Re: [PATCH V3 6/7] virtio: introduce a mdev based transport

On Fri, Oct 11, 2019 at 04:15:56PM +0800, Jason Wang wrote:

+struct virtio_mdev_device {

• struct virtio_device vdev;
• struct mdev_device *mdev;
• unsigned long version;
• struct virtqueue **vqs;
• /* The lock to protect virtqueue list */
• spinlock_t lock;
• struct list_head virtqueues;

Is this a list of struct virtio_mdev_vq_info? Please document the actual type in a comment.

+static int virtio_mdev_find_vqs(struct virtio_device *vdev, unsigned nvqs,

• 		struct virtqueue *vqs[],
  

• 		vq_callback_t *callbacks[],
  

• 		const char * const names[],
  

• 		const bool *ctx,
  

• 		struct irq_affinity *desc)
  

+{

• struct virtio_mdev_device *vm_dev = to_virtio_mdev_device(vdev);
• struct mdev_device *mdev = vm_get_mdev(vdev);
• const struct virtio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
• struct virtio_mdev_callback cb;
• int i, err, queue_idx = 0;
• vm_dev->vqs = kmalloc_array(queue_idx, sizeof(*vm_dev->vqs),

• 		    GFP_KERNEL);
  

kmalloc_array(0, ...)? I would have expected nvqs instead of queue_idx (0).

What is this the purpose of vm_dev->vqs and does anything ever access it?