From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34480) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cOSxf-0003tv-FP for qemu-devel@nongnu.org; Tue, 03 Jan 2017 12:33:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cOSxb-0003e0-JV for qemu-devel@nongnu.org; Tue, 03 Jan 2017 12:33:23 -0500 Received: from mail-qk0-f175.google.com ([209.85.220.175]:34763) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cOSxb-0003dj-Em for qemu-devel@nongnu.org; Tue, 03 Jan 2017 12:33:19 -0500 Received: by mail-qk0-f175.google.com with SMTP id h201so242435141qke.1 for ; Tue, 03 Jan 2017 09:33:18 -0800 (PST) Date: Tue, 3 Jan 2017 15:33:12 -0200 From: Flavio Leitner Message-ID: <20170103153312.083ef692@x240.lan> In-Reply-To: <8aae955f-44ff-134e-818f-31b0bd510ba1@redhat.com> References: <20161230104130.29ff671b@x240.lan> <4eda1813-d732-5dfc-e6ff-29ac95fe22d8@redhat.com> <8aae955f-44ff-134e-818f-31b0bd510ba1@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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: Jason Wang Cc: "Michael S. Tsirkin" , qemu-devel On Tue, 3 Jan 2017 18:28:18 +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: =20 > >> 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 here. > >> > >> 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 guest=20 > >> driver does > >> not use MSIX for this vritqueue at all. This will cause lots of > >> unnecessary userspace access and other checks for drivers does=20 > >> not use > >> interrupt at all (e.g virtio-net pmd). So check and clean vring=20 > >> call > >> fd if guest does not use any vector for this virtqueue at > >> all. > >> [...] > >> > >> Thanks, =20 > > > > Hi Flavio: > > > > Thanks for reporting this issue, could this be a bug of vhost-user? (I= =20 > > believe virito-net pmd does not use interrupt for rx/tx at all) > > > > Anyway, will try to reproduce it. > > =20 >=20 > Could not reproduce this issue on similar setups (the only difference is= =20 > I don't create dpdk port) with dpdk 16.11 and ovs.git HEAD. Suspect an=20 > issue dpdk. Will try OVS 2.5 + DPDK 2.2.0. Yeah, that's the combo I am testing and seeing the issue. I found the commit after bisecting qemu and then confirmed by testing up to the previous commit (works okay) and then the commit above (fails). I still have my test environment available, so I would be able to test any patch you might have. Thanks, --=20 Flavio