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 883927CBC for ; Mon, 5 Mar 2018 13:34:15 +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 BDAE44023150; Mon, 5 Mar 2018 12:34:14 +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 CABA7AFD6F; Mon, 5 Mar 2018 12:34:13 +0000 (UTC) From: Maxime Coquelin To: Luca Boccassi , stable@dpdk.org, Yuanhan Liu Cc: ktraynor@redhat.com References: <20180302171042.26094-1-maxime.coquelin@redhat.com> <1520011690.22753.86.camel@debian.org> <3106e381-ebd5-d628-fbc7-23a47f523711@redhat.com> Message-ID: <97270ccb-e40c-f141-0e80-33ed8ff2091f@redhat.com> Date: Mon, 5 Mar 2018 13:34:11 +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: <3106e381-ebd5-d628-fbc7-23a47f523711@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit 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 [10.11.55.6]); Mon, 05 Mar 2018 12:34:14 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Mon, 05 Mar 2018 12:34:14 +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 12:34:15 -0000 With up-to-date Yuanhan address. On 03/05/2018 01:32 PM, Maxime Coquelin wrote: > > > 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