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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 29FE4C282CE for ; Mon, 11 Feb 2019 14:26:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EEE2E2075C for ; Mon, 11 Feb 2019 14:26:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549895217; bh=1SdnDbIotud4h1uvDmQrJkx7PigJD95SbH2SP2QCJjs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=w5L+FAi2Tvp6EEQ/hx/YcdhJRtFt9U06FBXiHVQ7n6AoRuXEG3beGm7MFK9h3S0xQ aNpugFom/QTuNPKnn8Y3kQQhIZjd95g+vMZNWafGDxHirlg83fsKHjf/01VPeo6E3L OoTKe5aHGAbVbmBzpQRi/rFL1l6hVaex4gZ2DH3o= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728061AbfBKO0y (ORCPT ); Mon, 11 Feb 2019 09:26:54 -0500 Received: from mail.kernel.org ([198.145.29.99]:60780 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729608AbfBKO0w (ORCPT ); Mon, 11 Feb 2019 09:26:52 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 563F92075C; Mon, 11 Feb 2019 14:26:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549895211; bh=1SdnDbIotud4h1uvDmQrJkx7PigJD95SbH2SP2QCJjs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ThAWxSjWLWi6YNJJyN4N5h1dqMMMxTW89+aSfSD248OXfWMDyDBttiRxQfEcP5u7V mVdGrtG+YhNgtuMZrVaBUUZkOKGBmwEyqzIhB8SSqC/ME7ARgzOiLNJgXztbm64ZWW GdIBPgQBkNbEDq6eu0GlhUYG0hHSKV1nq7BnmIk8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yu Zhao , Joerg Roedel , Sasha Levin Subject: [PATCH 4.20 130/352] iommu/amd: Fix amd_iommu=force_isolation Date: Mon, 11 Feb 2019 15:15:57 +0100 Message-Id: <20190211141854.703324382@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190211141846.543045703@linuxfoundation.org> References: <20190211141846.543045703@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit c12b08ebbe16f0d3a96a116d86709b04c1ee8e74 ] The parameter is still there but it's ignored. We need to check its value before deciding to go into passthrough mode for AMD IOMMU v2 capable device. We occasionally use this parameter to force v2 capable device into translation mode to debug memory corruption that we suspect is caused by DMA writes. To address the following comment from Joerg Roedel on the first version, v2 capability of device is completely ignored. > This breaks the iommu_v2 use-case, as it needs a direct mapping for the > devices that support it. And from Documentation/admin-guide/kernel-parameters.txt: This option does not override iommu=pt Fixes: aafd8ba0ca74 ("iommu/amd: Implement add_device and remove_device") Signed-off-by: Yu Zhao Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin --- drivers/iommu/amd_iommu.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 1167ff0416cf..325f3bad118b 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -438,7 +438,14 @@ static int iommu_init_device(struct device *dev) dev_data->alias = get_alias(dev); - if (dev_is_pci(dev) && pci_iommuv2_capable(to_pci_dev(dev))) { + /* + * By default we use passthrough mode for IOMMUv2 capable device. + * But if amd_iommu=force_isolation is set (e.g. to debug DMA to + * invalid address), we ignore the capability for the device so + * it'll be forced to go into translation mode. + */ + if ((iommu_pass_through || !amd_iommu_force_isolation) && + dev_is_pci(dev) && pci_iommuv2_capable(to_pci_dev(dev))) { struct amd_iommu *iommu; iommu = amd_iommu_rlookup_table[dev_data->devid]; -- 2.19.1