@@ -245,11 +245,13 @@ The following is an overview of some key Vhost API functions:
Unregister the async copy device channel from a vhost queue.
-* ``rte_vhost_submit_enqueue_burst(vid, queue_id, pkts, count)``
+* ``rte_vhost_submit_enqueue_burst(vid, queue_id, pkts, count, comp_pkts, comp_count)``
Submit an enqueue request to transmit ``count`` packets from host to guest
- by async data path. Enqueue is not guaranteed to finish upon the return of
- this API call.
+ by async data path. Successfully enqueued packets can be transfer completed
+ or being occupied by DMA engines; transfer completed packets are returned in
+ ``comp_pkts``, but others are not guaranteed to finish, when this API
+ call returns.
Applications must not free the packets submitted for enqueue until the
packets are completed.
@@ -87,13 +87,8 @@ struct rte_vhost_async_channel_ops {
* inflight async packet information
*/
struct async_inflight_info {
- union {
- uint32_t info;
- struct {
- uint16_t descs; /* num of descs inflight */
- uint16_t segs; /* iov segs inflight */
- };
- };
+ struct rte_mbuf *mbuf;
+ uint16_t descs; /* num of descs inflight */
};
/**
@@ -147,9 +142,13 @@ __rte_experimental
int rte_vhost_async_channel_unregister(int vid, uint16_t queue_id);
/**
- * This function submits enqueue data to async engine. This function has
- * no guarantee to the transfer completion upon return. Applications
- * should poll transfer status by rte_vhost_poll_enqueue_completed()
+ * This function submits enqueue data to async engine. Successfully
+ * enqueued packets can be transfer completed or being occupied by DMA
+ * engines, when this API returns. Transfer completed packets are returned
+ * in comp_pkts, so users need to guarantee its size is greater than or
+ * equal to the size of pkts; for packets that are successfully enqueued
+ * but not transfer completed, users should poll transfer status by
+ * rte_vhost_poll_enqueue_completed().
*
* @param vid
* id of vhost device to enqueue data
@@ -159,12 +158,19 @@ int rte_vhost_async_channel_unregister(int vid, uint16_t queue_id);
* array of packets to be enqueued
* @param count
* packets num to be enqueued
+ * @param comp_pkts
+ * empty array to get transfer completed packets. Users need to
+ * guarantee its size is greater than or equal to that of pkts
+ * @param comp_count
+ * num of packets that are transfer completed, when this API returns.
+ * If no packets are transfer completed, its value is set to 0.
* @return
- * num of packets enqueued
+ * num of packets enqueued, including in-flight and transfer completed
*/
__rte_experimental
uint16_t rte_vhost_submit_enqueue_burst(int vid, uint16_t queue_id,
- struct rte_mbuf **pkts, uint16_t count);
+ struct rte_mbuf **pkts, uint16_t count,
+ struct rte_mbuf **comp_pkts, uint32_t *comp_count);
/**
* This function checks async completion status for a specific vhost
@@ -327,17 +327,17 @@ cleanup_device(struct virtio_net *dev, int destroy)
static void
vhost_free_async_mem(struct vhost_virtqueue *vq)
{
- if (vq->async_pkts_pending)
- rte_free(vq->async_pkts_pending);
if (vq->async_pkts_info)
rte_free(vq->async_pkts_info);
+ if (vq->async_descs_split)
+ rte_free(vq->async_descs_split);
if (vq->it_pool)
rte_free(vq->it_pool);
if (vq->vec_pool)
rte_free(vq->vec_pool);
- vq->async_pkts_pending = NULL;
vq->async_pkts_info = NULL;
+ vq->async_descs_split = NULL;
vq->it_pool = NULL;
vq->vec_pool = NULL;
}
@@ -1628,9 +1628,6 @@ int rte_vhost_async_channel_register(int vid, uint16_t queue_id,
node = SOCKET_ID_ANY;
#endif
- vq->async_pkts_pending = rte_malloc_socket(NULL,
- vq->size * sizeof(uintptr_t),
- RTE_CACHE_LINE_SIZE, node);
vq->async_pkts_info = rte_malloc_socket(NULL,
vq->size * sizeof(struct async_inflight_info),
RTE_CACHE_LINE_SIZE, node);
@@ -1640,7 +1637,10 @@ int rte_vhost_async_channel_register(int vid, uint16_t queue_id,
vq->vec_pool = rte_malloc_socket(NULL,
VHOST_MAX_ASYNC_VEC * sizeof(struct iovec),
RTE_CACHE_LINE_SIZE, node);
- if (!vq->async_pkts_pending || !vq->async_pkts_info ||
+ vq->async_descs_split = rte_malloc_socket(NULL,
+ vq->size * sizeof(struct vring_used_elem),
+ RTE_CACHE_LINE_SIZE, node);
+ if (!vq->async_descs_split || !vq->async_pkts_info ||
!vq->it_pool || !vq->vec_pool) {
vhost_free_async_mem(vq);
VHOST_LOG_CONFIG(ERR,
@@ -202,11 +202,13 @@ struct vhost_virtqueue {
struct iovec *vec_pool;
/* async data transfer status */
- uintptr_t **async_pkts_pending;
struct async_inflight_info *async_pkts_info;
uint16_t async_pkts_idx;
uint16_t async_pkts_inflight_n;
uint16_t async_last_pkts_n;
+ struct vring_used_elem *async_descs_split;
+ uint16_t async_desc_idx;
+ uint16_t last_async_desc_idx;
/* vq async features */
bool async_inorder;
@@ -733,8 +735,7 @@ vhost_vring_call_split(struct virtio_net *dev, struct vhost_virtqueue *vq)
/* Don't kick guest if we don't reach index specified by guest. */
if (dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX)) {
uint16_t old = vq->signalled_used;
- uint16_t new = vq->async_pkts_inflight_n ?
- vq->used->idx:vq->last_used_idx;
+ uint16_t new = vq->last_used_idx;
bool signalled_used_valid = vq->signalled_used_valid;
vq->signalled_used = new;
@@ -1967,12 +1967,13 @@ vhost_user_get_vring_base(struct virtio_net **pdev,
} else {
rte_free(vq->shadow_used_split);
vq->shadow_used_split = NULL;
- if (vq->async_pkts_pending)
- rte_free(vq->async_pkts_pending);
+
if (vq->async_pkts_info)
rte_free(vq->async_pkts_info);
- vq->async_pkts_pending = NULL;
+ if (vq->async_descs_split)
+ rte_free(vq->async_descs_split);
vq->async_pkts_info = NULL;
+ vq->async_descs_split = NULL;
}
rte_free(vq->batch_copy_elems);
@@ -118,31 +118,6 @@ flush_shadow_used_ring_split(struct virtio_net *dev, struct vhost_virtqueue *vq)
}
static __rte_always_inline void
-async_flush_shadow_used_ring_split(struct virtio_net *dev,
- struct vhost_virtqueue *vq)
-{
- uint16_t used_idx = vq->last_used_idx & (vq->size - 1);
-
- if (used_idx + vq->shadow_used_idx <= vq->size) {
- do_flush_shadow_used_ring_split(dev, vq, used_idx, 0,
- vq->shadow_used_idx);
- } else {
- uint16_t size;
-
- /* update used ring interval [used_idx, vq->size] */
- size = vq->size - used_idx;
- do_flush_shadow_used_ring_split(dev, vq, used_idx, 0, size);
-
- /* update the left half used ring interval [0, left_size] */
- do_flush_shadow_used_ring_split(dev, vq, 0, size,
- vq->shadow_used_idx - size);
- }
-
- vq->last_used_idx += vq->shadow_used_idx;
- vq->shadow_used_idx = 0;
-}
-
-static __rte_always_inline void
update_shadow_used_ring_split(struct vhost_virtqueue *vq,
uint16_t desc_idx, uint32_t len)
{
@@ -1480,7 +1455,8 @@ virtio_dev_rx_async_get_info_idx(uint16_t pkts_idx,
static __rte_noinline uint32_t
virtio_dev_rx_async_submit_split(struct virtio_net *dev,
struct vhost_virtqueue *vq, uint16_t queue_id,
- struct rte_mbuf **pkts, uint32_t count)
+ struct rte_mbuf **pkts, uint32_t count,
+ struct rte_mbuf **comp_pkts, uint32_t *comp_count)
{
uint32_t pkt_idx = 0, pkt_burst_idx = 0;
uint16_t num_buffers;
@@ -1494,10 +1470,15 @@ virtio_dev_rx_async_submit_split(struct virtio_net *dev,
struct iovec *dst_iovec = vec_pool + (VHOST_MAX_ASYNC_VEC >> 1);
struct rte_vhost_iov_iter *src_it = it_pool;
struct rte_vhost_iov_iter *dst_it = it_pool + 1;
- uint16_t n_free_slot, slot_idx = 0;
+ uint16_t slot_idx = 0;
uint16_t segs_await = 0;
struct async_inflight_info *pkts_info = vq->async_pkts_info;
uint32_t n_pkts = 0, pkt_err = 0;
+ uint32_t num_async_pkts = 0, num_done_pkts = 0;
+ struct {
+ uint16_t pkt_idx;
+ uint16_t last_avail_idx;
+ } async_pkts_log[MAX_PKT_BURST];
avail_head = __atomic_load_n(&vq->avail->idx, __ATOMIC_ACQUIRE);
@@ -1534,21 +1515,50 @@ virtio_dev_rx_async_submit_split(struct virtio_net *dev,
break;
}
- slot_idx = (vq->async_pkts_idx + pkt_idx) & (vq->size - 1);
+ slot_idx = (vq->async_pkts_idx + num_async_pkts) &
+ (vq->size - 1);
if (src_it->count) {
- async_fill_desc(&tdes[pkt_burst_idx], src_it, dst_it);
- pkt_burst_idx++;
+ uint16_t from, to;
+
+ async_fill_desc(&tdes[pkt_burst_idx++], src_it, dst_it);
pkts_info[slot_idx].descs = num_buffers;
- pkts_info[slot_idx].segs = src_it->nr_segs;
+ pkts_info[slot_idx].mbuf = pkts[pkt_idx];
+ async_pkts_log[num_async_pkts].pkt_idx = pkt_idx;
+ async_pkts_log[num_async_pkts++].last_avail_idx =
+ vq->last_avail_idx;
src_iovec += src_it->nr_segs;
dst_iovec += dst_it->nr_segs;
src_it += 2;
dst_it += 2;
segs_await += src_it->nr_segs;
- } else {
- pkts_info[slot_idx].info = num_buffers;
- vq->async_pkts_inflight_n++;
- }
+
+ /**
+ * recover shadow used ring and keep DMA-occupied
+ * descriptors.
+ */
+ from = vq->shadow_used_idx - num_buffers;
+ to = vq->async_desc_idx & (vq->size - 1);
+ if (num_buffers + to <= vq->size) {
+ rte_memcpy(&vq->async_descs_split[to],
+ &vq->shadow_used_split[from],
+ num_buffers *
+ sizeof(struct vring_used_elem));
+ } else {
+ int size = vq->size - to;
+
+ rte_memcpy(&vq->async_descs_split[to],
+ &vq->shadow_used_split[from],
+ size *
+ sizeof(struct vring_used_elem));
+ rte_memcpy(vq->async_descs_split,
+ &vq->shadow_used_split[from +
+ size], (num_buffers - size) *
+ sizeof(struct vring_used_elem));
+ }
+ vq->async_desc_idx += num_buffers;
+ vq->shadow_used_idx -= num_buffers;
+ } else
+ comp_pkts[num_done_pkts++] = pkts[pkt_idx];
vq->last_avail_idx += num_buffers;
@@ -1557,9 +1567,9 @@ virtio_dev_rx_async_submit_split(struct virtio_net *dev,
* - buffered packet number reaches transfer threshold
* - unused async iov number is less than max vhost vector
*/
- if (pkt_burst_idx >= VHOST_ASYNC_BATCH_THRESHOLD ||
- (VHOST_MAX_ASYNC_VEC / 2 - segs_await <
- BUF_VECTOR_MAX)) {
+ if (unlikely(pkt_burst_idx >= VHOST_ASYNC_BATCH_THRESHOLD ||
+ ((VHOST_MAX_ASYNC_VEC >> 1) - segs_await <
+ BUF_VECTOR_MAX))) {
n_pkts = vq->async_ops.transfer_data(dev->vid,
queue_id, tdes, 0, pkt_burst_idx);
src_iovec = vec_pool;
@@ -1567,7 +1577,7 @@ virtio_dev_rx_async_submit_split(struct virtio_net *dev,
src_it = it_pool;
dst_it = it_pool + 1;
segs_await = 0;
- vq->async_pkts_inflight_n += pkt_burst_idx;
+ vq->async_pkts_inflight_n += n_pkts;
if (unlikely(n_pkts < pkt_burst_idx)) {
/*
@@ -1587,7 +1597,7 @@ virtio_dev_rx_async_submit_split(struct virtio_net *dev,
if (pkt_burst_idx) {
n_pkts = vq->async_ops.transfer_data(dev->vid,
queue_id, tdes, 0, pkt_burst_idx);
- vq->async_pkts_inflight_n += pkt_burst_idx;
+ vq->async_pkts_inflight_n += n_pkts;
if (unlikely(n_pkts < pkt_burst_idx))
pkt_err = pkt_burst_idx - n_pkts;
@@ -1595,32 +1605,33 @@ virtio_dev_rx_async_submit_split(struct virtio_net *dev,
do_data_copy_enqueue(dev, vq);
- while (unlikely(pkt_err && pkt_idx)) {
- if (pkts_info[slot_idx].segs)
- pkt_err--;
- vq->last_avail_idx -= pkts_info[slot_idx].descs;
- vq->shadow_used_idx -= pkts_info[slot_idx].descs;
- vq->async_pkts_inflight_n--;
- slot_idx = (slot_idx - 1) & (vq->size - 1);
- pkt_idx--;
- }
-
- n_free_slot = vq->size - vq->async_pkts_idx;
- if (n_free_slot > pkt_idx) {
- rte_memcpy(&vq->async_pkts_pending[vq->async_pkts_idx],
- pkts, pkt_idx * sizeof(uintptr_t));
- vq->async_pkts_idx += pkt_idx;
- } else {
- rte_memcpy(&vq->async_pkts_pending[vq->async_pkts_idx],
- pkts, n_free_slot * sizeof(uintptr_t));
- rte_memcpy(&vq->async_pkts_pending[0],
- &pkts[n_free_slot],
- (pkt_idx - n_free_slot) * sizeof(uintptr_t));
- vq->async_pkts_idx = pkt_idx - n_free_slot;
+ if (unlikely(pkt_err)) {
+ uint16_t num_descs = 0;
+
+ num_async_pkts -= pkt_err;
+ /* calculate the sum fo descriptors of DMA-error packets. */
+ while (pkt_err-- > 0) {
+ num_descs += pkts_info[slot_idx & (vq->size - 1)].descs;
+ slot_idx--;
+ }
+ vq->async_desc_idx -= num_descs;
+ /* recover shadow used ring and available ring */
+ vq->shadow_used_idx -= (vq->last_avail_idx -
+ async_pkts_log[num_async_pkts].last_avail_idx -
+ num_descs);
+ vq->last_avail_idx =
+ async_pkts_log[num_async_pkts].last_avail_idx;
+ pkt_idx = async_pkts_log[num_async_pkts].pkt_idx;
+ num_done_pkts = pkt_idx - num_async_pkts;
}
- if (likely(vq->shadow_used_idx))
- async_flush_shadow_used_ring_split(dev, vq);
+ vq->async_pkts_idx += num_async_pkts;
+ *comp_count = num_done_pkts;
+
+ if (likely(vq->shadow_used_idx)) {
+ flush_shadow_used_ring_split(dev, vq);
+ vhost_vring_call_split(dev, vq);
+ }
return pkt_idx;
}
@@ -1632,8 +1643,8 @@ uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
struct vhost_virtqueue *vq;
uint16_t n_pkts_cpl = 0, n_pkts_put = 0, n_descs = 0;
uint16_t start_idx, pkts_idx, vq_size;
- uint16_t n_inflight;
struct async_inflight_info *pkts_info;
+ uint16_t from, i;
if (!dev)
return 0;
@@ -1655,8 +1666,7 @@ uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
rte_spinlock_lock(&vq->access_lock);
- n_inflight = vq->async_pkts_inflight_n;
- pkts_idx = vq->async_pkts_idx;
+ pkts_idx = vq->async_pkts_idx & (vq->size - 1);
pkts_info = vq->async_pkts_info;
vq_size = vq->size;
start_idx = virtio_dev_rx_async_get_info_idx(pkts_idx,
@@ -1667,42 +1677,61 @@ uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
queue_id, 0, count - vq->async_last_pkts_n);
n_pkts_cpl += vq->async_last_pkts_n;
- rte_smp_wmb();
-
- while (likely((n_pkts_put < count) && n_inflight)) {
- uint16_t info_idx = (start_idx + n_pkts_put) & (vq_size - 1);
- if (n_pkts_cpl && pkts_info[info_idx].segs)
- n_pkts_cpl--;
- else if (!n_pkts_cpl && pkts_info[info_idx].segs)
- break;
- n_pkts_put++;
- n_inflight--;
- n_descs += pkts_info[info_idx].descs;
- }
-
- vq->async_last_pkts_n = n_pkts_cpl;
+ n_pkts_put = RTE_MIN(count, n_pkts_cpl);
+ if (unlikely(n_pkts_put == 0)) {
+ vq->async_last_pkts_n = n_pkts_cpl;
+ goto done;
+ }
+
+ for (i = 0; i < n_pkts_put; i++) {
+ from = (start_idx + i) & (vq_size - 1);
+ n_descs += pkts_info[from].descs;
+ pkts[i] = pkts_info[from].mbuf;
+ }
+ vq->async_last_pkts_n = n_pkts_cpl - n_pkts_put;
+ vq->async_pkts_inflight_n -= n_pkts_put;
+
+ if (likely(vq->enabled && vq->access_ok)) {
+ uint16_t nr_left = n_descs;
+ uint16_t nr_copy;
+ uint16_t to;
+
+ /* write back completed descriptors to used ring */
+ do {
+ from = vq->last_async_desc_idx & (vq->size - 1);
+ nr_copy = nr_left + from <= vq->size ? nr_left :
+ vq->size - from;
+ to = vq->last_used_idx & (vq->size - 1);
+
+ if (to + nr_copy <= vq->size) {
+ rte_memcpy(&vq->used->ring[to],
+ &vq->async_descs_split[from],
+ nr_copy *
+ sizeof(struct vring_used_elem));
+ } else {
+ uint16_t size = vq->size - to;
+
+ rte_memcpy(&vq->used->ring[to],
+ &vq->async_descs_split[from],
+ size *
+ sizeof(struct vring_used_elem));
+ rte_memcpy(vq->used->ring,
+ &vq->async_descs_split[from +
+ size], (nr_copy - size) *
+ sizeof(struct vring_used_elem));
+ }
- if (n_pkts_put) {
- vq->async_pkts_inflight_n = n_inflight;
- if (likely(vq->enabled && vq->access_ok)) {
- __atomic_add_fetch(&vq->used->idx,
- n_descs, __ATOMIC_RELEASE);
- vhost_vring_call_split(dev, vq);
- }
+ vq->last_async_desc_idx += nr_copy;
+ vq->last_used_idx += nr_copy;
+ nr_left -= nr_copy;
+ } while (nr_left > 0);
- if (start_idx + n_pkts_put <= vq_size) {
- rte_memcpy(pkts, &vq->async_pkts_pending[start_idx],
- n_pkts_put * sizeof(uintptr_t));
- } else {
- rte_memcpy(pkts, &vq->async_pkts_pending[start_idx],
- (vq_size - start_idx) * sizeof(uintptr_t));
- rte_memcpy(&pkts[vq_size - start_idx],
- vq->async_pkts_pending,
- (n_pkts_put + start_idx - vq_size) *
- sizeof(uintptr_t));
- }
- }
+ __atomic_add_fetch(&vq->used->idx, n_descs, __ATOMIC_RELEASE);
+ vhost_vring_call_split(dev, vq);
+ } else
+ vq->last_async_desc_idx += n_descs;
+done:
rte_spinlock_unlock(&vq->access_lock);
return n_pkts_put;
@@ -1710,7 +1739,8 @@ uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
static __rte_always_inline uint32_t
virtio_dev_rx_async_submit(struct virtio_net *dev, uint16_t queue_id,
- struct rte_mbuf **pkts, uint32_t count)
+ struct rte_mbuf **pkts, uint32_t count,
+ struct rte_mbuf **comp_pkts, uint32_t *comp_count)
{
struct vhost_virtqueue *vq;
uint32_t nb_tx = 0;
@@ -1745,7 +1775,8 @@ virtio_dev_rx_async_submit(struct virtio_net *dev, uint16_t queue_id,
nb_tx = 0;
else
nb_tx = virtio_dev_rx_async_submit_split(dev,
- vq, queue_id, pkts, count);
+ vq, queue_id, pkts, count, comp_pkts,
+ comp_count);
out:
if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
@@ -1759,10 +1790,12 @@ virtio_dev_rx_async_submit(struct virtio_net *dev, uint16_t queue_id,
uint16_t
rte_vhost_submit_enqueue_burst(int vid, uint16_t queue_id,
- struct rte_mbuf **pkts, uint16_t count)
+ struct rte_mbuf **pkts, uint16_t count,
+ struct rte_mbuf **comp_pkts, uint32_t *comp_count)
{
struct virtio_net *dev = get_device(vid);
+ *comp_count = 0;
if (!dev)
return 0;
@@ -1773,7 +1806,8 @@ rte_vhost_submit_enqueue_burst(int vid, uint16_t queue_id,
return 0;
}
- return virtio_dev_rx_async_submit(dev, queue_id, pkts, count);
+ return virtio_dev_rx_async_submit(dev, queue_id, pkts, count, comp_pkts,
+ comp_count);
}
static inline bool