From patchwork Fri Dec 17 06:37:04 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolu Lu X-Patchwork-Id: 12683761 X-Patchwork-Delegate: bhelgaas@google.com 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 7DBC6C433FE for ; Fri, 17 Dec 2021 06:38:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233417AbhLQGis (ORCPT ); Fri, 17 Dec 2021 01:38:48 -0500 Received: from mga06.intel.com ([134.134.136.31]:50426 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233421AbhLQGis (ORCPT ); Fri, 17 Dec 2021 01:38:48 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10200"; a="300467728" X-IronPort-AV: E=Sophos;i="5.88,213,1635231600"; d="scan'208";a="300467728" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Dec 2021 22:38:47 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,213,1635231600"; d="scan'208";a="519623361" Received: from allen-box.sh.intel.com ([10.239.159.118]) by orsmga008.jf.intel.com with ESMTP; 16 Dec 2021 22:38:39 -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 v4 09/13] vfio: Remove use of vfio_group_viable() Date: Fri, 17 Dec 2021 14:37:04 +0800 Message-Id: <20211217063708.1740334-10-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211217063708.1740334-1-baolu.lu@linux.intel.com> References: <20211217063708.1740334-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org As DMA USER ownership is claimed for the iommu group when a vfio group is added to a vfio container, the vfio group viability is guaranteed as long as group->container_users > 0. Remove those unnecessary group viability checks which are only hit when group->container_users is not zero. The only remaining reference is in GROUP_GET_STATUS, which could be called at any time when group fd is valid. Here we just replace the vfio_group_viable() by directly calling iommu core to get viability status. Signed-off-by: Lu Baolu --- drivers/vfio/vfio.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-) diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index b75ba7551079..241756b85705 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -1316,12 +1316,6 @@ static int vfio_group_set_container(struct vfio_group *group, int container_fd) return ret; } -static bool vfio_group_viable(struct vfio_group *group) -{ - return (iommu_group_for_each_dev(group->iommu_group, - group, vfio_dev_viable) == 0); -} - static int vfio_group_add_container_user(struct vfio_group *group) { if (!atomic_inc_not_zero(&group->container_users)) @@ -1331,7 +1325,7 @@ static int vfio_group_add_container_user(struct vfio_group *group) atomic_dec(&group->container_users); return -EPERM; } - if (!group->container->iommu_driver || !vfio_group_viable(group)) { + if (!group->container->iommu_driver) { atomic_dec(&group->container_users); return -EINVAL; } @@ -1349,7 +1343,7 @@ static int vfio_group_get_device_fd(struct vfio_group *group, char *buf) int ret = 0; if (0 == atomic_read(&group->container_users) || - !group->container->iommu_driver || !vfio_group_viable(group)) + !group->container->iommu_driver) return -EINVAL; if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO)) @@ -1441,11 +1435,11 @@ static long vfio_group_fops_unl_ioctl(struct file *filep, status.flags = 0; - if (vfio_group_viable(group)) - status.flags |= VFIO_GROUP_FLAGS_VIABLE; - if (group->container) - status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET; + status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET | + VFIO_GROUP_FLAGS_VIABLE; + else if (iommu_group_dma_owner_unclaimed(group->iommu_group)) + status.flags |= VFIO_GROUP_FLAGS_VIABLE; if (copy_to_user((void __user *)arg, &status, minsz)) return -EFAULT;