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 X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA8ACC43603 for ; Thu, 12 Dec 2019 17:34:49 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id BAE06206C3 for ; Thu, 12 Dec 2019 17:34:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Dm0a1bgk" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BAE06206C3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:34764 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ifSMS-0002ql-32 for qemu-devel@archiver.kernel.org; Thu, 12 Dec 2019 12:34:48 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:56383) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ifRWG-0006j3-6y for qemu-devel@nongnu.org; Thu, 12 Dec 2019 11:40:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ifRWE-0003Jl-UR for qemu-devel@nongnu.org; Thu, 12 Dec 2019 11:40:52 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:33930 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ifRWE-0003Iy-QA for qemu-devel@nongnu.org; Thu, 12 Dec 2019 11:40:50 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1576168850; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=eY+55BwTU0WLN/1oqkrnIhPvRCBbXjGTdjkx2rfvddI=; b=Dm0a1bgky6Twmhnq3879jnH8OqaC5yDw5bfisUo594lbXQ62k5kvPM/8ur2DZ1i0STMSEo HIHnhCS6QbDhn8Sfs+fFWAkOGRfq9LhUtGdjdvB17C27QXqQaGuQ1DhPRGRoqa3/J8oS91 cBI1wcd7CjwgOIhoQIYQt9AZZFIWFsk= 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-260-JGlQqa6UNkSXa5h4lBeatQ-1; Thu, 12 Dec 2019 11:40:49 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B1F268017DF for ; Thu, 12 Dec 2019 16:40:47 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-116-226.ams2.redhat.com [10.36.116.226]) by smtp.corp.redhat.com (Postfix) with ESMTP id D663C60BE1; Thu, 12 Dec 2019 16:40:46 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, stefanha@redhat.com, vgoyal@redhat.com Subject: [PATCH 065/104] contrib/libvhost-user: Protect slave fd with mutex Date: Thu, 12 Dec 2019 16:38:25 +0000 Message-Id: <20191212163904.159893-66-dgilbert@redhat.com> In-Reply-To: <20191212163904.159893-1-dgilbert@redhat.com> References: <20191212163904.159893-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-MC-Unique: JGlQqa6UNkSXa5h4lBeatQ-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 205.139.110.120 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: "Dr. David Alan Gilbert" In future patches we'll be performing commands on the slave-fd driven by commands on queues, since those queues will be driven by individual threads we need to make sure they don't attempt to use the slave-fd for multiple commands in parallel. Signed-off-by: Dr. David Alan Gilbert --- contrib/libvhost-user/libvhost-user.c | 24 ++++++++++++++++++++---- contrib/libvhost-user/libvhost-user.h | 3 +++ 2 files changed, 23 insertions(+), 4 deletions(-) diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/= libvhost-user.c index ec27b78ff1..63e41062a4 100644 --- a/contrib/libvhost-user/libvhost-user.c +++ b/contrib/libvhost-user/libvhost-user.c @@ -392,26 +392,37 @@ vu_send_reply(VuDev *dev, int conn_fd, VhostUserMsg *= vmsg) return vu_message_write(dev, conn_fd, vmsg); } =20 +/* + * Processes a reply on the slave channel. + * Entered with slave_mutex held and releases it before exit. + * Returns true on success. + */ static bool vu_process_message_reply(VuDev *dev, const VhostUserMsg *vmsg) { VhostUserMsg msg_reply; + bool result =3D false; =20 if ((vmsg->flags & VHOST_USER_NEED_REPLY_MASK) =3D=3D 0) { - return true; + result =3D true; + goto out; } =20 if (!vu_message_read(dev, dev->slave_fd, &msg_reply)) { - return false; + goto out; } =20 if (msg_reply.request !=3D vmsg->request) { DPRINT("Received unexpected msg type. Expected %d received %d", vmsg->request, msg_reply.request); - return false; + goto out; } =20 - return msg_reply.payload.u64 =3D=3D 0; + result =3D msg_reply.payload.u64 =3D=3D 0; + +out: + pthread_mutex_unlock(&dev->slave_mutex); + return result; } =20 /* Kick the log_call_fd if required. */ @@ -1105,10 +1116,13 @@ bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq= *vq, int fd, return false; } =20 + pthread_mutex_lock(&dev->slave_mutex); if (!vu_message_write(dev, dev->slave_fd, &vmsg)) { + pthread_mutex_unlock(&dev->slave_mutex); return false; } =20 + /* Also unlocks the slave_mutex */ return vu_process_message_reply(dev, &vmsg); } =20 @@ -1628,6 +1642,7 @@ vu_deinit(VuDev *dev) close(dev->slave_fd); dev->slave_fd =3D -1; } + pthread_mutex_destroy(&dev->slave_mutex); =20 if (dev->sock !=3D -1) { close(dev->sock); @@ -1663,6 +1678,7 @@ vu_init(VuDev *dev, dev->remove_watch =3D remove_watch; dev->iface =3D iface; dev->log_call_fd =3D -1; + pthread_mutex_init(&dev->slave_mutex, NULL); dev->slave_fd =3D -1; dev->max_queues =3D max_queues; =20 diff --git a/contrib/libvhost-user/libvhost-user.h b/contrib/libvhost-user/= libvhost-user.h index 46b600799b..1844b6f8d4 100644 --- a/contrib/libvhost-user/libvhost-user.h +++ b/contrib/libvhost-user/libvhost-user.h @@ -19,6 +19,7 @@ #include #include #include +#include #include "standard-headers/linux/virtio_ring.h" =20 /* Based on qemu/hw/virtio/vhost-user.c */ @@ -355,6 +356,8 @@ struct VuDev { VuVirtq *vq; VuDevInflightInfo inflight_info; int log_call_fd; + /* Must be held while using slave_fd */ + pthread_mutex_t slave_mutex; int slave_fd; uint64_t log_size; uint8_t *log_table; --=20 2.23.0