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=-17.2 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 CE897C64E7B for ; Mon, 30 Nov 2020 20:59:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 726CD2073C for ; Mon, 30 Nov 2020 20:59:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="U4qTdxW9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730233AbgK3U7E (ORCPT ); Mon, 30 Nov 2020 15:59:04 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:45660 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726716AbgK3U7D (ORCPT ); Mon, 30 Nov 2020 15:59:03 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1606769856; 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=cq1No4dPtLmGbI2mqBJ+VtaVWU0d8csbHMbJytzQmX0=; b=U4qTdxW9R2WIenKyHG3fA3rQwjgHR9DhF/lj6hdKGvqtiTrUYpjJSjDhgWKAiKD2yXwTis I2cMsuax1/gxZFQCpxcPp0YfB+RHI+YB6l6DvQVp2SucOoMYwFCIWbxXLbfKgYlOjoW2su mNfb1Cfz4hpNnkVBZ+eOMK/LM3VRnd8= 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-268-Y7lpk6YDNsqnK6zdensHaA-1; Mon, 30 Nov 2020 15:57:29 -0500 X-MC-Unique: Y7lpk6YDNsqnK6zdensHaA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 71B6E1005D59; Mon, 30 Nov 2020 20:57:27 +0000 (UTC) Received: from w520.home (ovpn-112-10.phx2.redhat.com [10.3.112.10]) by smtp.corp.redhat.com (Postfix) with ESMTP id 656B219C71; Mon, 30 Nov 2020 20:57:26 +0000 (UTC) Date: Mon, 30 Nov 2020 13:57:25 -0700 From: Alex Williamson To: Lu Baolu Cc: Cornelia Huck , Joerg Roedel , Will Deacon , Robin Murphy , Jean-Philippe Brucker , Kevin Tian , Ashok Raj , Dave Jiang , Liu Yi L , Zeng Xin , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [PATCH v2 1/1] vfio/type1: Add vfio_group_domain() Message-ID: <20201130135725.70fdf17f@w520.home> In-Reply-To: <20201126012726.1185171-1-baolu.lu@linux.intel.com> References: <20201126012726.1185171-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 26 Nov 2020 09:27:26 +0800 Lu Baolu wrote: > Add the API for getting the domain from a vfio group. This could be used > by the physical device drivers which rely on the vfio/mdev framework for > mediated device user level access. The typical use case like below: > > unsigned int pasid; > struct vfio_group *vfio_group; > struct iommu_domain *iommu_domain; > struct device *dev = mdev_dev(mdev); > struct device *iommu_device = mdev_get_iommu_device(dev); > > if (!iommu_device || > !iommu_dev_feature_enabled(iommu_device, IOMMU_DEV_FEAT_AUX)) > return -EINVAL; > > vfio_group = vfio_group_get_external_user_from_dev(dev);(dev); > if (IS_ERR_OR_NULL(vfio_group)) > return -EFAULT; > > iommu_domain = vfio_group_domain(vfio_group); > if (IS_ERR_OR_NULL(iommu_domain)) { > vfio_group_put_external_user(vfio_group); > return -EFAULT; > } > > pasid = iommu_aux_get_pasid(iommu_domain, iommu_device); > if (pasid < 0) { > vfio_group_put_external_user(vfio_group); > return -EFAULT; > } > > /* Program device context with pasid value. */ > ... > > Signed-off-by: Lu Baolu > --- > drivers/vfio/vfio.c | 18 ++++++++++++++++++ > drivers/vfio/vfio_iommu_type1.c | 23 +++++++++++++++++++++++ > include/linux/vfio.h | 3 +++ > 3 files changed, 44 insertions(+) > > Change log: > - v1: https://lore.kernel.org/linux-iommu/20201112022407.2063896-1-baolu.lu@linux.intel.com/ > - Changed according to comments @ https://lore.kernel.org/linux-iommu/20201116125631.2d043fcd@w520.home/ > > diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c > index 2151bc7f87ab..62c652111c88 100644 > --- a/drivers/vfio/vfio.c > +++ b/drivers/vfio/vfio.c > @@ -2331,6 +2331,24 @@ int vfio_unregister_notifier(struct device *dev, enum vfio_notify_type type, > } > EXPORT_SYMBOL(vfio_unregister_notifier); > > +struct iommu_domain *vfio_group_domain(struct vfio_group *group) > +{ > + struct vfio_container *container; > + struct vfio_iommu_driver *driver; > + > + if (!group) > + return ERR_PTR(-EINVAL); > + > + container = group->container; > + driver = container->iommu_driver; > + if (likely(driver && driver->ops->group_domain)) > + return driver->ops->group_domain(container->iommu_data, > + group->iommu_group); > + else > + return ERR_PTR(-ENOTTY); > +} > +EXPORT_SYMBOL(vfio_group_domain); _GPL? I don't see that there's a way for a driver to get the vfio_group pointer that's not already _GPL. > + > /** > * Module/class support > */ > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > index 67e827638995..783f18f21b95 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c > @@ -2980,6 +2980,28 @@ static int vfio_iommu_type1_dma_rw(void *iommu_data, dma_addr_t user_iova, > return ret; > } > > +static void *vfio_iommu_type1_group_domain(void *iommu_data, > + struct iommu_group *iommu_group) > +{ > + struct vfio_iommu *iommu = iommu_data; > + struct iommu_domain *domain = NULL; > + struct vfio_domain *d; > + > + if (!iommu || !iommu_group) > + return ERR_PTR(-EINVAL); > + > + mutex_lock(&iommu->lock); > + list_for_each_entry(d, &iommu->domain_list, next) { > + if (find_iommu_group(d, iommu_group)) { > + domain = d->domain; > + break; > + } > + } > + mutex_unlock(&iommu->lock); > + > + return domain; > +} Why does this return void* rather than struct iommu_domain*, and why does the error case return an ERR_PTR but the not-found case returns NULL? Thanks, Alex > + > static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = { > .name = "vfio-iommu-type1", > .owner = THIS_MODULE, > @@ -2993,6 +3015,7 @@ static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = { > .register_notifier = vfio_iommu_type1_register_notifier, > .unregister_notifier = vfio_iommu_type1_unregister_notifier, > .dma_rw = vfio_iommu_type1_dma_rw, > + .group_domain = vfio_iommu_type1_group_domain, > }; > > static int __init vfio_iommu_type1_init(void) > diff --git a/include/linux/vfio.h b/include/linux/vfio.h > index 38d3c6a8dc7e..a0613a6f21cc 100644 > --- a/include/linux/vfio.h > +++ b/include/linux/vfio.h > @@ -90,6 +90,7 @@ struct vfio_iommu_driver_ops { > struct notifier_block *nb); > int (*dma_rw)(void *iommu_data, dma_addr_t user_iova, > void *data, size_t count, bool write); > + void *(*group_domain)(void *iommu_data, struct iommu_group *group); > }; > > extern int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops); > @@ -126,6 +127,8 @@ extern int vfio_group_unpin_pages(struct vfio_group *group, > extern int vfio_dma_rw(struct vfio_group *group, dma_addr_t user_iova, > void *data, size_t len, bool write); > > +extern struct iommu_domain *vfio_group_domain(struct vfio_group *group); > + > /* each type has independent events */ > enum vfio_notify_type { > VFIO_IOMMU_NOTIFY = 0,