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=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 E8194C43331 for ; Wed, 13 Nov 2019 15:01:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B102A222D3 for ; Wed, 13 Nov 2019 15:01:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="CP8tEFwh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727969AbfKMPBH (ORCPT ); Wed, 13 Nov 2019 10:01:07 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:45845 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727730AbfKMPBH (ORCPT ); Wed, 13 Nov 2019 10:01:07 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1573657265; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=pZrVnWf11qMep6zPjTPieof4+h3HJFQO0raZCoFr0t8=; b=CP8tEFwh9jaEnWgVFHWpo3y2rqEO4YM2NLhNunWji9w6mggb8Ly92yKCJAk7M2Qs+srFFh V/DSe1J8dA+m8JeP5caaFHznIdhJT7nOJbcQHnPMofVmwlMmlHeg2fZd2WCUZTagciKz7f zvRkq7wiPWb4W4xWwHIExEyMGI71W9k= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-349-oR_IZnsWO86m8XAGuP0U2w-1; Wed, 13 Nov 2019 10:01:04 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 093F118B5F76; Wed, 13 Nov 2019 15:01:02 +0000 (UTC) Received: from thinkpad.redhat.com (ovpn-117-236.ams2.redhat.com [10.36.117.236]) by smtp.corp.redhat.com (Postfix) with ESMTP id EDF3360308; Wed, 13 Nov 2019 15:00:56 +0000 (UTC) From: Laurent Vivier To: linux-kernel@vger.kernel.org Cc: Arnd Bergmann , Greg Kroah-Hartman , Amit Shah , "Michael S . Tsirkin" , virtualization@lists.linux-foundation.org, stable@vger.kernel.org, Laurent Vivier Subject: [PATCH v2] virtio_console: allocate inbufs in add_port() only if it is needed Date: Wed, 13 Nov 2019 16:00:56 +0100 Message-Id: <20191113150056.9990-1-lvivier@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-MC-Unique: oR_IZnsWO86m8XAGuP0U2w-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When we hot unplug a virtserialport and then try to hot plug again, it fails: (qemu) chardev-add socket,id=3Dserial0,path=3D/tmp/serial0,server,nowait (qemu) device_add virtserialport,bus=3Dvirtio-serial0.0,nr=3D2,\ chardev=3Dserial0,id=3Dserial0,name=3Dserial0 (qemu) device_del serial0 (qemu) device_add virtserialport,bus=3Dvirtio-serial0.0,nr=3D2,\ chardev=3Dserial0,id=3Dserial0,name=3Dserial0 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 --- Notes: v2: making fill_queue return int and testing return code for -ENOSPC drivers/char/virtio_console.c | 24 +++++++++--------------- 1 file changed, 9 insertions(+), 15 deletions(-) diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 7270e7b69262..9e6534fd1aa4 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) =09port->cons.ws.ws_col =3D cols; } =20 -static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock) +static int fill_queue(struct virtqueue *vq, spinlock_t *lock) { =09struct port_buffer *buf; -=09unsigned int nr_added_bufs; +=09int nr_added_bufs; =09int ret; =20 =09nr_added_bufs =3D 0; =09do { =09=09buf =3D alloc_buf(vq->vdev, PAGE_SIZE, 0); =09=09if (!buf) -=09=09=09break; +=09=09=09return -ENOMEM; =20 =09=09spin_lock_irq(lock); =09=09ret =3D add_inbuf(vq, buf); =09=09if (ret < 0) { =09=09=09spin_unlock_irq(lock); =09=09=09free_buf(buf, true); -=09=09=09break; +=09=09=09return ret; =09=09} =09=09nr_added_bufs++; =09=09spin_unlock_irq(lock); @@ -1362,7 +1362,6 @@ static int add_port(struct ports_device *portdev, u32= id) =09char debugfs_name[16]; =09struct port *port; =09dev_t devt; -=09unsigned int nr_added_bufs; =09int err; =20 =09port =3D kmalloc(sizeof(*port), GFP_KERNEL); @@ -1421,11 +1420,9 @@ static int add_port(struct ports_device *portdev, u3= 2 id) =09spin_lock_init(&port->outvq_lock); =09init_waitqueue_head(&port->waitqueue); =20 -=09/* Fill the in_vq with buffers so the host can send us data. */ -=09nr_added_bufs =3D fill_queue(port->in_vq, &port->inbuf_lock); -=09if (!nr_added_bufs) { +=09err =3D fill_queue(port->in_vq, &port->inbuf_lock); +=09if (err < 0 && err !=3D -ENOSPC) { =09=09dev_err(port->dev, "Error allocating inbufs\n"); -=09=09err =3D -ENOMEM; =09=09goto free_device; =09} =20 @@ -2059,14 +2056,11 @@ static int virtcons_probe(struct virtio_device *vde= v) =09INIT_WORK(&portdev->control_work, &control_work_handler); =20 =09if (multiport) { -=09=09unsigned int nr_added_bufs; - =09=09spin_lock_init(&portdev->c_ivq_lock); =09=09spin_lock_init(&portdev->c_ovq_lock); =20 -=09=09nr_added_bufs =3D fill_queue(portdev->c_ivq, -=09=09=09=09=09 &portdev->c_ivq_lock); -=09=09if (!nr_added_bufs) { +=09=09err =3D fill_queue(portdev->c_ivq, &portdev->c_ivq_lock); +=09=09if (err < 0) { =09=09=09dev_err(&vdev->dev, =09=09=09=09"Error allocating buffers for control queue\n"); =09=09=09/* @@ -2077,7 +2071,7 @@ static int virtcons_probe(struct virtio_device *vdev) =09=09=09=09=09 VIRTIO_CONSOLE_DEVICE_READY, 0); =09=09=09/* Device was functional: we need full cleanup. */ =09=09=09virtcons_remove(vdev); -=09=09=09return -ENOMEM; +=09=09=09return err; =09=09} =09} else { =09=09/* --=20 2.23.0