On Mon, Jul 02, 2018 at 10:16:25AM +0200, Maxime Coquelin wrote:
[...]
> +static __rte_always_inline int
> +fill_vec_buf_packed_indirect(struct virtio_net *dev,
> + struct vhost_virtqueue *vq,
> + struct vring_desc_packed *desc, uint16_t *vec_idx,
> + struct buf_vector *buf_vec, uint16_t *len, uint8_t perm)
> +{
> + uint16_t i;
> + uint32_t nr_decs;
> + uint16_t vec_id = *vec_idx;
> + uint64_t dlen;
> + struct vring_desc_packed *descs, *idescs = NULL;
> +
> + dlen = desc->len;
> + descs = (struct vring_desc_packed *)(uintptr_t)
> + vhost_iova_to_vva(dev, vq, desc->addr, &dlen, VHOST_ACCESS_RO);
> + if (unlikely(!descs))
> + return -1;
> +
> + if (unlikely(dlen < desc->len)) {
> + /*
> + * The indirect desc table is not contiguous
> + * in process VA space, we have to copy it.
> + */
> + idescs = alloc_copy_ind_table(dev, vq, desc->addr, desc->len);
> + if (unlikely(!idescs))
> + return -1;
> +
> + descs = idescs;
> + }
> +
> + nr_decs = desc->len / sizeof(struct vring_desc_packed);
s/nr_decs = /nr_desc = /
> + if (unlikely(nr_decs >= vq->size)) {
> + free_ind_table(idescs);
> + return -1;
> + }
[...]
> +
> +static inline int
> +fill_vec_buf_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
> + uint16_t avail_idx, uint16_t *desc_count,
> + struct buf_vector *buf_vec, uint16_t *vec_idx,
> + uint16_t *buf_id, uint16_t *len, uint8_t perm)
> +{
> + bool wrap_counter = vq->avail_wrap_counter;
> + struct vring_desc_packed *descs = vq->desc_packed;
> + uint16_t vec_id = *vec_idx;
> +
> + if (avail_idx < vq->last_avail_idx)
> + wrap_counter ^= 1;
In which case avail_idx will be less than vq->last_avail_idx
and we need to wrap the wrap_counter?
> +
> + if (unlikely(!desc_is_avail(&descs[avail_idx], wrap_counter)))
> + return -1;
> +
> + *desc_count = 0;
> +
> + while (1) {
> + if (unlikely(vec_id >= BUF_VECTOR_MAX))
> + return -1;
> +
> + *desc_count += 1;
> + *buf_id = descs[avail_idx].index;
> +
> + if (descs[avail_idx].flags & VRING_DESC_F_INDIRECT) {
> + if (unlikely(fill_vec_buf_packed_indirect(dev, vq,
> + &descs[avail_idx],
> + &vec_id, buf_vec,
> + len, perm) < 0))
> + return -1;
> + } else {
> + *len += descs[avail_idx].len;
> +
> + if (unlikely(map_one_desc(dev, vq, buf_vec, &vec_id,
> + descs[avail_idx].addr,
> + descs[avail_idx].len,
> + perm)))
> + return -1;
> + }
> +
> + if ((descs[avail_idx].flags & VRING_DESC_F_NEXT) == 0)
> + break;
> +
> + if (++avail_idx >= vq->size) {
> + avail_idx -= vq->size;
> + wrap_counter ^= 1;
> + }
> + }
> +
> + *vec_idx = vec_id;
> +
> + return 0;
> +}
[...]
