On Fri, Jun 22, 2018 at 03:43:21PM +0200, Maxime Coquelin wrote:
[...]
> index 671b4b3bf..62d49f238 100644
> --- a/lib/librte_vhost/vhost.h
> +++ b/lib/librte_vhost/vhost.h
> @@ -80,6 +80,12 @@ struct log_cache_entry {
> unsigned long val;
> };
>
> +struct vring_used_elem_packed {
> + uint32_t id;
Id in packed ring is 16 bits long. Maybe it's better
to define it as uint16_t here.
> + uint32_t len;
> + uint32_t count;
> +};
> +
[...]
> +
> +static __rte_always_inline void
> +flush_shadow_used_ring_packed(struct virtio_net *dev,
> + struct vhost_virtqueue *vq)
> +{
> + int i;
> + uint16_t used_idx = vq->last_used_idx;
> +
> + /* Split loop in two to save memory barriers */
> + for (i = 0; i < vq->shadow_used_idx; i++) {
> + vq->desc_packed[used_idx].index = vq->shadow_used_packed[i].id;
> + vq->desc_packed[used_idx].len = vq->shadow_used_packed[i].len;
> +
> + used_idx += vq->shadow_used_packed[i].count;
used_idx may wrap.
> + }
> +
> + rte_smp_wmb();
> +
> + for (i = 0; i < vq->shadow_used_idx; i++) {
> + uint16_t flags;
> +
> + if (vq->shadow_used_packed[i].len)
> + flags = VRING_DESC_F_WRITE;
> + else
> + flags = 0;
> +
> + if (vq->used_wrap_counter) {
> + flags |= VRING_DESC_F_USED;
> + flags |= VRING_DESC_F_AVAIL;
> + } else {
> + flags &= ~VRING_DESC_F_USED;
> + flags &= ~VRING_DESC_F_AVAIL;
> + }
> +
> + vq->desc_packed[vq->last_used_idx].flags = flags;
> +
> + vhost_log_cache_used_vring(dev, vq,
> + vq->last_used_idx *
> + sizeof(struct vring_desc_packed),
> + sizeof(struct vring_desc_packed));
> +
> + vq->last_used_idx += vq->shadow_used_packed[i].count;
> + if (vq->last_used_idx >= vq->size) {
> + vq->used_wrap_counter ^= 1;
> + vq->last_used_idx -= vq->size;
> + }
> + }
> +
> + rte_smp_wmb();
> + vq->shadow_used_idx = 0;
> + vhost_log_cache_sync(dev, vq);
> +}
> +
> +static __rte_always_inline void
> +update_shadow_used_ring_packed(struct vhost_virtqueue *vq,
> + uint16_t desc_idx, uint16_t len, uint16_t count)
> +{
> + uint16_t i = vq->shadow_used_idx++;
> +
> + vq->shadow_used_packed[i].id = desc_idx;
> + vq->shadow_used_packed[i].len = len;
> + vq->shadow_used_packed[i].count = count;
> }
>
> static inline void
> --
> 2.14.4
>
