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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 034A3C433FF for ; Wed, 7 Aug 2019 16:09:52 +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 CB7622229C for ; Wed, 7 Aug 2019 16:09:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CB7622229C 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]:43282 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hvOVb-0001hV-3L for qemu-devel@archiver.kernel.org; Wed, 07 Aug 2019 12:09:51 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:38842) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hvOVB-0001DG-WF for qemu-devel@nongnu.org; Wed, 07 Aug 2019 12:09:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hvOVB-00089X-1B for qemu-devel@nongnu.org; Wed, 07 Aug 2019 12:09:25 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45530) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hvOVA-00088O-S2 for qemu-devel@nongnu.org; Wed, 07 Aug 2019 12:09:24 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 69DC84FCC7; Wed, 7 Aug 2019 16:09:23 +0000 (UTC) Received: from work-vm (ovpn-117-204.ams2.redhat.com [10.36.117.204]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 566805D9CD; Wed, 7 Aug 2019 16:09:20 +0000 (UTC) Date: Wed, 7 Aug 2019 17:09:17 +0100 From: "Dr. David Alan Gilbert" To: "Boeuf, Sebastien" Message-ID: <20190807160917.GI2867@work-vm> References: <8df105774471bc72bca1397b4058ecc66d963848.camel@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8df105774471bc72bca1397b4058ecc66d963848.camel@intel.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Wed, 07 Aug 2019 16:09:23 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] libvhost-user: Fix the VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD check 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: , Cc: "marcandre.lureau@redhat.com" , "qemu-devel@nongnu.org" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Boeuf, Sebastien (sebastien.boeuf@intel.com) wrote: > From 0a53a81db6dd069f9b7bcdcd386845bceb3a2ac6 Mon Sep 17 00:00:00 2001 > From: Sebastien Boeuf > Date: Wed, 7 Aug 2019 07:15:32 -0700 > Subject: [PATCH] libvhost-user: Fix the > VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD > check > > Vhost user protocol features are set as a bitmask. And the following > constant VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD value is 10 because the > bit > 10 indicates if the features is set or not. > > The proper way to check for the presence or absence of this feature is > to shift 1 by the value of this constant and then mask it with the > actual bitmask representing the supported protocol features. > > This patch aims to fix the current code as it was not doing the > shifting, but instead it was masking directly with the value of the > constant itself. > > Signed-off-by: Sebastien Boeuf Nicely spotted. Two things; a) I think your mail client has wrapped the lines at some point. b) I think this is why the has_feature() functione exists, so does that become if (!has_feature(dev->protocol_features, VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD)) Dave > --- > contrib/libvhost-user/libvhost-user.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost- > user/libvhost-user.c > index fb61142bcc..11909fb7c1 100644 > --- a/contrib/libvhost-user/libvhost-user.c > +++ b/contrib/libvhost-user/libvhost-user.c > @@ -1112,7 +1112,7 @@ bool vu_set_queue_host_notifier(VuDev *dev, > VuVirtq *vq, int fd, > > vmsg.fd_num = fd_num; > > - if ((dev->protocol_features & VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD) > == 0) { > + if ((dev->protocol_features & (1ULL << > VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD)) == 0) { > return false; > } > > @@ -2537,7 +2537,7 @@ int64_t vu_fs_cache_request(VuDev *dev, > VhostUserSlaveRequest req, int fd, > > vmsg.fd_num = fd_num; > > - if ((dev->protocol_features & VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD) > == 0) { > + if ((dev->protocol_features & (1ULL << > VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD)) == 0) { > return -EINVAL; > } > > -- > 2.17.1 -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK