From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id C0D3C1B295 for ; Tue, 4 Dec 2018 12:59:49 +0100 (CET) Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id EE617307D840; Tue, 4 Dec 2018 11:59:48 +0000 (UTC) Received: from ovpn-112-74.ams2.redhat.com (ovpn-112-74.ams2.redhat.com [10.36.112.74]) by smtp.corp.redhat.com (Postfix) with ESMTP id 64FE0272DD; Tue, 4 Dec 2018 11:59:47 +0000 (UTC) Message-ID: <1543924786.5400.37.camel@redhat.com> From: Mohammed Gamal To: Stephen Hemminger Cc: dev@dpdk.org, Stephen Hemminger Date: Tue, 04 Dec 2018 12:59:46 +0100 In-Reply-To: <20181203084844.39c82962@shemminger-XPS-13-9360> References: <1543575881.5400.33.camel@redhat.com> <20181130202457.10888-1-stephen@networkplumber.org> <1543816975.5400.35.camel@redhat.com> <20181203084844.39c82962@shemminger-XPS-13-9360> Organization: Red Hat Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Tue, 04 Dec 2018 11:59:49 +0000 (UTC) Subject: Re: [dpdk-dev] [PATCH] bus/vmbus: fix race in sub channel creation X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list Reply-To: mgamal@redhat.com List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 04 Dec 2018 11:59:50 -0000 On Mon, 2018-12-03 at 08:48 -0800, Stephen Hemminger wrote: > On Mon, 03 Dec 2018 07:02:55 +0100 > Mohammed Gamal wrote: > > > On Fri, 2018-11-30 at 12:24 -0800, Stephen Hemminger wrote: > > > When using multiple queues, there was a race with the kernel > > > in setting up the second channel. This is do due to a kernel > > > change > > > whiche does not allow accessing sysfs files for Hyper-V > > > channels that are not opened. > > > > > > The fix is simple, just move the logic to detect not ready > > > sub channels earlier in the existing loop. > > > > > > Fixes: 831dba47bd36 ("bus/vmbus: add Hyper-V virtual bus > > > support") > > > Reported-by:Mohammed Gamal > > > Signed-off-by: Stephen Hemminger > > > --- > > >  drivers/bus/vmbus/linux/vmbus_uio.c | 12 ++++++------ > > >  1 file changed, 6 insertions(+), 6 deletions(-) > > > > > > diff --git a/drivers/bus/vmbus/linux/vmbus_uio.c > > > b/drivers/bus/vmbus/linux/vmbus_uio.c > > > index 12e97e3a420a..38df4d724ed5 100644 > > > --- a/drivers/bus/vmbus/linux/vmbus_uio.c > > > +++ b/drivers/bus/vmbus/linux/vmbus_uio.c > > > @@ -357,6 +357,12 @@ int vmbus_uio_get_subchan(struct > > > vmbus_channel > > > *primary, > > >   continue; > > >   } > > >   > > > + if (!vmbus_isnew_subchannel(primary, relid)) > > > + continue; /* Already know about > > > you > > > */ > > > + > > > + if (!vmbus_uio_ring_present(dev, relid)) > > > + continue; /* Ring may not be > > > ready > > > yet */ > > > + > > >   snprintf(subchan_path, sizeof(subchan_path), > > > "%s/%lu", > > >    chan_path, relid); > > >   err = vmbus_uio_sysfs_read(subchan_path, > > > "subchannel_id", > > > @@ -370,12 +376,6 @@ int vmbus_uio_get_subchan(struct > > > vmbus_channel > > > *primary, > > >   if (subid == 0) > > >   continue; /* skip primary channel > > > */ > > >   > > > - if (!vmbus_isnew_subchannel(primary, relid)) > > > - continue; > > > - > > > - if (!vmbus_uio_ring_present(dev, relid)) > > > - continue; /* Ring may not be > > > ready > > > yet */ > > > - > > >   err = vmbus_uio_sysfs_read(subchan_path, > > > "monitor_id", > > >      &monid, UINT8_MAX); > > >   if (err) {   > > > > With this patch I am now getting the following error: > > [...] > > Configuring Port 0 (socket 0) > > hn_dev_configure():  >>   > > hn_rndis_link_status(): link status 0x40020006 > > hn_subchan_configure(): open 1 subchannels > > hn_subchan_configure(): open subchannel failed: -2 > > hn_dev_configure(): subchannel configuration failed > > Port0 dev_configure = -2 > > hn_dev_rx_queue_release():  >> > > hn_dev_rx_queue_release():  >> > > hn_dev_tx_queue_release():  >> > > hn_dev_tx_queue_release():  >>   > > Fail to configure port 0 > > EAL: Error - exiting with code: 1 > >   Cause: Start ports failed > > > > Apparently, no subchannels were ready. Anything I may have missed > > or > > misconfigured? > > > > Regards, > > Mohammed > > Could you check the kernel log? > I did. No relevant messages seem to be there. > The way sub channel configuration works is that the userspace code in > DPDK > sends a message to the hypervisor that it would like N subchannels, > then > the response from the hypervisor is processed by the kernel causing > sysfs > files to be created. Meanwhile the userspace is polling waiting for > the > sysfs files to show up (for 10 seconds). You could increas the > timeout or > go looking in the sysfs directory  to see what is present. Tried increasing that up to 100 seconds, still nothing. Could it be a problem on my host? The VM I am using is on a local hyper-v instance. > > There is no good way to handle errors here, the hypervisor doesn't > really > give much feedback.