Applications need to stop DMA transfers and finish all the in-flight
pkts when in VM memory hot-plug case and async vhost is used. This
patch is to provide an unsafe API to drain in-flight pkts which are
submitted to DMA engine in vhost async data path. And enable it in
vhost example.
Signed-off-by: Cheng Jiang <cheng1.ji...@intel.com>
---
examples/vhost/main.c | 48 +++++++++++++++++++-
examples/vhost/main.h | 1 +
lib/vhost/rte_vhost_async.h | 22 +++++++++
lib/vhost/version.map | 3 ++
lib/vhost/virtio_net.c | 90 +++++++++++++++++++++++++++----------
5 files changed, 139 insertions(+), 25 deletions(-)
diff --git a/examples/vhost/main.c b/examples/vhost/main.c
index d2179eadb9..70bb67c7f8 100644
--- a/examples/vhost/main.c
+++ b/examples/vhost/main.c
@@ -851,8 +851,11 @@ complete_async_pkts(struct vhost_dev *vdev)
complete_count = rte_vhost_poll_enqueue_completed(vdev->vid,
VIRTIO_RXQ, p_cpl, MAX_PKT_BURST);
- if (complete_count)
+ if (complete_count) {
free_pkts(p_cpl, complete_count);
+ __atomic_sub_fetch(&vdev->pkts_inflight, complete_count,
__ATOMIC_SEQ_CST);
+ }
+
}
static __rte_always_inline void
@@ -895,6 +898,7 @@ drain_vhost(struct vhost_dev *vdev)
complete_async_pkts(vdev);
ret = rte_vhost_submit_enqueue_burst(vdev->vid, VIRTIO_RXQ,
m, nr_xmit, m_cpu_cpl, &cpu_cpl_nr);
+ __atomic_add_fetch(&vdev->pkts_inflight, ret - cpu_cpl_nr,
__ATOMIC_SEQ_CST);
if (cpu_cpl_nr)
free_pkts(m_cpu_cpl, cpu_cpl_nr);
@@ -1226,6 +1230,9 @@ drain_eth_rx(struct vhost_dev *vdev)
enqueue_count = rte_vhost_submit_enqueue_burst(vdev->vid,
VIRTIO_RXQ, pkts, rx_count,
m_cpu_cpl, &cpu_cpl_nr);
+ __atomic_add_fetch(&vdev->pkts_inflight, enqueue_count -
cpu_cpl_nr,
+ __ATOMIC_SEQ_CST);
+
if (cpu_cpl_nr)
free_pkts(m_cpu_cpl, cpu_cpl_nr);
@@ -1397,8 +1404,15 @@ destroy_device(int vid)
"(%d) device has been removed from data core\n",
vdev->vid);
- if (async_vhost_driver)
+ if (async_vhost_driver) {
+ uint16_t n_pkt = 0;
+ struct rte_mbuf *m_cpl[vdev->pkts_inflight];
+ n_pkt = rte_vhost_drain_queue_thread_unsafe(vid, VIRTIO_RXQ,
m_cpl,
+ vdev->pkts_inflight);
+
+ free_pkts(m_cpl, n_pkt);
rte_vhost_async_channel_unregister(vid, VIRTIO_RXQ);
+ }
rte_free(vdev);
}
@@ -1487,6 +1501,35 @@ new_device(int vid)
return 0;
}
+static int
+vring_state_changed(int vid, uint16_t queue_id, int enable)
+{
+ struct vhost_dev *vdev = NULL;
+
+ TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
+ if (vdev->vid == vid)
+ break;
+ }
+ if (!vdev)
+ return -1;
+
+ if (queue_id != VIRTIO_RXQ)
+ return 0;
+
+ if (async_vhost_driver) {
+ if (!enable) {
+ uint16_t n_pkt;
+ struct rte_mbuf *m_cpl[vdev->pkts_inflight];
+
+ n_pkt = rte_vhost_drain_queue_thread_unsafe(vid,
queue_id,
+ m_cpl,
vdev->pkts_inflight);
+ free_pkts(m_cpl, n_pkt);
+ }
+ }
+
+ return 0;
+}
+
/*
* These callback allow devices to be added to the data core when configuration
* has been fully complete.
@@ -1495,6 +1538,7 @@ static const struct vhost_device_ops
virtio_net_device_ops =
{
.new_device = new_device,
.destroy_device = destroy_device,
+ .vring_state_changed = vring_state_changed,
};
/*
diff --git a/examples/vhost/main.h b/examples/vhost/main.h
index 0ccdce4b4a..e7b1ac60a6 100644
--- a/examples/vhost/main.h
+++ b/examples/vhost/main.h
@@ -51,6 +51,7 @@ struct vhost_dev {
uint64_t features;
size_t hdr_len;
uint16_t nr_vrings;
+ uint16_t pkts_inflight;
struct rte_vhost_memory *mem;
struct device_statistics stats;
TAILQ_ENTRY(vhost_dev) global_vdev_entry;
diff --git a/lib/vhost/rte_vhost_async.h b/lib/vhost/rte_vhost_async.h
index 6faa31f5ad..041f40cf04 100644
--- a/lib/vhost/rte_vhost_async.h
+++ b/lib/vhost/rte_vhost_async.h
@@ -193,4 +193,26 @@ __rte_experimental
uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
struct rte_mbuf **pkts, uint16_t count);
+/**
+ * This function checks async completion status and empty all pakcets
+ * for a specific vhost device queue. Packets which are inflight will
+ * be returned in an array.
+ *
+ * @note This function does not perform any locking
+ *
+ * @param vid
+ * id of vhost device to enqueue data
+ * @param queue_id
+ * queue id to enqueue data
+ * @param pkts
+ * blank array to get return packet pointer
+ * @param count
+ * size of the packet array
+ * @return
+ * num of packets returned
+ */
+__rte_experimental
+uint16_t rte_vhost_drain_queue_thread_unsafe(int vid, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint16_t count);
+
#endif /* _RTE_VHOST_ASYNC_H_ */
diff --git a/lib/vhost/version.map b/lib/vhost/version.map
index 9103a23cd4..f480f188af 100644
--- a/lib/vhost/version.map
+++ b/lib/vhost/version.map
@@ -79,4 +79,7 @@ EXPERIMENTAL {
# added in 21.05
rte_vhost_get_negotiated_protocol_features;
+
+ # added in 21.08
+ rte_vhost_drain_queue_thread_unsafe;
};
diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c
index 8da8a86a10..793510974a 100644
--- a/lib/vhost/virtio_net.c
+++ b/lib/vhost/virtio_net.c
@@ -2082,36 +2082,18 @@ write_back_completed_descs_packed(struct
vhost_virtqueue *vq,
} while (nr_left > 0);
}
-uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
+static __rte_always_inline uint16_t
+vhost_poll_enqueue_completed(struct virtio_net *dev, uint16_t queue_id,
struct rte_mbuf **pkts, uint16_t count)
{
- struct virtio_net *dev = get_device(vid);
struct vhost_virtqueue *vq;
uint16_t n_pkts_cpl = 0, n_pkts_put = 0, n_descs = 0, n_buffers = 0;
uint16_t start_idx, pkts_idx, vq_size;
struct async_inflight_info *pkts_info;
uint16_t from, i;
- if (!dev)
- return 0;
-
- VHOST_LOG_DATA(DEBUG, "(%d) %s\n", dev->vid, __func__);
- if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->nr_vring))) {
- VHOST_LOG_DATA(ERR, "(%d) %s: invalid virtqueue idx %d.\n",
- dev->vid, __func__, queue_id);
- return 0;
- }
-
vq = dev->virtqueue[queue_id];
- if (unlikely(!vq->async_registered)) {
- VHOST_LOG_DATA(ERR, "(%d) %s: async not registered for queue id
%d.\n",
- dev->vid, __func__, queue_id);
- return 0;
- }
-
- rte_spinlock_lock(&vq->access_lock);
-
pkts_idx = vq->async_pkts_idx % vq->size;
pkts_info = vq->async_pkts_info;
vq_size = vq->size;
@@ -2119,14 +2101,14 @@ uint16_t rte_vhost_poll_enqueue_completed(int vid,
uint16_t queue_id,
vq_size, vq->async_pkts_inflight_n);
if (count > vq->async_last_pkts_n)
- n_pkts_cpl = vq->async_ops.check_completed_copies(vid,
+ n_pkts_cpl = vq->async_ops.check_completed_copies(dev->vid,
queue_id, 0, count - vq->async_last_pkts_n);
n_pkts_cpl += vq->async_last_pkts_n;
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;
+ return 0;
}
if (vq_is_packed(dev)) {
@@ -2165,12 +2147,74 @@ uint16_t rte_vhost_poll_enqueue_completed(int vid,
uint16_t queue_id,
vq->last_async_desc_idx_split += n_descs;
}
-done:
+ return n_pkts_put;
+}
+
+uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint16_t count)
+{
+ struct virtio_net *dev = get_device(vid);
+ struct vhost_virtqueue *vq;
+ uint16_t n_pkts_put = 0;
+
+ if (!dev)
+ return 0;
+
+ VHOST_LOG_DATA(DEBUG, "(%d) %s\n", dev->vid, __func__);
+ if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->nr_vring))) {
+ VHOST_LOG_DATA(ERR, "(%d) %s: invalid virtqueue idx %d.\n",
+ dev->vid, __func__, queue_id);
+ return 0;
+ }
+
+ vq = dev->virtqueue[queue_id];
+
+ if (unlikely(!vq->async_registered)) {
+ VHOST_LOG_DATA(ERR, "(%d) %s: async not registered for queue id
%d.\n",
+ dev->vid, __func__, queue_id);
+ return 0;
+ }
+
+ rte_spinlock_lock(&vq->access_lock);
+
+ n_pkts_put = vhost_poll_enqueue_completed(dev, queue_id, pkts, count);
+
rte_spinlock_unlock(&vq->access_lock);
return n_pkts_put;
}
+uint16_t rte_vhost_drain_queue_thread_unsafe(int vid, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint16_t count)
+{
+ struct virtio_net *dev = get_device(vid);
+ struct vhost_virtqueue *vq;
+ uint16_t n_pkts = count;
+
+ if (!dev)
+ return 0;
+
+ VHOST_LOG_DATA(DEBUG, "(%d) %s\n", dev->vid, __func__);
+ if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->nr_vring))) {
+ VHOST_LOG_DATA(ERR, "(%d) %s: invalid virtqueue idx %d.\n",
+ dev->vid, __func__, queue_id);
+ return 0;
+ }
+
+ vq = dev->virtqueue[queue_id];
+
+ if (unlikely(!vq->async_registered)) {
+ VHOST_LOG_DATA(ERR, "(%d) %s: async not registered for queue id
%d.\n",
+ dev->vid, __func__, queue_id);
+ return 0;
+ }
+
+ while (count)
+ count -= vhost_poll_enqueue_completed(dev, queue_id, pkts,
count);
+
+ return n_pkts;
+}
+
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,
--
2.29.2
