Messages in this thread Patch in this message | | | From | Jason Wang <> | Subject | [PATCH V3 1/2] virtio: introduce methods of sanitizing device features | Date | Mon, 17 Nov 2014 17:17:17 +0800 |
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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 <rusty@rustcorp.com.au> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Cc: Wanlong Gao <gaowanlong@cn.fujitsu.com> Signed-off-by: Jason Wang <jasowang@redhat.com> --- 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
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