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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY 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 C9F39C43381 for ; Thu, 14 Mar 2019 14:48:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7F80D2075C for ; Thu, 14 Mar 2019 14:48:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="tRUPdH9z" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727087AbfCNOsB (ORCPT ); Thu, 14 Mar 2019 10:48:01 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:49192 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726643AbfCNOsA (ORCPT ); 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Thu, 14 Mar 2019 14:47:46 +0000 Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id x2EEljt0024070 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 14 Mar 2019 14:47:45 GMT Received: from abhmp0013.oracle.com (abhmp0013.oracle.com [141.146.116.19]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x2EEliT6011525; Thu, 14 Mar 2019 14:47:44 GMT Received: from dhcp-burlington7-2nd-B-east-10-152-55-162.usdhcp.oraclecorp.com (/10.152.32.65) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 14 Mar 2019 14:47:43 +0000 Subject: Re: [Xen-devel][PATCH] xen/netfront: Remove unneeded .resume callback To: Oleksandr Andrushchenko , netdev@vger.kernel.org, xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, jgross@suse.com, sstabellini@kernel.org, davem@davemloft.net Cc: Oleksandr Andrushchenko References: <20190314131749.25706-1-andr2000@gmail.com> From: Boris Ostrovsky Openpgp: preference=signencrypt Autocrypt: addr=boris.ostrovsky@oracle.com; 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Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20190314131749.25706-1-andr2000@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9194 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=2 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1903140104 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/14/19 9:17 AM, Oleksandr Andrushchenko wrote: > From: Oleksandr Andrushchenko > > Currently on driver resume we remove all the network queues and > destroy shared Tx/Rx rings leaving the driver in its current state > and never signaling the backend of this frontend's state change. > This leads to the number of consequences: > - when frontend withdraws granted references to the rings etc. it cannot > be cleanly done as the backend still holds those (it was not told to > free the resources) > - it is not possible to resume driver operation as all the communication > means with the backned were destroyed by the frontend, thus > making the frontend appear to the guest OS as functional, but > not really. What do you mean? Are you saying that after resume you lose connectivity? -boris > > Fix this by not destroying communication channels/rings on driver > resume. > > Signed-off-by: Oleksandr Andrushchenko > --- > drivers/net/xen-netfront.c | 17 ----------------- > 1 file changed, 17 deletions(-) > > diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c > index c914c24f880b..2ca162048da4 100644 > --- a/drivers/net/xen-netfront.c > +++ b/drivers/net/xen-netfront.c > @@ -1422,22 +1422,6 @@ static void xennet_disconnect_backend(struct netfront_info *info) > } > } > > -/** > - * We are reconnecting to the backend, due to a suspend/resume, or a backend > - * driver restart. We tear down our netif structure and recreate it, but > - * leave the device-layer structures intact so that this is transparent to the > - * rest of the kernel. > - */ > -static int netfront_resume(struct xenbus_device *dev) > -{ > - struct netfront_info *info = dev_get_drvdata(&dev->dev); > - > - dev_dbg(&dev->dev, "%s\n", dev->nodename); > - > - xennet_disconnect_backend(info); > - return 0; > -} > - > static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[]) > { > char *s, *e, *macstr; > @@ -2185,7 +2169,6 @@ static struct xenbus_driver netfront_driver = { > .ids = netfront_ids, > .probe = netfront_probe, > .remove = xennet_remove, > - .resume = netfront_resume, > .otherend_changed = netback_changed, > }; >