return 0;
}
-/*
- * As many data cores may want to access available buffers
- * they need to be reserved.
- */
-static inline uint32_t
-reserve_avail_buf(struct vhost_virtqueue *vq, uint32_t count,
- uint16_t *start, uint16_t *end)
-{
- uint16_t res_start_idx;
- uint16_t res_end_idx;
- uint16_t avail_idx;
- uint16_t free_entries;
- int success;
-
- count = RTE_MIN(count, (uint32_t)MAX_PKT_BURST);
-
-again:
- res_start_idx = vq->last_used_idx_res;
- avail_idx = *((volatile uint16_t *)&vq->avail->idx);
-
- free_entries = avail_idx - res_start_idx;
- count = RTE_MIN(count, free_entries);
- if (count == 0)
- return 0;
-
- res_end_idx = res_start_idx + count;
-
- /*
- * update vq->last_used_idx_res atomically; try again if failed.
- *
- * TODO: Allow to disable cmpset if no concurrency in application.
- */
- success = rte_atomic16_cmpset(&vq->last_used_idx_res,
- res_start_idx, res_end_idx);
- if (unlikely(!success))
- goto again;
-
- *start = res_start_idx;
- *end = res_end_idx;
-
- return count;
-}
-
/**
* This function adds buffers to the virtio devices RX virtqueue. Buffers can
* be received from the physical port or from another virtio device. A packet
struct rte_mbuf **pkts, uint32_t count)
{
struct vhost_virtqueue *vq;
- uint16_t res_start_idx, res_end_idx;
+ uint16_t avail_idx, free_entries, start_idx;
uint16_t desc_indexes[MAX_PKT_BURST];
uint16_t used_idx;
uint32_t i;
if (unlikely(vq->enabled == 0))
return 0;
- count = reserve_avail_buf(vq, count, &res_start_idx, &res_end_idx);
+ avail_idx = *((volatile uint16_t *)&vq->avail->idx);
+ start_idx = vq->last_used_idx;
+ free_entries = avail_idx - start_idx;
+ count = RTE_MIN(count, free_entries);
+ count = RTE_MIN(count, (uint32_t)MAX_PKT_BURST);
if (count == 0)
return 0;
- LOG_DEBUG(VHOST_DATA, "(%d) res_start_idx %d | res_end_idx Index %d\n",
- dev->vid, res_start_idx, res_end_idx);
+ LOG_DEBUG(VHOST_DATA, "(%d) start_idx %d | end_idx %d\n",
+ dev->vid, start_idx, start_idx + count);
/* Retrieve all of the desc indexes first to avoid caching issues. */
- rte_prefetch0(&vq->avail->ring[res_start_idx & (vq->size - 1)]);
+ rte_prefetch0(&vq->avail->ring[start_idx & (vq->size - 1)]);
for (i = 0; i < count; i++) {
- used_idx = (res_start_idx + i) & (vq->size - 1);
+ used_idx = (start_idx + i) & (vq->size - 1);
desc_indexes[i] = vq->avail->ring[used_idx];
vq->used->ring[used_idx].id = desc_indexes[i];
vq->used->ring[used_idx].len = pkts[i]->pkt_len +
err = copy_mbuf_to_desc(dev, vq, pkts[i], desc_idx);
if (unlikely(err)) {
- used_idx = (res_start_idx + i) & (vq->size - 1);
+ used_idx = (start_idx + i) & (vq->size - 1);
vq->used->ring[used_idx].len = dev->vhost_hlen;
vhost_log_used_vring(dev, vq,
offsetof(struct vring_used, ring[used_idx]),
rte_smp_wmb();
- /* Wait until it's our turn to add our buffer to the used ring. */
- while (unlikely(vq->last_used_idx != res_start_idx))
- rte_pause();
-
*(volatile uint16_t *)&vq->used->idx += count;
- vq->last_used_idx = res_end_idx;
+ vq->last_used_idx += count;
vhost_log_used_vring(dev, vq,
offsetof(struct vring_used, idx),
sizeof(vq->used->idx));
}
/*
- * As many data cores may want to access available buffers concurrently,
- * they need to be reserved.
- *
* Returns -1 on fail, 0 on success
*/
static inline int
reserve_avail_buf_mergeable(struct vhost_virtqueue *vq, uint32_t size,
- uint16_t *start, uint16_t *end,
- struct buf_vector *buf_vec)
+ uint16_t *end, struct buf_vector *buf_vec)
{
- uint16_t res_start_idx;
- uint16_t res_cur_idx;
+ uint16_t cur_idx;
uint16_t avail_idx;
- uint32_t allocated;
- uint32_t vec_idx;
- uint16_t tries;
+ uint32_t allocated = 0;
+ uint32_t vec_idx = 0;
+ uint16_t tries = 0;
-again:
- res_start_idx = vq->last_used_idx_res;
- res_cur_idx = res_start_idx;
+ cur_idx = vq->last_used_idx;
- allocated = 0;
- vec_idx = 0;
- tries = 0;
while (1) {
avail_idx = *((volatile uint16_t *)&vq->avail->idx);
- if (unlikely(res_cur_idx == avail_idx))
+ if (unlikely(cur_idx == avail_idx))
return -1;
- if (unlikely(fill_vec_buf(vq, res_cur_idx, &allocated,
+ if (unlikely(fill_vec_buf(vq, cur_idx, &allocated,
&vec_idx, buf_vec) < 0))
return -1;
- res_cur_idx++;
+ cur_idx++;
tries++;
if (allocated >= size)
return -1;
}
- /*
- * update vq->last_used_idx_res atomically.
- * retry again if failed.
- */
- if (rte_atomic16_cmpset(&vq->last_used_idx_res,
- res_start_idx, res_cur_idx) == 0)
- goto again;
-
- *start = res_start_idx;
- *end = res_cur_idx;
+ *end = cur_idx;
return 0;
}
static inline uint32_t __attribute__((always_inline))
copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
- uint16_t res_start_idx, uint16_t res_end_idx,
- struct rte_mbuf *m, struct buf_vector *buf_vec)
+ uint16_t end_idx, struct rte_mbuf *m,
+ struct buf_vector *buf_vec)
{
struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, 0, 0, 0, 0, 0}, 0};
uint32_t vec_idx = 0;
- uint16_t cur_idx = res_start_idx;
+ uint16_t start_idx = vq->last_used_idx;
+ uint16_t cur_idx = start_idx;
uint64_t desc_addr;
uint32_t mbuf_offset, mbuf_avail;
uint32_t desc_offset, desc_avail;
return 0;
LOG_DEBUG(VHOST_DATA, "(%d) current index %d | end index %d\n",
- dev->vid, cur_idx, res_end_idx);
+ dev->vid, cur_idx, end_idx);
if (buf_vec[vec_idx].buf_len < dev->vhost_hlen)
return -1;
desc_addr = gpa_to_vva(dev, buf_vec[vec_idx].buf_addr);
rte_prefetch0((void *)(uintptr_t)desc_addr);
- virtio_hdr.num_buffers = res_end_idx - res_start_idx;
+ virtio_hdr.num_buffers = end_idx - start_idx;
LOG_DEBUG(VHOST_DATA, "(%d) RX: num merge buffers %d\n",
dev->vid, virtio_hdr.num_buffers);
offsetof(struct vring_used, ring[used_idx]),
sizeof(vq->used->ring[used_idx]));
- return res_end_idx - res_start_idx;
+ return end_idx - start_idx;
}
static inline uint32_t __attribute__((always_inline))
{
struct vhost_virtqueue *vq;
uint32_t pkt_idx = 0, nr_used = 0;
- uint16_t start, end;
+ uint16_t end;
struct buf_vector buf_vec[BUF_VECTOR_MAX];
LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
uint32_t pkt_len = pkts[pkt_idx]->pkt_len + dev->vhost_hlen;
- if (unlikely(reserve_avail_buf_mergeable(vq, pkt_len, &start,
+ if (unlikely(reserve_avail_buf_mergeable(vq, pkt_len,
&end, buf_vec) < 0)) {
LOG_DEBUG(VHOST_DATA,
"(%d) failed to get enough desc from vring\n",
break;
}
- nr_used = copy_mbuf_to_desc_mergeable(dev, vq, start, end,
+ nr_used = copy_mbuf_to_desc_mergeable(dev, vq, end,
pkts[pkt_idx], buf_vec);
rte_smp_wmb();
- /*
- * Wait until it's our turn to add our buffer
- * to the used ring.
- */
- while (unlikely(vq->last_used_idx != start))
- rte_pause();
-
*(volatile uint16_t *)&vq->used->idx += nr_used;
vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
sizeof(vq->used->idx));
git.droids-corp.org / dpdk.git / blobdiff