From patchwork Mon Nov 15 02:05:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolu Lu X-Patchwork-Id: 12618545 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 20C27C433EF for ; Mon, 15 Nov 2021 02:13:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 030F960FD8 for ; Mon, 15 Nov 2021 02:13:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236402AbhKOCQW (ORCPT ); Sun, 14 Nov 2021 21:16:22 -0500 Received: from mga05.intel.com ([192.55.52.43]:53956 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236317AbhKOCOR (ORCPT ); Sun, 14 Nov 2021 21:14:17 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10168"; a="319573956" X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="319573956" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Nov 2021 18:11:08 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="505714687" Received: from allen-box.sh.intel.com ([10.239.159.118]) by orsmga008.jf.intel.com with ESMTP; 14 Nov 2021 18:11:03 -0800 From: Lu Baolu To: Greg Kroah-Hartman , Joerg Roedel , Alex Williamson , Bjorn Helgaas , Jason Gunthorpe , Kevin Tian , Ashok Raj Cc: Will Deacon , rafael@kernel.org, Diana Craciun , Cornelia Huck , Eric Auger , Liu Yi L , Jacob jun Pan , Chaitanya Kulkarni , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH 08/11] vfio: Remove use of vfio_group_viable() Date: Mon, 15 Nov 2021 10:05:49 +0800 Message-Id: <20211115020552.2378167-9-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211115020552.2378167-1-baolu.lu@linux.intel.com> References: <20211115020552.2378167-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org As DMA_OWNER_USER 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 4e21b37e0ea8..6847117fac6a 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -1315,12 +1315,6 @@ 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)) @@ -1330,7 +1324,7 @@ 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; } @@ -1348,7 +1342,7 @@ 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)) @@ -1440,11 +1434,11 @@ 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;