From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by dpdk.org (Postfix) with ESMTP id 77BDE1396 for ; Fri, 17 Mar 2017 06:15:31 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=intel.com; i=@intel.com; q=dns/txt; s=intel; t=1489727731; x=1521263731; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=XIn82UX9xtXraTAwWgG/WfxKSBgrL8OgHJaveV1SCKA=; b=rRIBKuxxnN92dJxzBJgFVsW/uoWuq61ZZQMMiRl+TqjkmHK/r6X/8nEN TrTSlPQsnwx2G435vVnQ8U3wAdIyWg==; Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 16 Mar 2017 22:15:30 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,175,1486454400"; d="scan'208";a="237372697" Received: from yliu-dev.sh.intel.com (HELO yliu-dev) ([10.239.67.162]) by fmsmga004.fm.intel.com with ESMTP; 16 Mar 2017 22:15:29 -0700 Date: Fri, 17 Mar 2017 13:13:43 +0800 From: Yuanhan Liu To: Gopakumar Choorakkot Edakkunni Cc: dev@dpdk.org Message-ID: <20170317051343.GY18844@yliu-dev.sh.intel.com> References: <20170317020611.GV18844@yliu-dev.sh.intel.com> <20170317043526.GW18844@yliu-dev.sh.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Subject: Re: [dpdk-dev] virtio "how to restart applications" - //dpdk.org/doc/virtio-net-pmd X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Mar 2017 05:15:32 -0000 On Thu, Mar 16, 2017 at 09:56:01PM -0700, Gopakumar Choorakkot Edakkunni wrote: > Hi Yuanhan, > > Thanks for the confirmation about not having to do anything special to close > the ports on dpdk going down or coming up. > > As for the question about if I met any issue of ovs getting stuck - yes, my > guest process runs dpdk 16.07 as I mentioned earlier - and if I kill my guest > process, then the host OVS-dpdk on the host reports stall ! The OVS-dpdk and > emu versions I use are as below. But maybe that is because of the ovs missing > the fixes you mentioned ? When I was saying dpdk version, I meant the DPDK version with OVS. > ~# ovs-vswitchd --version > ovs-vswitchd (Open vSwitch) 2.4.1 And yes, the fixes are not included in the DPDK required for OVS 2.4. --yliu > Compiled Nov 14 2016 06:53:31 > # kvm --version > QEMU emulator version 2.2.0, Copyright (c) 2003-2008 Fabrice Bellard > ~# > > > Rgds, > Gopa. > > On Thu, Mar 16, 2017 at 9:35 PM, Yuanhan Liu > wrote: > > On Thu, Mar 16, 2017 at 07:48:28PM -0700, Gopakumar Choorakkot Edakkunni > wrote: > > Thanks a lot for the response Yuanhan. I am using dpdk v16.07. So what > you are > > saying is that in 16.07, we dont really need to call rte_eth_dev_close() > on > > exit, > > It's not about "don't really need", it's more like "it's hard to". Just > think that it may crash at any time. > > > because dpdk will ensure that it will do virtio reset before init when it > > comes up right ? > > No, It just handles the abnormal case well when guest APP restarts. > > > Regarding the vhost commits you mentioned - do we still need those fixes > if we > > have the "virtio reset before init" mechanism ? > > Yes, we still need them: just think some malicious guest may also forge > data like that. > > I'm a bit confused then. Have you actually met any issue (like got stucked) > with DPDK v16.07? > >         --yliu > > > Or that is a seperate problem > > altogether (and hence we would need those fixes) ? > > > > Rgds, > > Gopa. > > > > On Thu, Mar 16, 2017 at 7:06 PM, Yuanhan Liu > > > wrote: > > > >     On Thu, Mar 16, 2017 at 12:39:16PM -0700, Gopakumar Choorakkot > Edakkunni > >     wrote: > >     > So the doc says we should call rte_eth_dev_close() *before* going > down. > >     And I > >     > know that especially in dpdk-virtionet  in the guest + ovs-dpdk in > the > >     host, > >     > the ovs ends up getting stalled/stuck (!!) if I dont close the port > >     before > >     > starting() it when the guest dpdk process comes back up. > > > >     I'm assuming you were using an old version, something like dpdk v2.2? > >     IIRC, DPDK v16.04 should have fixed your issue. > > > >     > Considering that this not done properly can screw up the HOST ovs, > and I > >     want > >     > to do everything possible to avoid that, I want to be 200% sure > that I > >     call > >     > close even if my process gets a kill -9 .. So obviously the only > way of > >     doing > >     > that is to close the port when the dpdk process comes back up and > >     *before* we > >     > init the port. rte_eth_dev_close() is not capable of doing that as > it > >     expects > >     > the port parameters to be initialized etc.. before it can be > called. > > > >     We do virtio reset before init, which is basically what > rte_eth_dev_close() > >     mainly does. So I see no big issue here. > > > >     The stuck issue is due to hugepage reset by the guest DPDK > application, > >     leading all virtio vring elements being mem zeroed. The old vhost > doesn't > >     handle it well, as a result, it got stuck. And here are some relevant > >     commits: > > > >         a436f53 vhost: avoid dead loop chain > >         c687b0b vhost: check for ring descriptors overflow > >         623bc47 vhost: do sanity check for ring descriptor length > > > >             --yliu > > > >     > Any other > >     > suggestions on what can be done to close on restart rather than > close on > >     going > >     > down ? Thought of bouncing this by the alias before I add a version > of > >     close > >     > myself that can do this close-on-restart > > > > > >