From nobody Sat Apr 18 21:02:39 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A209BC43334 for ; Sun, 10 Jul 2022 18:15:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229622AbiGJSPB (ORCPT ); Sun, 10 Jul 2022 14:15:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59472 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229476AbiGJSO7 (ORCPT ); Sun, 10 Jul 2022 14:14:59 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id C5E0D6252; Sun, 10 Jul 2022 11:14:58 -0700 (PDT) Received: by linux.microsoft.com (Postfix, from userid 1134) id 51B5B204C41B; Sun, 10 Jul 2022 11:14:58 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 51B5B204C41B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1657476898; bh=nGGZGIK6XLCZSbEZ1/OXjmDPFwgUs7UXTafZHcI4weA=; h=Date:From:To:Cc:Subject:From; b=L2rBPxAIXmzEDtfVlcnmfOW1ImTkmiS9MkWSYI+VZlgAa5TyiEgoaE6X0WZptftvF UBd+8VelYU6+oYokZWk5lmHrjY/oDJey35+sHnVD1u6qrlSawb9jBC4BLnFYCJ3gLm w3jAC5LN5/jHfqQc6hkU4FjjZMMkwOekZVsuy64I= Date: Sun, 10 Jul 2022 11:14:58 -0700 From: Shradha Gupta To: linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org Cc: "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Wei Liu , Dexuan Cui , Shradha Gupta , Praveen Kumar Subject: [PATCH v2] Drivers: hv: vm_bus: Handle vmbus rescind calls after vmbus is suspended Message-ID: <20220710181458.GA20827@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add a flag to indicate that the vmbus is suspended so we should ignore any offer message. Add a new work_queue for rescind msg, so we could drain it along with other offer work_queues upon suspension. It was observed that in some hibernation related scenario testing, after vmbus_bus_suspend() we get rescind offer message for the vmbus. This would lead to processing of a rescind message for a channel that has already been suspended. Signed-off-by: Shradha Gupta Reported-by: kernel test robot --- Changes in v2: * Rename the ignore_offer_rescind_msg flag to ignore_any_offer_msg, to indicate that the flag can cause any offer message to be dropped. * Remove redundent tasklet_enable(), tasklet_disable() calls around ignore_any_offer_msg flag when value is changed from true to false. * Add comment about tasklet_enable() providing memory barrier. * In vmbus_bus_suspend() after we drain all workqueues, remove the code to wait for any offer_in_progress --- drivers/hv/connection.c | 11 +++++++++++ drivers/hv/hyperv_vmbus.h | 7 +++++++ drivers/hv/vmbus_drv.c | 29 +++++++++++++++++++++-------- 3 files changed, 39 insertions(+), 8 deletions(-) diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c index 6218bbf6863a..eca7afd366d6 100644 --- a/drivers/hv/connection.c +++ b/drivers/hv/connection.c @@ -171,6 +171,14 @@ int vmbus_connect(void) goto cleanup; } =20 + vmbus_connection.rescind_work_queue =3D + create_workqueue("hv_vmbus_rescind"); + if (!vmbus_connection.rescind_work_queue) { + ret =3D -ENOMEM; + goto cleanup; + } + vmbus_connection.ignore_any_offer_msg =3D false; + vmbus_connection.handle_primary_chan_wq =3D create_workqueue("hv_pri_chan"); if (!vmbus_connection.handle_primary_chan_wq) { @@ -357,6 +365,9 @@ void vmbus_disconnect(void) if (vmbus_connection.handle_primary_chan_wq) destroy_workqueue(vmbus_connection.handle_primary_chan_wq); =20 + if (vmbus_connection.rescind_work_queue) + destroy_workqueue(vmbus_connection.rescind_work_queue); + if (vmbus_connection.work_queue) destroy_workqueue(vmbus_connection.work_queue); =20 diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index 4f5b824b16cf..dc673edf053c 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -261,6 +261,13 @@ struct vmbus_connection { struct workqueue_struct *work_queue; struct workqueue_struct *handle_primary_chan_wq; struct workqueue_struct *handle_sub_chan_wq; + struct workqueue_struct *rescind_work_queue; + + /* + * On suspension of the vmbus, the accumulated offer messages + * must be dropped. + */ + bool ignore_any_offer_msg; =20 /* * The number of sub-channels and hv_sock channels that should be diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 547ae334e5cd..4ba0eb2441cf 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1160,7 +1160,9 @@ void vmbus_on_msg_dpc(unsigned long data) * work queue: the RESCIND handler can not start to * run before the OFFER handler finishes. */ - schedule_work(&ctx->work); + if (vmbus_connection.ignore_any_offer_msg) + break; + queue_work(vmbus_connection.rescind_work_queue, &ctx->work); break; =20 case CHANNELMSG_OFFERCHANNEL: @@ -1186,6 +1188,8 @@ void vmbus_on_msg_dpc(unsigned long data) * to the CPUs which will execute the offer & rescind * works by the time these works will start execution. */ + if (vmbus_connection.ignore_any_offer_msg) + break; atomic_inc(&vmbus_connection.offer_in_progress); fallthrough; =20 @@ -2446,15 +2450,20 @@ static int vmbus_acpi_add(struct acpi_device *devic= e) #ifdef CONFIG_PM_SLEEP static int vmbus_bus_suspend(struct device *dev) { + struct hv_per_cpu_context *hv_cpu =3D per_cpu_ptr( + hv_context.cpu_context, VMBUS_CONNECT_CPU); struct vmbus_channel *channel, *sc; =20 - while (atomic_read(&vmbus_connection.offer_in_progress) !=3D 0) { - /* - * We wait here until the completion of any channel - * offers that are currently in progress. - */ - usleep_range(1000, 2000); - } + tasklet_disable(&hv_cpu->msg_dpc); + vmbus_connection.ignore_any_offer_msg =3D true; + /* The tasklet_enable() takes care of providing a memory barrier */ + tasklet_enable(&hv_cpu->msg_dpc); + + /* Drain all the workqueues as we are in suspend */ + drain_workqueue(vmbus_connection.rescind_work_queue); + drain_workqueue(vmbus_connection.work_queue); + drain_workqueue(vmbus_connection.handle_primary_chan_wq); + drain_workqueue(vmbus_connection.handle_sub_chan_wq); =20 mutex_lock(&vmbus_connection.channel_mutex); list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { @@ -2527,10 +2536,14 @@ static int vmbus_bus_suspend(struct device *dev) =20 static int vmbus_bus_resume(struct device *dev) { + struct hv_per_cpu_context *hv_cpu =3D per_cpu_ptr( + hv_context.cpu_context, VMBUS_CONNECT_CPU); struct vmbus_channel_msginfo *msginfo; size_t msgsize; int ret; =20 + vmbus_connection.ignore_any_offer_msg =3D false; + /* * We only use the 'vmbus_proto_version', which was in use before * hibernation, to re-negotiate with the host. --=20 2.17.1