Re: [PATCH net-next RFC 1/5] vhost: split out ring head fetching logic

From: Jason Wang
Date: Sun Sep 24 2017 - 22:03:35 EST




On 2017å09æ22æ 16:31, Stefan Hajnoczi wrote:
On Fri, Sep 22, 2017 at 04:02:31PM +0800, Jason Wang wrote:
+/* This looks in the virtqueue and for the first available buffer, and converts
+ * it to an iovec for convenient access. Since descriptors consist of some
+ * number of output then some number of input descriptors, it's actually two
+ * iovecs, but we pack them into one and note how many of each there were.
+ *
+ * This function returns the descriptor number found, or vq->num (which is
+ * never a valid descriptor number) if none was found. A negative code is
+ * returned on error. */
+int __vhost_get_vq_desc(struct vhost_virtqueue *vq,
+ struct iovec iov[], unsigned int iov_size,
+ unsigned int *out_num, unsigned int *in_num,
+ struct vhost_log *log, unsigned int *log_num,
+ __virtio16 head)
[...]
+int vhost_get_vq_desc(struct vhost_virtqueue *vq,
+ struct iovec iov[], unsigned int iov_size,
+ unsigned int *out_num, unsigned int *in_num,
+ struct vhost_log *log, unsigned int *log_num)
Please document vhost_get_vq_desc().

Please also explain the difference between __vhost_get_vq_desc() and
vhost_get_vq_desc() in the documentation.

Right, will document this in next version.

Thanks