From nobody Fri May 8 06:49:51 2026 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 63621C43219 for ; Mon, 9 May 2022 07:25:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235047AbiEIHZM (ORCPT ); Mon, 9 May 2022 03:25:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34428 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236250AbiEIHSy (ORCPT ); Mon, 9 May 2022 03:18:54 -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 A6E2B1B1F56 for ; Mon, 9 May 2022 00:15:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1652080500; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=y4dvnbKnaNy27zkgDTuBkmRrOFE3VwNzMUWnMGEyi1M=; b=KWvmXAemBNaPs1byrk8UxqWu5XpLlqfHaxQPwTReuEQMB5eb/usKI6ucGEcwJzwsC7oHuO xSsiHVuo/srwVVcBaKACJ7NNVT1ZZyXpASkeHO1juq9GSj/G0qhrK87Wi62erTIFp7dYT9 C2lS9tBPRfcNcqoXLgquTlETlC3VJ5c= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-223-I9W7oumRPWWm6mGC5d-AGg-1; Mon, 09 May 2022 03:14:59 -0400 X-MC-Unique: I9W7oumRPWWm6mGC5d-AGg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 41A441C068C2; 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 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" We count pinned_vm as follow in vhost-vDPA lock_limit =3D rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; if (npages + atomic64_read(&dev->mm->pinned_vm) > lock_limit) { ret =3D -ENOMEM; goto unlock; } This means if we have two vDPA devices for the same VM the pages would be c= ounted twice So we add a tree to save the page that counted and we will not count it aga= in Signed-off-by: Cindy Lu 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 =20 #include "vhost.h" +#include +#include +#include =20 enum { VHOST_VDPA_BACKEND_FEATURES =3D @@ -505,6 +508,50 @@ static long vhost_vdpa_unlocked_ioctl(struct file *fil= ep, mutex_unlock(&d->mutex); return r; } +int vhost_vdpa_add_range_ctx(struct rb_root_cached *root, u64 start, u64 l= ast) +{ + 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 =3D=3D 0 && last =3D=3D ULONG_MAX) { + u64 mid =3D last / 2; + + vhost_vdpa_add_range_ctx(root, start, mid); + start =3D mid + 1; + } + + new_node =3D kmalloc(sizeof(struct interval_tree_node), GFP_ATOMIC); + if (!new_node) + return -ENOMEM; + + new_node->start =3D start; + new_node->last =3D 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 =3D 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); +} =20 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, u= 64 start, u64 last) struct vhost_iotlb_map *map; struct page *page; unsigned long pfn, pinned; + struct interval_tree_node *new_node =3D NULL; =20 while ((map =3D vhost_iotlb_itree_first(iotlb, start, last)) !=3D NULL) { pinned =3D 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 =3D 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 iov= a, struct vdpa_device *vdpa =3D v->vdpa; const struct vdpa_config_ops *ops =3D vdpa->config; int r =3D 0; + struct interval_tree_node *new_node =3D NULL; =20 r =3D 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 io= va, return r; } =20 - if (!vdpa->use_va) - atomic64_add(PFN_DOWN(size), &dev->mm->pinned_vm); + if (!vdpa->use_va) { + new_node =3D vhost_vdpa_search_range(&dev->mm->root_for_vdpa, + iova, iova + size - 1); + + if (new_node =3D=3D 0) { + r =3D 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; + } =20 + atomic64_add(PFN_DOWN(size), &dev->mm->pinned_vm); + } + } return 0; } =20 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; =20 /* --=20 2.34.1