From patchwork Wed Jan 29 12:11:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Liu, Yi L" X-Patchwork-Id: 11355993 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AB93F138C for ; Wed, 29 Jan 2020 12:06:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 94A262173E for ; Wed, 29 Jan 2020 12:06:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726772AbgA2MGw (ORCPT ); Wed, 29 Jan 2020 07:06:52 -0500 Received: from mga03.intel.com ([134.134.136.65]:59025 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726707AbgA2MGm (ORCPT ); Wed, 29 Jan 2020 07:06:42 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 29 Jan 2020 04:06:38 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,377,1574150400"; d="scan'208";a="222433142" Received: from jacob-builder.jf.intel.com ([10.7.199.155]) by orsmga008.jf.intel.com with ESMTP; 29 Jan 2020 04:06:38 -0800 From: "Liu, Yi L" To: alex.williamson@redhat.com, eric.auger@redhat.com Cc: kevin.tian@intel.com, jacob.jun.pan@linux.intel.com, joro@8bytes.org, ashok.raj@intel.com, yi.l.liu@intel.com, jun.j.tian@intel.com, yi.y.sun@intel.com, jean-philippe.brucker@arm.com, peterx@redhat.com, iommu@lists.linux-foundation.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC v3 3/8] vfio: Reclaim PASIDs when application is down Date: Wed, 29 Jan 2020 04:11:47 -0800 Message-Id: <1580299912-86084-4-git-send-email-yi.l.liu@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1580299912-86084-1-git-send-email-yi.l.liu@intel.com> References: <1580299912-86084-1-git-send-email-yi.l.liu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Liu Yi L When userspace application is down, kernel should reclaim the PASIDs allocated for this application to avoid PASID leak. This patch adds a PASID list in vfio_mm structure to track the allocated PASIDs. The PASID reclaim will be triggered when last vfio container is released. Previous discussions: https://patchwork.kernel.org/patch/11209429/ Cc: Kevin Tian CC: Jacob Pan Cc: Alex Williamson Cc: Eric Auger Cc: Jean-Philippe Brucker Signed-off-by: Liu Yi L --- drivers/vfio/vfio.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++--- include/linux/vfio.h | 6 ++++++ 2 files changed, 64 insertions(+), 3 deletions(-) diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index c43c757..425d60a 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -2148,15 +2148,31 @@ static struct vfio_mm *vfio_create_mm(struct mm_struct *mm) vmm->pasid_quota = VFIO_DEFAULT_PASID_QUOTA; vmm->pasid_count = 0; mutex_init(&vmm->pasid_lock); + INIT_LIST_HEAD(&vmm->pasid_list); list_add(&vmm->vfio_next, &vfio.vfio_mm_list); return vmm; } +static void vfio_mm_reclaim_pasid(struct vfio_mm *vmm) +{ + struct pasid_node *pnode, *tmp; + + mutex_lock(&vmm->pasid_lock); + list_for_each_entry_safe(pnode, tmp, &vmm->pasid_list, next) { + pr_info("%s, reclaim pasid: %u\n", __func__, pnode->pasid); + list_del(&pnode->next); + ioasid_free(pnode->pasid); + kfree(pnode); + } + mutex_unlock(&vmm->pasid_lock); +} + static void vfio_mm_unlock_and_free(struct vfio_mm *vmm) { mutex_unlock(&vfio.vfio_mm_lock); + vfio_mm_reclaim_pasid(vmm); kfree(vmm); } @@ -2204,6 +2220,39 @@ struct vfio_mm *vfio_mm_get_from_task(struct task_struct *task) } EXPORT_SYMBOL_GPL(vfio_mm_get_from_task); +/** + * Caller should hold vmm->pasid_lock + */ +static int vfio_mm_insert_pasid_node(struct vfio_mm *vmm, u32 pasid) +{ + struct pasid_node *pnode; + + pnode = kzalloc(sizeof(*pnode), GFP_KERNEL); + if (!pnode) + return -ENOMEM; + pnode->pasid = pasid; + list_add(&pnode->next, &vmm->pasid_list); + + return 0; +} + +/** + * Caller should hold vmm->pasid_lock + */ +static void vfio_mm_remove_pasid_node(struct vfio_mm *vmm, u32 pasid) +{ + struct pasid_node *pnode, *tmp; + + list_for_each_entry_safe(pnode, tmp, &vmm->pasid_list, next) { + if (pnode->pasid == pasid) { + list_del(&pnode->next); + kfree(pnode); + break; + } + } + +} + int vfio_mm_pasid_alloc(struct vfio_mm *vmm, int min, int max) { ioasid_t pasid; @@ -2221,9 +2270,15 @@ int vfio_mm_pasid_alloc(struct vfio_mm *vmm, int min, int max) ret = -ENOSPC; goto out_unlock; } - vmm->pasid_count++; - ret = pasid; + if (vfio_mm_insert_pasid_node(vmm, pasid)) { + ret = -ENOSPC; + ioasid_free(pasid); + } else { + ret = pasid; + vmm->pasid_count++; + } + out_unlock: mutex_unlock(&vmm->pasid_lock); return ret; @@ -2243,7 +2298,7 @@ int vfio_mm_pasid_free(struct vfio_mm *vmm, ioasid_t pasid) goto out_unlock; } ioasid_free(pasid); - + vfio_mm_remove_pasid_node(vmm, pasid); vmm->pasid_count--; out_unlock: mutex_unlock(&vmm->pasid_lock); diff --git a/include/linux/vfio.h b/include/linux/vfio.h index b6c9c8c..a2ea7e0 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -89,12 +89,18 @@ extern int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops); extern void vfio_unregister_iommu_driver( const struct vfio_iommu_driver_ops *ops); +struct pasid_node { + u32 pasid; + struct list_head next; +}; + #define VFIO_DEFAULT_PASID_QUOTA 1000 struct vfio_mm { struct kref kref; struct mutex pasid_lock; int pasid_quota; int pasid_count; + struct list_head pasid_list; struct mm_struct *mm; struct list_head vfio_next; };