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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 42659C47080 for ; Mon, 31 May 2021 16:47:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2030461005 for ; Mon, 31 May 2021 16:47:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232616AbhEaQsj (ORCPT ); Mon, 31 May 2021 12:48:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:48408 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232364AbhEaOzg (ORCPT ); Mon, 31 May 2021 10:55:36 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 64C3261935; Mon, 31 May 2021 13:59:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1622469587; bh=I3MFQZEYwlfs0WAgyazAsru7RkY9wmdUF6WGBdOVvN4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FWiVZySAWZLjIVSYVXDtTkDP36zCS49dMNPQZfoZ6WPAPDoHcnxuDMNAVtQlfGWvZ XMa4wkTzTXpZGuOHrQPZ0sr0BpSC57K1GNUC9teYJpHE59Cab/eH6gM6V1VNXDgddY 5Qn7IzChjdAPGfuzCQVDgYFJgIWkIzi1ZL6iGQwQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jean-Philippe Brucker , Joerg Roedel , Sasha Levin Subject: [PATCH 5.12 256/296] iommu/amd: Clear DMA ops when switching domain Date: Mon, 31 May 2021 15:15:11 +0200 Message-Id: <20210531130712.363990117@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210531130703.762129381@linuxfoundation.org> References: <20210531130703.762129381@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jean-Philippe Brucker [ Upstream commit d6177a6556f853785867e2ec6d5b7f4906f0d809 ] Since commit 08a27c1c3ecf ("iommu: Add support to change default domain of an iommu group") a user can switch a device between IOMMU and direct DMA through sysfs. This doesn't work for AMD IOMMU at the moment because dev->dma_ops is not cleared when switching from a DMA to an identity IOMMU domain. The DMA layer thus attempts to use the dma-iommu ops on an identity domain, causing an oops: # echo 0000:00:05.0 > /sys/sys/bus/pci/drivers/e1000e/unbind # echo identity > /sys/bus/pci/devices/0000:00:05.0/iommu_group/type # echo 0000:00:05.0 > /sys/sys/bus/pci/drivers/e1000e/bind ... BUG: kernel NULL pointer dereference, address: 0000000000000028 ... Call Trace: iommu_dma_alloc e1000e_setup_tx_resources e1000e_open Since iommu_change_dev_def_domain() calls probe_finalize() again, clear the dma_ops there like Vt-d does. Fixes: 08a27c1c3ecf ("iommu: Add support to change default domain of an iommu group") Signed-off-by: Jean-Philippe Brucker Link: https://lore.kernel.org/r/20210422094216.2282097-1-jean-philippe@linaro.org Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin --- drivers/iommu/amd/iommu.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index a69a8b573e40..7de7a260706b 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -1747,6 +1747,8 @@ static void amd_iommu_probe_finalize(struct device *dev) domain = iommu_get_domain_for_dev(dev); if (domain->type == IOMMU_DOMAIN_DMA) iommu_setup_dma_ops(dev, IOVA_START_PFN << PAGE_SHIFT, 0); + else + set_dma_ops(dev, NULL); } static void amd_iommu_release_device(struct device *dev) -- 2.30.2