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=-17.5 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,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,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 CB3F8C433E0 for ; Tue, 5 Jan 2021 03:57:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9865922581 for ; Tue, 5 Jan 2021 03:57:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728357AbhAED4v (ORCPT ); Mon, 4 Jan 2021 22:56:51 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:60030 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728234AbhAED4v (ORCPT ); Mon, 4 Jan 2021 22:56:51 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1609818924; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ij2Q4K/HNjjCnEbhR5nYkOPgqdZ08oveYJIO3xHvf3w=; b=H2A23f4WnzT0hdy5NTaUTETQvQRK7/9PdUMYSoDvBGiTFbgYd11pQnk64450DHbMeDqhr1 wySu7/rP6tLoAIeTwqPafQNNGWgpqKN0KCUPPLVBdti0ZwNh6hW6kbFlvlQ1vU/I6YLpsE BSooP200mNkWrrvJRvw3HGmgX6bYvBA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-24-Bh_QOVzBNd2_C-beX7WtwA-1; Mon, 04 Jan 2021 22:55:20 -0500 X-MC-Unique: Bh_QOVzBNd2_C-beX7WtwA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8DBE0800D62; Tue, 5 Jan 2021 03:55:19 +0000 (UTC) Received: from localhost.localdomain (ovpn-12-214.pek2.redhat.com [10.72.12.214]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 056981002382; Tue, 5 Jan 2021 03:55:16 +0000 (UTC) Subject: Re: [PATCH] iommu: check for the deferred attach when attaching a device From: lijiang To: linux-kernel@vger.kernel.org Cc: joro@8bytes.org, will@kernel.org, iommu@lists.linux-foundation.org, jroedel@suse.de References: <20201226053959.4222-1-lijiang@redhat.com> Message-ID: <33b6f925-71e6-5d9e-74c3-3e1eaf13398e@redhat.com> Date: Tue, 5 Jan 2021 11:55:09 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20201226053959.4222-1-lijiang@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Also add Joerg to cc list. Thanks. Lianbo 在 2020年12月26日 13:39, Lianbo Jiang 写道: > Currently, because domain attach allows to be deferred from iommu > driver to device driver, and when iommu initializes, the devices > on the bus will be scanned and the default groups will be allocated. > > Due to the above changes, some devices could be added to the same > group as below: > > [ 3.859417] pci 0000:01:00.0: Adding to iommu group 16 > [ 3.864572] pci 0000:01:00.1: Adding to iommu group 16 > [ 3.869738] pci 0000:02:00.0: Adding to iommu group 17 > [ 3.874892] pci 0000:02:00.1: Adding to iommu group 17 > > But when attaching these devices, it doesn't allow that a group has > more than one device, otherwise it will return an error. This conflicts > with the deferred attaching. Unfortunately, it has two devices in the > same group for my side, for example: > > [ 9.627014] iommu_group_device_count(): device name[0]:0000:01:00.0 > [ 9.633545] iommu_group_device_count(): device name[1]:0000:01:00.1 > ... > [ 10.255609] iommu_group_device_count(): device name[0]:0000:02:00.0 > [ 10.262144] iommu_group_device_count(): device name[1]:0000:02:00.1 > > Finally, which caused the failure of tg3 driver when tg3 driver calls > the dma_alloc_coherent() to allocate coherent memory in the tg3_test_dma(). > > [ 9.660310] tg3 0000:01:00.0: DMA engine test failed, aborting > [ 9.754085] tg3: probe of 0000:01:00.0 failed with error -12 > [ 9.997512] tg3 0000:01:00.1: DMA engine test failed, aborting > [ 10.043053] tg3: probe of 0000:01:00.1 failed with error -12 > [ 10.288905] tg3 0000:02:00.0: DMA engine test failed, aborting > [ 10.334070] tg3: probe of 0000:02:00.0 failed with error -12 > [ 10.578303] tg3 0000:02:00.1: DMA engine test failed, aborting > [ 10.622629] tg3: probe of 0000:02:00.1 failed with error -12 > > In addition, the similar situations also occur in other drivers such > as the bnxt_en driver. That can be reproduced easily in kdump kernel > when SME is active. > > Add a check for the deferred attach in the iommu_attach_device() and > allow to attach the deferred device regardless of how many devices > are in a group. > > Signed-off-by: Lianbo Jiang > --- > drivers/iommu/iommu.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > index ffeebda8d6de..dccab7b133fb 100644 > --- a/drivers/iommu/iommu.c > +++ b/drivers/iommu/iommu.c > @@ -1967,8 +1967,11 @@ int iommu_attach_device(struct iommu_domain *domain, struct device *dev) > */ > mutex_lock(&group->mutex); > ret = -EINVAL; > - if (iommu_group_device_count(group) != 1) > + if (!iommu_is_attach_deferred(domain, dev) && > + iommu_group_device_count(group) != 1) { > + dev_err_ratelimited(dev, "Group has more than one device\n"); > goto out_unlock; > + } > > ret = __iommu_attach_group(domain, group); > >