From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 685A6A0524; Tue, 13 Apr 2021 13:33:17 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id CE129160E47; Tue, 13 Apr 2021 13:33:16 +0200 (CEST) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by mails.dpdk.org (Postfix) with ESMTP id 87BC6160E2D for ; Tue, 13 Apr 2021 13:33:15 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1618313595; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Rjv0TEtTGTmX8ojwr3I4I0QEkRRafCAI+cpOTE7ywjI=; b=YEA0iLM6oSPpbs0C72EbloC8IEy7paOzY639FTrliLNQt2N7YfFBTE2j6b9oAqF53xDzX5 9HVzGZ1CjtfGFY8hRIYY2Nm0IpiPj3JiMoTwTvaSgyCVfSTGkPzhaltAWYAUj4nUFr1ho0 3xDtLOctZ5awBJj9kVC/ssz0XVwGQoA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-226-nqOwYtnyNaG9ihf-6B7rxw-1; Tue, 13 Apr 2021 07:33:13 -0400 X-MC-Unique: nqOwYtnyNaG9ihf-6B7rxw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5556083DEAA; Tue, 13 Apr 2021 11:33:12 +0000 (UTC) Received: from [10.36.110.28] (unknown [10.36.110.28]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E971410023AB; Tue, 13 Apr 2021 11:33:10 +0000 (UTC) To: Jiayu Hu , dev@dpdk.org Cc: chenbo.xia@intel.com, yinan.wang@intel.com, sunil.pai.g@intel.com, cheng1.jiang@intel.com References: <1615985773-406787-1-git-send-email-jiayu.hu@intel.com> <1617368642-131298-1-git-send-email-jiayu.hu@intel.com> <1617368642-131298-4-git-send-email-jiayu.hu@intel.com> From: Maxime Coquelin Message-ID: Date: Tue, 13 Apr 2021 13:33:09 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <1617368642-131298-4-git-send-email-jiayu.hu@intel.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=maxime.coquelin@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v2 3/4] vhost: avoid deadlock on async register X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 4/2/21 3:04 PM, Jiayu Hu wrote: > Users can register async copy device in vring_state_changed(), > when vhost queue is enabled. However, a deadlock occurs inside > rte_vhost_async_channel_register(), if VHOST_USER_F_PROTOCOL_FEATURES > is not supported, as vhost_user_msg_handler() takes vq->access_lock > before calling vhost_user_set_vring_kick(). > > This patch avoids async register deadlock by removing calling > vring_state_changed() in vhost_user_set_vring_kick(). It's safe > as vhost_user_msg_handler() will call vring_state_changed() anyway. > > Signed-off-by: Jiayu Hu > --- > lib/librte_vhost/vhost_user.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c > index 44c0452..8f0eba6 100644 > --- a/lib/librte_vhost/vhost_user.c > +++ b/lib/librte_vhost/vhost_user.c > @@ -1918,9 +1918,6 @@ vhost_user_set_vring_kick(struct virtio_net **pdev, struct VhostUserMsg *msg, > */ > if (!(dev->features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES))) { > vq->enabled = true; > - if (dev->notify_ops->vring_state_changed) > - dev->notify_ops->vring_state_changed( > - dev->vid, file.index, 1); > } > > if (vq->ready) { > As replied earlier on v1, I agree the call to vring_state_changed here is not needed. But it might not be enough, there are other cases where you could have issues. Please add stable and Fixes tag. Thanks, Maxime