From: Patrick Fu <patrick...@intel.com>
Vhost async enqueue assumes that all async copies should break at packet
boundary. i.e. if a packet is splited into multiple copy segments, the
async engine should always report copy completion when entire packet is
finished. This patch removes the assumption.
Fixes: cd6760da1076 ("vhost: introduce async enqueue for split ring")
Signed-off-by: Patrick Fu <patrick...@intel.com>
---
v2:
- fix an issue that can stuck async poll when packets buffer is full
- rename a local variable to better reflect its usage
lib/librte_vhost/vhost.h | 3 +++
lib/librte_vhost/virtio_net.c | 17 ++++++++++++-----
2 files changed, 15 insertions(+), 5 deletions(-)
diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index 8c01cee42..0f7212f88 100644
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -46,6 +46,8 @@
#define MAX_PKT_BURST 32
+#define ASYNC_MAX_POLL_SEG 255
+
#define VHOST_MAX_ASYNC_IT (MAX_PKT_BURST * 2)
#define VHOST_MAX_ASYNC_VEC (BUF_VECTOR_MAX * 2)
@@ -225,6 +227,7 @@ struct vhost_virtqueue {
uint64_t *async_pending_info;
uint16_t async_pkts_idx;
uint16_t async_pkts_inflight_n;
+ uint16_t async_last_seg_n;
/* vq async features */
bool async_inorder;
diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index 1d0be3dd4..17808ab29 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -1633,6 +1633,7 @@ uint16_t rte_vhost_poll_enqueue_completed(int vid,
uint16_t queue_id,
struct vhost_virtqueue *vq;
uint16_t n_pkts_cpl, n_pkts_put = 0, n_descs = 0;
uint16_t start_idx, pkts_idx, vq_size;
+ uint16_t n_inflight;
uint64_t *async_pending_info;
VHOST_LOG_DATA(DEBUG, "(%d) %s\n", dev->vid, __func__);
@@ -1646,28 +1647,32 @@ 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;
async_pending_info = vq->async_pending_info;
vq_size = vq->size;
start_idx = virtio_dev_rx_async_get_info_idx(pkts_idx,
vq_size, vq->async_pkts_inflight_n);
- n_pkts_cpl =
- vq->async_ops.check_completed_copies(vid, queue_id, 0, count);
+ n_pkts_cpl = vq->async_ops.check_completed_copies(vid, queue_id,
+ 0, ASYNC_MAX_POLL_SEG - vq->async_last_seg_n) +
+ vq->async_last_seg_n;
rte_smp_wmb();
- while (likely(((start_idx + n_pkts_put) & (vq_size - 1)) != pkts_idx)) {
+ while (likely((n_pkts_put < count) && n_inflight)) {
uint64_t info = async_pending_info[
(start_idx + n_pkts_put) & (vq_size - 1)];
uint64_t n_segs;
n_pkts_put++;
+ n_inflight--;
n_descs += info & ASYNC_PENDING_INFO_N_MSK;
n_segs = info >> ASYNC_PENDING_INFO_N_SFT;
if (n_segs) {
- if (!n_pkts_cpl || n_pkts_cpl < n_segs) {
+ if (unlikely(n_pkts_cpl < n_segs)) {
n_pkts_put--;
+ n_inflight++;
n_descs -= info & ASYNC_PENDING_INFO_N_MSK;
if (n_pkts_cpl) {
async_pending_info[
@@ -1684,8 +1689,10 @@ uint16_t rte_vhost_poll_enqueue_completed(int vid,
uint16_t queue_id,
}
}
+ vq->async_last_seg_n = n_pkts_cpl;
+
if (n_pkts_put) {
- vq->async_pkts_inflight_n -= n_pkts_put;
+ vq->async_pkts_inflight_n = n_inflight;
__atomic_add_fetch(&vq->used->idx, n_descs, __ATOMIC_RELEASE);
vhost_vring_call_split(dev, vq);
--
2.18.4
