@@ -112,6 +112,9 @@ API Changes
* Add a short 1-2 sentence description of the API change. Use fixed width
quotes for ``rte_function_names`` or ``rte_struct_names``. Use the past tense.
+* The function ``rte_vhost_enqueue_burst`` no longer supports concurrent enqueuing
+ packets to the same queue.
+
* The following counters are removed from ``rte_eth_stats`` structure:
ibadcrc, ibadlen, imcasts, fdirmatch, fdirmiss,
tx_pause_xon, rx_pause_xon, tx_pause_xoff, rx_pause_xoff.
@@ -88,7 +88,6 @@ struct vhost_virtqueue {
uint32_t backend; /**< Backend value to determine if device should started/stopped. */
uint16_t vhost_hlen; /**< Vhost header length (varies depending on RX merge buffers. */
volatile uint16_t last_used_idx; /**< Last index used on the available ring */
- volatile uint16_t last_used_idx_res; /**< Used for multiple devices reserving buffers. */
#define VIRTIO_INVALID_EVENTFD (-1)
#define VIRTIO_UNINITIALIZED_EVENTFD (-2)
int callfd; /**< Used to notify the guest (trigger interrupt). */
@@ -192,7 +191,7 @@ rte_vring_available_entries(struct virtio_net *dev, uint16_t queue_id)
if (!vq->enabled)
return 0;
- return *(volatile uint16_t *)&vq->avail->idx - vq->last_used_idx_res;
+ return *(volatile uint16_t *)&vq->avail->idx - vq->last_used_idx;
}
/**
@@ -205,49 +205,6 @@ copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
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
@@ -260,7 +217,7 @@ virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
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, res_start_idx;
uint16_t desc_indexes[MAX_PKT_BURST];
uint32_t i;
@@ -276,13 +233,19 @@ virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
if (unlikely(vq->enabled == 0))
return 0;
- count = reserve_avail_buf(vq, count, &res_start_idx, &res_end_idx);
+
+ count = RTE_MIN(count, (uint32_t)MAX_PKT_BURST);
+ avail_idx = *((volatile uint16_t *)&vq->avail->idx);
+ res_start_idx = vq->last_used_idx;
+ free_entries = avail_idx - res_start_idx;
+ count = RTE_MIN(count, free_entries);
+
if (count == 0)
return 0;
LOG_DEBUG(VHOST_DATA,
"(%"PRIu64") res_start_idx %d| res_end_idx Index %d\n",
- dev->device_fh, res_start_idx, res_end_idx);
+ dev->device_fh, res_start_idx, res_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)]);
@@ -315,12 +278,8 @@ virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
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));
@@ -366,29 +325,20 @@ fill_vec_buf(struct vhost_virtqueue *vq, uint32_t avail_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)
+ uint16_t *end)
{
- uint16_t res_start_idx;
uint16_t res_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;
+ res_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))
@@ -413,26 +363,17 @@ again:
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;
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)
+ uint16_t res_end_idx, struct rte_mbuf *m)
{
struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, 0, 0, 0, 0, 0}, 0};
uint32_t vec_idx = 0;
+ uint16_t res_start_idx = vq->last_used_idx;
uint16_t cur_idx = res_start_idx;
uint64_t desc_addr;
uint32_t mbuf_offset, mbuf_avail;
@@ -531,7 +472,7 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
{
struct vhost_virtqueue *vq;
uint32_t pkt_idx = 0, nr_used = 0;
- uint16_t start, end;
+ uint16_t end;
LOG_DEBUG(VHOST_DATA, "(%"PRIu64") virtio_dev_merge_rx()\n",
dev->device_fh);
@@ -554,24 +495,17 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
uint32_t pkt_len = pkts[pkt_idx]->pkt_len + vq->vhost_hlen;
if (unlikely(reserve_avail_buf_mergeable(vq, pkt_len,
- &start, &end) < 0)) {
+ &end) < 0)) {
LOG_DEBUG(VHOST_DATA,
"(%" PRIu64 ") Failed to get enough desc from vring\n",
dev->device_fh);
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]);
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));
@@ -601,7 +601,6 @@ vhost_set_vring_base(struct vhost_device_ctx ctx,
/* State->index refers to the queue index. The txq is 1, rxq is 0. */
dev->virtqueue[state->index]->last_used_idx = state->num;
- dev->virtqueue[state->index]->last_used_idx_res = state->num;
return 0;
}