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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,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 A82F5C432C0 for ; Mon, 25 Nov 2019 17:44:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7FBF820740 for ; Mon, 25 Nov 2019 17:44:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574703858; bh=twyrS+L2PZXX9e8tJr9s2br+48c9cVdeXMiJJDoa4pA=; h=Subject:To:Cc:From:Date:List-ID:From; b=ngB58Li1oiRvjHjUKxgWsmWpO3fM5TyKO/EOzua3xCo65shJAoztTwzq53f78rF1m TsujWD5hVuJuahK4db4G4lrebQFtbIPvOB6L98Tn0740MQM2CzyJ6Ww49Ii55svdlm g+ykd8JCVOBZmtkxKg+r8PoHUxb1UYHwZ5QXse3E= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727026AbfKYRoS (ORCPT ); Mon, 25 Nov 2019 12:44:18 -0500 Received: from out2-smtp.messagingengine.com ([66.111.4.26]:46829 "EHLO out2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725851AbfKYRoS (ORCPT ); Mon, 25 Nov 2019 12:44:18 -0500 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailout.nyi.internal (Postfix) with ESMTP id C5AC8226BD; Mon, 25 Nov 2019 12:44:16 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute6.internal (MEProxy); Mon, 25 Nov 2019 12:44:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; bh=jJM6cN DsH2Xfhix74A8EDdfdPkulZRRBt+7pUbVyewQ=; b=iRRncW4UAvwJIEGyRzZXuI 4nKtXV6GxI8xszSvTZNtCF3TJpoxXUrV5+Ythc1QhGD1w9NfS0ZNY98vVgEH2fQv fuXogh3u4AhaUEKD74qgUtXcX65EvSVF59dRpMMmEeOVBpUwWFYMg8aYidNwE5eQ eKgZMxZ90QeP2/V8/z0UC8uU7GrBn3n+qAhZGOHDO0Wq5RsaCcf1stLznZ5FioTA vdkxi1jsF4IopvsXn3mya2UQfiOzfJ0hT0o+KljUizFG6REaM7WMF7xNlBevhtkW 2cCvWTFGJgX7rWwky0Qh7rkxLTO1qjtj1C5EEF2HdnVFtq9YZ2ouRwicFw9k4nNQ == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedufedrudeiuddguddthecutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfgh necuuegrihhlohhuthemuceftddtnecunecujfgurhepuffvhfffkfggtgfgsehtkeertd dttdflnecuhfhrohhmpeeoghhrvghgkhhhsehlihhnuhigfhhouhhnuggrthhiohhnrdho rhhgqeenucfkphepkeefrdekiedrkeelrddutdejnecurfgrrhgrmhepmhgrihhlfhhroh hmpehgrhgvgheskhhrohgrhhdrtghomhenucevlhhushhtvghrufhiiigvpedu X-ME-Proxy: Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) by mail.messagingengine.com (Postfix) with ESMTPA id 3FC5C80061; Mon, 25 Nov 2019 12:44:16 -0500 (EST) Subject: FAILED: patch "[PATCH] virtio_console: allocate inbufs in add_port() only if it is" failed to apply to 4.4-stable tree To: lvivier@redhat.com, mst@redhat.com Cc: From: Date: Mon, 25 Nov 2019 18:44:06 +0100 Message-ID: <157470384623143@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From d791cfcbf98191122af70b053a21075cb450d119 Mon Sep 17 00:00:00 2001 From: Laurent Vivier Date: Thu, 14 Nov 2019 13:25:48 +0100 Subject: [PATCH] virtio_console: allocate inbufs in add_port() only if it is needed When we hot unplug a virtserialport and then try to hot plug again, it fails: (qemu) chardev-add socket,id=serial0,path=/tmp/serial0,server,nowait (qemu) device_add virtserialport,bus=virtio-serial0.0,nr=2,\ chardev=serial0,id=serial0,name=serial0 (qemu) device_del serial0 (qemu) device_add virtserialport,bus=virtio-serial0.0,nr=2,\ chardev=serial0,id=serial0,name=serial0 kernel error: virtio-ports vport2p2: Error allocating inbufs qemu error: virtio-serial-bus: Guest failure in adding port 2 for device \ virtio-serial0.0 This happens because buffers for the in_vq are allocated when the port is added but are not released when the port is unplugged. They are only released when virtconsole is removed (see a7a69ec0d8e4) To avoid the problem and to be symmetric, we could allocate all the buffers in init_vqs() as they are released in remove_vqs(), but it sounds like a waste of memory. Rather than that, this patch changes add_port() logic to ignore ENOSPC error in fill_queue(), which means queue has already been filled. Fixes: a7a69ec0d8e4 ("virtio_console: free buffers after reset") Cc: mst@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Laurent Vivier Signed-off-by: Michael S. Tsirkin diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 7270e7b69262..3259426f01dc 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -1325,24 +1325,24 @@ static void set_console_size(struct port *port, u16 rows, u16 cols) port->cons.ws.ws_col = cols; } -static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock) +static int fill_queue(struct virtqueue *vq, spinlock_t *lock) { struct port_buffer *buf; - unsigned int nr_added_bufs; + int nr_added_bufs; int ret; nr_added_bufs = 0; do { buf = alloc_buf(vq->vdev, PAGE_SIZE, 0); if (!buf) - break; + return -ENOMEM; spin_lock_irq(lock); ret = add_inbuf(vq, buf); if (ret < 0) { spin_unlock_irq(lock); free_buf(buf, true); - break; + return ret; } nr_added_bufs++; spin_unlock_irq(lock); @@ -1362,7 +1362,6 @@ static int add_port(struct ports_device *portdev, u32 id) char debugfs_name[16]; struct port *port; dev_t devt; - unsigned int nr_added_bufs; int err; port = kmalloc(sizeof(*port), GFP_KERNEL); @@ -1421,11 +1420,13 @@ static int add_port(struct ports_device *portdev, u32 id) spin_lock_init(&port->outvq_lock); init_waitqueue_head(&port->waitqueue); - /* Fill the in_vq with buffers so the host can send us data. */ - nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock); - if (!nr_added_bufs) { + /* We can safely ignore ENOSPC because it means + * the queue already has buffers. Buffers are removed + * only by virtcons_remove(), not by unplug_port() + */ + err = fill_queue(port->in_vq, &port->inbuf_lock); + if (err < 0 && err != -ENOSPC) { dev_err(port->dev, "Error allocating inbufs\n"); - err = -ENOMEM; goto free_device; } @@ -2059,14 +2060,11 @@ static int virtcons_probe(struct virtio_device *vdev) INIT_WORK(&portdev->control_work, &control_work_handler); if (multiport) { - unsigned int nr_added_bufs; - spin_lock_init(&portdev->c_ivq_lock); spin_lock_init(&portdev->c_ovq_lock); - nr_added_bufs = fill_queue(portdev->c_ivq, - &portdev->c_ivq_lock); - if (!nr_added_bufs) { + err = fill_queue(portdev->c_ivq, &portdev->c_ivq_lock); + if (err < 0) { dev_err(&vdev->dev, "Error allocating buffers for control queue\n"); /* @@ -2077,7 +2075,7 @@ static int virtcons_probe(struct virtio_device *vdev) VIRTIO_CONSOLE_DEVICE_READY, 0); /* Device was functional: we need full cleanup. */ virtcons_remove(vdev); - return -ENOMEM; + return err; } } else { /*