From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39912) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cOcDW-0000q9-QE for qemu-devel@nongnu.org; Tue, 03 Jan 2017 22:26:23 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cOcDT-0002NF-Jr for qemu-devel@nongnu.org; Tue, 03 Jan 2017 22:26:22 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56448) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cOcDT-0002MC-Cu for qemu-devel@nongnu.org; Tue, 03 Jan 2017 22:26:19 -0500 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E6C538DEE4 for ; Wed, 4 Jan 2017 03:26:18 +0000 (UTC) References: <20161230104130.29ff671b@x240.lan> <4eda1813-d732-5dfc-e6ff-29ac95fe22d8@redhat.com> <8aae955f-44ff-134e-818f-31b0bd510ba1@redhat.com> <20170103182332-mutt-send-email-mst@kernel.org> From: Jason Wang Message-ID: <007b2d16-56f6-a551-815a-527f6732fae7@redhat.com> Date: Wed, 4 Jan 2017 11:26:11 +0800 MIME-Version: 1.0 In-Reply-To: <20170103182332-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] vhost-user breaks after 96a3d98. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Flavio Leitner , qemu-devel On 2017=E5=B9=B401=E6=9C=8804=E6=97=A5 00:27, Michael S. Tsirkin wrote: > On Tue, Jan 03, 2017 at 06:28:18PM +0800, Jason Wang wrote: >> >> On 2017=E5=B9=B401=E6=9C=8803=E6=97=A5 11:09, Jason Wang wrote: >>> >>> On 2016=E5=B9=B412=E6=9C=8830=E6=97=A5 20:41, Flavio Leitner wrote: >>>> Hi, >>>> >>>> While I was testing vhost-user using OVS 2.5 and DPDK 2.2.0 in the >>>> host and testpmd dpdk 2.2.0 in the guest, I found that the commit >>>> below breaks the environment and no packets gets into the guest. >>>> >>>> dpdk port --> OVS --> vhost-user --> guest --> testpmd >>>> ^--- drops here ^--- no packets h= ere. >>>> >>>> commit 96a3d98d2cdbd897ff5ab33427aa4cfb94077665 >>>> Author: Jason Wang >>>> Date: Mon Aug 1 16:07:58 2016 +0800 >>>> >>>> vhost: don't set vring call if no vector >>>> We used to set vring call fd unconditionally even if gues= t >>>> driver does >>>> not use MSIX for this vritqueue at all. This will cause lots o= f >>>> unnecessary userspace access and other checks for drivers does >>>> not use >>>> interrupt at all (e.g virtio-net pmd). So check and clean vrin= g >>>> call >>>> fd if guest does not use any vector for this virtqueue at >>>> all. >>>> [...] >>>> >>>> Thanks, >>> Hi Flavio: >>> >>> Thanks for reporting this issue, could this be a bug of vhost-user? (= I >>> believe virito-net pmd does not use interrupt for rx/tx at all) >>> >>> Anyway, will try to reproduce it. >>> >> Could not reproduce this issue on similar setups (the only difference = is I >> don't create dpdk port) with dpdk 16.11 and ovs.git HEAD. Suspect an i= ssue >> dpdk. Will try OVS 2.5 + DPDK 2.2.0. >> >> Thanks > Possibly dpdk assumed that call fd must be present unconditionally. > Limit this patch to when protocol is updated? add a new protocol flag? If this is a bug of dpdk, I tend to fix it (or just disable this patch=20 for vhost-user). I'm not sure whether or not it's worthwhile to add a=20 new protocol flag which was used to tell qemu that bug X was fixed. Thanks