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 02, 2021, Borislav Petkov wrote: > On Fri, Apr 02, 2021 at 03:42:51PM +0000, Sean Christopherson wrote: > > Nope! That's wrong, as sgx_epc_init() will not be called if sgx_drv_init() > > succeeds. And writing it as "if (sgx_drv_init() || sgx_vepc_init())" is also > > wrong since that would kill SGX when one of the drivers is alive and well. > > Bah, right you are. > > How about: > > /* Error out only if both fail to initialize. */ > ret = sgx_drv_init(); > > if (sgx_vepc_init() && ret) > goto err_kthread; Heh, that's what I had originally and used for literally years. IIRC, I suggested the "!! & !!" abomination after internal review complained about the oddness of the above. FWIW, I think the above is far less likely to be misread, even though I love the cleverness of the bitwise AND. > > And yah, this looks strange so it needs the comment to explain what's > going on here. > > Thx. > > -- > Regards/Gruss, > Boris. > > https://people.kernel.org/tglx/notes-about-netiquette