From patchwork Mon May 9 07:14:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cindy Lu X-Patchwork-Id: 12843089 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 F06D3C4321E for ; Mon, 9 May 2022 07:33:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234199AbiEIHgh (ORCPT ); Mon, 9 May 2022 03:36:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34620 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236252AbiEIHS5 (ORCPT ); Mon, 9 May 2022 03:18:57 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id B113F1B1F56 for ; Mon, 9 May 2022 00:15:03 -0700 (PDT) DKIM-Signature: v=1; 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Mon, 9 May 2022 07:14:59 +0000 (UTC) Received: from server.redhat.com (ovpn-12-229.pek2.redhat.com [10.72.12.229]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 44B40111F3DB; Mon, 9 May 2022 07:14:51 +0000 (UTC) From: Cindy Lu To: lulu@redhat.com, jasowang@redhat.com, mst@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org Subject: [PATCH v1] vdpa: Do not count the pages that were already pinned in the vhost-vDPA Date: Mon, 9 May 2022 15:14:26 +0800 Message-Id: <20220509071426.155941-1-lulu@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org We count pinned_vm as follow in vhost-vDPA lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; if (npages + atomic64_read(&dev->mm->pinned_vm) > lock_limit) { ret = -ENOMEM; goto unlock; } This means if we have two vDPA devices for the same VM the pages would be counted twice So we add a tree to save the page that counted and we will not count it again Signed-off-by: Cindy Lu Reported-by: kernel test robot Reported-by: kernel test robot Reported-by: kernel test robot --- drivers/vhost/vdpa.c | 79 ++++++++++++++++++++++++++++++++++++++-- include/linux/mm_types.h | 2 + 2 files changed, 78 insertions(+), 3 deletions(-) diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index 05f5fd2af58f..48cb5c8264b5 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -24,6 +24,9 @@ #include #include "vhost.h" +#include +#include +#include enum { VHOST_VDPA_BACKEND_FEATURES = @@ -505,6 +508,50 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, mutex_unlock(&d->mutex); return r; } +int vhost_vdpa_add_range_ctx(struct rb_root_cached *root, u64 start, u64 last) +{ + struct interval_tree_node *new_node; + + if (last < start) + return -EFAULT; + + /* If the range being mapped is [0, ULONG_MAX], split it into two entries + * otherwise its size would overflow u64. + */ + if (start == 0 && last == ULONG_MAX) { + u64 mid = last / 2; + + vhost_vdpa_add_range_ctx(root, start, mid); + start = mid + 1; + } + + new_node = kmalloc(sizeof(struct interval_tree_node), GFP_ATOMIC); + if (!new_node) + return -ENOMEM; + + new_node->start = start; + new_node->last = last; + + interval_tree_insert(new_node, root); + + return 0; +} + +void vhost_vdpa_del_range(struct rb_root_cached *root, u64 start, u64 last) +{ + struct interval_tree_node *new_node; + + while ((new_node = interval_tree_iter_first(root, start, last))) { + interval_tree_remove(new_node, root); + kfree(new_node); + } +} + +struct interval_tree_node *vhost_vdpa_search_range(struct rb_root_cached *root, + u64 start, u64 last) +{ + return interval_tree_iter_first(root, start, last); +} static void vhost_vdpa_pa_unmap(struct vhost_vdpa *v, u64 start, u64 last) { @@ -513,6 +560,7 @@ static void vhost_vdpa_pa_unmap(struct vhost_vdpa *v, u64 start, u64 last) struct vhost_iotlb_map *map; struct page *page; unsigned long pfn, pinned; + struct interval_tree_node *new_node = NULL; while ((map = vhost_iotlb_itree_first(iotlb, start, last)) != NULL) { pinned = PFN_DOWN(map->size); @@ -523,7 +571,18 @@ static void vhost_vdpa_pa_unmap(struct vhost_vdpa *v, u64 start, u64 last) set_page_dirty_lock(page); unpin_user_page(page); } - atomic64_sub(PFN_DOWN(map->size), &dev->mm->pinned_vm); + + new_node = vhost_vdpa_search_range(&dev->mm->root_for_vdpa, + map->start, + map->start + map->size - 1); + + if (new_node) { + vhost_vdpa_del_range(&dev->mm->root_for_vdpa, + map->start, + map->start + map->size - 1); + atomic64_sub(PFN_DOWN(map->size), &dev->mm->pinned_vm); + } + vhost_iotlb_map_free(iotlb, map); } } @@ -591,6 +650,7 @@ static int vhost_vdpa_map(struct vhost_vdpa *v, u64 iova, struct vdpa_device *vdpa = v->vdpa; const struct vdpa_config_ops *ops = vdpa->config; int r = 0; + struct interval_tree_node *new_node = NULL; r = vhost_iotlb_add_range_ctx(dev->iotlb, iova, iova + size - 1, pa, perm, opaque); @@ -611,9 +671,22 @@ static int vhost_vdpa_map(struct vhost_vdpa *v, u64 iova, return r; } - if (!vdpa->use_va) - atomic64_add(PFN_DOWN(size), &dev->mm->pinned_vm); + if (!vdpa->use_va) { + new_node = vhost_vdpa_search_range(&dev->mm->root_for_vdpa, + iova, iova + size - 1); + + if (new_node == 0) { + r = vhost_vdpa_add_range_ctx(&dev->mm->root_for_vdpa, + iova, iova + size - 1); + if (r) { + vhost_iotlb_del_range(dev->iotlb, iova, + iova + size - 1); + return r; + } + atomic64_add(PFN_DOWN(size), &dev->mm->pinned_vm); + } + } return 0; } diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 5140e5feb486..46eaa6d0560b 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -634,6 +634,8 @@ struct mm_struct { #ifdef CONFIG_IOMMU_SUPPORT u32 pasid; #endif + struct rb_root_cached root_for_vdpa; + } __randomize_layout; /*