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=-11.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 C2949C388F9 for ; Mon, 9 Nov 2020 03:15:26 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 168AD20757 for ; Mon, 9 Nov 2020 03:15:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 168AD20757 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 85E4A868A5; Mon, 9 Nov 2020 03:15:25 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id h-XAMN4K30nZ; Mon, 9 Nov 2020 03:15:22 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id 7AB6F86813; Mon, 9 Nov 2020 03:15:22 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 53F65C088B; Mon, 9 Nov 2020 03:15:22 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id EDE1DC016F for ; Mon, 9 Nov 2020 03:15:19 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id D6CFF20414 for ; Mon, 9 Nov 2020 03:15:19 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id AjnJm3ngE7-G for ; Mon, 9 Nov 2020 03:15:18 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by silver.osuosl.org (Postfix) with ESMTPS id 136E820410 for ; Mon, 9 Nov 2020 03:15:18 +0000 (UTC) IronPort-SDR: KqBbfAOouuX9wXulEmU6DfE4uhYs5E2skgiTGbrJ+ZUH5zOimqeM06QvzSNWWQAoPWnYdjOVF+ 2CQOSWvW9Vhw== X-IronPort-AV: E=McAfee;i="6000,8403,9799"; a="187688710" X-IronPort-AV: E=Sophos;i="5.77,462,1596524400"; d="scan'208";a="187688710" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Nov 2020 19:15:17 -0800 IronPort-SDR: BQ6faZthxtz9NEKFYN02lfH9pzHFOpSiZswcFpSFStqw/05RK49JnfwRcpUnepgs1gl8CKXjiw SD4plW6brfuw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,462,1596524400"; d="scan'208";a="427854948" Received: from allen-box.sh.intel.com (HELO [10.239.159.28]) ([10.239.159.28]) by fmsmga001.fm.intel.com with ESMTP; 08 Nov 2020 19:15:14 -0800 Subject: Re: [PATCH] iommu/vt-d: avoid unnecessory panic if iommu init fail in tboot To: Zhenzhong Duan , linux-kernel References: <20201104081438.2075-1-zhenzhong.duan@gmail.com> From: Lu Baolu Message-ID: <9e5e5f48-e91d-adce-cbf5-b98fee3b56a6@linux.intel.com> Date: Mon, 9 Nov 2020 11:08:17 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US Cc: jroedel@suse.de, x86@kernel.org, iommu@lists.linux-foundation.org, ning.sun@intel.com, tboot-devel@lists.sourceforge.net, Ingo Molnar , Borislav Petkov , Thomas Gleixner , David Woodhouse X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" Hi Zhenzhong, On 11/9/20 10:27 AM, Zhenzhong Duan wrote: > +intel iommu maintainers, > > Can anyone help review this patch? Thanks > > Zhenzhong > > On Wed, Nov 4, 2020 at 4:15 PM Zhenzhong Duan wrote: >> >> "intel_iommu=off" command line is used to disable iommu and iommu is force >> enabled in a tboot system. Meanwhile "intel_iommu=tboot_noforce,off" >> could be used to force disable iommu in tboot for better performance. >> >> 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 it by return 0 in tboot_force_iommu() so that force_on is not set. >> >> Fixes: 7304e8f28bb2 ("iommu/vt-d: Correctly disable Intel IOMMU force on") >> Signed-off-by: Zhenzhong Duan >> --- >> arch/x86/kernel/tboot.c | 5 +---- >> 1 file changed, 1 insertion(+), 4 deletions(-) >> >> diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c >> index 992fb1415c0f..9fd4d162b331 100644 >> --- a/arch/x86/kernel/tboot.c >> +++ b/arch/x86/kernel/tboot.c >> @@ -511,12 +511,9 @@ struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tb >> >> int tboot_force_iommu(void) >> { >> - if (!tboot_enabled()) >> + if (!tboot_enabled() || intel_iommu_tboot_noforce) >> return 0; >> >> - if (intel_iommu_tboot_noforce) >> - return 1; This was obviously wrong. It should return false, right? It looks odd that intel_iommu_tboot_noforce is defined in Intel iommu implementation, but is used here. How about moving it back to the iommu driver? diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c index 992fb1415c0f..420be871d9d4 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 a41f9f13cc86..ba90eb4325d0 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -179,7 +179,7 @@ static int rwbf_quirk; * (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)) @@ -4212,7 +4212,8 @@ 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 fbf5b3e7707e..d956987ed032 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -798,7 +798,6 @@ extern int iommu_calculate_agaw(struct intel_iommu *iommu); 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) >> - >> if (no_iommu || swiotlb || dmar_disabled) >> pr_warn("Forcing Intel-IOMMU to enabled\n"); >> >> -- >> 2.25.1 >> Best regards, baolu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu