From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B7B1C04EBD for ; Tue, 16 Oct 2018 08:53:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1140B2083C for ; Tue, 16 Oct 2018 08:53:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1140B2083C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727409AbeJPQmn (ORCPT ); Tue, 16 Oct 2018 12:42:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60544 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726541AbeJPQmm (ORCPT ); Tue, 16 Oct 2018 12:42:42 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 025B71766D2; Tue, 16 Oct 2018 08:53:20 +0000 (UTC) Received: from [10.72.12.35] (ovpn-12-35.pek2.redhat.com [10.72.12.35]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 88A5C4C47F; Tue, 16 Oct 2018 08:53:14 +0000 (UTC) Subject: Re: [PATCH] virtio_net: enable tx after resuming from suspend To: ake Cc: "Michael S. Tsirkin" , "David S. Miller" , virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <20181011075127.2608-1-ake@igel.co.jp> <7e87b140-79ae-c79e-40ed-dc76b38eeae4@igel.co.jp> <4918ed7c-4c63-6f19-530b-8e16b0c496d4@redhat.com> <1aff0ad2-9d63-6d38-6b25-5c681eafdfb2@igel.co.jp> From: Jason Wang Message-ID: <024619cc-9b1b-dac2-18cc-5d757a76b1e3@redhat.com> Date: Tue, 16 Oct 2018 16:53:12 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Tue, 16 Oct 2018 08:53:20 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018/10/15 下午6:08, ake wrote: > > On 2018年10月12日 18:18, ake wrote: >> >> On 2018年10月12日 17:23, Jason Wang wrote: >>> >>> On 2018年10月12日 12:30, ake wrote: >>>> On 2018年10月11日 22:06, Jason Wang wrote: >>>>> On 2018年10月11日 18:22, ake wrote: >>>>>> On 2018年10月11日 18:44, Jason Wang wrote: >>>>>>> On 2018年10月11日 15:51, Ake Koomsin wrote: >>>>>>>> commit 713a98d90c5e ("virtio-net: serialize tx routine during reset") >>>>>>>> disabled the virtio tx before going to suspend to avoid a use after >>>>>>>> free. >>>>>>>> However, after resuming, it causes the virtio_net device to lose its >>>>>>>> network connectivity. >>>>>>>> >>>>>>>> To solve the issue, we need to enable tx after resuming. >>>>>>>> >>>>>>>> Fixes commit 713a98d90c5e ("virtio-net: serialize tx routine during >>>>>>>> reset") >>>>>>>> Signed-off-by: Ake Koomsin >>>>>>>> --- >>>>>>>>     drivers/net/virtio_net.c | 1 + >>>>>>>>     1 file changed, 1 insertion(+) >>>>>>>> >>>>>>>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c >>>>>>>> index dab504ec5e50..3453d80f5f81 100644 >>>>>>>> --- a/drivers/net/virtio_net.c >>>>>>>> +++ b/drivers/net/virtio_net.c >>>>>>>> @@ -2256,6 +2256,7 @@ static int virtnet_restore_up(struct >>>>>>>> virtio_device *vdev) >>>>>>>>         } >>>>>>>>           netif_device_attach(vi->dev); >>>>>>>> +    netif_start_queue(vi->dev); >>>>>>> I believe this is duplicated with netif_tx_wake_all_queues() in >>>>>>> netif_device_attach() above? >>>>>> Thank you for your review. >>>>>> >>>>>> If both netif_tx_wake_all_queues() and netif_start_queue() result in >>>>>> clearing __QUEUE_STATE_DRV_XOFF, then is it possible that some >>>>>> conditions in netif_device_attach() is not satisfied? >>>>> Yes, maybe. One case I can see now is when the device is down, in this >>>>> case netif_device_attach() won't try to wakeup the queue. >>>>> >>>>>>    Without >>>>>> netif_start_queue(), the virtio_net device does not resume properly >>>>>> after waking up. >>>>> How do you trigger the issue? Just do suspend/resume? >>>> Yes, simply suspend and resume. >>>> >>>> Here is how I trigger the issue: >>>> >>>> 1) Start the Virtual Machine Manager GUI program. >>>> 2) Create a guest Linux OS. Make sure that the guest OS kernel is >>>>     >= 4.12. Make sure that it uses virtio_net as its network device. >>>>     In addition, make sure that the video adapter is VGA. Otherwise, >>>>     waking up with the virtual power button does not work. >>>> 3) After installing the guest OS, log in, and test the network >>>>     connectivity by ping the host machine. >>>> 4) Suspend. After this, the screen is blank. >>>> 5) Resume by hitting the virtual power button. The login screen >>>>     appears again. >>>> 6) Log in again. The guest loses its network connection. >>>> >>>> In my test: >>>> Guest: Ubuntu 16.04/18.04 with kernel 4.15.0-36-generic >>>> Host: Ubuntu 16.04 with kernel 4.15.0-36-generic/4.4.0-137-generic >>> I can not reproduce this issue if virtio-net interface is up in guest >>> before the suspend. I'm using net-next.git and qemu master. But I do >>> reproduce when virtio-net interface is down in guest before suspend, >>> after resume, even if I make it up, the network is still lost. >>> >>> I think the interface is up in your case, but please confirm this. >> If you mean the interface state before I hit the suspend button, >> the answer is yes. The interface is up before I suspend the guest >> machine. >> >> Note that my current QEMU version is QEMU emulator version 2.5.0 >> (Debian 1:2.5+dfsg-5ubuntu10.32). >> >> I will try with net-next.git and qemu master later and see if I can >> reproduce the issue. > Update. I tried with net-next and qemu master. Interestingly, the result > is different from yours. The network is lost even if the virtio_net > interface is up before suspending. > > Host: Ubuntu 16.04 with net-next kernel (default configuration) > Guest: Ubuntu 18.04 with net-next kernel (default configuration) > Qemu: master > Qemu command: > qemu-system-x86_64 -cpu host -m 2048 -enable-kvm \ > -bios /usr/share/OVMF/OVMF_CODE.fd \ > -drive file=/var/lib/libvirt/images/virtio_test.qcow2,if=virtio \ > -netdev user,id=hostnet0 \ > -device virtio-net-pci,netdev=hostnet0 \ > -device VGA,id=video0,vgamem_mb=16 \ > -global PIIX4_PM.disable_s3=1 \ > -global PIIX4_PM.disable_s4=1 -monitor stdio Interesting, just notice you're using userspace network. To isolate the issue, can you retry with e.g tap or e1000 to make sure it's not a fault of slirp or virito-net? Thanks