From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by dpdk.org (Postfix) with ESMTP id 5501A7CB6 for ; Mon, 5 Mar 2018 13:33:03 +0100 (CET) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8C9838182D0C; Mon, 5 Mar 2018 12:33:02 +0000 (UTC) Received: from [10.36.112.55] (ovpn-112-55.ams2.redhat.com [10.36.112.55]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 92EC6AFD6D; Mon, 5 Mar 2018 12:33:01 +0000 (UTC) To: Luca Boccassi , stable@dpdk.org, Yuanhan Liu References: <20180302171042.26094-1-maxime.coquelin@redhat.com> <1520011690.22753.86.camel@debian.org> Cc: ktraynor@redhat.com From: Maxime Coquelin Message-ID: <3106e381-ebd5-d628-fbc7-23a47f523711@redhat.com> Date: Mon, 5 Mar 2018 13:32:59 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <1520011690.22753.86.camel@debian.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Mon, 05 Mar 2018 12:33:02 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Mon, 05 Mar 2018 12:33:02 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'maxime.coquelin@redhat.com' RCPT:'' Subject: Re: [dpdk-stable] [PATCH v16.11 LTS] vhost: protect active rings from async ring changes X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 05 Mar 2018 12:33:03 -0000 On 03/02/2018 06:28 PM, Luca Boccassi wrote: > On Fri, 2018-03-02 at 18:10 +0100, Maxime Coquelin wrote: >> From: Victor Kaplansky >> >> [ backported from upstream commit >> a3688046995f88c518fa27c45b39ae389260b18d ] >> >> When performing live migration or memory hot-plugging, >> the changes to the device and vrings made by message handler >> done independently from vring usage by PMD threads. >> >> This causes for example segfaults during live-migration >> with MQ enable, but in general virtually any request >> sent by qemu changing the state of device can cause >> problems. >> >> These patches fixes all above issues by adding a spinlock >> to every vring and requiring message handler to start operation >> only after ensuring that all PMD threads related to the device >> are out of critical section accessing the vring data. >> >> Each vring has its own lock in order to not create contention >> between PMD threads of different vrings and to prevent >> performance degradation by scaling queue pair number. >> >> See https://bugzilla.redhat.com/show_bug.cgi?id=1450680 >> >> Cc: stable@dpdk.org >> Signed-off-by: Victor Kaplansky >> Reviewed-by: Maxime Coquelin >> Acked-by: Yuanhan Liu >> >> Backport conflicts: >> lib/librte_vhost/vhost.c >> lib/librte_vhost/vhost.h >> lib/librte_vhost/vhost_user.c >> lib/librte_vhost/virtio_net.c >> >> Signed-off-by: Maxime Coquelin >> --- >> >> Hi Luca, All, >> >> This is the v16.11 backport for Victor's patch already available in >> master and v17.11 LTS. It needed some rework to be applied to v16.11. > > Thank you, applied and pushed to dpdk-stable/16.11. > Thanks Luca, There is another patch that would be applied on top of it, as Victor's patch introduce a regression with Virtio-user. I see it is neither in 16.11 nor 17.11 LTS: commit 9fce5d0b401fc2c13a860bbbfdebcf85080334e1 Author: Maxime Coquelin Date: Mon Feb 12 16:46:12 2018 +0100 vhost: do not take lock on owner reset A deadlock happens when handling VHOST_USER_RESET_OWNER request for the same reason the lock is not taken for VHOST_USER_GET_VRING_BASE. It is safe not to take the lock, as the queues are no more used by the application when the virtqueues and the device are reset. Fixes: a3688046995f ("vhost: protect active rings from async ring changes") Cc: stable@dpdk.org Signed-off-by: Maxime Coquelin Reviewed-by: Tiwei Bie Reviewed-by: Jianfeng Tan Let me know if you want me to post the backport to stable@dpdk.org, or if you can pick it directly from upstream master. Cheers, Maxime