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=-16.1 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 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 36A71C433E6 for ; Wed, 27 Jan 2021 23:48:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F1B8064DD7 for ; Wed, 27 Jan 2021 23:48:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231908AbhA0XsZ (ORCPT ); Wed, 27 Jan 2021 18:48:25 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:53953 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231265AbhA0XsT (ORCPT ); Wed, 27 Jan 2021 18:48:19 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611791211; 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=xJ/gs4iMushfcp0d07qS8uhcoreW6Bo1+Q0lKFHyKMM=; b=K5q5sx0F9JmAI66uRYMLVsuL2ASVd1C1MBvfcLdioqyRaISG82gNBKRXCOrZROvGZUtiZ9 y8zLocIlesXDIlwnh/KO/rQHKSzyd2x9YFRztxl1jASYcsw02vT4spmDS7FUni8+tDC6VS 4GxYoVfQdLf09Xl43EWhR+DbtvOVo2k= 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-159-WQ5wUpHQOfu8sZ2HJIUVTg-1; Wed, 27 Jan 2021 18:46:47 -0500 X-MC-Unique: WQ5wUpHQOfu8sZ2HJIUVTg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C137E8030A0; Wed, 27 Jan 2021 23:46:43 +0000 (UTC) Received: from omen.home.shazbot.org (ovpn-112-255.phx2.redhat.com [10.3.112.255]) by smtp.corp.redhat.com (Postfix) with ESMTP id E50C25C1BB; Wed, 27 Jan 2021 23:46:41 +0000 (UTC) Date: Wed, 27 Jan 2021 16:46:41 -0700 From: Alex Williamson To: Keqian Zhu Cc: , , , , , Kirti Wankhede , "Cornelia Huck" , Will Deacon , Marc Zyngier , "Catalin Marinas" , Mark Rutland , "James Morse" , Robin Murphy , "Joerg Roedel" , Daniel Lezcano , "Thomas Gleixner" , Suzuki K Poulose , Julien Thierry , Andrew Morton , Alexios Zavras , , Subject: Re: [PATCH v3 2/2] vfio/iommu_type1: Fix some sanity checks in detach group Message-ID: <20210127164641.36e17bf5@omen.home.shazbot.org> In-Reply-To: <20210122092635.19900-3-zhukeqian1@huawei.com> References: <20210122092635.19900-1-zhukeqian1@huawei.com> <20210122092635.19900-3-zhukeqian1@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 22 Jan 2021 17:26:35 +0800 Keqian Zhu wrote: > vfio_sanity_check_pfn_list() is used to check whether pfn_list and > notifier are empty when remove the external domain, so it makes a > wrong assumption that only external domain will use the pinning > interface. > > Now we apply the pfn_list check when a vfio_dma is removed and apply > the notifier check when all domains are removed. > > Fixes: a54eb55045ae ("vfio iommu type1: Add support for mediated devices") > Signed-off-by: Keqian Zhu > --- > drivers/vfio/vfio_iommu_type1.c | 33 ++++++++++----------------------- > 1 file changed, 10 insertions(+), 23 deletions(-) > > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > index 161725395f2f..d8c10f508321 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c > @@ -957,6 +957,7 @@ static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma, > > static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma) > { > + WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)); > vfio_unmap_unpin(iommu, dma, true); > vfio_unlink_dma(iommu, dma); > put_task_struct(dma->task); > @@ -2250,23 +2251,6 @@ static void vfio_iommu_unmap_unpin_reaccount(struct vfio_iommu *iommu) > } > } > > -static void vfio_sanity_check_pfn_list(struct vfio_iommu *iommu) > -{ > - struct rb_node *n; > - > - n = rb_first(&iommu->dma_list); > - for (; n; n = rb_next(n)) { > - struct vfio_dma *dma; > - > - dma = rb_entry(n, struct vfio_dma, node); > - > - if (WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list))) > - break; > - } > - /* mdev vendor driver must unregister notifier */ > - WARN_ON(iommu->notifier.head); > -} > - > /* > * Called when a domain is removed in detach. It is possible that > * the removed domain decided the iova aperture window. Modify the > @@ -2366,10 +2350,10 @@ static void vfio_iommu_type1_detach_group(void *iommu_data, > kfree(group); > > if (list_empty(&iommu->external_domain->group_list)) { > - vfio_sanity_check_pfn_list(iommu); > - > - if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu)) > + if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu)) { > + WARN_ON(iommu->notifier.head); > vfio_iommu_unmap_unpin_all(iommu); > + } > > kfree(iommu->external_domain); > iommu->external_domain = NULL; > @@ -2403,10 +2387,12 @@ static void vfio_iommu_type1_detach_group(void *iommu_data, > */ > if (list_empty(&domain->group_list)) { > if (list_is_singular(&iommu->domain_list)) { > - if (!iommu->external_domain) > + if (!iommu->external_domain) { > + WARN_ON(iommu->notifier.head); > vfio_iommu_unmap_unpin_all(iommu); > - else > + } else { > vfio_iommu_unmap_unpin_reaccount(iommu); > + } > } > iommu_domain_free(domain->domain); > list_del(&domain->next); > @@ -2488,9 +2474,10 @@ static void vfio_iommu_type1_release(void *iommu_data) > struct vfio_iommu *iommu = iommu_data; > struct vfio_domain *domain, *domain_tmp; > > + WARN_ON(iommu->notifier.head); I don't see that this does any harm, but isn't it actually redundant? It seems vfio-core only calls the iommu backend release function after removing all the groups, so the tests in _detach_group should catch all cases. We're expecting the vfio bus/mdev driver to remove the notifier when a device is closed, which necessarily occurs before detaching the group. Thanks, Alex > + > if (iommu->external_domain) { > vfio_release_domain(iommu->external_domain, true); > - vfio_sanity_check_pfn_list(iommu); > kfree(iommu->external_domain); > } >