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=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 D05A4C2D0A3 for ; Mon, 16 Nov 2020 19:56:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5FCFA20825 for ; Mon, 16 Nov 2020 19:56:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="dDE9to1s" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731129AbgKPT4j (ORCPT ); Mon, 16 Nov 2020 14:56:39 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:42728 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731069AbgKPT4i (ORCPT ); Mon, 16 Nov 2020 14:56:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605556597; 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=0bA4pw5q7HHQg8TpZjusnVos/EyOd9oFFb9XD9wHdZQ=; b=dDE9to1siFCi4UoOIT9a5mHll6oq0GuEheiyMclmUXE+jixnwpSVkH5W3yh3u5xx2EGfBS hoQNTdAnqSU6PUbGyYUSL3zxCON2K07npaYZNSiwDS2e++0ibeV6pQsjqxyoRW+Uw5Y9No MPwusWNtW0E1bSN39uAfJmO6mevWWg8= 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-538-5Rg_nuSINhuae9dCIcPnLw-1; Mon, 16 Nov 2020 14:56:35 -0500 X-MC-Unique: 5Rg_nuSINhuae9dCIcPnLw-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 18B43802B6D; Mon, 16 Nov 2020 19:56:33 +0000 (UTC) Received: from w520.home (ovpn-112-213.phx2.redhat.com [10.3.112.213]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3514819C66; Mon, 16 Nov 2020 19:56:32 +0000 (UTC) Date: Mon, 16 Nov 2020 12:56:31 -0700 From: Alex Williamson To: Lu Baolu Cc: Cornelia Huck , Joerg Roedel , 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 1/1] vfio/type1: Add subdev_ioasid callback to vfio_iommu_driver_ops Message-ID: <20201116125631.2d043fcd@w520.home> In-Reply-To: <20201112022407.2063896-1-baolu.lu@linux.intel.com> References: <20201112022407.2063896-1-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, 12 Nov 2020 10:24:07 +0800 Lu Baolu wrote: > Add API for getting the ioasid of a subdevice (vfio/mdev). This calls > into the backend IOMMU module to get the actual value or error number > if ioasid for subdevice is not supported. The physical device driver > implementations which rely on the vfio/mdev framework for mediated > device user level access could typically consume this interface like > below: > > struct device *dev = mdev_dev(mdev); > unsigned int pasid; > int ret; > > ret = vfio_subdev_ioasid(dev, &pasid); > if (ret < 0) > return ret; > > /* Program device context with pasid value. */ > .... Seems like an overly specific callback. We already export means for you to get a vfio_group, test that a device is an mdev, and get the iommu device from an mdev. So you can already test whether a given device is an mdev with an iommu backing device that supports aux domains. The only missing piece seems to be that you can't get the domain for a group in order to retrieve the pasid. So why aren't we exporting a callback that given a vfio_group provides the iommu domain? Thanks, Alex > Signed-off-by: Lu Baolu > --- > drivers/vfio/vfio.c | 34 ++++++++++++++++++++ > drivers/vfio/vfio_iommu_type1.c | 57 +++++++++++++++++++++++++++++++++ > include/linux/vfio.h | 4 +++ > 3 files changed, 95 insertions(+) > > diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c > index 2151bc7f87ab..4931e1492921 100644 > --- a/drivers/vfio/vfio.c > +++ b/drivers/vfio/vfio.c > @@ -2331,6 +2331,40 @@ int vfio_unregister_notifier(struct device *dev, enum vfio_notify_type type, > } > EXPORT_SYMBOL(vfio_unregister_notifier); > > +int vfio_subdev_ioasid(struct device *dev, unsigned int *id) > +{ > + struct vfio_container *container; > + struct vfio_iommu_driver *driver; > + struct vfio_group *group; > + int ret; > + > + if (!dev || !id) > + return -EINVAL; > + > + group = vfio_group_get_from_dev(dev); > + if (!group) > + return -ENODEV; > + > + ret = vfio_group_add_container_user(group); > + if (ret) > + goto out; > + > + container = group->container; > + driver = container->iommu_driver; > + if (likely(driver && driver->ops->subdev_ioasid)) > + ret = driver->ops->subdev_ioasid(container->iommu_data, > + group->iommu_group, id); > + else > + ret = -ENOTTY; > + > + vfio_group_try_dissolve_container(group); > + > +out: > + vfio_group_put(group); > + return ret; > +} > +EXPORT_SYMBOL(vfio_subdev_ioasid); > + > /** > * Module/class support > */ > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > index 67e827638995..f94cc7707d7e 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c > @@ -2980,6 +2980,62 @@ static int vfio_iommu_type1_dma_rw(void *iommu_data, dma_addr_t user_iova, > return ret; > } > > +static int vfio_iommu_type1_subdev_ioasid(void *iommu_data, > + struct iommu_group *iommu_group, > + unsigned int *id) > +{ > + struct vfio_iommu *iommu = iommu_data; > + struct vfio_domain *domain = NULL, *d; > + struct device *iommu_device = NULL; > + struct bus_type *bus = NULL; > + int ret; > + > + if (!iommu || !iommu_group || !id) > + return -EINVAL; > + > + mutex_lock(&iommu->lock); > + ret = iommu_group_for_each_dev(iommu_group, &bus, vfio_bus_type); > + if (ret) > + goto out; > + > + if (!vfio_bus_is_mdev(bus)) { > + ret = -EINVAL; > + goto out; > + } > + > + ret = iommu_group_for_each_dev(iommu_group, &iommu_device, > + vfio_mdev_iommu_device); > + if (ret || !iommu_device || > + !iommu_dev_feature_enabled(iommu_device, IOMMU_DEV_FEAT_AUX)) { > + ret = -ENODEV; > + goto out; > + } > + > + list_for_each_entry(d, &iommu->domain_list, next) { > + if (find_iommu_group(d, iommu_group)) { > + domain = d; > + break; > + } > + } > + > + if (!domain) { > + ret = -ENODEV; > + goto out; > + } > + > + ret = iommu_aux_get_pasid(domain->domain, iommu_device); > + if (ret > 0) { > + *id = ret; > + ret = 0; > + } else { > + ret = -ENOSPC; > + } > + > +out: > + mutex_unlock(&iommu->lock); > + return ret; > +} > + > static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = { > .name = "vfio-iommu-type1", > .owner = THIS_MODULE, > @@ -2993,6 +3049,7 @@ 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, > + .subdev_ioasid = vfio_iommu_type1_subdev_ioasid, > }; > > static int __init vfio_iommu_type1_init(void) > diff --git a/include/linux/vfio.h b/include/linux/vfio.h > index 38d3c6a8dc7e..6dcf09a2796d 100644 > --- a/include/linux/vfio.h > +++ b/include/linux/vfio.h > @@ -90,6 +90,9 @@ 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); > + int (*subdev_ioasid)(void *iommu_data, > + struct iommu_group *group, > + unsigned int *id); > }; > > extern int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops); > @@ -125,6 +128,7 @@ 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 int vfio_subdev_ioasid(struct device *dev, unsigned int *id); > > /* each type has independent events */ > enum vfio_notify_type {