From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751683AbaKQJRn (ORCPT ); Mon, 17 Nov 2014 04:17:43 -0500 Received: from mx1.redhat.com ([209.132.183.28]:37098 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751092AbaKQJRl (ORCPT ); Mon, 17 Nov 2014 04:17:41 -0500 From: Jason Wang To: rusty@rustcorp.com.au, mst@redhat.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Jason Wang , Cornelia Huck , Wanlong Gao Subject: [PATCH V3 1/2] virtio: introduce methods of sanitizing device features Date: Mon, 17 Nov 2014 17:17:17 +0800 Message-Id: <1416215838-21700-1-git-send-email-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Buggy host may advertised buggy host features (a usual case is that host advertise a feature whose dependencies were missed). In this case, driver should detect and disable the buggy features by itself. This patch introduces driver specific sanitize_features() method which is called just before features finalizing to detect and disable buggy features advertised by host. Virtio-net will be the first user. Cc: Rusty Russell Cc: Michael S. Tsirkin Cc: Cornelia Huck Cc: Wanlong Gao Signed-off-by: Jason Wang --- Changes from V2: - fix typo - rename fix_features to sanitize_features --- drivers/virtio/virtio.c | 4 ++++ include/linux/virtio.h | 1 + include/linux/virtio_config.h | 12 ++++++++++++ 3 files changed, 17 insertions(+) diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index df598dd..6a86b4f 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -181,6 +181,10 @@ static int virtio_dev_probe(struct device *_d) if (device_features & (1 << i)) set_bit(i, dev->features); + /* Sanitize buggy features advertised by host */ + if (drv->sanitize_features) + drv->sanitize_features(dev); + dev->config->finalize_features(dev); err = drv->probe(dev); diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 65261a7..5aed283 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -142,6 +142,7 @@ struct virtio_driver { void (*scan)(struct virtio_device *dev); void (*remove)(struct virtio_device *dev); void (*config_changed)(struct virtio_device *dev); + void (*sanitize_features)(struct virtio_device *dev); #ifdef CONFIG_PM int (*freeze)(struct virtio_device *dev); int (*restore)(struct virtio_device *dev); diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index 7f4ef66..7bd89ea 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -96,6 +96,18 @@ static inline bool virtio_has_feature(const struct virtio_device *vdev, return test_bit(fbit, vdev->features); } +static inline void virtio_disable_feature(struct virtio_device *vdev, + unsigned int fbit) +{ + BUG_ON(fbit >= VIRTIO_TRANSPORT_F_START); + BUG_ON(vdev->config->get_status(vdev) & + ~(VIRTIO_CONFIG_S_ACKNOWLEDGE | VIRTIO_CONFIG_S_DRIVER)); + + virtio_check_driver_offered_feature(vdev, fbit); + + clear_bit(fbit, vdev->features); +} + static inline struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev, vq_callback_t *c, const char *n) -- 1.9.1