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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 B2F2BC433FF for ; Fri, 9 Aug 2019 15:22:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9524C20C01 for ; Fri, 9 Aug 2019 15:22:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2407364AbfHIPWn (ORCPT ); Fri, 9 Aug 2019 11:22:43 -0400 Received: from 8bytes.org ([81.169.241.247]:48534 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2407220AbfHIPWi (ORCPT ); Fri, 9 Aug 2019 11:22:38 -0400 Received: by theia.8bytes.org (Postfix, from userid 1000) id 5E8DB45B; Fri, 9 Aug 2019 17:22:36 +0200 (CEST) From: Joerg Roedel To: Joerg Roedel Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Thomas.Lendacky@amd.com, Suravee.Suthikulpanit@amd.com, bp@alien8.de, Joerg Roedel Subject: [PATCH 3/3] iommu: Disable passthrough mode when SME is active Date: Fri, 9 Aug 2019 17:22:33 +0200 Message-Id: <20190809152233.2829-4-joro@8bytes.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190809152233.2829-1-joro@8bytes.org> References: <20190809152233.2829-1-joro@8bytes.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joerg Roedel Using Passthrough mode when SME is active causes certain devices to use the SWIOTLB bounce buffer. The bounce buffer code has an upper limit of 256kb for the size of DMA allocations, which is too small for certain devices and causes them to fail. With this patch we enable IOMMU by default when SME is active in the system, making the default configuration work for more systems than it does now. Users that don't want IOMMUs to be enabled still can disable them with kernel parameters. Signed-off-by: Joerg Roedel --- drivers/iommu/iommu.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 62cae6db0970..fbe1aa51bce9 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -104,6 +104,12 @@ static int __init iommu_subsys_init(void) else iommu_def_domain_type = IOMMU_DOMAIN_DMA; + if ((iommu_def_domain_type == IOMMU_DOMAIN_IDENTITY) && + sme_active()) { + pr_info("SME detected - Disabling default IOMMU passthrough\n"); + iommu_def_domain_type = IOMMU_DOMAIN_DMA; + } + pr_info("Default domain type: %s\n", iommu_domain_type_str(iommu_def_domain_type)); -- 2.17.1