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=-15.3 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,USER_AGENT_SANE_1 autolearn=unavailable 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 718F9C2D0E4 for ; Tue, 17 Nov 2020 23:32:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2E59F2417E for ; Tue, 17 Nov 2020 23:32:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728487AbgKQXcc (ORCPT ); Tue, 17 Nov 2020 18:32:32 -0500 Received: from mga04.intel.com ([192.55.52.120]:51171 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725779AbgKQXcb (ORCPT ); Tue, 17 Nov 2020 18:32:31 -0500 IronPort-SDR: S6lC9JeWep0S01W7DjuWhMandJhDKLd4iv7+2/iXQJ7JappZ1WdNgb/CRpEB8lTYmps9M73nli S1g5B/DnQGLg== X-IronPort-AV: E=McAfee;i="6000,8403,9808"; a="168461202" X-IronPort-AV: E=Sophos;i="5.77,486,1596524400"; d="scan'208";a="168461202" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Nov 2020 15:32:31 -0800 IronPort-SDR: 5382oeKWx+HYT1RMhyNPodt0b+9JjqrE65FbskKgyoQWOCiOkPDwmesPlkd4bELgNbAbYweNIN IIUaC5ZVD7Zw== X-IronPort-AV: E=Sophos;i="5.77,486,1596524400"; d="scan'208";a="532413741" Received: from jli128-mobl1.ccr.corp.intel.com (HELO [10.254.209.252]) ([10.254.209.252]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Nov 2020 15:32:28 -0800 Cc: baolu.lu@linux.intel.com, ning.sun@intel.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, dwmw2@infradead.org, joro@8bytes.org, iommu@lists.linux-foundation.org, tboot-devel@lists.sourceforge.net Subject: Re: [PATCH v2] iommu/vt-d: avoid unnecessory panic if iommu init fail in tboot system To: Zhenzhong Duan , linux-kernel@vger.kernel.org, Will Deacon References: <20201110071908.3133-1-zhenzhong.duan@gmail.com> From: Lu Baolu Message-ID: <34e8f6c6-e9f7-634b-8f68-3645261fd882@linux.intel.com> Date: Wed, 18 Nov 2020 07:32:25 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.4.3 MIME-Version: 1.0 In-Reply-To: <20201110071908.3133-1-zhenzhong.duan@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org +Will Please consider this patch for v5.10. Best regards, baolu On 2020/11/10 15:19, Zhenzhong Duan wrote: > "intel_iommu=off" command line is used to disable iommu but iommu is force > enabled in a tboot system for security reason. > > However for better performance on high speed network device, a new option > "intel_iommu=tboot_noforce" is introduced to disable the force on. > > By default kernel should panic if iommu init fail in tboot for security > reason, but it's unnecessory if we use "intel_iommu=tboot_noforce,off". > > Fix the code setting force_on and move intel_iommu_tboot_noforce > from tboot code to intel iommu code. > > Fixes: 7304e8f28bb2 ("iommu/vt-d: Correctly disable Intel IOMMU force on") > Signed-off-by: Zhenzhong Duan > --- > v2: move ckeck of intel_iommu_tboot_noforce into iommu code per Baolu. > > arch/x86/kernel/tboot.c | 3 --- > drivers/iommu/intel/iommu.c | 5 +++-- > include/linux/intel-iommu.h | 1 - > 3 files changed, 3 insertions(+), 6 deletions(-) > > diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c > index 992fb14..420be87 100644 > --- a/arch/x86/kernel/tboot.c > +++ b/arch/x86/kernel/tboot.c > @@ -514,9 +514,6 @@ int tboot_force_iommu(void) > if (!tboot_enabled()) > return 0; > > - if (intel_iommu_tboot_noforce) > - return 1; > - > if (no_iommu || swiotlb || dmar_disabled) > pr_warn("Forcing Intel-IOMMU to enabled\n"); > > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c > index 1b1ca63..4d9b298 100644 > --- a/drivers/iommu/intel/iommu.c > +++ b/drivers/iommu/intel/iommu.c > @@ -179,7 +179,7 @@ static inline unsigned long virt_to_dma_pfn(void *p) > * (used when kernel is launched w/ TXT) > */ > static int force_on = 0; > -int intel_iommu_tboot_noforce; > +static int intel_iommu_tboot_noforce; > static int no_platform_optin; > > #define ROOT_ENTRY_NR (VTD_PAGE_SIZE/sizeof(struct root_entry)) > @@ -4885,7 +4885,8 @@ int __init intel_iommu_init(void) > * Intel IOMMU is required for a TXT/tboot launch or platform > * opt in, so enforce that. > */ > - force_on = tboot_force_iommu() || platform_optin_force_iommu(); > + force_on = (!intel_iommu_tboot_noforce && tboot_force_iommu()) || > + platform_optin_force_iommu(); > > if (iommu_init_mempool()) { > if (force_on) > diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h > index fbf5b3e..d956987 100644 > --- a/include/linux/intel-iommu.h > +++ b/include/linux/intel-iommu.h > @@ -798,7 +798,6 @@ struct context_entry *iommu_context_addr(struct intel_iommu *iommu, u8 bus, > extern int iommu_calculate_max_sagaw(struct intel_iommu *iommu); > extern int dmar_disabled; > extern int intel_iommu_enabled; > -extern int intel_iommu_tboot_noforce; > extern int intel_iommu_gfx_mapped; > #else > static inline int iommu_calculate_agaw(struct intel_iommu *iommu) >