Re: [PATCH v9 02/32] virtio: struct virtio_config_ops add callbacks for queue_reset

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




在 2022/4/6 上午11:43, Xuan Zhuo 写道:
Performing reset on a queue is divided into four steps:

  1. transport: notify the device to reset the queue
  2. vring:     recycle the buffer submitted
  3. vring:     reset/resize the vring (may re-alloc)
  4. transport: mmap vring to device, and enable the queue


Nit: it looks to me we'd better say it's an example (since step 3 or even 2 is not a must).



In order to support queue reset, add two callbacks(reset_vq,
enable_reset_vq) in struct virtio_config_ops to implement steps 1 and 4.

Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
  include/linux/virtio_config.h | 12 ++++++++++++
  1 file changed, 12 insertions(+)

diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 4d107ad31149..d4adcd0e1c57 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -74,6 +74,16 @@ struct virtio_shm_region {
   * @set_vq_affinity: set the affinity for a virtqueue (optional).
   * @get_vq_affinity: get the affinity for a virtqueue (optional).
   * @get_shm_region: get a shared memory region based on the index.
+ * @reset_vq: reset a queue individually (optional).
+ *	vq: the virtqueue
+ *	Returns 0 on success or error status
+ *	reset_vq will guarantee that the callbacks are disabled and synchronized.
+ *	Except for the callback, the caller should guarantee that the vring is


I wonder what's the implications for virtio hardening[1]. In that series, we agree to have a synchronize_vqs() config ops to make sure callbacks are synchronized.

It uses a global flag and a device wise synchronization mechanism. It looks to me we need to switch to

1) per virtqueue flag
2) per virtqueue synchronization

Thanks


+ *	not accessed by any functions of virtqueue.
+ * @enable_reset_vq: enable a reset queue
+ *	vq: the virtqueue
+ *	Returns 0 on success or error status
+ *	If reset_vq is set, then enable_reset_vq must also be set.
   */
  typedef void vq_callback_t(struct virtqueue *);
  struct virtio_config_ops {
@@ -100,6 +110,8 @@ struct virtio_config_ops {
  			int index);
  	bool (*get_shm_region)(struct virtio_device *vdev,
  			       struct virtio_shm_region *region, u8 id);
+	int (*reset_vq)(struct virtqueue *vq);
+	int (*enable_reset_vq)(struct virtqueue *vq);
  };
/* If driver didn't advertise the feature, it will never appear. */




[Index of Archives]     [Linux Sound]     [ALSA Users]     [ALSA Devel]     [Linux Audio Users]     [Linux Media]     [Kernel]     [Photo Sharing]     [Gimp]     [Yosemite News]     [Linux Media]

  Powered by Linux