From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heinz Graalfs Subject: [PATCH 1/1] virtio_ccw: introduce device_lost in virtio_ccw_device Date: Fri, 25 Apr 2014 14:35:27 +0200 Message-ID: <1398429327-31391-2-git-send-email-graalfs@linux.vnet.ibm.com> References: <1398429327-31391-1-git-send-email-graalfs@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1398429327-31391-1-git-send-email-graalfs@linux.vnet.ibm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: rusty@rustcorp.com.au Cc: borntraeger@de.ibm.com, virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.org When a device is lost, the common I/O layer calls the notification handler with CIO_GONE: In that event, flag device_lost as true. In case the device had been flagged as lost when the remove/offline callbacks are called, call the new virtio_break_device() function prior to invoking device_unregister(). This avoids hangs of I/O triggered via the device unregistration callbacks. Signed-off-by: Heinz Graalfs Reviewed-by: Cornelia Huck --- drivers/s390/kvm/virtio_ccw.c | 49 ++++++++++++++++++++++++++++++++----------- 1 file changed, 37 insertions(+), 12 deletions(-) diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c index 1e1fc67..d2c0b44 100644 --- a/drivers/s390/kvm/virtio_ccw.c +++ b/drivers/s390/kvm/virtio_ccw.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include #include @@ -62,6 +63,7 @@ struct virtio_ccw_device { struct vq_config_block *config_block; bool is_thinint; bool going_away; + bool device_lost; void *airq_info; }; @@ -1010,11 +1012,14 @@ static void virtio_ccw_remove(struct ccw_device *cdev) unsigned long flags; struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev); - if (vcdev && cdev->online) + if (vcdev && cdev->online) { + if (vcdev->device_lost) + virtio_break_device(&vcdev->vdev); unregister_virtio_device(&vcdev->vdev); - spin_lock_irqsave(get_ccwdev_lock(cdev), flags); - dev_set_drvdata(&cdev->dev, NULL); - spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags); + spin_lock_irqsave(get_ccwdev_lock(cdev), flags); + dev_set_drvdata(&cdev->dev, NULL); + spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags); + } cdev->handler = NULL; } @@ -1023,12 +1028,14 @@ static int virtio_ccw_offline(struct ccw_device *cdev) unsigned long flags; struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev); - if (vcdev) { - unregister_virtio_device(&vcdev->vdev); - spin_lock_irqsave(get_ccwdev_lock(cdev), flags); - dev_set_drvdata(&cdev->dev, NULL); - spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags); - } + if (!vcdev) + return 0; + if (vcdev->device_lost) + virtio_break_device(&vcdev->vdev); + unregister_virtio_device(&vcdev->vdev); + spin_lock_irqsave(get_ccwdev_lock(cdev), flags); + dev_set_drvdata(&cdev->dev, NULL); + spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags); return 0; } @@ -1096,8 +1103,26 @@ out_free: static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event) { - /* TODO: Check whether we need special handling here. */ - return 0; + int rc; + struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev); + + /* + * Make sure vcdev is set + * i.e. set_offline/remove callback not already running + */ + if (!vcdev) + return NOTIFY_DONE; + + switch (event) { + case CIO_GONE: + vcdev->device_lost = true; + rc = NOTIFY_DONE; + break; + default: + rc = NOTIFY_DONE; + break; + } + return rc; } static struct ccw_device_id virtio_ids[] = { -- 1.8.3.1