From patchwork Mon Dec 6 01:58:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolu Lu X-Patchwork-Id: 12657551 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 30C31C433EF for ; Mon, 6 Dec 2021 02:00:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232505AbhLFCDt (ORCPT ); Sun, 5 Dec 2021 21:03:49 -0500 Received: from mga05.intel.com ([192.55.52.43]:57750 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232560AbhLFCDq (ORCPT ); Sun, 5 Dec 2021 21:03:46 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10189"; a="323482804" X-IronPort-AV: E=Sophos;i="5.87,290,1631602800"; d="scan'208";a="323482804" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Dec 2021 18:00:15 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,290,1631602800"; d="scan'208";a="514542278" Received: from allen-box.sh.intel.com ([10.239.159.118]) by orsmga008.jf.intel.com with ESMTP; 05 Dec 2021 18:00:06 -0800 From: Lu Baolu To: Greg Kroah-Hartman , Joerg Roedel , Alex Williamson , Bjorn Helgaas , Jason Gunthorpe , Christoph Hellwig , Kevin Tian , Ashok Raj Cc: Will Deacon , Robin Murphy , Dan Williams , rafael@kernel.org, Diana Craciun , Cornelia Huck , Eric Auger , Liu Yi L , Jacob jun Pan , Chaitanya Kulkarni , Stuart Yoder , Laurentiu Tudor , Thierry Reding , David Airlie , Daniel Vetter , Jonathan Hunter , Li Yang , Dmitry Osipenko , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH v3 07/18] PCI: Add driver dma ownership management Date: Mon, 6 Dec 2021 09:58:52 +0800 Message-Id: <20211206015903.88687-8-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211206015903.88687-1-baolu.lu@linux.intel.com> References: <20211206015903.88687-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Multiple PCI devices may be placed in the same IOMMU group because they cannot be isolated from each other. These devices must either be entirely under kernel control or userspace control, never a mixture. This checks and sets DMA ownership during driver binding, and vice versa, release the ownership during driver unbinding. Driver may set a new flag (suppress_auto_claim_dma_owner) to disable auto claiming DMA_OWNER_DMA_API ownership in the binding process. For instance, the userspace framework drivers (vfio etc.) which need to manually claim DMA_OWNER_PRIVATE_DOMAIN_USER when assigning a device to userspace. Signed-off-by: Lu Baolu --- include/linux/pci.h | 5 +++++ drivers/pci/pci-driver.c | 21 +++++++++++++++++++++ 2 files changed, 26 insertions(+) diff --git a/include/linux/pci.h b/include/linux/pci.h index 18a75c8e615c..1b29af0ab43b 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -882,6 +882,10 @@ struct module; * created once it is bound to the driver. * @driver: Driver model structure. * @dynids: List of dynamically added device IDs. + * @suppress_auto_claim_dma_owner: Disable auto claiming of kernel DMA owner. + * Drivers which don't require DMA or want to manually claim the + * owner type (e.g. userspace driver frameworks) could set this + * flag. */ struct pci_driver { struct list_head node; @@ -900,6 +904,7 @@ struct pci_driver { const struct attribute_group **dev_groups; struct device_driver driver; struct pci_dynids dynids; + bool suppress_auto_claim_dma_owner; }; static inline struct pci_driver *to_pci_driver(struct device_driver *drv) diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 588588cfda48..92712645e179 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -20,6 +20,7 @@ #include #include #include +#include #include "pci.h" #include "pcie/portdrv.h" @@ -1590,9 +1591,16 @@ static int pci_bus_num_vf(struct device *dev) */ static int pci_dma_configure(struct device *dev) { + struct pci_driver *driver = to_pci_driver(dev->driver); struct device *bridge; int ret = 0; + if (!driver->suppress_auto_claim_dma_owner) { + ret = iommu_device_set_dma_owner(dev, DMA_OWNER_DMA_API, NULL); + if (ret) + return ret; + } + bridge = pci_get_host_bridge_device(to_pci_dev(dev)); if (IS_ENABLED(CONFIG_OF) && bridge->parent && @@ -1605,9 +1613,21 @@ static int pci_dma_configure(struct device *dev) } pci_put_host_bridge_device(bridge); + + if (ret && !driver->suppress_auto_claim_dma_owner) + iommu_device_release_dma_owner(dev, DMA_OWNER_DMA_API); + return ret; } +static void pci_dma_cleanup(struct device *dev) +{ + struct pci_driver *driver = to_pci_driver(dev->driver); + + if (!driver->suppress_auto_claim_dma_owner) + iommu_device_release_dma_owner(dev, DMA_OWNER_DMA_API); +} + struct bus_type pci_bus_type = { .name = "pci", .match = pci_bus_match, @@ -1621,6 +1641,7 @@ struct bus_type pci_bus_type = { .pm = PCI_PM_OPS_PTR, .num_vf = pci_bus_num_vf, .dma_configure = pci_dma_configure, + .dma_cleanup = pci_dma_cleanup, }; EXPORT_SYMBOL(pci_bus_type);