From mboxrd@z Thu Jan 1 00:00:00 1970 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 380EEC43334 for ; Mon, 27 Jun 2022 10:01:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234067AbiF0KBj (ORCPT ); Mon, 27 Jun 2022 06:01:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47806 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233617AbiF0KBb (ORCPT ); Mon, 27 Jun 2022 06:01:31 -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 9C00B63FE for ; Mon, 27 Jun 2022 03:01:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1656324088; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=XfIYzOFq9+jwXTV0OEEFxQKh2b4fXVCS3UReweWTk08=; b=WjnT3nZ0TJW/DocrYhkxmD1ysgBXs7SfBNp9jPUZWfAYjX1hAgHYsQ4sdIWURUaA/4EZkc o71lfUC9VXHeXTIC3aQFlAAklA3R9AqgpEhM6Q8fVhcRgTgmVwVSqCorCQeiQivjxmg0P9 /iXoNYm5MYa/rolOddVPmeuggkwwIus= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-7-7uOl0VN8MNKUerh85r9Nkg-1; Mon, 27 Jun 2022 06:01:27 -0400 X-MC-Unique: 7uOl0VN8MNKUerh85r9Nkg-1 Received: by mail-wm1-f71.google.com with SMTP id p22-20020a05600c359600b0039c7b23a1c7so7105209wmq.2 for ; Mon, 27 Jun 2022 03:01:27 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=XfIYzOFq9+jwXTV0OEEFxQKh2b4fXVCS3UReweWTk08=; b=tGgQmsb7kEn5BUZgFgWQT5MR0F0MeareLOlEYlV3VjwxlR1Q6Euv5Xay2ddT+QUczB fD+NTpTRVMrVWHiy//kbZ4JhLT+VRgA3NLS4V+ug/Q/y5fARPtN2+Rk9PwmQvidzB5Kb PBznvI7jZm4Lt3oEW3WOTMJKKJtzb/feLC+WKi7tpMo6rQMTdJhge27wyyqRnXeU3987 qbFJQ4snqyaBbjiIuzmvfL0M12s9jymcrfzyNuJSH9MO32K4sOTinYzhX5mTvPNQgCWE 13xqJklWHLoYzo7IkfNw5P2tQTHGY4lGWcxLBBPdZz5My1tJZWwVbOhXOBGSkdCdWpkA 2Hpg== X-Gm-Message-State: AJIora+B7sxQAME7TRem4oNbzPZ6eTOTYQ4x7WERc2Yyo0d/J0XyLwOa Lwt0s9ykh44SKstiZaYQNRgysbm+KYjTaN/L2Q+NGLIkjTEphEsi4cnm5Zsur/J+h4UAfXQS//q ZtZGqXACf3Q50XltxMpK+t18l X-Received: by 2002:adf:d20e:0:b0:21b:9bf8:75e with SMTP id j14-20020adfd20e000000b0021b9bf8075emr11372945wrh.416.1656324086147; Mon, 27 Jun 2022 03:01:26 -0700 (PDT) X-Google-Smtp-Source: AGRyM1u71NWi+QLUpjcQmtx2VVGYmH07xgw2ZqtlMg5pGrYX9gCttKo+VrvS67vS2J5YcclFCLqr9Q== X-Received: by 2002:adf:d20e:0:b0:21b:9bf8:75e with SMTP id j14-20020adfd20e000000b0021b9bf8075emr11372921wrh.416.1656324085841; Mon, 27 Jun 2022 03:01:25 -0700 (PDT) Received: from redhat.com ([2.54.45.90]) by smtp.gmail.com with ESMTPSA id c17-20020a05600c0ad100b003973ea7e725sm23047559wmr.0.2022.06.27.03.01.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Jun 2022 03:01:25 -0700 (PDT) Date: Mon, 27 Jun 2022 06:01:21 -0400 From: "Michael S. Tsirkin" To: Cindy Lu Cc: Jason Wang , virtualization , linux-kernel Subject: Re: [PATCH v3 1/2] vhost: Add rbtree vdpa_mem_tree to saved the counted mem Message-ID: <20220627055826-mutt-send-email-mst@kernel.org> References: <20220626090409.1011144-1-lulu@redhat.com> <20220626055420-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 27, 2022 at 04:12:57PM +0800, Cindy Lu wrote: > On Sun, Jun 26, 2022 at 6:01 PM Michael S. Tsirkin wrote: > > > > On Sun, Jun 26, 2022 at 05:04:08PM +0800, Cindy Lu wrote: > > > 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. > > > > > > Add vdpa_mem_tree to saved the mem that already counted. > > > use a hlist to saved the root for vdpa_mem_tree. > > > > > > Signed-off-by: Cindy Lu > > > --- > > > drivers/vhost/vhost.c | 63 +++++++++++++++++++++++++++++++++++++++++++ > > > drivers/vhost/vhost.h | 1 + > > > 2 files changed, 64 insertions(+) > > > > > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > > > index 40097826cff0..4ca8b1ed944b 100644 > > > --- a/drivers/vhost/vhost.c > > > +++ b/drivers/vhost/vhost.c > > > @@ -32,6 +32,8 @@ > > > #include > > > > > > #include "vhost.h" > > > +#include > > > +#include > > > > > > static ushort max_mem_regions = 64; > > > module_param(max_mem_regions, ushort, 0444); > > > @@ -49,6 +51,14 @@ enum { > > > #define vhost_used_event(vq) ((__virtio16 __user *)&vq->avail->ring[vq->num]) > > > #define vhost_avail_event(vq) ((__virtio16 __user *)&vq->used->ring[vq->num]) > > > > > > +struct vhost_vdpa_rbtree_node { > > > + struct hlist_node node; > > > + struct rb_root_cached vdpa_mem_tree; > > > + struct mm_struct *mm_using; > > > +}; > > > +static DECLARE_HASHTABLE(vhost_vdpa_rbtree_hlist, 8); > > > +int vhost_vdpa_rbtree_hlist_status; > > > + > > > #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY > > > static void vhost_disable_cross_endian(struct vhost_virtqueue *vq) > > > { > > > > Are you trying to save some per-mm information here? > > Can't we just add it to mm_struct? > > > yes, this is a per-mm information, but I have checked with jason before, > seems it maybe difficult to change the mm_struct in upstream > so I add an to add a hlist instead > Thanks > Cindy Difficult how? You get more scrutiny if you try, for sure, and you need to need to generalize it enough that it looks useful outside the driver. But I guess that's good? > > > > > > > @@ -571,6 +581,51 @@ static void vhost_detach_mm(struct vhost_dev *dev) > > > dev->mm = NULL; > > > } > > > > > > +struct rb_root_cached *vhost_vdpa_get_mem_tree(struct mm_struct *mm) > > > +{ > > > + struct vhost_vdpa_rbtree_node *rbtree_root = NULL; > > > + struct rb_root_cached *vdpa_tree; > > > + u32 key; > > > + > > > + /* No hased table, init one */ > > > + if (vhost_vdpa_rbtree_hlist_status == 0) { > > > + hash_init(vhost_vdpa_rbtree_hlist); > > > + vhost_vdpa_rbtree_hlist_status = 1; > > > + } > > > + > > > + key = jhash_1word((u64)mm, JHASH_INITVAL); > > > + hash_for_each_possible(vhost_vdpa_rbtree_hlist, rbtree_root, node, > > > + key) { > > > + if (rbtree_root->mm_using == mm) > > > + return &(rbtree_root->vdpa_mem_tree); > > > + } > > > + rbtree_root = kmalloc(sizeof(*rbtree_root), GFP_KERNEL); > > > + if (!rbtree_root) > > > + return NULL; > > > + rbtree_root->mm_using = mm; > > > + rbtree_root->vdpa_mem_tree = RB_ROOT_CACHED; > > > + hash_add(vhost_vdpa_rbtree_hlist, &rbtree_root->node, key); > > > + vdpa_tree = &(rbtree_root->vdpa_mem_tree); > > > + return vdpa_tree; > > > +} > > > + > > > +void vhost_vdpa_relase_mem_tree(struct mm_struct *mm) > > > +{ > > > + struct vhost_vdpa_rbtree_node *rbtree_root = NULL; > > > + u32 key; > > > + > > > + key = jhash_1word((u64)mm, JHASH_INITVAL); > > > + > > > + /* No hased table, init one */ > > > + hash_for_each_possible(vhost_vdpa_rbtree_hlist, rbtree_root, node, > > > + key) { > > > + if (rbtree_root->mm_using == mm) { > > > + hash_del(&rbtree_root->node); > > > + kfree(rbtree_root); > > > + } > > > + } > > > +} > > > + > > > /* Caller should have device mutex */ > > > long vhost_dev_set_owner(struct vhost_dev *dev) > > > { > > > @@ -605,6 +660,11 @@ long vhost_dev_set_owner(struct vhost_dev *dev) > > > err = vhost_dev_alloc_iovecs(dev); > > > if (err) > > > goto err_cgroup; > > > + dev->vdpa_mem_tree = vhost_vdpa_get_mem_tree(dev->mm); > > > + if (dev->vdpa_mem_tree == NULL) { > > > + err = -ENOMEM; > > > + goto err_cgroup; > > > + } > > > > > > return 0; > > > err_cgroup: > > > @@ -613,6 +673,7 @@ long vhost_dev_set_owner(struct vhost_dev *dev) > > > dev->worker = NULL; > > > } > > > err_worker: > > > + vhost_vdpa_relase_mem_tree(dev->mm); > > > vhost_detach_mm(dev); > > > dev->kcov_handle = 0; > > > err_mm: > > > @@ -710,6 +771,8 @@ void vhost_dev_cleanup(struct vhost_dev *dev) > > > dev->worker = NULL; > > > dev->kcov_handle = 0; > > > } > > > + > > > + vhost_vdpa_relase_mem_tree(dev->mm); > > > vhost_detach_mm(dev); > > > } > > > EXPORT_SYMBOL_GPL(vhost_dev_cleanup); > > > diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h > > > index d9109107af08..84de33de3abf 100644 > > > --- a/drivers/vhost/vhost.h > > > +++ b/drivers/vhost/vhost.h > > > @@ -160,6 +160,7 @@ struct vhost_dev { > > > int byte_weight; > > > u64 kcov_handle; > > > bool use_worker; > > > + struct rb_root_cached *vdpa_mem_tree; > > > int (*msg_handler)(struct vhost_dev *dev, u32 asid, > > > struct vhost_iotlb_msg *msg); > > > }; > > > -- > > > 2.34.3 > >