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=-13.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 E8236C433E0 for ; Tue, 2 Feb 2021 18:52:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A397B64F66 for ; Tue, 2 Feb 2021 18:52:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239038AbhBBSwh (ORCPT ); Tue, 2 Feb 2021 13:52:37 -0500 Received: from mga17.intel.com ([192.55.52.151]:27098 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236794AbhBBSug (ORCPT ); Tue, 2 Feb 2021 13:50:36 -0500 IronPort-SDR: eY4m2ZcGJ/ZKYrRSL9y3g/hXMREy0Wyo5UirBZ57Go1La4a6FYllYrN6+YRBO6CYQLYBB8WKLk ERG2V4ITF0BA== X-IronPort-AV: E=McAfee;i="6000,8403,9883"; a="160674917" X-IronPort-AV: E=Sophos;i="5.79,396,1602572400"; d="scan'208";a="160674917" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Feb 2021 10:49:51 -0800 IronPort-SDR: RHEFA3wL1qnQS5Y8mIIsJtbUKkn5IafRFf/lzt4UCgSLHXskVm96SR6yXiWt0Ch7n9rD+eS0Ys U3tkci7cpNHw== X-IronPort-AV: E=Sophos;i="5.79,396,1602572400"; d="scan'208";a="391621380" Received: from asalasax-mobl2.amr.corp.intel.com (HELO khuang2-desk.gar.corp.intel.com) ([10.251.7.175]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Feb 2021 10:49:48 -0800 Date: Wed, 3 Feb 2021 07:49:45 +1300 From: Kai Huang To: Jarkko Sakkinen Cc: linux-sgx@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org, seanjc@google.com, luto@kernel.org, dave.hansen@intel.com, haitao.huang@intel.com, pbonzini@redhat.com, bp@alien8.de, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com Subject: Re: [RFC PATCH v3 08/27] x86/sgx: Initialize virtual EPC driver even when SGX driver is disabled Message-Id: <20210203074945.0e836486d6afc29e9b44fdbf@intel.com> In-Reply-To: References: <5076ed2c486ac33bfd87dc0e17047a1673692b53.1611634586.git.kai.huang@intel.com> <20210201184040.646ea9923c2119c205b3378d@intel.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, 2 Feb 2021 19:32:30 +0200 Jarkko Sakkinen wrote: > On Mon, Feb 01, 2021 at 06:40:40PM +1300, Kai Huang wrote: > > On Sat, 30 Jan 2021 16:45:43 +0200 Jarkko Sakkinen wrote: > > > On Tue, Jan 26, 2021 at 10:31:00PM +1300, Kai Huang wrote: > > > > Modify sgx_init() to always try to initialize the virtual EPC driver, > > > > even if the bare-metal SGX driver is disabled. The bare-metal driver > > > > might be disabled if SGX Launch Control is in locked mode, or not > > > > supported in the hardware at all. This allows (non-Linux) guests that > > > > support non-LC configurations to use SGX. > > > > > > > > Signed-off-by: Kai Huang > > > > --- > > > > v2->v3: > > > > > > > > - Changed from sgx_virt_epc_init() to sgx_vepc_init(). > > > > > > > > --- > > > > arch/x86/kernel/cpu/sgx/main.c | 4 +++- > > > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c > > > > index 21c2ffa13870..93d249f7bff3 100644 > > > > --- a/arch/x86/kernel/cpu/sgx/main.c > > > > +++ b/arch/x86/kernel/cpu/sgx/main.c > > > > @@ -12,6 +12,7 @@ > > > > #include "driver.h" > > > > #include "encl.h" > > > > #include "encls.h" > > > > +#include "virt.h" > > > > > > > > struct sgx_epc_section sgx_epc_sections[SGX_MAX_EPC_SECTIONS]; > > > > static int sgx_nr_epc_sections; > > > > @@ -712,7 +713,8 @@ static int __init sgx_init(void) > > > > goto err_page_cache; > > > > } > > > > > > > > - ret = sgx_drv_init(); > > > > + /* Success if the native *or* virtual EPC driver initialized cleanly. */ > > > > + ret = !!sgx_drv_init() & !!sgx_vepc_init(); > > > > > > If would create more dumb code and just add > > > > > > ret = sgx_vepc_init() > > > if (ret) > > > goto err_kthread; > > > > Do you mean you want below? > > > > ret = sgx_drv_init(); > > ret = sgx_vepc_init(); > > if (ret) > > goto err_kthread; > > > > This was Sean's original code, but Dave didn't like it. > > I think it should be like: > > ret = sgx_drv_init(); > if (ret) > pr_warn("Driver initialization failed with %d\n", ret); > > ret = sgx_vepc_init(); > if (ret) > goto err_kthread; > > There is problem here anyhow. I.e. -ENODEV's from sgx_drv_init(). I think > how driver.c should be changed would be just to return 0 in the places > where it now return -ENODEV. Consider "not initialized" as a successful > initialization. Hi Jarkko, Dave already pointed out above code won't work. The problem is failure to initialize vepc will just goto err_kthread, no matter whether driver has been initialized successfully or not. I am sticking to the original way (!! & !!). > > /Jarkko