* [RFC 0/2] vhost: support async dequeue data path
@ 2022-01-01 0:12 xuan.ding
2022-01-01 0:12 ` [RFC 1/2] vhost: support async dequeue for split ring xuan.ding
` (3 more replies)
0 siblings, 4 replies; 11+ messages in thread
From: xuan.ding @ 2022-01-01 0:12 UTC (permalink / raw)
To: maxime.coquelin, chenbo.xia
Cc: dev, jiayu.hu, sunil.pai.g, liangma, yuanx.wang, cheng1.jiang,
wenwux.ma, Xuan Ding
From: Xuan Ding <xuan.ding@intel.com>
Hi everyone,
The presence of an asynchronous path allows applications to offload memory
copies to DMA engine, so as to save CPU cycles and improve the copy
performance. This patch set is a draft implementation for split
ring in vhost async dequeue data path. The code is based on latest
enqueue changes [1].
This patch set is a new design and implementation of [2]. Since dmadev
is introduced in 21.11, to simplify application logics, this patch
integrates dmadev in vhost. With dmadev integrated, vhost supports M:N
mapping between vrings and DMA virtual channels. Specifically, one vring
can use multiple different DMA channels and one DMA channel can be
shared by multiple vrings at the same time.
A new asynchronous dequeue function is introduced:
1) rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id,
struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts,
uint16_t count, int *nr_inflight,
uint16_t dma_id, uint16_t dma_vchan)
Receive packets from the guest and offloads copies to DMA
virtual channel.
[1] https://mails.dpdk.org/archives/dev/2021-December/231889.html.
[2] https://mails.dpdk.org/archives/dev/2021-September/218591.html.
Your comments are welcomed and appreciated!
Thanks!
Xuan
Xuan Ding (2):
vhost: support async dequeue for split ring
examples/vhost: support async dequeue data path
doc/guides/sample_app_ug/vhost.rst | 9 +-
examples/vhost/main.c | 305 ++++++++++++------
examples/vhost/main.h | 35 +-
examples/vhost/virtio_net.c | 16 +-
lib/vhost/rte_vhost_async.h | 29 ++
lib/vhost/version.map | 1 +
lib/vhost/vhost.h | 1 +
lib/vhost/virtio_net.c | 493 +++++++++++++++++++++++++++++
8 files changed, 783 insertions(+), 106 deletions(-)
--
2.17.1
^ permalink raw reply [flat|nested] 11+ messages in thread
* [RFC 1/2] vhost: support async dequeue for split ring
2022-01-01 0:12 [RFC 0/2] vhost: support async dequeue data path xuan.ding
@ 2022-01-01 0:12 ` xuan.ding
2022-01-01 0:12 ` [RFC 2/2] examples/vhost: support async dequeue data path xuan.ding
` (2 subsequent siblings)
3 siblings, 0 replies; 11+ messages in thread
From: xuan.ding @ 2022-01-01 0:12 UTC (permalink / raw)
To: maxime.coquelin, chenbo.xia
Cc: dev, jiayu.hu, sunil.pai.g, liangma, yuanx.wang, cheng1.jiang,
wenwux.ma, Xuan Ding
From: Xuan Ding <xuan.ding@intel.com>
This patch implements asynchronous dequeue data path for vhost split
ring, with dmadev library integrated.
Signed-off-by: Yuan Wang <yuanx.wang@intel.com>
Signed-off-by: Xuan Ding <xuan.ding@intel.com>
---
lib/vhost/rte_vhost_async.h | 29 +++
lib/vhost/version.map | 1 +
lib/vhost/vhost.h | 1 +
lib/vhost/virtio_net.c | 494 ++++++++++++++++++++++++++++++++++++
4 files changed, 525 insertions(+)
diff --git a/lib/vhost/rte_vhost_async.h b/lib/vhost/rte_vhost_async.h
index 23a7a2d8b3..b1249382cd 100644
--- a/lib/vhost/rte_vhost_async.h
+++ b/lib/vhost/rte_vhost_async.h
@@ -203,4 +203,33 @@ __rte_experimental
int rte_vhost_async_dma_configure(struct rte_vhost_async_dma_info *dmas,
uint16_t count);
+/**
+ * This function tries to receive packets from the guest with offloading
+ * copies to the async channel. The packets that are transfer completed
+ * are returned in "pkts". The other packets that their copies are submitted to
+ * the async channel but not completed are called "in-flight packets".
+ * This function will not return in-flight packets until their copies are
+ * completed by the async channel.
+ *
+ * @param vid
+ * ID of vhost device to dequeue data
+ * @param queue_id
+ * ID of virtqueue to dequeue data
+ * @param mbuf_pool
+ * Mbuf_pool where host mbuf is allocated.
+ * @param pkts
+ * Blank array to keep successfully dequeued packets
+ * @param count
+ * Size of the packet array
+ * @param nr_inflight
+ * The amount of in-flight packets. If error occurred, its value is set to -1.
+ * @return
+ * Num of successfully dequeued packets
+ */
+__rte_experimental
+uint16_t
+rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count,
+ int *nr_inflight, uint16_t dma_id, uint16_t dma_vchan);
+
#endif /* _RTE_VHOST_ASYNC_H_ */
diff --git a/lib/vhost/version.map b/lib/vhost/version.map
index 1202ba9c1a..816a6dc942 100644
--- a/lib/vhost/version.map
+++ b/lib/vhost/version.map
@@ -87,6 +87,7 @@ EXPERIMENTAL {
# added in 22.03
rte_vhost_async_dma_configure;
+ rte_vhost_async_try_dequeue_burst;
};
INTERNAL {
diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
index d9bda34e11..17166607ea 100644
--- a/lib/vhost/vhost.h
+++ b/lib/vhost/vhost.h
@@ -161,6 +161,7 @@ extern struct async_dma_info dma_copy_track[RTE_DMADEV_DEFAULT_MAX];
*/
struct async_inflight_info {
struct rte_mbuf *mbuf;
+ struct virtio_net_hdr nethdr;
uint16_t descs; /* num of descs inflight */
uint16_t nr_buffers; /* num of buffers inflight for packed ring */
};
diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c
index 9f81fc9733..148709f2c5 100644
--- a/lib/vhost/virtio_net.c
+++ b/lib/vhost/virtio_net.c
@@ -3092,3 +3092,497 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
return count;
}
+
+static __rte_always_inline int
+async_desc_to_mbuf_seg(struct virtio_net *dev, struct vhost_virtqueue *vq,
+ struct rte_mbuf *m, uint32_t mbuf_offset,
+ uint64_t buf_iova, uint32_t cpy_len)
+{
+ uint64_t mapped_len;
+ uint32_t buf_offset = 0;
+ void *hpa;
+
+ while (cpy_len) {
+ hpa = (void *)(uintptr_t)gpa_to_first_hpa(dev,
+ buf_iova + buf_offset, cpy_len,
+ &mapped_len);
+ if (unlikely(!hpa)) {
+ VHOST_LOG_DATA(ERR, "(%d) %s: failed to get hpa.\n",
+ dev->vid, __func__);
+ return -1;
+ }
+
+ if (unlikely(async_iter_add_iovec(vq->async, hpa,
+ (void *)(uintptr_t)rte_pktmbuf_iova_offset(m, mbuf_offset),
+ (size_t)mapped_len)))
+ return -1;
+
+ cpy_len -= (uint32_t)mapped_len;
+ mbuf_offset += (uint32_t)mapped_len;
+ buf_offset += (uint32_t)mapped_len;
+ }
+
+ return 0;
+}
+
+static __rte_always_inline int
+async_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
+ struct buf_vector *buf_vec, uint16_t nr_vec,
+ struct rte_mbuf *m, struct rte_mempool *mbuf_pool,
+ struct virtio_net_hdr *nethdr)
+{
+ uint64_t buf_addr, buf_iova;
+ uint32_t buf_avail, buf_offset, buf_len;
+ uint32_t mbuf_avail, mbuf_offset;
+ uint32_t cpy_len;
+ /* A counter to avoid desc dead loop chain */
+ uint16_t vec_idx = 0;
+ struct rte_mbuf *cur = m, *prev = m;
+ struct virtio_net_hdr tmp_hdr;
+ struct virtio_net_hdr *hdr = NULL;
+ struct vhost_async *async = vq->async;
+
+ buf_addr = buf_vec[vec_idx].buf_addr;
+ buf_len = buf_vec[vec_idx].buf_len;
+ buf_iova = buf_vec[vec_idx].buf_iova;
+
+ if (unlikely(buf_len < dev->vhost_hlen && nr_vec <= 1))
+ return -1;
+
+ if (virtio_net_with_host_offload(dev)) {
+ if (unlikely(buf_len < sizeof(struct virtio_net_hdr))) {
+ /*
+ * No luck, the virtio-net header doesn't fit
+ * in a contiguous virtual area.
+ */
+ copy_vnet_hdr_from_desc(&tmp_hdr, buf_vec);
+ hdr = &tmp_hdr;
+ } else {
+ hdr = (struct virtio_net_hdr *)((uintptr_t)buf_addr);
+ }
+ }
+
+ /*
+ * A virtio driver normally uses at least 2 desc buffers
+ * for Tx: the first for storing the header, and others
+ * for storing the data.
+ */
+ if (unlikely(buf_len < dev->vhost_hlen)) {
+ buf_offset = dev->vhost_hlen - buf_len;
+ vec_idx++;
+ buf_addr = buf_vec[vec_idx].buf_addr;
+ buf_iova = buf_vec[vec_idx].buf_iova;
+ buf_len = buf_vec[vec_idx].buf_len;
+ buf_avail = buf_len - buf_offset;
+ } else if (buf_len == dev->vhost_hlen) {
+ if (unlikely(++vec_idx >= nr_vec))
+ return -1;
+ buf_addr = buf_vec[vec_idx].buf_addr;
+ buf_iova = buf_vec[vec_idx].buf_iova;
+ buf_len = buf_vec[vec_idx].buf_len;
+
+ buf_offset = 0;
+ buf_avail = buf_len;
+ } else {
+ buf_offset = dev->vhost_hlen;
+ buf_avail = buf_vec[vec_idx].buf_len - dev->vhost_hlen;
+ }
+
+ PRINT_PACKET(dev, (uintptr_t)(buf_addr + buf_offset), (uint32_t)buf_avail, 0);
+
+ mbuf_offset = 0;
+ mbuf_avail = m->buf_len - RTE_PKTMBUF_HEADROOM;
+
+ if (async_iter_initialize(async))
+ return -1;
+
+ while (1) {
+ cpy_len = RTE_MIN(buf_avail, mbuf_avail);
+
+ if (async_desc_to_mbuf_seg(dev, vq, cur, mbuf_offset, buf_iova + buf_offset,
+ cpy_len) < 0)
+ goto error;
+
+ mbuf_avail -= cpy_len;
+ buf_avail -= cpy_len;
+ mbuf_offset += cpy_len;
+ buf_offset += cpy_len;
+
+ /* This buf reaches to its end, get the next one */
+ if (buf_avail == 0) {
+ if (++vec_idx >= nr_vec)
+ break;
+
+ buf_addr = buf_vec[vec_idx].buf_addr;
+ buf_iova = buf_vec[vec_idx].buf_iova;
+ buf_len = buf_vec[vec_idx].buf_len;
+
+ buf_offset = 0;
+ buf_avail = buf_len;
+
+ PRINT_PACKET(dev, (uintptr_t)buf_addr, (uint32_t)buf_avail, 0);
+ }
+
+ /*
+ * This mbuf reaches to its end, get a new one
+ * to hold more data.
+ */
+ if (mbuf_avail == 0) {
+ cur = rte_pktmbuf_alloc(mbuf_pool);
+ if (unlikely(cur == NULL)) {
+ VHOST_LOG_DATA(ERR,
+ "(%d) %s: failed to allocate memory for mbuf.\n",
+ dev->vid, __func__);
+ goto error;
+ }
+
+ prev->next = cur;
+ prev->data_len = mbuf_offset;
+ m->nb_segs += 1;
+ m->pkt_len += mbuf_offset;
+ prev = cur;
+
+ mbuf_offset = 0;
+ mbuf_avail = cur->buf_len - RTE_PKTMBUF_HEADROOM;
+ }
+ }
+
+ prev->data_len = mbuf_offset;
+ m->pkt_len += mbuf_offset;
+
+ async_iter_finalize(async);
+ if (hdr)
+ *nethdr = *hdr;
+
+ return 0;
+
+error:
+ async_iter_cancel(async);
+ return -1;
+}
+
+static __rte_always_inline uint16_t
+async_poll_dequeue_completed_split(struct virtio_net *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint16_t count, uint16_t dma_id, uint16_t dma_vchan,
+ bool legacy_ol_flags)
+{
+ uint16_t start_idx, from, i;
+ uint16_t nr_cpl_pkts = 0;
+ struct async_inflight_info *pkts_info;
+ struct vhost_virtqueue *vq = dev->virtqueue[queue_id];
+
+ pkts_info = vq->async->pkts_info;
+
+ vhost_async_dma_check_completed(dma_id, dma_vchan, count);
+
+ start_idx = async_get_first_inflight_pkt_idx(vq);
+
+ from = start_idx;
+ while (vq->async->pkts_cmpl_flag[from] && count--) {
+ vq->async->pkts_cmpl_flag[from] = false;
+ from = (from + 1) & (vq->size - 1);
+ nr_cpl_pkts++;
+ }
+
+ for (i = 0; i < nr_cpl_pkts; i++) {
+ from = (start_idx + i) & (vq->size - 1);
+ pkts[i] = pkts_info[from].mbuf;
+
+ if (virtio_net_with_host_offload(dev))
+ vhost_dequeue_offload(&pkts_info[from].nethdr, pkts[i], legacy_ol_flags);
+ }
+
+ /* write back completed descs to used ring and update used idx */
+ write_back_completed_descs_split(vq, nr_cpl_pkts);
+ __atomic_add_fetch(&vq->used->idx, nr_cpl_pkts, __ATOMIC_RELEASE);
+ vhost_vring_call_split(dev, vq);
+
+ vq->async->pkts_inflight_n -= nr_cpl_pkts;
+
+ return nr_cpl_pkts;
+}
+
+static __rte_always_inline uint16_t
+virtio_dev_tx_async_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
+ uint16_t queue_id, struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts,
+ uint16_t count, uint16_t dma_id, uint16_t dma_vchan, bool legacy_ol_flags)
+{
+ static bool allocerr_warned;
+ bool dropped = false;
+ uint16_t free_entries;
+ uint16_t pkt_idx, slot_idx = 0;
+ uint16_t nr_done_pkts = 0;
+ uint16_t pkt_err = 0;
+ int32_t n_xfer;
+ struct vhost_async *async = vq->async;
+ struct async_inflight_info *pkts_info = async->pkts_info;
+ struct rte_mbuf *pkts_prealloc[MAX_PKT_BURST];
+ uint16_t pkts_size = count;
+
+ /**
+ * The ordering between avail index and
+ * desc reads needs to be enforced.
+ */
+ free_entries = __atomic_load_n(&vq->avail->idx, __ATOMIC_ACQUIRE) - vq->last_avail_idx;
+ if (free_entries == 0)
+ goto out;
+
+ rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
+
+ async_iter_reset(async);
+
+ count = RTE_MIN(count, MAX_PKT_BURST);
+ count = RTE_MIN(count, free_entries);
+ VHOST_LOG_DATA(DEBUG, "(%d) about to dequeue %u buffers\n", dev->vid, count);
+
+ if (rte_pktmbuf_alloc_bulk(mbuf_pool, pkts_prealloc, count))
+ goto out;
+
+ for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
+ uint16_t head_idx = 0;
+ uint16_t nr_vec = 0;
+ uint16_t to;
+ uint32_t buf_len;
+ int err;
+ struct buf_vector buf_vec[BUF_VECTOR_MAX];
+ struct rte_mbuf *pkt = pkts_prealloc[pkt_idx];
+
+ if (unlikely(fill_vec_buf_split(dev, vq, vq->last_avail_idx,
+ &nr_vec, buf_vec,
+ &head_idx, &buf_len,
+ VHOST_ACCESS_RO) < 0)) {
+ dropped = true;
+ break;
+ }
+
+ err = virtio_dev_pktmbuf_prep(dev, pkt, buf_len);
+ if (unlikely(err)) {
+ /**
+ * mbuf allocation fails for jumbo packets when external
+ * buffer allocation is not allowed and linear buffer
+ * is required. Drop this packet.
+ */
+ if (!allocerr_warned) {
+ VHOST_LOG_DATA(ERR,
+ "(%d) %s: Failed mbuf alloc of size %d from %s on %s.\n",
+ dev->vid, __func__, buf_len, mbuf_pool->name, dev->ifname);
+ allocerr_warned = true;
+ }
+ dropped = true;
+ break;
+ }
+
+ slot_idx = (async->pkts_idx + pkt_idx) & (vq->size - 1);
+ err = async_desc_to_mbuf(dev, vq, buf_vec, nr_vec, pkt, mbuf_pool,
+ &pkts_info[slot_idx].nethdr);
+ if (unlikely(err)) {
+ if (!allocerr_warned) {
+ VHOST_LOG_DATA(ERR,
+ "(%d) %s: Failed to offload copies to async channel %s.\n",
+ dev->vid, __func__, dev->ifname);
+ allocerr_warned = true;
+ }
+ dropped = true;
+ break;
+ }
+
+ pkts_info[slot_idx].mbuf = pkt;
+
+ /* store used descs */
+ to = async->desc_idx_split & (vq->size - 1);
+ async->descs_split[to].id = head_idx;
+ async->descs_split[to].len = 0;
+ async->desc_idx_split++;
+
+ vq->last_avail_idx++;
+ }
+
+ if (unlikely(dropped))
+ rte_pktmbuf_free_bulk(&pkts_prealloc[pkt_idx], count - pkt_idx);
+
+ n_xfer = vhost_async_dma_transfer(vq, dma_id, dma_vchan, async->pkts_idx, async->iov_iter,
+ pkt_idx);
+
+ async->pkts_inflight_n += n_xfer;
+
+ pkt_err = pkt_idx - n_xfer;
+ if (unlikely(pkt_err)) {
+ VHOST_LOG_DATA(DEBUG,
+ "(%d) %s: failed to transfer data for queue id %d.\n",
+ dev->vid, __func__, queue_id);
+
+ pkt_idx = n_xfer;
+ /* recover available ring */
+ vq->last_avail_idx -= pkt_err;
+
+ /**
+ * recover async channel copy related structures and free pktmbufs
+ * for error pkts.
+ */
+ async->desc_idx_split -= pkt_err;
+ while (pkt_err-- > 0) {
+ rte_pktmbuf_free(pkts_info[slot_idx & (vq->size - 1)].mbuf);
+ slot_idx--;
+ }
+ }
+
+ async->pkts_idx += pkt_idx;
+ if (async->pkts_idx >= vq->size)
+ async->pkts_idx -= vq->size;
+
+out:
+ if (async->pkts_inflight_n > 0) {
+ nr_done_pkts = async_poll_dequeue_completed_split(dev, queue_id, pkts, pkts_size,
+ dma_id, dma_vchan, legacy_ol_flags);
+ }
+
+ return nr_done_pkts;
+}
+
+__rte_noinline
+static uint16_t
+virtio_dev_tx_async_split_legacy(struct virtio_net *dev,
+ struct vhost_virtqueue *vq, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts,
+ uint16_t count, uint16_t dma_id, uint16_t dma_vchan)
+{
+ return virtio_dev_tx_async_split(dev, vq, queue_id, mbuf_pool,
+ pkts, count, dma_id, dma_vchan, true);
+}
+
+__rte_noinline
+static uint16_t
+virtio_dev_tx_async_split_compliant(struct virtio_net *dev,
+ struct vhost_virtqueue *vq, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts,
+ uint16_t count, uint16_t dma_id, uint16_t dma_vchan)
+{
+ return virtio_dev_tx_async_split(dev, vq, queue_id, mbuf_pool,
+ pkts, count, dma_id, dma_vchan, false);
+}
+
+uint16_t
+rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count,
+ int *nr_inflight, uint16_t dma_id, uint16_t dma_vchan)
+{
+ struct virtio_net *dev;
+ struct rte_mbuf *rarp_mbuf = NULL;
+ struct vhost_virtqueue *vq;
+ int16_t success = 1;
+
+ *nr_inflight = -1;
+
+ dev = get_device(vid);
+ if (!dev)
+ return 0;
+
+ if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) {
+ VHOST_LOG_DATA(ERR,
+ "(%d) %s: built-in vhost net backend is disabled.\n",
+ dev->vid, __func__);
+ return 0;
+ }
+
+ if (unlikely(!is_valid_virt_queue_idx(queue_id, 1, 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(rte_spinlock_trylock(&vq->access_lock) == 0))
+ return 0;
+
+ if (unlikely(vq->enabled == 0)) {
+ count = 0;
+ goto out_access_unlock;
+ }
+
+ if (unlikely(!vq->async)) {
+ VHOST_LOG_DATA(ERR, "(%d) %s: async not registered for queue id %d.\n",
+ dev->vid, __func__, queue_id);
+ count = 0;
+ goto out_access_unlock;
+ }
+
+ if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
+ vhost_user_iotlb_rd_lock(vq);
+
+ if (unlikely(vq->access_ok == 0))
+ if (unlikely(vring_translate(dev, vq) < 0)) {
+ count = 0;
+ goto out;
+ }
+
+ /*
+ * Construct a RARP broadcast packet, and inject it to the "pkts"
+ * array, to looks like that guest actually send such packet.
+ *
+ * Check user_send_rarp() for more information.
+ *
+ * broadcast_rarp shares a cacheline in the virtio_net structure
+ * with some fields that are accessed during enqueue and
+ * __atomic_compare_exchange_n causes a write if performed compare
+ * and exchange. This could result in false sharing between enqueue
+ * and dequeue.
+ *
+ * Prevent unnecessary false sharing by reading broadcast_rarp first
+ * and only performing compare and exchange if the read indicates it
+ * is likely to be set.
+ */
+ if (unlikely(__atomic_load_n(&dev->broadcast_rarp, __ATOMIC_ACQUIRE) &&
+ __atomic_compare_exchange_n(&dev->broadcast_rarp,
+ &success, 0, 0, __ATOMIC_RELEASE, __ATOMIC_RELAXED))) {
+
+ rarp_mbuf = rte_net_make_rarp_packet(mbuf_pool, &dev->mac);
+ if (rarp_mbuf == NULL) {
+ VHOST_LOG_DATA(ERR, "Failed to make RARP packet.\n");
+ count = 0;
+ goto out;
+ }
+ count -= 1;
+ }
+
+ if (unlikely(vq_is_packed(dev))) {
+ static bool not_support_pack_log;
+ if (!not_support_pack_log) {
+ VHOST_LOG_DATA(ERR,
+ "(%d) %s: async dequeue does not support packed ring.\n",
+ dev->vid, __func__);
+ not_support_pack_log = true;
+ }
+ count = 0;
+ goto out;
+ }
+
+ if (dev->flags & VIRTIO_DEV_LEGACY_OL_FLAGS)
+ count = virtio_dev_tx_async_split_legacy(dev, vq, queue_id,
+ mbuf_pool, pkts, count, dma_id, dma_vchan);
+ else
+ count = virtio_dev_tx_async_split_compliant(dev, vq, queue_id,
+ mbuf_pool, pkts, count, dma_id, dma_vchan);
+
+ *nr_inflight = vq->async->pkts_inflight_n;
+
+out:
+ if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
+ vhost_user_iotlb_rd_unlock(vq);
+
+out_access_unlock:
+ rte_spinlock_unlock(&vq->access_lock);
+
+ if (unlikely(rarp_mbuf != NULL)) {
+ /*
+ * Inject it to the head of "pkts" array, so that switch's mac
+ * learning table will get updated first.
+ */
+ memmove(&pkts[1], pkts, count * sizeof(struct rte_mbuf *));
+ pkts[0] = rarp_mbuf;
+ count += 1;
+ }
+
+ return count;
+}
--
2.17.1
^ permalink raw reply [flat|nested] 11+ messages in thread
* [RFC 2/2] examples/vhost: support async dequeue data path
2022-01-01 0:12 [RFC 0/2] vhost: support async dequeue data path xuan.ding
2022-01-01 0:12 ` [RFC 1/2] vhost: support async dequeue for split ring xuan.ding
@ 2022-01-01 0:12 ` xuan.ding
2022-02-24 11:03 ` [RFC,v2 0/2] vhost: " xuan.ding
2022-03-10 6:54 ` [RFC,v3 0/2] vhost: " xuan.ding
3 siblings, 0 replies; 11+ messages in thread
From: xuan.ding @ 2022-01-01 0:12 UTC (permalink / raw)
To: maxime.coquelin, chenbo.xia
Cc: dev, jiayu.hu, sunil.pai.g, liangma, yuanx.wang, cheng1.jiang,
wenwux.ma, Xuan Ding, Yuan Wang
From: Xuan Ding <xuan.ding@intel.com>
This patch adds the use case for async dequeue API. Vswitch can
leverage DMA device to accelerate vhost async dequeue path.
Signed-off-by: Wenwu Ma <wenwux.ma@intel.com>
Signed-off-by: Yuan Wang <yuan.wangx@intel.com>
Signed-off-by: Xuan Ding <xuan.ding@intel.com>
---
doc/guides/sample_app_ug/vhost.rst | 9 +-
examples/vhost/main.c | 301 +++++++++++++++++++----------
examples/vhost/main.h | 35 +++-
examples/vhost/virtio_net.c | 16 +-
4 files changed, 255 insertions(+), 106 deletions(-)
diff --git a/doc/guides/sample_app_ug/vhost.rst b/doc/guides/sample_app_ug/vhost.rst
index a6ce4bc8ac..09db965e70 100644
--- a/doc/guides/sample_app_ug/vhost.rst
+++ b/doc/guides/sample_app_ug/vhost.rst
@@ -169,9 +169,12 @@ demonstrates how to use the async vhost APIs. It's used in combination with dmas
**--dmas**
This parameter is used to specify the assigned DMA device of a vhost device.
Async vhost-user net driver will be used if --dmas is set. For example
---dmas [txd0@00:04.0,txd1@00:04.1] means use DMA channel 00:04.0 for vhost
-device 0 enqueue operation and use DMA channel 00:04.1 for vhost device 1
-enqueue operation.
+--dmas [txd0@00:04.0,txd1@00:04.1,rxd0@00:04.2,rxd1@00:04.3] means use
+DMA channel 00:04.0/00:04.2 for vhost device 0 enqueue/dequeue operation
+and use DMA channel 00:04.1/00:04.3 for vhost device 1 enqueue/dequeue
+operation. The index of the device corresponds to the socket file in order,
+that means vhost device 0 is created through the first socket file, vhost
+device 1 is created through the second socket file, and so on.
Common Issues
-------------
diff --git a/examples/vhost/main.c b/examples/vhost/main.c
index 44073499bc..8c952d3874 100644
--- a/examples/vhost/main.c
+++ b/examples/vhost/main.c
@@ -62,6 +62,9 @@
#define MAX_VHOST_DEVICE 1024
#define DMA_RING_SIZE 4096
+#define ASYNC_ENQUEUE_VHOST 1
+#define ASYNC_DEQUEUE_VHOST 2
+
struct dma_for_vhost dma_bind[MAX_VHOST_DEVICE];
struct rte_vhost_async_dma_info dma_config[RTE_DMADEV_DEFAULT_MAX];
static int dma_count;
@@ -103,8 +106,6 @@ static int client_mode;
static int builtin_net_driver;
-static int async_vhost_driver;
-
/* Specify timeout (in useconds) between retries on RX. */
static uint32_t burst_rx_delay_time = BURST_RX_WAIT_US;
/* Specify the number of retries on RX. */
@@ -114,6 +115,8 @@ static uint32_t burst_rx_retry_num = BURST_RX_RETRIES;
static char *socket_files;
static int nb_sockets;
+static struct vhost_queue_ops vdev_queue_ops[MAX_VHOST_DEVICE];
+
/* empty vmdq configuration structure. Filled in programatically */
static struct rte_eth_conf vmdq_conf_default = {
.rxmode = {
@@ -203,6 +206,18 @@ struct vhost_bufftable *vhost_txbuff[RTE_MAX_LCORE * MAX_VHOST_DEVICE];
#define MBUF_TABLE_DRAIN_TSC ((rte_get_tsc_hz() + US_PER_S - 1) \
/ US_PER_S * BURST_TX_DRAIN_US)
+static int vid2socketid[MAX_VHOST_DEVICE];
+
+static uint32_t get_async_flag_by_socketid(int socketid)
+{
+ return dma_bind[socketid].async_flag;
+}
+
+static void init_vid2socketid_array(int vid, int socketid)
+{
+ vid2socketid[vid] = socketid;
+}
+
static inline bool
is_dma_configured(int16_t dev_id)
{
@@ -224,7 +239,7 @@ open_dma(const char *value)
char *addrs = input;
char *ptrs[2];
char *start, *end, *substr;
- int64_t vid, vring_id;
+ int64_t socketid, vring_id;
struct rte_dma_info info;
struct rte_dma_conf dev_config = { .nb_vchans = 1 };
@@ -263,7 +278,9 @@ open_dma(const char *value)
while (i < args_nr) {
char *arg_temp = dma_arg[i];
+ char *txd, *rxd;
uint8_t sub_nr;
+ int async_flag;
sub_nr = rte_strsplit(arg_temp, strlen(arg_temp), ptrs, 2, '@');
if (sub_nr != 2) {
@@ -271,21 +288,28 @@ open_dma(const char *value)
goto out;
}
- start = strstr(ptrs[0], "txd");
- if (start == NULL) {
+ txd = strstr(ptrs[0], "txd");
+ rxd = strstr(ptrs[0], "rxd");
+ if (txd) {
+ start = txd;
+ vring_id = VIRTIO_RXQ;
+ async_flag = ASYNC_ENQUEUE_VHOST;
+ } else if (rxd) {
+ start = rxd;
+ vring_id = VIRTIO_TXQ;
+ async_flag = ASYNC_DEQUEUE_VHOST;
+ } else {
ret = -1;
goto out;
}
start += 3;
- vid = strtol(start, &end, 0);
+ socketid = strtol(start, &end, 0);
if (end == start) {
ret = -1;
goto out;
}
- vring_id = 0 + VIRTIO_RXQ;
-
dev_id = rte_dma_get_dev_id_by_name(ptrs[1]);
if (dev_id < 0) {
RTE_LOG(ERR, VHOST_CONFIG, "Fail to find DMA %s.\n", ptrs[1]);
@@ -325,7 +349,8 @@ open_dma(const char *value)
dma_config[dma_count++].max_desc = DMA_RING_SIZE;
done:
- (dma_info + vid)->dmas[vring_id].dev_id = dev_id;
+ (dma_info + socketid)->dmas[vring_id].dev_id = dev_id;
+ (dma_info + socketid)->async_flag |= async_flag;
i++;
}
out:
@@ -792,7 +817,6 @@ us_vhost_parse_args(int argc, char **argv)
us_vhost_usage(prgname);
return -1;
}
- async_vhost_driver = 1;
break;
case OPT_CLIENT_NUM:
@@ -961,13 +985,13 @@ complete_async_pkts(struct vhost_dev *vdev)
{
struct rte_mbuf *p_cpl[MAX_PKT_BURST];
uint16_t complete_count;
- int16_t dma_id = dma_bind[vdev->vid].dmas[VIRTIO_RXQ].dev_id;
+ int16_t dma_id = dma_bind[vid2socketid[vdev->vid]].dmas[VIRTIO_RXQ].dev_id;
complete_count = rte_vhost_poll_enqueue_completed(vdev->vid,
VIRTIO_RXQ, p_cpl, MAX_PKT_BURST, dma_id, 0);
if (complete_count) {
free_pkts(p_cpl, complete_count);
- __atomic_sub_fetch(&vdev->pkts_inflight, complete_count, __ATOMIC_SEQ_CST);
+ __atomic_sub_fetch(&vdev->pkts_enq_inflight, complete_count, __ATOMIC_SEQ_CST);
}
}
@@ -1002,23 +1026,7 @@ drain_vhost(struct vhost_dev *vdev)
uint16_t nr_xmit = vhost_txbuff[buff_idx]->len;
struct rte_mbuf **m = vhost_txbuff[buff_idx]->m_table;
- if (builtin_net_driver) {
- ret = vs_enqueue_pkts(vdev, VIRTIO_RXQ, m, nr_xmit);
- } else if (dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled) {
- uint16_t enqueue_fail = 0;
- int16_t dma_id = dma_bind[vdev->vid].dmas[VIRTIO_RXQ].dev_id;
-
- complete_async_pkts(vdev);
- ret = rte_vhost_submit_enqueue_burst(vdev->vid, VIRTIO_RXQ, m, nr_xmit, dma_id, 0);
- __atomic_add_fetch(&vdev->pkts_inflight, ret, __ATOMIC_SEQ_CST);
-
- enqueue_fail = nr_xmit - ret;
- if (enqueue_fail)
- free_pkts(&m[ret], nr_xmit - ret);
- } else {
- ret = rte_vhost_enqueue_burst(vdev->vid, VIRTIO_RXQ,
- m, nr_xmit);
- }
+ ret = vdev_queue_ops[vdev->vid].enqueue_pkt_burst(vdev, VIRTIO_RXQ, m, nr_xmit);
if (enable_stats) {
__atomic_add_fetch(&vdev->stats.rx_total_atomic, nr_xmit,
@@ -1027,7 +1035,7 @@ drain_vhost(struct vhost_dev *vdev)
__ATOMIC_SEQ_CST);
}
- if (!dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled)
+ if (!dma_bind[vid2socketid[vdev->vid]].dmas[VIRTIO_RXQ].async_enabled)
free_pkts(m, nr_xmit);
}
@@ -1300,6 +1308,33 @@ drain_mbuf_table(struct mbuf_table *tx_q)
}
}
+uint16_t
+async_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t rx_count)
+{
+ uint16_t enqueue_count;
+ uint16_t enqueue_fail = 0;
+ uint16_t dma_id = dma_bind[vid2socketid[dev->vid]].dmas[VIRTIO_RXQ].dev_id;
+
+ complete_async_pkts(dev);
+ enqueue_count = rte_vhost_submit_enqueue_burst(dev->vid, queue_id,
+ pkts, rx_count, dma_id, 0);
+ __atomic_add_fetch(&dev->pkts_enq_inflight, enqueue_count, __ATOMIC_SEQ_CST);
+
+ enqueue_fail = rx_count - enqueue_count;
+ if (enqueue_fail)
+ free_pkts(&pkts[enqueue_count], enqueue_fail);
+
+ return enqueue_count;
+}
+
+uint16_t
+sync_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t rx_count)
+{
+ return rte_vhost_enqueue_burst(dev->vid, queue_id, pkts, rx_count);
+}
+
static __rte_always_inline void
drain_eth_rx(struct vhost_dev *vdev)
{
@@ -1330,26 +1365,8 @@ drain_eth_rx(struct vhost_dev *vdev)
}
}
- if (builtin_net_driver) {
- enqueue_count = vs_enqueue_pkts(vdev, VIRTIO_RXQ,
- pkts, rx_count);
- } else if (dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled) {
- uint16_t enqueue_fail = 0;
- int16_t dma_id = dma_bind[vdev->vid].dmas[VIRTIO_RXQ].dev_id;
-
- complete_async_pkts(vdev);
- enqueue_count = rte_vhost_submit_enqueue_burst(vdev->vid,
- VIRTIO_RXQ, pkts, rx_count, dma_id, 0);
- __atomic_add_fetch(&vdev->pkts_inflight, enqueue_count, __ATOMIC_SEQ_CST);
-
- enqueue_fail = rx_count - enqueue_count;
- if (enqueue_fail)
- free_pkts(&pkts[enqueue_count], enqueue_fail);
-
- } else {
- enqueue_count = rte_vhost_enqueue_burst(vdev->vid, VIRTIO_RXQ,
- pkts, rx_count);
- }
+ enqueue_count = vdev_queue_ops[vdev->vid].enqueue_pkt_burst(vdev,
+ VIRTIO_RXQ, pkts, rx_count);
if (enable_stats) {
__atomic_add_fetch(&vdev->stats.rx_total_atomic, rx_count,
@@ -1358,10 +1375,33 @@ drain_eth_rx(struct vhost_dev *vdev)
__ATOMIC_SEQ_CST);
}
- if (!dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled)
+ if (!dma_bind[vid2socketid[vdev->vid]].dmas[VIRTIO_RXQ].async_enabled)
free_pkts(pkts, rx_count);
}
+uint16_t async_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool,
+ struct rte_mbuf **pkts, uint16_t count)
+{
+ int nr_inflight;
+ uint16_t dequeue_count;
+ uint16_t dma_id = dma_bind[vid2socketid[dev->vid]].dmas[VIRTIO_TXQ].dev_id;
+
+ dequeue_count = rte_vhost_async_try_dequeue_burst(dev->vid, queue_id,
+ mbuf_pool, pkts, count, &nr_inflight, dma_id, 0);
+ if (likely(nr_inflight != -1))
+ dev->pkts_deq_inflight = nr_inflight;
+
+ return dequeue_count;
+}
+
+uint16_t sync_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool,
+ struct rte_mbuf **pkts, uint16_t count)
+{
+ return rte_vhost_dequeue_burst(dev->vid, queue_id, mbuf_pool, pkts, count);
+}
+
static __rte_always_inline void
drain_virtio_tx(struct vhost_dev *vdev)
{
@@ -1369,13 +1409,8 @@ drain_virtio_tx(struct vhost_dev *vdev)
uint16_t count;
uint16_t i;
- if (builtin_net_driver) {
- count = vs_dequeue_pkts(vdev, VIRTIO_TXQ, mbuf_pool,
- pkts, MAX_PKT_BURST);
- } else {
- count = rte_vhost_dequeue_burst(vdev->vid, VIRTIO_TXQ,
- mbuf_pool, pkts, MAX_PKT_BURST);
- }
+ count = vdev_queue_ops[vdev->vid].dequeue_pkt_burst(vdev,
+ VIRTIO_TXQ, mbuf_pool, pkts, MAX_PKT_BURST);
/* setup VMDq for the first packet */
if (unlikely(vdev->ready == DEVICE_MAC_LEARNING) && count) {
@@ -1454,6 +1489,31 @@ switch_worker(void *arg __rte_unused)
return 0;
}
+static void
+vhost_clear_queue_thread_unsafe(struct vhost_dev *vdev, uint16_t queue_id)
+{
+ uint16_t n_pkt = 0;
+ uint16_t dma_id = dma_bind[vid2socketid[vdev->vid]].dmas[queue_id].dev_id;
+ struct rte_mbuf *m_enq_cpl[vdev->pkts_enq_inflight];
+ struct rte_mbuf *m_deq_cpl[vdev->pkts_deq_inflight];
+
+ if (queue_id % 2 == 0) {
+ while (vdev->pkts_enq_inflight) {
+ n_pkt = rte_vhost_clear_queue_thread_unsafe(vdev->vid,
+ queue_id, m_enq_cpl, vdev->pkts_enq_inflight, dma_id, 0);
+ free_pkts(m_enq_cpl, n_pkt);
+ __atomic_sub_fetch(&vdev->pkts_enq_inflight, n_pkt, __ATOMIC_SEQ_CST);
+ }
+ } else {
+ while (vdev->pkts_deq_inflight) {
+ n_pkt = rte_vhost_clear_queue_thread_unsafe(vdev->vid,
+ queue_id, m_deq_cpl, vdev->pkts_deq_inflight, dma_id, 0);
+ free_pkts(m_deq_cpl, n_pkt);
+ __atomic_sub_fetch(&vdev->pkts_deq_inflight, n_pkt, __ATOMIC_SEQ_CST);
+ }
+ }
+}
+
/*
* Remove a device from the specific data core linked list and from the
* main linked list. Synchonization occurs through the use of the
@@ -1510,25 +1570,83 @@ destroy_device(int vid)
"(%d) device has been removed from data core\n",
vdev->vid);
- if (dma_bind[vid].dmas[VIRTIO_RXQ].async_enabled) {
- uint16_t n_pkt = 0;
- int16_t dma_id = dma_bind[vid].dmas[VIRTIO_RXQ].dev_id;
- struct rte_mbuf *m_cpl[vdev->pkts_inflight];
-
- while (vdev->pkts_inflight) {
- n_pkt = rte_vhost_clear_queue_thread_unsafe(vid, VIRTIO_RXQ,
- m_cpl, vdev->pkts_inflight, dma_id, 0);
- free_pkts(m_cpl, n_pkt);
- __atomic_sub_fetch(&vdev->pkts_inflight, n_pkt, __ATOMIC_SEQ_CST);
- }
-
+ if (dma_bind[vid2socketid[vid]].dmas[VIRTIO_RXQ].async_enabled) {
+ vhost_clear_queue_thread_unsafe(vdev, VIRTIO_RXQ);
rte_vhost_async_channel_unregister(vid, VIRTIO_RXQ);
- dma_bind[vid].dmas[VIRTIO_RXQ].async_enabled = false;
+ dma_bind[vid2socketid[vid]].dmas[VIRTIO_RXQ].async_enabled = false;
+ }
+ if (dma_bind[vid2socketid[vid]].dmas[VIRTIO_TXQ].async_enabled) {
+ vhost_clear_queue_thread_unsafe(vdev, VIRTIO_TXQ);
+ rte_vhost_async_channel_unregister(vid, VIRTIO_TXQ);
+ dma_bind[vid2socketid[vid]].dmas[VIRTIO_TXQ].async_enabled = false;
}
rte_free(vdev);
}
+static int
+get_socketid_by_vid(int vid)
+{
+ int i;
+ char ifname[PATH_MAX];
+ rte_vhost_get_ifname(vid, ifname, sizeof(ifname));
+
+ for (i = 0; i < nb_sockets; i++) {
+ char *file = socket_files + i * PATH_MAX;
+ if (strcmp(file, ifname) == 0)
+ return i;
+ }
+
+ return -1;
+}
+
+static int
+init_vhost_queue_ops(int vid)
+{
+ int socketid = get_socketid_by_vid(vid);
+ if (socketid == -1)
+ return -1;
+
+ init_vid2socketid_array(vid, socketid);
+ if (builtin_net_driver) {
+ vdev_queue_ops[vid].enqueue_pkt_burst = builtin_enqueue_pkts;
+ vdev_queue_ops[vid].dequeue_pkt_burst = builtin_dequeue_pkts;
+ } else {
+ if (dma_bind[vid2socketid[vid]].dmas[VIRTIO_RXQ].async_enabled)
+ vdev_queue_ops[vid].enqueue_pkt_burst = async_enqueue_pkts;
+ else
+ vdev_queue_ops[vid].enqueue_pkt_burst = sync_enqueue_pkts;
+
+ if (dma_bind[vid2socketid[vid]].dmas[VIRTIO_TXQ].async_enabled)
+ vdev_queue_ops[vid].dequeue_pkt_burst = async_dequeue_pkts;
+ else
+ vdev_queue_ops[vid].dequeue_pkt_burst = sync_dequeue_pkts;
+ }
+
+ return 0;
+}
+
+static int
+vhost_async_channel_register(int vid)
+{
+ int rx_ret = 0, tx_ret = 0;
+
+ if (dma_bind[vid2socketid[vid]].dmas[VIRTIO_RXQ].dev_id != INVALID_DMA_ID) {
+ rx_ret = rte_vhost_async_channel_register(vid, VIRTIO_RXQ);
+ if (rx_ret == 0)
+ dma_bind[vid2socketid[vid]].dmas[VIRTIO_RXQ].async_enabled = true;
+ }
+
+ if (dma_bind[vid2socketid[vid]].dmas[VIRTIO_TXQ].dev_id != INVALID_DMA_ID) {
+ tx_ret = rte_vhost_async_channel_register(vid, VIRTIO_TXQ);
+ if (tx_ret == 0)
+ dma_bind[vid2socketid[vid]].dmas[VIRTIO_TXQ].async_enabled = true;
+ }
+
+ return rx_ret | tx_ret;
+}
+
+
/*
* A new device is added to a data core. First the device is added to the main linked list
* and then allocated to a specific data core.
@@ -1540,6 +1658,8 @@ new_device(int vid)
uint16_t i;
uint32_t device_num_min = num_devices;
struct vhost_dev *vdev;
+ int ret;
+
vdev = rte_zmalloc("vhost device", sizeof(*vdev), RTE_CACHE_LINE_SIZE);
if (vdev == NULL) {
RTE_LOG(INFO, VHOST_DATA,
@@ -1593,17 +1713,12 @@ new_device(int vid)
"(%d) device has been added to data core %d\n",
vid, vdev->coreid);
- if (dma_bind[vid].dmas[VIRTIO_RXQ].dev_id != INVALID_DMA_ID) {
- int ret;
+ ret = vhost_async_channel_register(vid);
- ret = rte_vhost_async_channel_register(vid, VIRTIO_RXQ);
- if (ret == 0) {
- dma_bind[vid].dmas[VIRTIO_RXQ].async_enabled = true;
- }
- return ret;
- }
+ if (init_vhost_queue_ops(vid) != 0)
+ return -1;
- return 0;
+ return ret;
}
static int
@@ -1621,19 +1736,9 @@ vring_state_changed(int vid, uint16_t queue_id, int enable)
if (queue_id != VIRTIO_RXQ)
return 0;
- if (dma_bind[vid].dmas[queue_id].async_enabled) {
- if (!enable) {
- uint16_t n_pkt = 0;
- int16_t dma_id = dma_bind[vid].dmas[VIRTIO_RXQ].dev_id;
- struct rte_mbuf *m_cpl[vdev->pkts_inflight];
-
- while (vdev->pkts_inflight) {
- n_pkt = rte_vhost_clear_queue_thread_unsafe(vid, queue_id,
- m_cpl, vdev->pkts_inflight, dma_id, 0);
- free_pkts(m_cpl, n_pkt);
- __atomic_sub_fetch(&vdev->pkts_inflight, n_pkt, __ATOMIC_SEQ_CST);
- }
- }
+ if (dma_bind[vid2socketid[vid]].dmas[queue_id].async_enabled) {
+ if (!enable)
+ vhost_clear_queue_thread_unsafe(vdev, queue_id);
}
return 0;
@@ -1896,7 +2001,7 @@ main(int argc, char *argv[])
if (client_mode)
flags |= RTE_VHOST_USER_CLIENT;
- if (async_vhost_driver) {
+ if (dma_count > 0) {
if (rte_vhost_async_dma_configure(dma_config, dma_count) < 0) {
RTE_LOG(ERR, VHOST_PORT, "Failed to configure DMA in vhost.\n");
for (i = 0; i < dma_count; i++) {
@@ -1906,18 +2011,18 @@ main(int argc, char *argv[])
}
}
dma_count = 0;
- async_vhost_driver = false;
}
}
/* Register vhost user driver to handle vhost messages. */
for (i = 0; i < nb_sockets; i++) {
char *file = socket_files + i * PATH_MAX;
+ uint64_t flag = flags;
- if (async_vhost_driver)
- flags = flags | RTE_VHOST_USER_ASYNC_COPY;
+ if (dma_count > 0 && get_async_flag_by_socketid(i) != 0)
+ flag |= RTE_VHOST_USER_ASYNC_COPY;
- ret = rte_vhost_driver_register(file, flags);
+ ret = rte_vhost_driver_register(file, flag);
if (ret != 0) {
unregister_drivers(i);
rte_exit(EXIT_FAILURE,
diff --git a/examples/vhost/main.h b/examples/vhost/main.h
index b4a453e77e..40ac2841d1 100644
--- a/examples/vhost/main.h
+++ b/examples/vhost/main.h
@@ -52,7 +52,8 @@ struct vhost_dev {
uint64_t features;
size_t hdr_len;
uint16_t nr_vrings;
- uint16_t pkts_inflight;
+ uint16_t pkts_enq_inflight;
+ uint16_t pkts_deq_inflight;
struct rte_vhost_memory *mem;
struct device_statistics stats;
TAILQ_ENTRY(vhost_dev) global_vdev_entry;
@@ -62,6 +63,19 @@ struct vhost_dev {
struct vhost_queue queues[MAX_QUEUE_PAIRS * 2];
} __rte_cache_aligned;
+typedef uint16_t (*vhost_enqueue_burst_t)(struct vhost_dev *dev,
+ uint16_t queue_id, struct rte_mbuf **pkts,
+ uint32_t count);
+
+typedef uint16_t (*vhost_dequeue_burst_t)(struct vhost_dev *dev,
+ uint16_t queue_id, struct rte_mempool *mbuf_pool,
+ struct rte_mbuf **pkts, uint16_t count);
+
+struct vhost_queue_ops {
+ vhost_enqueue_burst_t enqueue_pkt_burst;
+ vhost_dequeue_burst_t dequeue_pkt_burst;
+};
+
TAILQ_HEAD(vhost_dev_tailq_list, vhost_dev);
@@ -88,6 +102,7 @@ struct dma_info {
struct dma_for_vhost {
struct dma_info dmas[RTE_MAX_QUEUES_PER_PORT * 2];
+ uint32_t async_flag;
};
/* we implement non-extra virtio net features */
@@ -98,7 +113,19 @@ void vs_vhost_net_remove(struct vhost_dev *dev);
uint16_t vs_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
struct rte_mbuf **pkts, uint32_t count);
-uint16_t vs_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
- struct rte_mempool *mbuf_pool,
- struct rte_mbuf **pkts, uint16_t count);
+uint16_t builtin_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t count);
+uint16_t builtin_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool,
+ struct rte_mbuf **pkts, uint16_t count);
+uint16_t sync_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t count);
+uint16_t sync_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool,
+ struct rte_mbuf **pkts, uint16_t count);
+uint16_t async_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t count);
+uint16_t async_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool,
+ struct rte_mbuf **pkts, uint16_t count);
#endif /* _MAIN_H_ */
diff --git a/examples/vhost/virtio_net.c b/examples/vhost/virtio_net.c
index 9064fc3a82..2432a96566 100644
--- a/examples/vhost/virtio_net.c
+++ b/examples/vhost/virtio_net.c
@@ -238,6 +238,13 @@ vs_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
return count;
}
+uint16_t
+builtin_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t count)
+{
+ return vs_enqueue_pkts(dev, queue_id, pkts, count);
+}
+
static __rte_always_inline int
dequeue_pkt(struct vhost_dev *dev, struct rte_vhost_vring *vr,
struct rte_mbuf *m, uint16_t desc_idx,
@@ -363,7 +370,7 @@ dequeue_pkt(struct vhost_dev *dev, struct rte_vhost_vring *vr,
return 0;
}
-uint16_t
+static uint16_t
vs_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
{
@@ -440,3 +447,10 @@ vs_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
return i;
}
+
+uint16_t
+builtin_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
+{
+ return vs_dequeue_pkts(dev, queue_id, mbuf_pool, pkts, count);
+}
--
2.17.1
^ permalink raw reply [flat|nested] 11+ messages in thread
* [RFC,v2 0/2] vhost: support async dequeue data path
2022-01-01 0:12 [RFC 0/2] vhost: support async dequeue data path xuan.ding
2022-01-01 0:12 ` [RFC 1/2] vhost: support async dequeue for split ring xuan.ding
2022-01-01 0:12 ` [RFC 2/2] examples/vhost: support async dequeue data path xuan.ding
@ 2022-02-24 11:03 ` xuan.ding
2022-02-24 11:03 ` [RFC,v2 1/2] vhost: support async dequeue for split ring xuan.ding
2022-02-24 11:04 ` [RFC,v2 2/2] examples/vhost: support async dequeue data path xuan.ding
2022-03-10 6:54 ` [RFC,v3 0/2] vhost: " xuan.ding
3 siblings, 2 replies; 11+ messages in thread
From: xuan.ding @ 2022-02-24 11:03 UTC (permalink / raw)
To: maxime.coquelin, chenbo.xia
Cc: dev, jiayu.hu, cheng1.jiang, sunil.pai.g, liangma, Xuan Ding
From: Xuan Ding <xuan.ding@intel.com>
The presence of an asynchronous path allows applications to offload
memory copies to DMA engine, so as to save CPU cycles and improve
the copy performance. This patch set is a draft implementation for
split ring in vhost async dequeue data path. The code is based on
latest enqueue changes [1].
This patch set is a new design and implementation of [2]. Since dmadev
was introduced in DPDK 21.11, to simplify application logics, this patch
integrates dmadev in vhost. With dmadev integrated, vhost supports M:N
mapping between vrings and DMA virtual channels. Specifically, one vring
can use multiple different DMA channels and one DMA channel can be
shared by multiple vrings at the same time.
A new asynchronous dequeue function is introduced:
1) rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id,
struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts,
uint16_t count, int *nr_inflight,
uint16_t dma_id, uint16_t vchan_id)
Receive packets from the guest and offloads copies to DMA
virtual channel.
[1] https://mails.dpdk.org/archives/dev/2022-February/234555.html
[2] https://mails.dpdk.org/archives/dev/2021-September/218591.html
RFC v1 -> v2:
* fix one bug in example
* rename vchan to vchan_id
* check if dma_id and vchan_id valid
* rework all the logs to new standard
Xuan Ding (2):
vhost: support async dequeue for split ring
examples/vhost: support async dequeue data path
doc/guides/sample_app_ug/vhost.rst | 9 +-
examples/vhost/main.c | 292 +++++++++++------
examples/vhost/main.h | 35 +-
examples/vhost/virtio_net.c | 16 +-
lib/vhost/rte_vhost_async.h | 33 ++
lib/vhost/version.map | 1 +
lib/vhost/vhost.h | 1 +
lib/vhost/virtio_net.c | 504 +++++++++++++++++++++++++++++
8 files changed, 793 insertions(+), 98 deletions(-)
--
2.17.1
^ permalink raw reply [flat|nested] 11+ messages in thread
* [RFC,v2 1/2] vhost: support async dequeue for split ring
2022-02-24 11:03 ` [RFC,v2 0/2] vhost: " xuan.ding
@ 2022-02-24 11:03 ` xuan.ding
2022-02-24 11:04 ` [RFC,v2 2/2] examples/vhost: support async dequeue data path xuan.ding
1 sibling, 0 replies; 11+ messages in thread
From: xuan.ding @ 2022-02-24 11:03 UTC (permalink / raw)
To: maxime.coquelin, chenbo.xia
Cc: dev, jiayu.hu, cheng1.jiang, sunil.pai.g, liangma, Xuan Ding, Yuan Wang
From: Xuan Ding <xuan.ding@intel.com>
This patch implements asynchronous dequeue data path for vhost split
ring, with dmadev library integrated.
Signed-off-by: Xuan Ding <xuan.ding@intel.com>
Signed-off-by: Yuan Wang <yuanx.wang@intel.com>
---
lib/vhost/rte_vhost_async.h | 37 ++-
lib/vhost/version.map | 1 +
lib/vhost/vhost.h | 1 +
lib/vhost/virtio_net.c | 504 ++++++++++++++++++++++++++++++++++++
4 files changed, 541 insertions(+), 2 deletions(-)
diff --git a/lib/vhost/rte_vhost_async.h b/lib/vhost/rte_vhost_async.h
index 838c4778cc..a84f7cde9f 100644
--- a/lib/vhost/rte_vhost_async.h
+++ b/lib/vhost/rte_vhost_async.h
@@ -151,9 +151,9 @@ int rte_vhost_async_get_inflight(int vid, uint16_t queue_id);
* @param count
* Size of the packet array
* @param dma_id
- * the identifier of DMA device
+ * The identifier of DMA device
* @param vchan_id
- * the identifier of virtual DMA channel
+ * The identifier of virtual DMA channel
* @return
* Number of packets returned
*/
@@ -183,4 +183,37 @@ uint16_t rte_vhost_clear_queue_thread_unsafe(int vid, uint16_t queue_id,
__rte_experimental
int rte_vhost_async_dma_configure(int16_t dma_id, uint16_t vchan_id);
+/**
+ * This function tries to receive packets from the guest with offloading
+ * copies to the async channel. The packets that are transfer completed
+ * are returned in "pkts". The other packets that their copies are submitted to
+ * the async channel but not completed are called "in-flight packets".
+ * This function will not return in-flight packets until their copies are
+ * completed by the async channel.
+ *
+ * @param vid
+ * ID of vhost device to dequeue data
+ * @param queue_id
+ * ID of virtqueue to dequeue data
+ * @param mbuf_pool
+ * Mbuf_pool where host mbuf is allocated
+ * @param pkts
+ * Blank array to keep successfully dequeued packets
+ * @param count
+ * Size of the packet array
+ * @param nr_inflight
+ * The amount of in-flight packets. If error occurred, its value is set to -1.
+ * @param dma_id
+ * The identifier of DMA device
+ * @param vchan_id
+ * The identifier of virtual DMA channel
+ * @return
+ * Number of successfully dequeued packets
+ */
+__rte_experimental
+uint16_t
+rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count,
+ int *nr_inflight, uint16_t dma_id, uint16_t vchan_id);
+
#endif /* _RTE_VHOST_ASYNC_H_ */
diff --git a/lib/vhost/version.map b/lib/vhost/version.map
index 1202ba9c1a..816a6dc942 100644
--- a/lib/vhost/version.map
+++ b/lib/vhost/version.map
@@ -87,6 +87,7 @@ EXPERIMENTAL {
# added in 22.03
rte_vhost_async_dma_configure;
+ rte_vhost_async_try_dequeue_burst;
};
INTERNAL {
diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
index 21e1866a52..ba9d1f487d 100644
--- a/lib/vhost/vhost.h
+++ b/lib/vhost/vhost.h
@@ -180,6 +180,7 @@ extern struct async_dma_info dma_copy_track[RTE_DMADEV_DEFAULT_MAX];
*/
struct async_inflight_info {
struct rte_mbuf *mbuf;
+ struct virtio_net_hdr nethdr;
uint16_t descs; /* num of descs inflight */
uint16_t nr_buffers; /* num of buffers inflight for packed ring */
};
diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c
index 5f432b0d77..3816caca79 100644
--- a/lib/vhost/virtio_net.c
+++ b/lib/vhost/virtio_net.c
@@ -3141,3 +3141,507 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
return count;
}
+
+static __rte_always_inline int
+async_desc_to_mbuf_seg(struct virtio_net *dev, struct vhost_virtqueue *vq,
+ struct rte_mbuf *m, uint32_t mbuf_offset,
+ uint64_t buf_iova, uint32_t cpy_len)
+{
+ struct vhost_async *async = vq->async;
+ uint64_t mapped_len;
+ uint32_t buf_offset = 0;
+ void *host_iova;
+
+ while (cpy_len) {
+ host_iova = (void *)(uintptr_t)gpa_to_first_hpa(dev,
+ buf_iova + buf_offset, cpy_len,
+ &mapped_len);
+ if (unlikely(!host_iova)) {
+ VHOST_LOG_DATA(ERR, "(%s) %s: failed to get host_iova.\n",
+ dev->ifname, __func__);
+ return -1;
+ }
+
+ if (unlikely(async_iter_add_iovec(dev, async, host_iova,
+ (void *)(uintptr_t)rte_pktmbuf_iova_offset(m, mbuf_offset),
+ (size_t)mapped_len)))
+ return -1;
+
+ cpy_len -= (uint32_t)mapped_len;
+ mbuf_offset += (uint32_t)mapped_len;
+ buf_offset += (uint32_t)mapped_len;
+ }
+
+ return 0;
+}
+
+static __rte_always_inline int
+async_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
+ struct buf_vector *buf_vec, uint16_t nr_vec,
+ struct rte_mbuf *m, struct rte_mempool *mbuf_pool,
+ struct virtio_net_hdr *nethdr)
+{
+ uint64_t buf_addr, buf_iova;
+ uint32_t buf_avail, buf_offset, buf_len;
+ uint32_t mbuf_avail, mbuf_offset;
+ uint32_t cpy_len;
+ /* A counter to avoid desc dead loop chain */
+ uint16_t vec_idx = 0;
+ struct rte_mbuf *cur = m, *prev = m;
+ struct virtio_net_hdr tmp_hdr;
+ struct virtio_net_hdr *hdr = NULL;
+ struct vhost_async *async = vq->async;
+
+ buf_addr = buf_vec[vec_idx].buf_addr;
+ buf_len = buf_vec[vec_idx].buf_len;
+ buf_iova = buf_vec[vec_idx].buf_iova;
+
+ if (unlikely(buf_len < dev->vhost_hlen && nr_vec <= 1))
+ return -1;
+
+ if (virtio_net_with_host_offload(dev)) {
+ if (unlikely(buf_len < sizeof(struct virtio_net_hdr))) {
+ /*
+ * No luck, the virtio-net header doesn't fit
+ * in a contiguous virtual area.
+ */
+ copy_vnet_hdr_from_desc(&tmp_hdr, buf_vec);
+ hdr = &tmp_hdr;
+ } else {
+ hdr = (struct virtio_net_hdr *)((uintptr_t)buf_addr);
+ }
+ }
+
+ /*
+ * A virtio driver normally uses at least 2 desc buffers
+ * for Tx: the first for storing the header, and others
+ * for storing the data.
+ */
+ if (unlikely(buf_len < dev->vhost_hlen)) {
+ buf_offset = dev->vhost_hlen - buf_len;
+ vec_idx++;
+ buf_addr = buf_vec[vec_idx].buf_addr;
+ buf_iova = buf_vec[vec_idx].buf_iova;
+ buf_len = buf_vec[vec_idx].buf_len;
+ buf_avail = buf_len - buf_offset;
+ } else if (buf_len == dev->vhost_hlen) {
+ if (unlikely(++vec_idx >= nr_vec))
+ return -1;
+ buf_addr = buf_vec[vec_idx].buf_addr;
+ buf_iova = buf_vec[vec_idx].buf_iova;
+ buf_len = buf_vec[vec_idx].buf_len;
+
+ buf_offset = 0;
+ buf_avail = buf_len;
+ } else {
+ buf_offset = dev->vhost_hlen;
+ buf_avail = buf_vec[vec_idx].buf_len - dev->vhost_hlen;
+ }
+
+ PRINT_PACKET(dev, (uintptr_t)(buf_addr + buf_offset), (uint32_t)buf_avail, 0);
+
+ mbuf_offset = 0;
+ mbuf_avail = m->buf_len - RTE_PKTMBUF_HEADROOM;
+
+ if (async_iter_initialize(dev, async))
+ return -1;
+
+ while (1) {
+ cpy_len = RTE_MIN(buf_avail, mbuf_avail);
+
+ if (async_desc_to_mbuf_seg(dev, vq, cur, mbuf_offset, buf_iova + buf_offset,
+ cpy_len) < 0)
+ goto error;
+
+ mbuf_avail -= cpy_len;
+ buf_avail -= cpy_len;
+ mbuf_offset += cpy_len;
+ buf_offset += cpy_len;
+
+ /* This buf reaches to its end, get the next one */
+ if (buf_avail == 0) {
+ if (++vec_idx >= nr_vec)
+ break;
+
+ buf_addr = buf_vec[vec_idx].buf_addr;
+ buf_iova = buf_vec[vec_idx].buf_iova;
+ buf_len = buf_vec[vec_idx].buf_len;
+
+ buf_offset = 0;
+ buf_avail = buf_len;
+
+ PRINT_PACKET(dev, (uintptr_t)buf_addr, (uint32_t)buf_avail, 0);
+ }
+
+ /*
+ * This mbuf reaches to its end, get a new one
+ * to hold more data.
+ */
+ if (mbuf_avail == 0) {
+ cur = rte_pktmbuf_alloc(mbuf_pool);
+ if (unlikely(cur == NULL)) {
+ VHOST_LOG_DATA(ERR,
+ "(%s) %s: failed to allocate memory for mbuf.\n",
+ dev->ifname, __func__);
+ goto error;
+ }
+
+ prev->next = cur;
+ prev->data_len = mbuf_offset;
+ m->nb_segs += 1;
+ m->pkt_len += mbuf_offset;
+ prev = cur;
+
+ mbuf_offset = 0;
+ mbuf_avail = cur->buf_len - RTE_PKTMBUF_HEADROOM;
+ }
+ }
+
+ prev->data_len = mbuf_offset;
+ m->pkt_len += mbuf_offset;
+
+ async_iter_finalize(async);
+ if (hdr)
+ *nethdr = *hdr;
+
+ return 0;
+
+error:
+ async_iter_cancel(async);
+ return -1;
+}
+
+static __rte_always_inline uint16_t
+async_poll_dequeue_completed_split(struct virtio_net *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint16_t count, uint16_t dma_id,
+ uint16_t vchan_id, bool legacy_ol_flags)
+{
+ uint16_t start_idx, from, i;
+ uint16_t nr_cpl_pkts = 0;
+ struct async_inflight_info *pkts_info;
+ struct vhost_virtqueue *vq = dev->virtqueue[queue_id];
+
+ pkts_info = vq->async->pkts_info;
+
+ vhost_async_dma_check_completed(dev, dma_id, vchan_id, VHOST_DMA_MAX_COPY_COMPLETE);
+
+ start_idx = async_get_first_inflight_pkt_idx(vq);
+
+ from = start_idx;
+ while (vq->async->pkts_cmpl_flag[from] && count--) {
+ vq->async->pkts_cmpl_flag[from] = false;
+ from = (from + 1) & (vq->size - 1);
+ nr_cpl_pkts++;
+ }
+
+ if (nr_cpl_pkts == 0)
+ return 0;
+
+ for (i = 0; i < nr_cpl_pkts; i++) {
+ from = (start_idx + i) & (vq->size - 1);
+ pkts[i] = pkts_info[from].mbuf;
+
+ if (virtio_net_with_host_offload(dev))
+ vhost_dequeue_offload(dev, &pkts_info[from].nethdr, pkts[i],
+ legacy_ol_flags);
+ }
+
+ /* write back completed descs to used ring and update used idx */
+ write_back_completed_descs_split(vq, nr_cpl_pkts);
+ __atomic_add_fetch(&vq->used->idx, nr_cpl_pkts, __ATOMIC_RELEASE);
+ vhost_vring_call_split(dev, vq);
+
+ vq->async->pkts_inflight_n -= nr_cpl_pkts;
+
+ return nr_cpl_pkts;
+}
+
+static __rte_always_inline uint16_t
+virtio_dev_tx_async_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
+ uint16_t queue_id, struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts,
+ uint16_t count, uint16_t dma_id, uint16_t vchan_id, bool legacy_ol_flags)
+{
+ static bool allocerr_warned;
+ bool dropped = false;
+ uint16_t free_entries;
+ uint16_t pkt_idx, slot_idx = 0;
+ uint16_t nr_done_pkts = 0;
+ uint16_t pkt_err = 0;
+ uint16_t n_xfer;
+ struct vhost_async *async = vq->async;
+ struct async_inflight_info *pkts_info = async->pkts_info;
+ struct rte_mbuf *pkts_prealloc[MAX_PKT_BURST];
+ uint16_t pkts_size = count;
+
+ /**
+ * The ordering between avail index and
+ * desc reads needs to be enforced.
+ */
+ free_entries = __atomic_load_n(&vq->avail->idx, __ATOMIC_ACQUIRE) - vq->last_avail_idx;
+ if (free_entries == 0)
+ goto out;
+
+ rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
+
+ async_iter_reset(async);
+
+ count = RTE_MIN(count, MAX_PKT_BURST);
+ count = RTE_MIN(count, free_entries);
+ VHOST_LOG_DATA(DEBUG, "(%s) about to dequeue %u buffers\n", dev->ifname, count);
+
+ if (rte_pktmbuf_alloc_bulk(mbuf_pool, pkts_prealloc, count))
+ goto out;
+
+ for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
+ uint16_t head_idx = 0;
+ uint16_t nr_vec = 0;
+ uint16_t to;
+ uint32_t buf_len;
+ int err;
+ struct buf_vector buf_vec[BUF_VECTOR_MAX];
+ struct rte_mbuf *pkt = pkts_prealloc[pkt_idx];
+
+ if (unlikely(fill_vec_buf_split(dev, vq, vq->last_avail_idx,
+ &nr_vec, buf_vec,
+ &head_idx, &buf_len,
+ VHOST_ACCESS_RO) < 0)) {
+ dropped = true;
+ break;
+ }
+
+ err = virtio_dev_pktmbuf_prep(dev, pkt, buf_len);
+ if (unlikely(err)) {
+ /**
+ * mbuf allocation fails for jumbo packets when external
+ * buffer allocation is not allowed and linear buffer
+ * is required. Drop this packet.
+ */
+ if (!allocerr_warned) {
+ VHOST_LOG_DATA(ERR,
+ "(%s) %s: Failed mbuf alloc of size %d from %s\n",
+ dev->ifname, __func__, buf_len, mbuf_pool->name);
+ allocerr_warned = true;
+ }
+ dropped = true;
+ break;
+ }
+
+ slot_idx = (async->pkts_idx + pkt_idx) & (vq->size - 1);
+ err = async_desc_to_mbuf(dev, vq, buf_vec, nr_vec, pkt, mbuf_pool,
+ &pkts_info[slot_idx].nethdr);
+ if (unlikely(err)) {
+ if (!allocerr_warned) {
+ VHOST_LOG_DATA(ERR,
+ "(%s) %s: Failed to offload copies to async channel.\n",
+ dev->ifname, __func__);
+ allocerr_warned = true;
+ }
+ dropped = true;
+ break;
+ }
+
+ pkts_info[slot_idx].mbuf = pkt;
+
+ /* store used descs */
+ to = async->desc_idx_split & (vq->size - 1);
+ async->descs_split[to].id = head_idx;
+ async->descs_split[to].len = 0;
+ async->desc_idx_split++;
+
+ vq->last_avail_idx++;
+ }
+
+ if (unlikely(dropped))
+ rte_pktmbuf_free_bulk(&pkts_prealloc[pkt_idx], count - pkt_idx);
+
+ n_xfer = vhost_async_dma_transfer(dev, vq, dma_id, vchan_id, async->pkts_idx,
+ async->iov_iter, pkt_idx);
+
+ async->pkts_inflight_n += n_xfer;
+
+ pkt_err = pkt_idx - n_xfer;
+ if (unlikely(pkt_err)) {
+ VHOST_LOG_DATA(DEBUG,
+ "(%s) %s: failed to transfer data for queue id %d.\n",
+ dev->ifname, __func__, queue_id);
+
+ pkt_idx = n_xfer;
+ /* recover available ring */
+ vq->last_avail_idx -= pkt_err;
+
+ /**
+ * recover async channel copy related structures and free pktmbufs
+ * for error pkts.
+ */
+ async->desc_idx_split -= pkt_err;
+ while (pkt_err-- > 0) {
+ rte_pktmbuf_free(pkts_info[slot_idx & (vq->size - 1)].mbuf);
+ slot_idx--;
+ }
+ }
+
+ async->pkts_idx += pkt_idx;
+ if (async->pkts_idx >= vq->size)
+ async->pkts_idx -= vq->size;
+
+out:
+ /* DMA device may serve other queues, unconditionally check completed. */
+ nr_done_pkts = async_poll_dequeue_completed_split(dev, queue_id, pkts, pkts_size,
+ dma_id, vchan_id, legacy_ol_flags);
+
+ return nr_done_pkts;
+}
+
+__rte_noinline
+static uint16_t
+virtio_dev_tx_async_split_legacy(struct virtio_net *dev,
+ struct vhost_virtqueue *vq, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts,
+ uint16_t count, uint16_t dma_id, uint16_t vchan_id)
+{
+ return virtio_dev_tx_async_split(dev, vq, queue_id, mbuf_pool,
+ pkts, count, dma_id, vchan_id, true);
+}
+
+__rte_noinline
+static uint16_t
+virtio_dev_tx_async_split_compliant(struct virtio_net *dev,
+ struct vhost_virtqueue *vq, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts,
+ uint16_t count, uint16_t dma_id, uint16_t vchan_id)
+{
+ return virtio_dev_tx_async_split(dev, vq, queue_id, mbuf_pool,
+ pkts, count, dma_id, vchan_id, false);
+}
+
+uint16_t
+rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count,
+ int *nr_inflight, uint16_t dma_id, uint16_t vchan_id)
+{
+ struct virtio_net *dev;
+ struct rte_mbuf *rarp_mbuf = NULL;
+ struct vhost_virtqueue *vq;
+ int16_t success = 1;
+
+ *nr_inflight = -1;
+
+ dev = get_device(vid);
+ if (!dev)
+ return 0;
+
+ if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) {
+ VHOST_LOG_DATA(ERR,
+ "(%s) %s: built-in vhost net backend is disabled.\n",
+ dev->ifname, __func__);
+ return 0;
+ }
+
+ if (unlikely(!is_valid_virt_queue_idx(queue_id, 1, dev->nr_vring))) {
+ VHOST_LOG_DATA(ERR,
+ "(%s) %s: invalid virtqueue idx %d.\n",
+ dev->ifname, __func__, queue_id);
+ return 0;
+ }
+
+ if (unlikely(!dma_copy_track[dma_id].vchans ||
+ !dma_copy_track[dma_id].vchans[vchan_id].pkts_cmpl_flag_addr)) {
+ VHOST_LOG_DATA(ERR, "(%s) %s: invalid channel %d:%u.\n", dev->ifname, __func__,
+ dma_id, vchan_id);
+ return 0;
+ }
+
+ vq = dev->virtqueue[queue_id];
+
+ if (unlikely(rte_spinlock_trylock(&vq->access_lock) == 0))
+ return 0;
+
+ if (unlikely(vq->enabled == 0)) {
+ count = 0;
+ goto out_access_unlock;
+ }
+
+ if (unlikely(!vq->async)) {
+ VHOST_LOG_DATA(ERR, "(%s) %s: async not registered for queue id %d.\n",
+ dev->ifname, __func__, queue_id);
+ count = 0;
+ goto out_access_unlock;
+ }
+
+ if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
+ vhost_user_iotlb_rd_lock(vq);
+
+ if (unlikely(vq->access_ok == 0))
+ if (unlikely(vring_translate(dev, vq) < 0)) {
+ count = 0;
+ goto out;
+ }
+
+ /*
+ * Construct a RARP broadcast packet, and inject it to the "pkts"
+ * array, to looks like that guest actually send such packet.
+ *
+ * Check user_send_rarp() for more information.
+ *
+ * broadcast_rarp shares a cacheline in the virtio_net structure
+ * with some fields that are accessed during enqueue and
+ * __atomic_compare_exchange_n causes a write if performed compare
+ * and exchange. This could result in false sharing between enqueue
+ * and dequeue.
+ *
+ * Prevent unnecessary false sharing by reading broadcast_rarp first
+ * and only performing compare and exchange if the read indicates it
+ * is likely to be set.
+ */
+ if (unlikely(__atomic_load_n(&dev->broadcast_rarp, __ATOMIC_ACQUIRE) &&
+ __atomic_compare_exchange_n(&dev->broadcast_rarp,
+ &success, 0, 0, __ATOMIC_RELEASE, __ATOMIC_RELAXED))) {
+
+ rarp_mbuf = rte_net_make_rarp_packet(mbuf_pool, &dev->mac);
+ if (rarp_mbuf == NULL) {
+ VHOST_LOG_DATA(ERR, "Failed to make RARP packet.\n");
+ count = 0;
+ goto out;
+ }
+ /*
+ * Inject it to the head of "pkts" array, so that switch's mac
+ * learning table will get updated first.
+ */
+ pkts[0] = rarp_mbuf;
+ pkts++;
+ count -= 1;
+ }
+
+ if (unlikely(vq_is_packed(dev))) {
+ static bool not_support_pack_log;
+ if (!not_support_pack_log) {
+ VHOST_LOG_DATA(ERR,
+ "(%s) %s: async dequeue does not support packed ring.\n",
+ dev->ifname, __func__);
+ not_support_pack_log = true;
+ }
+ count = 0;
+ goto out;
+ }
+
+ if (dev->flags & VIRTIO_DEV_LEGACY_OL_FLAGS)
+ count = virtio_dev_tx_async_split_legacy(dev, vq, queue_id,
+ mbuf_pool, pkts, count, dma_id, vchan_id);
+ else
+ count = virtio_dev_tx_async_split_compliant(dev, vq, queue_id,
+ mbuf_pool, pkts, count, dma_id, vchan_id);
+
+ *nr_inflight = vq->async->pkts_inflight_n;
+
+out:
+ if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
+ vhost_user_iotlb_rd_unlock(vq);
+
+out_access_unlock:
+ rte_spinlock_unlock(&vq->access_lock);
+
+ if (unlikely(rarp_mbuf != NULL))
+ count += 1;
+
+ return count;
+}
--
2.17.1
^ permalink raw reply [flat|nested] 11+ messages in thread
* [RFC,v2 2/2] examples/vhost: support async dequeue data path
2022-02-24 11:03 ` [RFC,v2 0/2] vhost: " xuan.ding
2022-02-24 11:03 ` [RFC,v2 1/2] vhost: support async dequeue for split ring xuan.ding
@ 2022-02-24 11:04 ` xuan.ding
1 sibling, 0 replies; 11+ messages in thread
From: xuan.ding @ 2022-02-24 11:04 UTC (permalink / raw)
To: maxime.coquelin, chenbo.xia
Cc: dev, jiayu.hu, cheng1.jiang, sunil.pai.g, liangma, Xuan Ding,
Wenwu Ma, Yuan Wang
From: Xuan Ding <xuan.ding@intel.com>
This patch adds the use case for async dequeue API. Vswitch can
leverage DMA device to accelerate vhost async dequeue path.
Signed-off-by: Wenwu Ma <wenwux.ma@intel.com>
Signed-off-by: Yuan Wang <yuan.wangx@intel.com>
Signed-off-by: Xuan Ding <xuan.ding@intel.com>
---
doc/guides/sample_app_ug/vhost.rst | 9 +-
examples/vhost/main.c | 292 ++++++++++++++++++++---------
examples/vhost/main.h | 35 +++-
examples/vhost/virtio_net.c | 16 +-
4 files changed, 254 insertions(+), 98 deletions(-)
diff --git a/doc/guides/sample_app_ug/vhost.rst b/doc/guides/sample_app_ug/vhost.rst
index a6ce4bc8ac..09db965e70 100644
--- a/doc/guides/sample_app_ug/vhost.rst
+++ b/doc/guides/sample_app_ug/vhost.rst
@@ -169,9 +169,12 @@ demonstrates how to use the async vhost APIs. It's used in combination with dmas
**--dmas**
This parameter is used to specify the assigned DMA device of a vhost device.
Async vhost-user net driver will be used if --dmas is set. For example
---dmas [txd0@00:04.0,txd1@00:04.1] means use DMA channel 00:04.0 for vhost
-device 0 enqueue operation and use DMA channel 00:04.1 for vhost device 1
-enqueue operation.
+--dmas [txd0@00:04.0,txd1@00:04.1,rxd0@00:04.2,rxd1@00:04.3] means use
+DMA channel 00:04.0/00:04.2 for vhost device 0 enqueue/dequeue operation
+and use DMA channel 00:04.1/00:04.3 for vhost device 1 enqueue/dequeue
+operation. The index of the device corresponds to the socket file in order,
+that means vhost device 0 is created through the first socket file, vhost
+device 1 is created through the second socket file, and so on.
Common Issues
-------------
diff --git a/examples/vhost/main.c b/examples/vhost/main.c
index 68afd398bb..8417ac0f81 100644
--- a/examples/vhost/main.c
+++ b/examples/vhost/main.c
@@ -61,6 +61,9 @@
#define DMA_RING_SIZE 4096
+#define ASYNC_ENQUEUE_VHOST 1
+#define ASYNC_DEQUEUE_VHOST 2
+
struct dma_for_vhost dma_bind[RTE_MAX_VHOST_DEVICE];
int16_t dmas_id[RTE_DMADEV_DEFAULT_MAX];
static int dma_count;
@@ -111,6 +114,8 @@ static uint32_t burst_rx_retry_num = BURST_RX_RETRIES;
static char *socket_files;
static int nb_sockets;
+static struct vhost_queue_ops vdev_queue_ops[RTE_MAX_VHOST_DEVICE];
+
/* empty VMDq configuration structure. Filled in programmatically */
static struct rte_eth_conf vmdq_conf_default = {
.rxmode = {
@@ -200,6 +205,18 @@ struct vhost_bufftable *vhost_txbuff[RTE_MAX_LCORE * RTE_MAX_VHOST_DEVICE];
#define MBUF_TABLE_DRAIN_TSC ((rte_get_tsc_hz() + US_PER_S - 1) \
/ US_PER_S * BURST_TX_DRAIN_US)
+static int vid2socketid[RTE_MAX_VHOST_DEVICE];
+
+static uint32_t get_async_flag_by_socketid(int socketid)
+{
+ return dma_bind[socketid].async_flag;
+}
+
+static void init_vid2socketid_array(int vid, int socketid)
+{
+ vid2socketid[vid] = socketid;
+}
+
static inline bool
is_dma_configured(int16_t dev_id)
{
@@ -219,7 +236,7 @@ open_dma(const char *value)
char *addrs = input;
char *ptrs[2];
char *start, *end, *substr;
- int64_t vid;
+ int64_t socketid, vring_id;
struct rte_dma_info info;
struct rte_dma_conf dev_config = { .nb_vchans = 1 };
@@ -257,7 +274,9 @@ open_dma(const char *value)
while (i < args_nr) {
char *arg_temp = dma_arg[i];
+ char *txd, *rxd;
uint8_t sub_nr;
+ int async_flag;
sub_nr = rte_strsplit(arg_temp, strlen(arg_temp), ptrs, 2, '@');
if (sub_nr != 2) {
@@ -265,14 +284,23 @@ open_dma(const char *value)
goto out;
}
- start = strstr(ptrs[0], "txd");
- if (start == NULL) {
+ txd = strstr(ptrs[0], "txd");
+ rxd = strstr(ptrs[0], "rxd");
+ if (txd) {
+ start = txd;
+ vring_id = VIRTIO_RXQ;
+ async_flag = ASYNC_ENQUEUE_VHOST;
+ } else if (rxd) {
+ start = rxd;
+ vring_id = VIRTIO_TXQ;
+ async_flag = ASYNC_DEQUEUE_VHOST;
+ } else {
ret = -1;
goto out;
}
start += 3;
- vid = strtol(start, &end, 0);
+ socketid = strtol(start, &end, 0);
if (end == start) {
ret = -1;
goto out;
@@ -333,7 +361,8 @@ open_dma(const char *value)
dmas_id[dma_count++] = dev_id;
done:
- (dma_info + vid)->dmas[VIRTIO_RXQ].dev_id = dev_id;
+ (dma_info + socketid)->dmas[vring_id].dev_id = dev_id;
+ (dma_info + socketid)->async_flag |= async_flag;
i++;
}
out:
@@ -967,13 +996,13 @@ complete_async_pkts(struct vhost_dev *vdev)
{
struct rte_mbuf *p_cpl[MAX_PKT_BURST];
uint16_t complete_count;
- int16_t dma_id = dma_bind[vdev->vid].dmas[VIRTIO_RXQ].dev_id;
+ int16_t dma_id = dma_bind[vid2socketid[vdev->vid]].dmas[VIRTIO_RXQ].dev_id;
complete_count = rte_vhost_poll_enqueue_completed(vdev->vid,
VIRTIO_RXQ, p_cpl, MAX_PKT_BURST, dma_id, 0);
if (complete_count) {
free_pkts(p_cpl, complete_count);
- __atomic_sub_fetch(&vdev->pkts_inflight, complete_count, __ATOMIC_SEQ_CST);
+ __atomic_sub_fetch(&vdev->pkts_enq_inflight, complete_count, __ATOMIC_SEQ_CST);
}
}
@@ -1008,23 +1037,7 @@ drain_vhost(struct vhost_dev *vdev)
uint16_t nr_xmit = vhost_txbuff[buff_idx]->len;
struct rte_mbuf **m = vhost_txbuff[buff_idx]->m_table;
- if (builtin_net_driver) {
- ret = vs_enqueue_pkts(vdev, VIRTIO_RXQ, m, nr_xmit);
- } else if (dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled) {
- uint16_t enqueue_fail = 0;
- int16_t dma_id = dma_bind[vdev->vid].dmas[VIRTIO_RXQ].dev_id;
-
- complete_async_pkts(vdev);
- ret = rte_vhost_submit_enqueue_burst(vdev->vid, VIRTIO_RXQ, m, nr_xmit, dma_id, 0);
- __atomic_add_fetch(&vdev->pkts_inflight, ret, __ATOMIC_SEQ_CST);
-
- enqueue_fail = nr_xmit - ret;
- if (enqueue_fail)
- free_pkts(&m[ret], nr_xmit - ret);
- } else {
- ret = rte_vhost_enqueue_burst(vdev->vid, VIRTIO_RXQ,
- m, nr_xmit);
- }
+ ret = vdev_queue_ops[vdev->vid].enqueue_pkt_burst(vdev, VIRTIO_RXQ, m, nr_xmit);
if (enable_stats) {
__atomic_add_fetch(&vdev->stats.rx_total_atomic, nr_xmit,
@@ -1033,7 +1046,7 @@ drain_vhost(struct vhost_dev *vdev)
__ATOMIC_SEQ_CST);
}
- if (!dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled)
+ if (!dma_bind[vid2socketid[vdev->vid]].dmas[VIRTIO_RXQ].async_enabled)
free_pkts(m, nr_xmit);
}
@@ -1305,6 +1318,33 @@ drain_mbuf_table(struct mbuf_table *tx_q)
}
}
+uint16_t
+async_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t rx_count)
+{
+ uint16_t enqueue_count;
+ uint16_t enqueue_fail = 0;
+ uint16_t dma_id = dma_bind[vid2socketid[dev->vid]].dmas[VIRTIO_RXQ].dev_id;
+
+ complete_async_pkts(dev);
+ enqueue_count = rte_vhost_submit_enqueue_burst(dev->vid, queue_id,
+ pkts, rx_count, dma_id, 0);
+ __atomic_add_fetch(&dev->pkts_enq_inflight, enqueue_count, __ATOMIC_SEQ_CST);
+
+ enqueue_fail = rx_count - enqueue_count;
+ if (enqueue_fail)
+ free_pkts(&pkts[enqueue_count], enqueue_fail);
+
+ return enqueue_count;
+}
+
+uint16_t
+sync_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t rx_count)
+{
+ return rte_vhost_enqueue_burst(dev->vid, queue_id, pkts, rx_count);
+}
+
static __rte_always_inline void
drain_eth_rx(struct vhost_dev *vdev)
{
@@ -1335,26 +1375,8 @@ drain_eth_rx(struct vhost_dev *vdev)
}
}
- if (builtin_net_driver) {
- enqueue_count = vs_enqueue_pkts(vdev, VIRTIO_RXQ,
- pkts, rx_count);
- } else if (dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled) {
- uint16_t enqueue_fail = 0;
- int16_t dma_id = dma_bind[vdev->vid].dmas[VIRTIO_RXQ].dev_id;
-
- complete_async_pkts(vdev);
- enqueue_count = rte_vhost_submit_enqueue_burst(vdev->vid,
- VIRTIO_RXQ, pkts, rx_count, dma_id, 0);
- __atomic_add_fetch(&vdev->pkts_inflight, enqueue_count, __ATOMIC_SEQ_CST);
-
- enqueue_fail = rx_count - enqueue_count;
- if (enqueue_fail)
- free_pkts(&pkts[enqueue_count], enqueue_fail);
-
- } else {
- enqueue_count = rte_vhost_enqueue_burst(vdev->vid, VIRTIO_RXQ,
- pkts, rx_count);
- }
+ enqueue_count = vdev_queue_ops[vdev->vid].enqueue_pkt_burst(vdev,
+ VIRTIO_RXQ, pkts, rx_count);
if (enable_stats) {
__atomic_add_fetch(&vdev->stats.rx_total_atomic, rx_count,
@@ -1363,10 +1385,33 @@ drain_eth_rx(struct vhost_dev *vdev)
__ATOMIC_SEQ_CST);
}
- if (!dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled)
+ if (!dma_bind[vid2socketid[vdev->vid]].dmas[VIRTIO_RXQ].async_enabled)
free_pkts(pkts, rx_count);
}
+uint16_t async_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool,
+ struct rte_mbuf **pkts, uint16_t count)
+{
+ int nr_inflight;
+ uint16_t dequeue_count;
+ uint16_t dma_id = dma_bind[vid2socketid[dev->vid]].dmas[VIRTIO_TXQ].dev_id;
+
+ dequeue_count = rte_vhost_async_try_dequeue_burst(dev->vid, queue_id,
+ mbuf_pool, pkts, count, &nr_inflight, dma_id, 0);
+ if (likely(nr_inflight != -1))
+ dev->pkts_deq_inflight = nr_inflight;
+
+ return dequeue_count;
+}
+
+uint16_t sync_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool,
+ struct rte_mbuf **pkts, uint16_t count)
+{
+ return rte_vhost_dequeue_burst(dev->vid, queue_id, mbuf_pool, pkts, count);
+}
+
static __rte_always_inline void
drain_virtio_tx(struct vhost_dev *vdev)
{
@@ -1374,13 +1419,8 @@ drain_virtio_tx(struct vhost_dev *vdev)
uint16_t count;
uint16_t i;
- if (builtin_net_driver) {
- count = vs_dequeue_pkts(vdev, VIRTIO_TXQ, mbuf_pool,
- pkts, MAX_PKT_BURST);
- } else {
- count = rte_vhost_dequeue_burst(vdev->vid, VIRTIO_TXQ,
- mbuf_pool, pkts, MAX_PKT_BURST);
- }
+ count = vdev_queue_ops[vdev->vid].dequeue_pkt_burst(vdev,
+ VIRTIO_TXQ, mbuf_pool, pkts, MAX_PKT_BURST);
/* setup VMDq for the first packet */
if (unlikely(vdev->ready == DEVICE_MAC_LEARNING) && count) {
@@ -1459,6 +1499,31 @@ switch_worker(void *arg __rte_unused)
return 0;
}
+static void
+vhost_clear_queue_thread_unsafe(struct vhost_dev *vdev, uint16_t queue_id)
+{
+ uint16_t n_pkt = 0;
+ uint16_t dma_id = dma_bind[vid2socketid[vdev->vid]].dmas[queue_id].dev_id;
+ struct rte_mbuf *m_enq_cpl[vdev->pkts_enq_inflight];
+ struct rte_mbuf *m_deq_cpl[vdev->pkts_deq_inflight];
+
+ if (queue_id % 2 == 0) {
+ while (vdev->pkts_enq_inflight) {
+ n_pkt = rte_vhost_clear_queue_thread_unsafe(vdev->vid,
+ queue_id, m_enq_cpl, vdev->pkts_enq_inflight, dma_id, 0);
+ free_pkts(m_enq_cpl, n_pkt);
+ __atomic_sub_fetch(&vdev->pkts_enq_inflight, n_pkt, __ATOMIC_SEQ_CST);
+ }
+ } else {
+ while (vdev->pkts_deq_inflight) {
+ n_pkt = rte_vhost_clear_queue_thread_unsafe(vdev->vid,
+ queue_id, m_deq_cpl, vdev->pkts_deq_inflight, dma_id, 0);
+ free_pkts(m_deq_cpl, n_pkt);
+ __atomic_sub_fetch(&vdev->pkts_deq_inflight, n_pkt, __ATOMIC_SEQ_CST);
+ }
+ }
+}
+
/*
* Remove a device from the specific data core linked list and from the
* main linked list. Synchronization occurs through the use of the
@@ -1515,25 +1580,78 @@ destroy_device(int vid)
"(%d) device has been removed from data core\n",
vdev->vid);
- if (dma_bind[vid].dmas[VIRTIO_RXQ].async_enabled) {
- uint16_t n_pkt = 0;
- int16_t dma_id = dma_bind[vid].dmas[VIRTIO_RXQ].dev_id;
- struct rte_mbuf *m_cpl[vdev->pkts_inflight];
-
- while (vdev->pkts_inflight) {
- n_pkt = rte_vhost_clear_queue_thread_unsafe(vid, VIRTIO_RXQ,
- m_cpl, vdev->pkts_inflight, dma_id, 0);
- free_pkts(m_cpl, n_pkt);
- __atomic_sub_fetch(&vdev->pkts_inflight, n_pkt, __ATOMIC_SEQ_CST);
- }
-
+ if (dma_bind[vid2socketid[vid]].dmas[VIRTIO_RXQ].async_enabled) {
+ vhost_clear_queue_thread_unsafe(vdev, VIRTIO_RXQ);
rte_vhost_async_channel_unregister(vid, VIRTIO_RXQ);
- dma_bind[vid].dmas[VIRTIO_RXQ].async_enabled = false;
+ dma_bind[vid2socketid[vid]].dmas[VIRTIO_RXQ].async_enabled = false;
+ }
+ if (dma_bind[vid2socketid[vid]].dmas[VIRTIO_TXQ].async_enabled) {
+ vhost_clear_queue_thread_unsafe(vdev, VIRTIO_TXQ);
+ rte_vhost_async_channel_unregister(vid, VIRTIO_TXQ);
+ dma_bind[vid2socketid[vid]].dmas[VIRTIO_TXQ].async_enabled = false;
}
rte_free(vdev);
}
+static int
+get_socketid_by_vid(int vid)
+{
+ int i;
+ char ifname[PATH_MAX];
+ rte_vhost_get_ifname(vid, ifname, sizeof(ifname));
+
+ for (i = 0; i < nb_sockets; i++) {
+ char *file = socket_files + i * PATH_MAX;
+ if (strcmp(file, ifname) == 0)
+ return i;
+ }
+
+ return -1;
+}
+
+static int
+init_vhost_queue_ops(int vid)
+{
+ if (builtin_net_driver) {
+ vdev_queue_ops[vid].enqueue_pkt_burst = builtin_enqueue_pkts;
+ vdev_queue_ops[vid].dequeue_pkt_burst = builtin_dequeue_pkts;
+ } else {
+ if (dma_bind[vid2socketid[vid]].dmas[VIRTIO_RXQ].async_enabled)
+ vdev_queue_ops[vid].enqueue_pkt_burst = async_enqueue_pkts;
+ else
+ vdev_queue_ops[vid].enqueue_pkt_burst = sync_enqueue_pkts;
+
+ if (dma_bind[vid2socketid[vid]].dmas[VIRTIO_TXQ].async_enabled)
+ vdev_queue_ops[vid].dequeue_pkt_burst = async_dequeue_pkts;
+ else
+ vdev_queue_ops[vid].dequeue_pkt_burst = sync_dequeue_pkts;
+ }
+
+ return 0;
+}
+
+static int
+vhost_async_channel_register(int vid)
+{
+ int rx_ret = 0, tx_ret = 0;
+
+ if (dma_bind[vid2socketid[vid]].dmas[VIRTIO_RXQ].dev_id != INVALID_DMA_ID) {
+ rx_ret = rte_vhost_async_channel_register(vid, VIRTIO_RXQ);
+ if (rx_ret == 0)
+ dma_bind[vid2socketid[vid]].dmas[VIRTIO_RXQ].async_enabled = true;
+ }
+
+ if (dma_bind[vid2socketid[vid]].dmas[VIRTIO_TXQ].dev_id != INVALID_DMA_ID) {
+ tx_ret = rte_vhost_async_channel_register(vid, VIRTIO_TXQ);
+ if (tx_ret == 0)
+ dma_bind[vid2socketid[vid]].dmas[VIRTIO_TXQ].async_enabled = true;
+ }
+
+ return rx_ret | tx_ret;
+}
+
+
/*
* A new device is added to a data core. First the device is added to the main linked list
* and then allocated to a specific data core.
@@ -1545,6 +1663,8 @@ new_device(int vid)
uint16_t i;
uint32_t device_num_min = num_devices;
struct vhost_dev *vdev;
+ int ret;
+
vdev = rte_zmalloc("vhost device", sizeof(*vdev), RTE_CACHE_LINE_SIZE);
if (vdev == NULL) {
RTE_LOG(INFO, VHOST_DATA,
@@ -1567,6 +1687,17 @@ new_device(int vid)
}
}
+ int socketid = get_socketid_by_vid(vid);
+ if (socketid == -1)
+ return -1;
+
+ init_vid2socketid_array(vid, socketid);
+
+ ret = vhost_async_channel_register(vid);
+
+ if (init_vhost_queue_ops(vid) != 0)
+ return -1;
+
if (builtin_net_driver)
vs_vhost_net_setup(vdev);
@@ -1598,16 +1729,7 @@ new_device(int vid)
"(%d) device has been added to data core %d\n",
vid, vdev->coreid);
- if (dma_bind[vid].dmas[VIRTIO_RXQ].dev_id != INVALID_DMA_ID) {
- int ret;
-
- ret = rte_vhost_async_channel_register(vid, VIRTIO_RXQ);
- if (ret == 0)
- dma_bind[vid].dmas[VIRTIO_RXQ].async_enabled = true;
- return ret;
- }
-
- return 0;
+ return ret;
}
static int
@@ -1625,19 +1747,9 @@ vring_state_changed(int vid, uint16_t queue_id, int enable)
if (queue_id != VIRTIO_RXQ)
return 0;
- if (dma_bind[vid].dmas[queue_id].async_enabled) {
- if (!enable) {
- uint16_t n_pkt = 0;
- int16_t dma_id = dma_bind[vid].dmas[VIRTIO_RXQ].dev_id;
- struct rte_mbuf *m_cpl[vdev->pkts_inflight];
-
- while (vdev->pkts_inflight) {
- n_pkt = rte_vhost_clear_queue_thread_unsafe(vid, queue_id,
- m_cpl, vdev->pkts_inflight, dma_id, 0);
- free_pkts(m_cpl, n_pkt);
- __atomic_sub_fetch(&vdev->pkts_inflight, n_pkt, __ATOMIC_SEQ_CST);
- }
- }
+ if (dma_bind[vid2socketid[vid]].dmas[queue_id].async_enabled) {
+ if (!enable)
+ vhost_clear_queue_thread_unsafe(vdev, queue_id);
}
return 0;
@@ -1910,7 +2022,7 @@ main(int argc, char *argv[])
for (i = 0; i < nb_sockets; i++) {
char *file = socket_files + i * PATH_MAX;
- if (dma_count)
+ if (dma_count && get_async_flag_by_socketid(i) != 0)
flags = flags | RTE_VHOST_USER_ASYNC_COPY;
ret = rte_vhost_driver_register(file, flags);
diff --git a/examples/vhost/main.h b/examples/vhost/main.h
index b4a453e77e..40ac2841d1 100644
--- a/examples/vhost/main.h
+++ b/examples/vhost/main.h
@@ -52,7 +52,8 @@ struct vhost_dev {
uint64_t features;
size_t hdr_len;
uint16_t nr_vrings;
- uint16_t pkts_inflight;
+ uint16_t pkts_enq_inflight;
+ uint16_t pkts_deq_inflight;
struct rte_vhost_memory *mem;
struct device_statistics stats;
TAILQ_ENTRY(vhost_dev) global_vdev_entry;
@@ -62,6 +63,19 @@ struct vhost_dev {
struct vhost_queue queues[MAX_QUEUE_PAIRS * 2];
} __rte_cache_aligned;
+typedef uint16_t (*vhost_enqueue_burst_t)(struct vhost_dev *dev,
+ uint16_t queue_id, struct rte_mbuf **pkts,
+ uint32_t count);
+
+typedef uint16_t (*vhost_dequeue_burst_t)(struct vhost_dev *dev,
+ uint16_t queue_id, struct rte_mempool *mbuf_pool,
+ struct rte_mbuf **pkts, uint16_t count);
+
+struct vhost_queue_ops {
+ vhost_enqueue_burst_t enqueue_pkt_burst;
+ vhost_dequeue_burst_t dequeue_pkt_burst;
+};
+
TAILQ_HEAD(vhost_dev_tailq_list, vhost_dev);
@@ -88,6 +102,7 @@ struct dma_info {
struct dma_for_vhost {
struct dma_info dmas[RTE_MAX_QUEUES_PER_PORT * 2];
+ uint32_t async_flag;
};
/* we implement non-extra virtio net features */
@@ -98,7 +113,19 @@ void vs_vhost_net_remove(struct vhost_dev *dev);
uint16_t vs_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
struct rte_mbuf **pkts, uint32_t count);
-uint16_t vs_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
- struct rte_mempool *mbuf_pool,
- struct rte_mbuf **pkts, uint16_t count);
+uint16_t builtin_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t count);
+uint16_t builtin_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool,
+ struct rte_mbuf **pkts, uint16_t count);
+uint16_t sync_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t count);
+uint16_t sync_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool,
+ struct rte_mbuf **pkts, uint16_t count);
+uint16_t async_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t count);
+uint16_t async_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool,
+ struct rte_mbuf **pkts, uint16_t count);
#endif /* _MAIN_H_ */
diff --git a/examples/vhost/virtio_net.c b/examples/vhost/virtio_net.c
index 9064fc3a82..2432a96566 100644
--- a/examples/vhost/virtio_net.c
+++ b/examples/vhost/virtio_net.c
@@ -238,6 +238,13 @@ vs_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
return count;
}
+uint16_t
+builtin_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t count)
+{
+ return vs_enqueue_pkts(dev, queue_id, pkts, count);
+}
+
static __rte_always_inline int
dequeue_pkt(struct vhost_dev *dev, struct rte_vhost_vring *vr,
struct rte_mbuf *m, uint16_t desc_idx,
@@ -363,7 +370,7 @@ dequeue_pkt(struct vhost_dev *dev, struct rte_vhost_vring *vr,
return 0;
}
-uint16_t
+static uint16_t
vs_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
{
@@ -440,3 +447,10 @@ vs_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
return i;
}
+
+uint16_t
+builtin_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
+{
+ return vs_dequeue_pkts(dev, queue_id, mbuf_pool, pkts, count);
+}
--
2.17.1
^ permalink raw reply [flat|nested] 11+ messages in thread
* [RFC,v3 0/2] vhost: support async dequeue data path
2022-01-01 0:12 [RFC 0/2] vhost: support async dequeue data path xuan.ding
` (2 preceding siblings ...)
2022-02-24 11:03 ` [RFC,v2 0/2] vhost: " xuan.ding
@ 2022-03-10 6:54 ` xuan.ding
2022-03-10 6:54 ` [RFC,v3 1/2] vhost: support async dequeue for split ring xuan.ding
2022-03-10 6:54 ` [RFC,v3 2/2] examples/vhost: support async dequeue data path xuan.ding
3 siblings, 2 replies; 11+ messages in thread
From: xuan.ding @ 2022-03-10 6:54 UTC (permalink / raw)
To: maxime.coquelin, chenbo.xia
Cc: dev, jiayu.hu, cheng1.jiang, sunil.pai.g, liangma, Xuan Ding
From: Xuan Ding <xuan.ding@intel.com>
The presence of asynchronous path allows applications to offload
memory copies to DMA engine, so as to save CPU cycles and improve
the copy performance. This patch set is a draft implementation for
split ring in vhost async dequeue data path. The code is based on
latest enqueue changes [1].
This patch set is a new design and implementation of [2]. Since dmadev
was introduced in DPDK 21.11, to simplify application logics, this patch
integrates dmadev in vhost. With dmadev integrated, vhost supports M:N
mapping between vrings and DMA virtual channels. Specifically, one vring
can use multiple different DMA channels and one DMA channel can be
shared by multiple vrings at the same time.
A new asynchronous dequeue function is introduced:
1) rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id,
struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts,
uint16_t count, int *nr_inflight,
uint16_t dma_id, uint16_t vchan_id)
Receive packets from the guest and offloads copies to DMA
virtual channel.
[1] https://mails.dpdk.org/archives/dev/2022-February/234555.html
[2] https://mails.dpdk.org/archives/dev/2021-September/218591.html
RFC v2->v3:
* rebase to latest DPDK version
RFC v1 -> v2:
* fix one bug in example
* rename vchan to vchan_id
* check if dma_id and vchan_id valid
* rework all the logs to new standard
Xuan Ding (2):
vhost: support async dequeue for split ring
examples/vhost: support async dequeue data path
doc/guides/sample_app_ug/vhost.rst | 9 +-
examples/vhost/main.c | 292 +++++++++++------
examples/vhost/main.h | 35 +-
examples/vhost/virtio_net.c | 16 +-
lib/vhost/rte_vhost_async.h | 37 ++-
lib/vhost/version.map | 1 +
lib/vhost/vhost.h | 1 +
lib/vhost/virtio_net.c | 504 +++++++++++++++++++++++++++++
8 files changed, 795 insertions(+), 100 deletions(-)
--
2.17.1
^ permalink raw reply [flat|nested] 11+ messages in thread
* [RFC,v3 1/2] vhost: support async dequeue for split ring
2022-03-10 6:54 ` [RFC,v3 0/2] vhost: " xuan.ding
@ 2022-03-10 6:54 ` xuan.ding
2022-03-31 9:15 ` Maxime Coquelin
2022-03-10 6:54 ` [RFC,v3 2/2] examples/vhost: support async dequeue data path xuan.ding
1 sibling, 1 reply; 11+ messages in thread
From: xuan.ding @ 2022-03-10 6:54 UTC (permalink / raw)
To: maxime.coquelin, chenbo.xia
Cc: dev, jiayu.hu, cheng1.jiang, sunil.pai.g, liangma, Xuan Ding, Yuan Wang
From: Xuan Ding <xuan.ding@intel.com>
This patch implements asynchronous dequeue data path for vhost split
ring, with dmadev library integrated.
Signed-off-by: Xuan Ding <xuan.ding@intel.com>
Signed-off-by: Yuan Wang <yuanx.wang@intel.com>
---
lib/vhost/rte_vhost_async.h | 37 ++-
lib/vhost/version.map | 1 +
lib/vhost/vhost.h | 1 +
lib/vhost/virtio_net.c | 504 ++++++++++++++++++++++++++++++++++++
4 files changed, 541 insertions(+), 2 deletions(-)
diff --git a/lib/vhost/rte_vhost_async.h b/lib/vhost/rte_vhost_async.h
index f1293c6a9d..b6ab0b06a2 100644
--- a/lib/vhost/rte_vhost_async.h
+++ b/lib/vhost/rte_vhost_async.h
@@ -155,9 +155,9 @@ int rte_vhost_async_get_inflight(int vid, uint16_t queue_id);
* @param count
* Size of the packet array
* @param dma_id
- * the identifier of DMA device
+ * The identifier of DMA device
* @param vchan_id
- * the identifier of virtual DMA channel
+ * The identifier of virtual DMA channel
* @return
* Number of packets returned
*/
@@ -187,6 +187,39 @@ uint16_t rte_vhost_clear_queue_thread_unsafe(int vid, uint16_t queue_id,
__rte_experimental
int rte_vhost_async_dma_configure(int16_t dma_id, uint16_t vchan_id);
+/**
+ * This function tries to receive packets from the guest with offloading
+ * copies to the async channel. The packets that are transfer completed
+ * are returned in "pkts". The other packets that their copies are submitted to
+ * the async channel but not completed are called "in-flight packets".
+ * This function will not return in-flight packets until their copies are
+ * completed by the async channel.
+ *
+ * @param vid
+ * ID of vhost device to dequeue data
+ * @param queue_id
+ * ID of virtqueue to dequeue data
+ * @param mbuf_pool
+ * Mbuf_pool where host mbuf is allocated
+ * @param pkts
+ * Blank array to keep successfully dequeued packets
+ * @param count
+ * Size of the packet array
+ * @param nr_inflight
+ * The amount of in-flight packets. If error occurred, its value is set to -1.
+ * @param dma_id
+ * The identifier of DMA device
+ * @param vchan_id
+ * The identifier of virtual DMA channel
+ * @return
+ * Number of successfully dequeued packets
+ */
+__rte_experimental
+uint16_t
+rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count,
+ int *nr_inflight, uint16_t dma_id, uint16_t vchan_id);
+
#ifdef __cplusplus
}
#endif
diff --git a/lib/vhost/version.map b/lib/vhost/version.map
index 0a66c5840c..968d6d4290 100644
--- a/lib/vhost/version.map
+++ b/lib/vhost/version.map
@@ -87,6 +87,7 @@ EXPERIMENTAL {
# added in 22.03
rte_vhost_async_dma_configure;
+ rte_vhost_async_try_dequeue_burst;
};
INTERNAL {
diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
index a9edc271aa..3799d41089 100644
--- a/lib/vhost/vhost.h
+++ b/lib/vhost/vhost.h
@@ -178,6 +178,7 @@ extern struct async_dma_info dma_copy_track[RTE_DMADEV_DEFAULT_MAX];
*/
struct async_inflight_info {
struct rte_mbuf *mbuf;
+ struct virtio_net_hdr nethdr;
uint16_t descs; /* num of descs inflight */
uint16_t nr_buffers; /* num of buffers inflight for packed ring */
};
diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c
index 5f432b0d77..3816caca79 100644
--- a/lib/vhost/virtio_net.c
+++ b/lib/vhost/virtio_net.c
@@ -3141,3 +3141,507 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
return count;
}
+
+static __rte_always_inline int
+async_desc_to_mbuf_seg(struct virtio_net *dev, struct vhost_virtqueue *vq,
+ struct rte_mbuf *m, uint32_t mbuf_offset,
+ uint64_t buf_iova, uint32_t cpy_len)
+{
+ struct vhost_async *async = vq->async;
+ uint64_t mapped_len;
+ uint32_t buf_offset = 0;
+ void *host_iova;
+
+ while (cpy_len) {
+ host_iova = (void *)(uintptr_t)gpa_to_first_hpa(dev,
+ buf_iova + buf_offset, cpy_len,
+ &mapped_len);
+ if (unlikely(!host_iova)) {
+ VHOST_LOG_DATA(ERR, "(%s) %s: failed to get host_iova.\n",
+ dev->ifname, __func__);
+ return -1;
+ }
+
+ if (unlikely(async_iter_add_iovec(dev, async, host_iova,
+ (void *)(uintptr_t)rte_pktmbuf_iova_offset(m, mbuf_offset),
+ (size_t)mapped_len)))
+ return -1;
+
+ cpy_len -= (uint32_t)mapped_len;
+ mbuf_offset += (uint32_t)mapped_len;
+ buf_offset += (uint32_t)mapped_len;
+ }
+
+ return 0;
+}
+
+static __rte_always_inline int
+async_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
+ struct buf_vector *buf_vec, uint16_t nr_vec,
+ struct rte_mbuf *m, struct rte_mempool *mbuf_pool,
+ struct virtio_net_hdr *nethdr)
+{
+ uint64_t buf_addr, buf_iova;
+ uint32_t buf_avail, buf_offset, buf_len;
+ uint32_t mbuf_avail, mbuf_offset;
+ uint32_t cpy_len;
+ /* A counter to avoid desc dead loop chain */
+ uint16_t vec_idx = 0;
+ struct rte_mbuf *cur = m, *prev = m;
+ struct virtio_net_hdr tmp_hdr;
+ struct virtio_net_hdr *hdr = NULL;
+ struct vhost_async *async = vq->async;
+
+ buf_addr = buf_vec[vec_idx].buf_addr;
+ buf_len = buf_vec[vec_idx].buf_len;
+ buf_iova = buf_vec[vec_idx].buf_iova;
+
+ if (unlikely(buf_len < dev->vhost_hlen && nr_vec <= 1))
+ return -1;
+
+ if (virtio_net_with_host_offload(dev)) {
+ if (unlikely(buf_len < sizeof(struct virtio_net_hdr))) {
+ /*
+ * No luck, the virtio-net header doesn't fit
+ * in a contiguous virtual area.
+ */
+ copy_vnet_hdr_from_desc(&tmp_hdr, buf_vec);
+ hdr = &tmp_hdr;
+ } else {
+ hdr = (struct virtio_net_hdr *)((uintptr_t)buf_addr);
+ }
+ }
+
+ /*
+ * A virtio driver normally uses at least 2 desc buffers
+ * for Tx: the first for storing the header, and others
+ * for storing the data.
+ */
+ if (unlikely(buf_len < dev->vhost_hlen)) {
+ buf_offset = dev->vhost_hlen - buf_len;
+ vec_idx++;
+ buf_addr = buf_vec[vec_idx].buf_addr;
+ buf_iova = buf_vec[vec_idx].buf_iova;
+ buf_len = buf_vec[vec_idx].buf_len;
+ buf_avail = buf_len - buf_offset;
+ } else if (buf_len == dev->vhost_hlen) {
+ if (unlikely(++vec_idx >= nr_vec))
+ return -1;
+ buf_addr = buf_vec[vec_idx].buf_addr;
+ buf_iova = buf_vec[vec_idx].buf_iova;
+ buf_len = buf_vec[vec_idx].buf_len;
+
+ buf_offset = 0;
+ buf_avail = buf_len;
+ } else {
+ buf_offset = dev->vhost_hlen;
+ buf_avail = buf_vec[vec_idx].buf_len - dev->vhost_hlen;
+ }
+
+ PRINT_PACKET(dev, (uintptr_t)(buf_addr + buf_offset), (uint32_t)buf_avail, 0);
+
+ mbuf_offset = 0;
+ mbuf_avail = m->buf_len - RTE_PKTMBUF_HEADROOM;
+
+ if (async_iter_initialize(dev, async))
+ return -1;
+
+ while (1) {
+ cpy_len = RTE_MIN(buf_avail, mbuf_avail);
+
+ if (async_desc_to_mbuf_seg(dev, vq, cur, mbuf_offset, buf_iova + buf_offset,
+ cpy_len) < 0)
+ goto error;
+
+ mbuf_avail -= cpy_len;
+ buf_avail -= cpy_len;
+ mbuf_offset += cpy_len;
+ buf_offset += cpy_len;
+
+ /* This buf reaches to its end, get the next one */
+ if (buf_avail == 0) {
+ if (++vec_idx >= nr_vec)
+ break;
+
+ buf_addr = buf_vec[vec_idx].buf_addr;
+ buf_iova = buf_vec[vec_idx].buf_iova;
+ buf_len = buf_vec[vec_idx].buf_len;
+
+ buf_offset = 0;
+ buf_avail = buf_len;
+
+ PRINT_PACKET(dev, (uintptr_t)buf_addr, (uint32_t)buf_avail, 0);
+ }
+
+ /*
+ * This mbuf reaches to its end, get a new one
+ * to hold more data.
+ */
+ if (mbuf_avail == 0) {
+ cur = rte_pktmbuf_alloc(mbuf_pool);
+ if (unlikely(cur == NULL)) {
+ VHOST_LOG_DATA(ERR,
+ "(%s) %s: failed to allocate memory for mbuf.\n",
+ dev->ifname, __func__);
+ goto error;
+ }
+
+ prev->next = cur;
+ prev->data_len = mbuf_offset;
+ m->nb_segs += 1;
+ m->pkt_len += mbuf_offset;
+ prev = cur;
+
+ mbuf_offset = 0;
+ mbuf_avail = cur->buf_len - RTE_PKTMBUF_HEADROOM;
+ }
+ }
+
+ prev->data_len = mbuf_offset;
+ m->pkt_len += mbuf_offset;
+
+ async_iter_finalize(async);
+ if (hdr)
+ *nethdr = *hdr;
+
+ return 0;
+
+error:
+ async_iter_cancel(async);
+ return -1;
+}
+
+static __rte_always_inline uint16_t
+async_poll_dequeue_completed_split(struct virtio_net *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint16_t count, uint16_t dma_id,
+ uint16_t vchan_id, bool legacy_ol_flags)
+{
+ uint16_t start_idx, from, i;
+ uint16_t nr_cpl_pkts = 0;
+ struct async_inflight_info *pkts_info;
+ struct vhost_virtqueue *vq = dev->virtqueue[queue_id];
+
+ pkts_info = vq->async->pkts_info;
+
+ vhost_async_dma_check_completed(dev, dma_id, vchan_id, VHOST_DMA_MAX_COPY_COMPLETE);
+
+ start_idx = async_get_first_inflight_pkt_idx(vq);
+
+ from = start_idx;
+ while (vq->async->pkts_cmpl_flag[from] && count--) {
+ vq->async->pkts_cmpl_flag[from] = false;
+ from = (from + 1) & (vq->size - 1);
+ nr_cpl_pkts++;
+ }
+
+ if (nr_cpl_pkts == 0)
+ return 0;
+
+ for (i = 0; i < nr_cpl_pkts; i++) {
+ from = (start_idx + i) & (vq->size - 1);
+ pkts[i] = pkts_info[from].mbuf;
+
+ if (virtio_net_with_host_offload(dev))
+ vhost_dequeue_offload(dev, &pkts_info[from].nethdr, pkts[i],
+ legacy_ol_flags);
+ }
+
+ /* write back completed descs to used ring and update used idx */
+ write_back_completed_descs_split(vq, nr_cpl_pkts);
+ __atomic_add_fetch(&vq->used->idx, nr_cpl_pkts, __ATOMIC_RELEASE);
+ vhost_vring_call_split(dev, vq);
+
+ vq->async->pkts_inflight_n -= nr_cpl_pkts;
+
+ return nr_cpl_pkts;
+}
+
+static __rte_always_inline uint16_t
+virtio_dev_tx_async_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
+ uint16_t queue_id, struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts,
+ uint16_t count, uint16_t dma_id, uint16_t vchan_id, bool legacy_ol_flags)
+{
+ static bool allocerr_warned;
+ bool dropped = false;
+ uint16_t free_entries;
+ uint16_t pkt_idx, slot_idx = 0;
+ uint16_t nr_done_pkts = 0;
+ uint16_t pkt_err = 0;
+ uint16_t n_xfer;
+ struct vhost_async *async = vq->async;
+ struct async_inflight_info *pkts_info = async->pkts_info;
+ struct rte_mbuf *pkts_prealloc[MAX_PKT_BURST];
+ uint16_t pkts_size = count;
+
+ /**
+ * The ordering between avail index and
+ * desc reads needs to be enforced.
+ */
+ free_entries = __atomic_load_n(&vq->avail->idx, __ATOMIC_ACQUIRE) - vq->last_avail_idx;
+ if (free_entries == 0)
+ goto out;
+
+ rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
+
+ async_iter_reset(async);
+
+ count = RTE_MIN(count, MAX_PKT_BURST);
+ count = RTE_MIN(count, free_entries);
+ VHOST_LOG_DATA(DEBUG, "(%s) about to dequeue %u buffers\n", dev->ifname, count);
+
+ if (rte_pktmbuf_alloc_bulk(mbuf_pool, pkts_prealloc, count))
+ goto out;
+
+ for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
+ uint16_t head_idx = 0;
+ uint16_t nr_vec = 0;
+ uint16_t to;
+ uint32_t buf_len;
+ int err;
+ struct buf_vector buf_vec[BUF_VECTOR_MAX];
+ struct rte_mbuf *pkt = pkts_prealloc[pkt_idx];
+
+ if (unlikely(fill_vec_buf_split(dev, vq, vq->last_avail_idx,
+ &nr_vec, buf_vec,
+ &head_idx, &buf_len,
+ VHOST_ACCESS_RO) < 0)) {
+ dropped = true;
+ break;
+ }
+
+ err = virtio_dev_pktmbuf_prep(dev, pkt, buf_len);
+ if (unlikely(err)) {
+ /**
+ * mbuf allocation fails for jumbo packets when external
+ * buffer allocation is not allowed and linear buffer
+ * is required. Drop this packet.
+ */
+ if (!allocerr_warned) {
+ VHOST_LOG_DATA(ERR,
+ "(%s) %s: Failed mbuf alloc of size %d from %s\n",
+ dev->ifname, __func__, buf_len, mbuf_pool->name);
+ allocerr_warned = true;
+ }
+ dropped = true;
+ break;
+ }
+
+ slot_idx = (async->pkts_idx + pkt_idx) & (vq->size - 1);
+ err = async_desc_to_mbuf(dev, vq, buf_vec, nr_vec, pkt, mbuf_pool,
+ &pkts_info[slot_idx].nethdr);
+ if (unlikely(err)) {
+ if (!allocerr_warned) {
+ VHOST_LOG_DATA(ERR,
+ "(%s) %s: Failed to offload copies to async channel.\n",
+ dev->ifname, __func__);
+ allocerr_warned = true;
+ }
+ dropped = true;
+ break;
+ }
+
+ pkts_info[slot_idx].mbuf = pkt;
+
+ /* store used descs */
+ to = async->desc_idx_split & (vq->size - 1);
+ async->descs_split[to].id = head_idx;
+ async->descs_split[to].len = 0;
+ async->desc_idx_split++;
+
+ vq->last_avail_idx++;
+ }
+
+ if (unlikely(dropped))
+ rte_pktmbuf_free_bulk(&pkts_prealloc[pkt_idx], count - pkt_idx);
+
+ n_xfer = vhost_async_dma_transfer(dev, vq, dma_id, vchan_id, async->pkts_idx,
+ async->iov_iter, pkt_idx);
+
+ async->pkts_inflight_n += n_xfer;
+
+ pkt_err = pkt_idx - n_xfer;
+ if (unlikely(pkt_err)) {
+ VHOST_LOG_DATA(DEBUG,
+ "(%s) %s: failed to transfer data for queue id %d.\n",
+ dev->ifname, __func__, queue_id);
+
+ pkt_idx = n_xfer;
+ /* recover available ring */
+ vq->last_avail_idx -= pkt_err;
+
+ /**
+ * recover async channel copy related structures and free pktmbufs
+ * for error pkts.
+ */
+ async->desc_idx_split -= pkt_err;
+ while (pkt_err-- > 0) {
+ rte_pktmbuf_free(pkts_info[slot_idx & (vq->size - 1)].mbuf);
+ slot_idx--;
+ }
+ }
+
+ async->pkts_idx += pkt_idx;
+ if (async->pkts_idx >= vq->size)
+ async->pkts_idx -= vq->size;
+
+out:
+ /* DMA device may serve other queues, unconditionally check completed. */
+ nr_done_pkts = async_poll_dequeue_completed_split(dev, queue_id, pkts, pkts_size,
+ dma_id, vchan_id, legacy_ol_flags);
+
+ return nr_done_pkts;
+}
+
+__rte_noinline
+static uint16_t
+virtio_dev_tx_async_split_legacy(struct virtio_net *dev,
+ struct vhost_virtqueue *vq, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts,
+ uint16_t count, uint16_t dma_id, uint16_t vchan_id)
+{
+ return virtio_dev_tx_async_split(dev, vq, queue_id, mbuf_pool,
+ pkts, count, dma_id, vchan_id, true);
+}
+
+__rte_noinline
+static uint16_t
+virtio_dev_tx_async_split_compliant(struct virtio_net *dev,
+ struct vhost_virtqueue *vq, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts,
+ uint16_t count, uint16_t dma_id, uint16_t vchan_id)
+{
+ return virtio_dev_tx_async_split(dev, vq, queue_id, mbuf_pool,
+ pkts, count, dma_id, vchan_id, false);
+}
+
+uint16_t
+rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count,
+ int *nr_inflight, uint16_t dma_id, uint16_t vchan_id)
+{
+ struct virtio_net *dev;
+ struct rte_mbuf *rarp_mbuf = NULL;
+ struct vhost_virtqueue *vq;
+ int16_t success = 1;
+
+ *nr_inflight = -1;
+
+ dev = get_device(vid);
+ if (!dev)
+ return 0;
+
+ if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) {
+ VHOST_LOG_DATA(ERR,
+ "(%s) %s: built-in vhost net backend is disabled.\n",
+ dev->ifname, __func__);
+ return 0;
+ }
+
+ if (unlikely(!is_valid_virt_queue_idx(queue_id, 1, dev->nr_vring))) {
+ VHOST_LOG_DATA(ERR,
+ "(%s) %s: invalid virtqueue idx %d.\n",
+ dev->ifname, __func__, queue_id);
+ return 0;
+ }
+
+ if (unlikely(!dma_copy_track[dma_id].vchans ||
+ !dma_copy_track[dma_id].vchans[vchan_id].pkts_cmpl_flag_addr)) {
+ VHOST_LOG_DATA(ERR, "(%s) %s: invalid channel %d:%u.\n", dev->ifname, __func__,
+ dma_id, vchan_id);
+ return 0;
+ }
+
+ vq = dev->virtqueue[queue_id];
+
+ if (unlikely(rte_spinlock_trylock(&vq->access_lock) == 0))
+ return 0;
+
+ if (unlikely(vq->enabled == 0)) {
+ count = 0;
+ goto out_access_unlock;
+ }
+
+ if (unlikely(!vq->async)) {
+ VHOST_LOG_DATA(ERR, "(%s) %s: async not registered for queue id %d.\n",
+ dev->ifname, __func__, queue_id);
+ count = 0;
+ goto out_access_unlock;
+ }
+
+ if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
+ vhost_user_iotlb_rd_lock(vq);
+
+ if (unlikely(vq->access_ok == 0))
+ if (unlikely(vring_translate(dev, vq) < 0)) {
+ count = 0;
+ goto out;
+ }
+
+ /*
+ * Construct a RARP broadcast packet, and inject it to the "pkts"
+ * array, to looks like that guest actually send such packet.
+ *
+ * Check user_send_rarp() for more information.
+ *
+ * broadcast_rarp shares a cacheline in the virtio_net structure
+ * with some fields that are accessed during enqueue and
+ * __atomic_compare_exchange_n causes a write if performed compare
+ * and exchange. This could result in false sharing between enqueue
+ * and dequeue.
+ *
+ * Prevent unnecessary false sharing by reading broadcast_rarp first
+ * and only performing compare and exchange if the read indicates it
+ * is likely to be set.
+ */
+ if (unlikely(__atomic_load_n(&dev->broadcast_rarp, __ATOMIC_ACQUIRE) &&
+ __atomic_compare_exchange_n(&dev->broadcast_rarp,
+ &success, 0, 0, __ATOMIC_RELEASE, __ATOMIC_RELAXED))) {
+
+ rarp_mbuf = rte_net_make_rarp_packet(mbuf_pool, &dev->mac);
+ if (rarp_mbuf == NULL) {
+ VHOST_LOG_DATA(ERR, "Failed to make RARP packet.\n");
+ count = 0;
+ goto out;
+ }
+ /*
+ * Inject it to the head of "pkts" array, so that switch's mac
+ * learning table will get updated first.
+ */
+ pkts[0] = rarp_mbuf;
+ pkts++;
+ count -= 1;
+ }
+
+ if (unlikely(vq_is_packed(dev))) {
+ static bool not_support_pack_log;
+ if (!not_support_pack_log) {
+ VHOST_LOG_DATA(ERR,
+ "(%s) %s: async dequeue does not support packed ring.\n",
+ dev->ifname, __func__);
+ not_support_pack_log = true;
+ }
+ count = 0;
+ goto out;
+ }
+
+ if (dev->flags & VIRTIO_DEV_LEGACY_OL_FLAGS)
+ count = virtio_dev_tx_async_split_legacy(dev, vq, queue_id,
+ mbuf_pool, pkts, count, dma_id, vchan_id);
+ else
+ count = virtio_dev_tx_async_split_compliant(dev, vq, queue_id,
+ mbuf_pool, pkts, count, dma_id, vchan_id);
+
+ *nr_inflight = vq->async->pkts_inflight_n;
+
+out:
+ if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
+ vhost_user_iotlb_rd_unlock(vq);
+
+out_access_unlock:
+ rte_spinlock_unlock(&vq->access_lock);
+
+ if (unlikely(rarp_mbuf != NULL))
+ count += 1;
+
+ return count;
+}
--
2.17.1
^ permalink raw reply [flat|nested] 11+ messages in thread
* [RFC,v3 2/2] examples/vhost: support async dequeue data path
2022-03-10 6:54 ` [RFC,v3 0/2] vhost: " xuan.ding
2022-03-10 6:54 ` [RFC,v3 1/2] vhost: support async dequeue for split ring xuan.ding
@ 2022-03-10 6:54 ` xuan.ding
1 sibling, 0 replies; 11+ messages in thread
From: xuan.ding @ 2022-03-10 6:54 UTC (permalink / raw)
To: maxime.coquelin, chenbo.xia
Cc: dev, jiayu.hu, cheng1.jiang, sunil.pai.g, liangma, Xuan Ding,
Wenwu Ma, Yuan Wang
From: Xuan Ding <xuan.ding@intel.com>
This patch adds the use case for async dequeue API. Vswitch can
leverage DMA device to accelerate vhost async dequeue path.
Signed-off-by: Wenwu Ma <wenwux.ma@intel.com>
Signed-off-by: Yuan Wang <yuan.wangx@intel.com>
Signed-off-by: Xuan Ding <xuan.ding@intel.com>
---
doc/guides/sample_app_ug/vhost.rst | 9 +-
examples/vhost/main.c | 292 ++++++++++++++++++++---------
examples/vhost/main.h | 35 +++-
examples/vhost/virtio_net.c | 16 +-
4 files changed, 254 insertions(+), 98 deletions(-)
diff --git a/doc/guides/sample_app_ug/vhost.rst b/doc/guides/sample_app_ug/vhost.rst
index a6ce4bc8ac..09db965e70 100644
--- a/doc/guides/sample_app_ug/vhost.rst
+++ b/doc/guides/sample_app_ug/vhost.rst
@@ -169,9 +169,12 @@ demonstrates how to use the async vhost APIs. It's used in combination with dmas
**--dmas**
This parameter is used to specify the assigned DMA device of a vhost device.
Async vhost-user net driver will be used if --dmas is set. For example
---dmas [txd0@00:04.0,txd1@00:04.1] means use DMA channel 00:04.0 for vhost
-device 0 enqueue operation and use DMA channel 00:04.1 for vhost device 1
-enqueue operation.
+--dmas [txd0@00:04.0,txd1@00:04.1,rxd0@00:04.2,rxd1@00:04.3] means use
+DMA channel 00:04.0/00:04.2 for vhost device 0 enqueue/dequeue operation
+and use DMA channel 00:04.1/00:04.3 for vhost device 1 enqueue/dequeue
+operation. The index of the device corresponds to the socket file in order,
+that means vhost device 0 is created through the first socket file, vhost
+device 1 is created through the second socket file, and so on.
Common Issues
-------------
diff --git a/examples/vhost/main.c b/examples/vhost/main.c
index d94fabb060..d26e40ab73 100644
--- a/examples/vhost/main.c
+++ b/examples/vhost/main.c
@@ -63,6 +63,9 @@
#define DMA_RING_SIZE 4096
+#define ASYNC_ENQUEUE_VHOST 1
+#define ASYNC_DEQUEUE_VHOST 2
+
/* number of mbufs in all pools - if specified on command-line. */
static int total_num_mbufs = NUM_MBUFS_DEFAULT;
@@ -116,6 +119,8 @@ static uint32_t burst_rx_retry_num = BURST_RX_RETRIES;
static char *socket_files;
static int nb_sockets;
+static struct vhost_queue_ops vdev_queue_ops[RTE_MAX_VHOST_DEVICE];
+
/* empty VMDq configuration structure. Filled in programmatically */
static struct rte_eth_conf vmdq_conf_default = {
.rxmode = {
@@ -205,6 +210,18 @@ struct vhost_bufftable *vhost_txbuff[RTE_MAX_LCORE * RTE_MAX_VHOST_DEVICE];
#define MBUF_TABLE_DRAIN_TSC ((rte_get_tsc_hz() + US_PER_S - 1) \
/ US_PER_S * BURST_TX_DRAIN_US)
+static int vid2socketid[RTE_MAX_VHOST_DEVICE];
+
+static uint32_t get_async_flag_by_socketid(int socketid)
+{
+ return dma_bind[socketid].async_flag;
+}
+
+static void init_vid2socketid_array(int vid, int socketid)
+{
+ vid2socketid[vid] = socketid;
+}
+
static inline bool
is_dma_configured(int16_t dev_id)
{
@@ -224,7 +241,7 @@ open_dma(const char *value)
char *addrs = input;
char *ptrs[2];
char *start, *end, *substr;
- int64_t vid;
+ int64_t socketid, vring_id;
struct rte_dma_info info;
struct rte_dma_conf dev_config = { .nb_vchans = 1 };
@@ -262,7 +279,9 @@ open_dma(const char *value)
while (i < args_nr) {
char *arg_temp = dma_arg[i];
+ char *txd, *rxd;
uint8_t sub_nr;
+ int async_flag;
sub_nr = rte_strsplit(arg_temp, strlen(arg_temp), ptrs, 2, '@');
if (sub_nr != 2) {
@@ -270,14 +289,23 @@ open_dma(const char *value)
goto out;
}
- start = strstr(ptrs[0], "txd");
- if (start == NULL) {
+ txd = strstr(ptrs[0], "txd");
+ rxd = strstr(ptrs[0], "rxd");
+ if (txd) {
+ start = txd;
+ vring_id = VIRTIO_RXQ;
+ async_flag = ASYNC_ENQUEUE_VHOST;
+ } else if (rxd) {
+ start = rxd;
+ vring_id = VIRTIO_TXQ;
+ async_flag = ASYNC_DEQUEUE_VHOST;
+ } else {
ret = -1;
goto out;
}
start += 3;
- vid = strtol(start, &end, 0);
+ socketid = strtol(start, &end, 0);
if (end == start) {
ret = -1;
goto out;
@@ -338,7 +366,8 @@ open_dma(const char *value)
dmas_id[dma_count++] = dev_id;
done:
- (dma_info + vid)->dmas[VIRTIO_RXQ].dev_id = dev_id;
+ (dma_info + socketid)->dmas[vring_id].dev_id = dev_id;
+ (dma_info + socketid)->async_flag |= async_flag;
i++;
}
out:
@@ -990,13 +1019,13 @@ complete_async_pkts(struct vhost_dev *vdev)
{
struct rte_mbuf *p_cpl[MAX_PKT_BURST];
uint16_t complete_count;
- int16_t dma_id = dma_bind[vdev->vid].dmas[VIRTIO_RXQ].dev_id;
+ int16_t dma_id = dma_bind[vid2socketid[vdev->vid]].dmas[VIRTIO_RXQ].dev_id;
complete_count = rte_vhost_poll_enqueue_completed(vdev->vid,
VIRTIO_RXQ, p_cpl, MAX_PKT_BURST, dma_id, 0);
if (complete_count) {
free_pkts(p_cpl, complete_count);
- __atomic_sub_fetch(&vdev->pkts_inflight, complete_count, __ATOMIC_SEQ_CST);
+ __atomic_sub_fetch(&vdev->pkts_enq_inflight, complete_count, __ATOMIC_SEQ_CST);
}
}
@@ -1031,23 +1060,7 @@ drain_vhost(struct vhost_dev *vdev)
uint16_t nr_xmit = vhost_txbuff[buff_idx]->len;
struct rte_mbuf **m = vhost_txbuff[buff_idx]->m_table;
- if (builtin_net_driver) {
- ret = vs_enqueue_pkts(vdev, VIRTIO_RXQ, m, nr_xmit);
- } else if (dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled) {
- uint16_t enqueue_fail = 0;
- int16_t dma_id = dma_bind[vdev->vid].dmas[VIRTIO_RXQ].dev_id;
-
- complete_async_pkts(vdev);
- ret = rte_vhost_submit_enqueue_burst(vdev->vid, VIRTIO_RXQ, m, nr_xmit, dma_id, 0);
- __atomic_add_fetch(&vdev->pkts_inflight, ret, __ATOMIC_SEQ_CST);
-
- enqueue_fail = nr_xmit - ret;
- if (enqueue_fail)
- free_pkts(&m[ret], nr_xmit - ret);
- } else {
- ret = rte_vhost_enqueue_burst(vdev->vid, VIRTIO_RXQ,
- m, nr_xmit);
- }
+ ret = vdev_queue_ops[vdev->vid].enqueue_pkt_burst(vdev, VIRTIO_RXQ, m, nr_xmit);
if (enable_stats) {
__atomic_add_fetch(&vdev->stats.rx_total_atomic, nr_xmit,
@@ -1056,7 +1069,7 @@ drain_vhost(struct vhost_dev *vdev)
__ATOMIC_SEQ_CST);
}
- if (!dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled)
+ if (!dma_bind[vid2socketid[vdev->vid]].dmas[VIRTIO_RXQ].async_enabled)
free_pkts(m, nr_xmit);
}
@@ -1328,6 +1341,33 @@ drain_mbuf_table(struct mbuf_table *tx_q)
}
}
+uint16_t
+async_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t rx_count)
+{
+ uint16_t enqueue_count;
+ uint16_t enqueue_fail = 0;
+ uint16_t dma_id = dma_bind[vid2socketid[dev->vid]].dmas[VIRTIO_RXQ].dev_id;
+
+ complete_async_pkts(dev);
+ enqueue_count = rte_vhost_submit_enqueue_burst(dev->vid, queue_id,
+ pkts, rx_count, dma_id, 0);
+ __atomic_add_fetch(&dev->pkts_enq_inflight, enqueue_count, __ATOMIC_SEQ_CST);
+
+ enqueue_fail = rx_count - enqueue_count;
+ if (enqueue_fail)
+ free_pkts(&pkts[enqueue_count], enqueue_fail);
+
+ return enqueue_count;
+}
+
+uint16_t
+sync_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t rx_count)
+{
+ return rte_vhost_enqueue_burst(dev->vid, queue_id, pkts, rx_count);
+}
+
static __rte_always_inline void
drain_eth_rx(struct vhost_dev *vdev)
{
@@ -1358,26 +1398,8 @@ drain_eth_rx(struct vhost_dev *vdev)
}
}
- if (builtin_net_driver) {
- enqueue_count = vs_enqueue_pkts(vdev, VIRTIO_RXQ,
- pkts, rx_count);
- } else if (dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled) {
- uint16_t enqueue_fail = 0;
- int16_t dma_id = dma_bind[vdev->vid].dmas[VIRTIO_RXQ].dev_id;
-
- complete_async_pkts(vdev);
- enqueue_count = rte_vhost_submit_enqueue_burst(vdev->vid,
- VIRTIO_RXQ, pkts, rx_count, dma_id, 0);
- __atomic_add_fetch(&vdev->pkts_inflight, enqueue_count, __ATOMIC_SEQ_CST);
-
- enqueue_fail = rx_count - enqueue_count;
- if (enqueue_fail)
- free_pkts(&pkts[enqueue_count], enqueue_fail);
-
- } else {
- enqueue_count = rte_vhost_enqueue_burst(vdev->vid, VIRTIO_RXQ,
- pkts, rx_count);
- }
+ enqueue_count = vdev_queue_ops[vdev->vid].enqueue_pkt_burst(vdev,
+ VIRTIO_RXQ, pkts, rx_count);
if (enable_stats) {
__atomic_add_fetch(&vdev->stats.rx_total_atomic, rx_count,
@@ -1386,10 +1408,33 @@ drain_eth_rx(struct vhost_dev *vdev)
__ATOMIC_SEQ_CST);
}
- if (!dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled)
+ if (!dma_bind[vid2socketid[vdev->vid]].dmas[VIRTIO_RXQ].async_enabled)
free_pkts(pkts, rx_count);
}
+uint16_t async_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool,
+ struct rte_mbuf **pkts, uint16_t count)
+{
+ int nr_inflight;
+ uint16_t dequeue_count;
+ uint16_t dma_id = dma_bind[vid2socketid[dev->vid]].dmas[VIRTIO_TXQ].dev_id;
+
+ dequeue_count = rte_vhost_async_try_dequeue_burst(dev->vid, queue_id,
+ mbuf_pool, pkts, count, &nr_inflight, dma_id, 0);
+ if (likely(nr_inflight != -1))
+ dev->pkts_deq_inflight = nr_inflight;
+
+ return dequeue_count;
+}
+
+uint16_t sync_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool,
+ struct rte_mbuf **pkts, uint16_t count)
+{
+ return rte_vhost_dequeue_burst(dev->vid, queue_id, mbuf_pool, pkts, count);
+}
+
static __rte_always_inline void
drain_virtio_tx(struct vhost_dev *vdev)
{
@@ -1397,13 +1442,8 @@ drain_virtio_tx(struct vhost_dev *vdev)
uint16_t count;
uint16_t i;
- if (builtin_net_driver) {
- count = vs_dequeue_pkts(vdev, VIRTIO_TXQ, mbuf_pool,
- pkts, MAX_PKT_BURST);
- } else {
- count = rte_vhost_dequeue_burst(vdev->vid, VIRTIO_TXQ,
- mbuf_pool, pkts, MAX_PKT_BURST);
- }
+ count = vdev_queue_ops[vdev->vid].dequeue_pkt_burst(vdev,
+ VIRTIO_TXQ, mbuf_pool, pkts, MAX_PKT_BURST);
/* setup VMDq for the first packet */
if (unlikely(vdev->ready == DEVICE_MAC_LEARNING) && count) {
@@ -1482,6 +1522,31 @@ switch_worker(void *arg __rte_unused)
return 0;
}
+static void
+vhost_clear_queue_thread_unsafe(struct vhost_dev *vdev, uint16_t queue_id)
+{
+ uint16_t n_pkt = 0;
+ uint16_t dma_id = dma_bind[vid2socketid[vdev->vid]].dmas[queue_id].dev_id;
+ struct rte_mbuf *m_enq_cpl[vdev->pkts_enq_inflight];
+ struct rte_mbuf *m_deq_cpl[vdev->pkts_deq_inflight];
+
+ if (queue_id % 2 == 0) {
+ while (vdev->pkts_enq_inflight) {
+ n_pkt = rte_vhost_clear_queue_thread_unsafe(vdev->vid,
+ queue_id, m_enq_cpl, vdev->pkts_enq_inflight, dma_id, 0);
+ free_pkts(m_enq_cpl, n_pkt);
+ __atomic_sub_fetch(&vdev->pkts_enq_inflight, n_pkt, __ATOMIC_SEQ_CST);
+ }
+ } else {
+ while (vdev->pkts_deq_inflight) {
+ n_pkt = rte_vhost_clear_queue_thread_unsafe(vdev->vid,
+ queue_id, m_deq_cpl, vdev->pkts_deq_inflight, dma_id, 0);
+ free_pkts(m_deq_cpl, n_pkt);
+ __atomic_sub_fetch(&vdev->pkts_deq_inflight, n_pkt, __ATOMIC_SEQ_CST);
+ }
+ }
+}
+
/*
* Remove a device from the specific data core linked list and from the
* main linked list. Synchronization occurs through the use of the
@@ -1538,25 +1603,78 @@ destroy_device(int vid)
"(%d) device has been removed from data core\n",
vdev->vid);
- if (dma_bind[vid].dmas[VIRTIO_RXQ].async_enabled) {
- uint16_t n_pkt = 0;
- int16_t dma_id = dma_bind[vid].dmas[VIRTIO_RXQ].dev_id;
- struct rte_mbuf *m_cpl[vdev->pkts_inflight];
-
- while (vdev->pkts_inflight) {
- n_pkt = rte_vhost_clear_queue_thread_unsafe(vid, VIRTIO_RXQ,
- m_cpl, vdev->pkts_inflight, dma_id, 0);
- free_pkts(m_cpl, n_pkt);
- __atomic_sub_fetch(&vdev->pkts_inflight, n_pkt, __ATOMIC_SEQ_CST);
- }
-
+ if (dma_bind[vid2socketid[vid]].dmas[VIRTIO_RXQ].async_enabled) {
+ vhost_clear_queue_thread_unsafe(vdev, VIRTIO_RXQ);
rte_vhost_async_channel_unregister(vid, VIRTIO_RXQ);
- dma_bind[vid].dmas[VIRTIO_RXQ].async_enabled = false;
+ dma_bind[vid2socketid[vid]].dmas[VIRTIO_RXQ].async_enabled = false;
+ }
+ if (dma_bind[vid2socketid[vid]].dmas[VIRTIO_TXQ].async_enabled) {
+ vhost_clear_queue_thread_unsafe(vdev, VIRTIO_TXQ);
+ rte_vhost_async_channel_unregister(vid, VIRTIO_TXQ);
+ dma_bind[vid2socketid[vid]].dmas[VIRTIO_TXQ].async_enabled = false;
}
rte_free(vdev);
}
+static int
+get_socketid_by_vid(int vid)
+{
+ int i;
+ char ifname[PATH_MAX];
+ rte_vhost_get_ifname(vid, ifname, sizeof(ifname));
+
+ for (i = 0; i < nb_sockets; i++) {
+ char *file = socket_files + i * PATH_MAX;
+ if (strcmp(file, ifname) == 0)
+ return i;
+ }
+
+ return -1;
+}
+
+static int
+init_vhost_queue_ops(int vid)
+{
+ if (builtin_net_driver) {
+ vdev_queue_ops[vid].enqueue_pkt_burst = builtin_enqueue_pkts;
+ vdev_queue_ops[vid].dequeue_pkt_burst = builtin_dequeue_pkts;
+ } else {
+ if (dma_bind[vid2socketid[vid]].dmas[VIRTIO_RXQ].async_enabled)
+ vdev_queue_ops[vid].enqueue_pkt_burst = async_enqueue_pkts;
+ else
+ vdev_queue_ops[vid].enqueue_pkt_burst = sync_enqueue_pkts;
+
+ if (dma_bind[vid2socketid[vid]].dmas[VIRTIO_TXQ].async_enabled)
+ vdev_queue_ops[vid].dequeue_pkt_burst = async_dequeue_pkts;
+ else
+ vdev_queue_ops[vid].dequeue_pkt_burst = sync_dequeue_pkts;
+ }
+
+ return 0;
+}
+
+static int
+vhost_async_channel_register(int vid)
+{
+ int rx_ret = 0, tx_ret = 0;
+
+ if (dma_bind[vid2socketid[vid]].dmas[VIRTIO_RXQ].dev_id != INVALID_DMA_ID) {
+ rx_ret = rte_vhost_async_channel_register(vid, VIRTIO_RXQ);
+ if (rx_ret == 0)
+ dma_bind[vid2socketid[vid]].dmas[VIRTIO_RXQ].async_enabled = true;
+ }
+
+ if (dma_bind[vid2socketid[vid]].dmas[VIRTIO_TXQ].dev_id != INVALID_DMA_ID) {
+ tx_ret = rte_vhost_async_channel_register(vid, VIRTIO_TXQ);
+ if (tx_ret == 0)
+ dma_bind[vid2socketid[vid]].dmas[VIRTIO_TXQ].async_enabled = true;
+ }
+
+ return rx_ret | tx_ret;
+}
+
+
/*
* A new device is added to a data core. First the device is added to the main linked list
* and then allocated to a specific data core.
@@ -1568,6 +1686,8 @@ new_device(int vid)
uint16_t i;
uint32_t device_num_min = num_devices;
struct vhost_dev *vdev;
+ int ret;
+
vdev = rte_zmalloc("vhost device", sizeof(*vdev), RTE_CACHE_LINE_SIZE);
if (vdev == NULL) {
RTE_LOG(INFO, VHOST_DATA,
@@ -1590,6 +1710,17 @@ new_device(int vid)
}
}
+ int socketid = get_socketid_by_vid(vid);
+ if (socketid == -1)
+ return -1;
+
+ init_vid2socketid_array(vid, socketid);
+
+ ret = vhost_async_channel_register(vid);
+
+ if (init_vhost_queue_ops(vid) != 0)
+ return -1;
+
if (builtin_net_driver)
vs_vhost_net_setup(vdev);
@@ -1621,16 +1752,7 @@ new_device(int vid)
"(%d) device has been added to data core %d\n",
vid, vdev->coreid);
- if (dma_bind[vid].dmas[VIRTIO_RXQ].dev_id != INVALID_DMA_ID) {
- int ret;
-
- ret = rte_vhost_async_channel_register(vid, VIRTIO_RXQ);
- if (ret == 0)
- dma_bind[vid].dmas[VIRTIO_RXQ].async_enabled = true;
- return ret;
- }
-
- return 0;
+ return ret;
}
static int
@@ -1648,19 +1770,9 @@ vring_state_changed(int vid, uint16_t queue_id, int enable)
if (queue_id != VIRTIO_RXQ)
return 0;
- if (dma_bind[vid].dmas[queue_id].async_enabled) {
- if (!enable) {
- uint16_t n_pkt = 0;
- int16_t dma_id = dma_bind[vid].dmas[VIRTIO_RXQ].dev_id;
- struct rte_mbuf *m_cpl[vdev->pkts_inflight];
-
- while (vdev->pkts_inflight) {
- n_pkt = rte_vhost_clear_queue_thread_unsafe(vid, queue_id,
- m_cpl, vdev->pkts_inflight, dma_id, 0);
- free_pkts(m_cpl, n_pkt);
- __atomic_sub_fetch(&vdev->pkts_inflight, n_pkt, __ATOMIC_SEQ_CST);
- }
- }
+ if (dma_bind[vid2socketid[vid]].dmas[queue_id].async_enabled) {
+ if (!enable)
+ vhost_clear_queue_thread_unsafe(vdev, queue_id);
}
return 0;
@@ -1885,7 +1997,7 @@ main(int argc, char *argv[])
for (i = 0; i < nb_sockets; i++) {
char *file = socket_files + i * PATH_MAX;
- if (dma_count)
+ if (dma_count && get_async_flag_by_socketid(i) != 0)
flags = flags | RTE_VHOST_USER_ASYNC_COPY;
ret = rte_vhost_driver_register(file, flags);
diff --git a/examples/vhost/main.h b/examples/vhost/main.h
index b4a453e77e..40ac2841d1 100644
--- a/examples/vhost/main.h
+++ b/examples/vhost/main.h
@@ -52,7 +52,8 @@ struct vhost_dev {
uint64_t features;
size_t hdr_len;
uint16_t nr_vrings;
- uint16_t pkts_inflight;
+ uint16_t pkts_enq_inflight;
+ uint16_t pkts_deq_inflight;
struct rte_vhost_memory *mem;
struct device_statistics stats;
TAILQ_ENTRY(vhost_dev) global_vdev_entry;
@@ -62,6 +63,19 @@ struct vhost_dev {
struct vhost_queue queues[MAX_QUEUE_PAIRS * 2];
} __rte_cache_aligned;
+typedef uint16_t (*vhost_enqueue_burst_t)(struct vhost_dev *dev,
+ uint16_t queue_id, struct rte_mbuf **pkts,
+ uint32_t count);
+
+typedef uint16_t (*vhost_dequeue_burst_t)(struct vhost_dev *dev,
+ uint16_t queue_id, struct rte_mempool *mbuf_pool,
+ struct rte_mbuf **pkts, uint16_t count);
+
+struct vhost_queue_ops {
+ vhost_enqueue_burst_t enqueue_pkt_burst;
+ vhost_dequeue_burst_t dequeue_pkt_burst;
+};
+
TAILQ_HEAD(vhost_dev_tailq_list, vhost_dev);
@@ -88,6 +102,7 @@ struct dma_info {
struct dma_for_vhost {
struct dma_info dmas[RTE_MAX_QUEUES_PER_PORT * 2];
+ uint32_t async_flag;
};
/* we implement non-extra virtio net features */
@@ -98,7 +113,19 @@ void vs_vhost_net_remove(struct vhost_dev *dev);
uint16_t vs_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
struct rte_mbuf **pkts, uint32_t count);
-uint16_t vs_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
- struct rte_mempool *mbuf_pool,
- struct rte_mbuf **pkts, uint16_t count);
+uint16_t builtin_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t count);
+uint16_t builtin_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool,
+ struct rte_mbuf **pkts, uint16_t count);
+uint16_t sync_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t count);
+uint16_t sync_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool,
+ struct rte_mbuf **pkts, uint16_t count);
+uint16_t async_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t count);
+uint16_t async_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool,
+ struct rte_mbuf **pkts, uint16_t count);
#endif /* _MAIN_H_ */
diff --git a/examples/vhost/virtio_net.c b/examples/vhost/virtio_net.c
index 9064fc3a82..2432a96566 100644
--- a/examples/vhost/virtio_net.c
+++ b/examples/vhost/virtio_net.c
@@ -238,6 +238,13 @@ vs_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
return count;
}
+uint16_t
+builtin_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t count)
+{
+ return vs_enqueue_pkts(dev, queue_id, pkts, count);
+}
+
static __rte_always_inline int
dequeue_pkt(struct vhost_dev *dev, struct rte_vhost_vring *vr,
struct rte_mbuf *m, uint16_t desc_idx,
@@ -363,7 +370,7 @@ dequeue_pkt(struct vhost_dev *dev, struct rte_vhost_vring *vr,
return 0;
}
-uint16_t
+static uint16_t
vs_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
{
@@ -440,3 +447,10 @@ vs_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
return i;
}
+
+uint16_t
+builtin_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
+{
+ return vs_dequeue_pkts(dev, queue_id, mbuf_pool, pkts, count);
+}
--
2.17.1
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [RFC,v3 1/2] vhost: support async dequeue for split ring
2022-03-10 6:54 ` [RFC,v3 1/2] vhost: support async dequeue for split ring xuan.ding
@ 2022-03-31 9:15 ` Maxime Coquelin
2022-03-31 11:20 ` Ding, Xuan
0 siblings, 1 reply; 11+ messages in thread
From: Maxime Coquelin @ 2022-03-31 9:15 UTC (permalink / raw)
To: xuan.ding, chenbo.xia
Cc: dev, jiayu.hu, cheng1.jiang, sunil.pai.g, liangma, Yuan Wang
On 3/10/22 07:54, xuan.ding@intel.com wrote:
> From: Xuan Ding <xuan.ding@intel.com>
>
> This patch implements asynchronous dequeue data path for vhost split
> ring, with dmadev library integrated.
>
> Signed-off-by: Xuan Ding <xuan.ding@intel.com>
> Signed-off-by: Yuan Wang <yuanx.wang@intel.com>
> ---
> lib/vhost/rte_vhost_async.h | 37 ++-
> lib/vhost/version.map | 1 +
> lib/vhost/vhost.h | 1 +
> lib/vhost/virtio_net.c | 504 ++++++++++++++++++++++++++++++++++++
> 4 files changed, 541 insertions(+), 2 deletions(-)
>
> diff --git a/lib/vhost/rte_vhost_async.h b/lib/vhost/rte_vhost_async.h
> index f1293c6a9d..b6ab0b06a2 100644
> --- a/lib/vhost/rte_vhost_async.h
> +++ b/lib/vhost/rte_vhost_async.h
> @@ -155,9 +155,9 @@ int rte_vhost_async_get_inflight(int vid, uint16_t queue_id);
> * @param count
> * Size of the packet array
> * @param dma_id
> - * the identifier of DMA device
> + * The identifier of DMA device
> * @param vchan_id
> - * the identifier of virtual DMA channel
> + * The identifier of virtual DMA channel
This is unrelated to the purpose of this patch, it can be moved in a
dedicated trivial patch.
> * @return
> * Number of packets returned
> */
> @@ -187,6 +187,39 @@ uint16_t rte_vhost_clear_queue_thread_unsafe(int vid, uint16_t queue_id,
> __rte_experimental
> int rte_vhost_async_dma_configure(int16_t dma_id, uint16_t vchan_id);
>
> +/**
> + * This function tries to receive packets from the guest with offloading
> + * copies to the async channel. The packets that are transfer completed
> + * are returned in "pkts". The other packets that their copies are submitted to
> + * the async channel but not completed are called "in-flight packets".
> + * This function will not return in-flight packets until their copies are
> + * completed by the async channel.
> + *
> + * @param vid
> + * ID of vhost device to dequeue data
> + * @param queue_id
> + * ID of virtqueue to dequeue data
> + * @param mbuf_pool
> + * Mbuf_pool where host mbuf is allocated
> + * @param pkts
> + * Blank array to keep successfully dequeued packets
> + * @param count
> + * Size of the packet array
> + * @param nr_inflight
> + * The amount of in-flight packets. If error occurred, its value is set to -1.
> + * @param dma_id
> + * The identifier of DMA device
> + * @param vchan_id
> + * The identifier of virtual DMA channel
> + * @return
> + * Number of successfully dequeued packets
> + */
> +__rte_experimental
> +uint16_t
> +rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id,
> + struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count,
> + int *nr_inflight, uint16_t dma_id, uint16_t vchan_id);
> +
> #ifdef __cplusplus
> }
> #endif
> diff --git a/lib/vhost/version.map b/lib/vhost/version.map
> index 0a66c5840c..968d6d4290 100644
> --- a/lib/vhost/version.map
> +++ b/lib/vhost/version.map
> @@ -87,6 +87,7 @@ EXPERIMENTAL {
>
> # added in 22.03
> rte_vhost_async_dma_configure;
# added in 22.07
> + rte_vhost_async_try_dequeue_burst;
> };
>
> INTERNAL {
> diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
> index a9edc271aa..3799d41089 100644
> --- a/lib/vhost/vhost.h
> +++ b/lib/vhost/vhost.h
> @@ -178,6 +178,7 @@ extern struct async_dma_info dma_copy_track[RTE_DMADEV_DEFAULT_MAX];
> */
> struct async_inflight_info {
> struct rte_mbuf *mbuf;
> + struct virtio_net_hdr nethdr;
> uint16_t descs; /* num of descs inflight */
> uint16_t nr_buffers; /* num of buffers inflight for packed ring */
> };
> diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c
> index 5f432b0d77..3816caca79 100644
> --- a/lib/vhost/virtio_net.c
> +++ b/lib/vhost/virtio_net.c
> @@ -3141,3 +3141,507 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
>
> return count;
> }
> +
> +static __rte_always_inline int
> +async_desc_to_mbuf_seg(struct virtio_net *dev, struct vhost_virtqueue *vq,
> + struct rte_mbuf *m, uint32_t mbuf_offset,
> + uint64_t buf_iova, uint32_t cpy_len)
> +{
> + struct vhost_async *async = vq->async;
> + uint64_t mapped_len;
> + uint32_t buf_offset = 0;
> + void *host_iova;
> +
> + while (cpy_len) {
> + host_iova = (void *)(uintptr_t)gpa_to_first_hpa(dev,
> + buf_iova + buf_offset, cpy_len,
> + &mapped_len);
> + if (unlikely(!host_iova)) {
> + VHOST_LOG_DATA(ERR, "(%s) %s: failed to get host_iova.\n",
> + dev->ifname, __func__);
> + return -1;
> + }
> +
> + if (unlikely(async_iter_add_iovec(dev, async, host_iova,
> + (void *)(uintptr_t)rte_pktmbuf_iova_offset(m, mbuf_offset),
> + (size_t)mapped_len)))
> + return -1;
> +
> + cpy_len -= (uint32_t)mapped_len;
> + mbuf_offset += (uint32_t)mapped_len;
> + buf_offset += (uint32_t)mapped_len;
> + }
> +
> + return 0;
> +}
It looks really similar to async_mbuf_to_desc_seg(), just the direction
of the DMA copoy is changed.
Maybe we could refactor the two functions in a single one with adding a
parameter for the direction. Something like this:
static __rte_always_inline int
async_fill_seg(struct virtio_net *dev, struct vhost_virtqueue *vq,
struct rte_mbuf *m, uint32_t mbuf_offset,
uint64_t buf_iova, uint32_t cpy_len, bool to_desc)
{
struct vhost_async *async = vq->async;
uint64_t mapped_len;
uint32_t buf_offset = 0;
void *src, *dst
void *host_iova;
while (cpy_len) {
host_iova = (void *)(uintptr_t)gpa_to_first_hpa(dev,
buf_iova + buf_offset, cpy_len, &mapped_len);
if (unlikely(!host_iova)) {
VHOST_LOG_DATA(ERR, "(%s) %s: failed to get host iova.\n",
dev->ifname, __func__);
return -1;
}
if (to_desc) {
src = (void *)(uintptr_t)rte_pktmbuf_iova_offset(m, mbuff_offset);
dst = host_iova
} else {
dst = host_iova
src = (void *)(uintptr_t)rte_pktmbuf_iova_offset(m, mbuff_offset);
}
if (unlikely(async_iter_add_iovec(dev, async, src, dst,
(size_t)mapped_len)))
return -1;
cpy_len -= (uint32_t)mapped_len;
mbuf_offset += (uint32_t)mapped_len;
buf_offset += (uint32_t)mapped_len;
}
return 0;
}
Then if you don't pass a variable but a static true/false value for
to_desc, the compiler should generate the same code, so no performance
degradation.
> +
> +static __rte_always_inline int
> +async_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
> + struct buf_vector *buf_vec, uint16_t nr_vec,
> + struct rte_mbuf *m, struct rte_mempool *mbuf_pool,
> + struct virtio_net_hdr *nethdr)
> +{
> + uint64_t buf_addr, buf_iova;
> + uint32_t buf_avail, buf_offset, buf_len;
> + uint32_t mbuf_avail, mbuf_offset;
> + uint32_t cpy_len;
> + /* A counter to avoid desc dead loop chain */
> + uint16_t vec_idx = 0;
> + struct rte_mbuf *cur = m, *prev = m;
> + struct virtio_net_hdr tmp_hdr;
> + struct virtio_net_hdr *hdr = NULL;
> + struct vhost_async *async = vq->async;
> +
> + buf_addr = buf_vec[vec_idx].buf_addr;
> + buf_len = buf_vec[vec_idx].buf_len;
> + buf_iova = buf_vec[vec_idx].buf_iova;
> +
> + if (unlikely(buf_len < dev->vhost_hlen && nr_vec <= 1))
> + return -1;
> +
> + if (virtio_net_with_host_offload(dev)) {
> + if (unlikely(buf_len < sizeof(struct virtio_net_hdr))) {
> + /*
> + * No luck, the virtio-net header doesn't fit
> + * in a contiguous virtual area.
> + */
> + copy_vnet_hdr_from_desc(&tmp_hdr, buf_vec);
> + hdr = &tmp_hdr;
> + } else {
> + hdr = (struct virtio_net_hdr *)((uintptr_t)buf_addr);
> + }
> + }
> +
> + /*
> + * A virtio driver normally uses at least 2 desc buffers
> + * for Tx: the first for storing the header, and others
> + * for storing the data.
> + */
> + if (unlikely(buf_len < dev->vhost_hlen)) {
> + buf_offset = dev->vhost_hlen - buf_len;
> + vec_idx++;
> + buf_addr = buf_vec[vec_idx].buf_addr;
> + buf_iova = buf_vec[vec_idx].buf_iova;
> + buf_len = buf_vec[vec_idx].buf_len;
> + buf_avail = buf_len - buf_offset;
> + } else if (buf_len == dev->vhost_hlen) {
> + if (unlikely(++vec_idx >= nr_vec))
> + return -1;
> + buf_addr = buf_vec[vec_idx].buf_addr;
> + buf_iova = buf_vec[vec_idx].buf_iova;
> + buf_len = buf_vec[vec_idx].buf_len;
> +
> + buf_offset = 0;
> + buf_avail = buf_len;
> + } else {
> + buf_offset = dev->vhost_hlen;
> + buf_avail = buf_vec[vec_idx].buf_len - dev->vhost_hlen;
> + }
> +
> + PRINT_PACKET(dev, (uintptr_t)(buf_addr + buf_offset), (uint32_t)buf_avail, 0);
> +
> + mbuf_offset = 0;
> + mbuf_avail = m->buf_len - RTE_PKTMBUF_HEADROOM;
> +
> + if (async_iter_initialize(dev, async))
> + return -1;
> +
> + while (1) {
> + cpy_len = RTE_MIN(buf_avail, mbuf_avail);
> +
> + if (async_desc_to_mbuf_seg(dev, vq, cur, mbuf_offset, buf_iova + buf_offset,
> + cpy_len) < 0)
> + goto error;
> +
> + mbuf_avail -= cpy_len;
> + buf_avail -= cpy_len;
> + mbuf_offset += cpy_len;
> + buf_offset += cpy_len;
> +
> + /* This buf reaches to its end, get the next one */
> + if (buf_avail == 0) {
> + if (++vec_idx >= nr_vec)
> + break;
> +
> + buf_addr = buf_vec[vec_idx].buf_addr;
> + buf_iova = buf_vec[vec_idx].buf_iova;
> + buf_len = buf_vec[vec_idx].buf_len;
> +
> + buf_offset = 0;
> + buf_avail = buf_len;
> +
> + PRINT_PACKET(dev, (uintptr_t)buf_addr, (uint32_t)buf_avail, 0);
> + }
> +
> + /*
> + * This mbuf reaches to its end, get a new one
> + * to hold more data.
> + */
> + if (mbuf_avail == 0) {
> + cur = rte_pktmbuf_alloc(mbuf_pool);
> + if (unlikely(cur == NULL)) {
> + VHOST_LOG_DATA(ERR,
> + "(%s) %s: failed to allocate memory for mbuf.\n",
> + dev->ifname, __func__);
> + goto error;
> + }
> +
> + prev->next = cur;
> + prev->data_len = mbuf_offset;
> + m->nb_segs += 1;
> + m->pkt_len += mbuf_offset;
> + prev = cur;
> +
> + mbuf_offset = 0;
> + mbuf_avail = cur->buf_len - RTE_PKTMBUF_HEADROOM;
> + }
> + }
> +
> + prev->data_len = mbuf_offset;
> + m->pkt_len += mbuf_offset;
> +
> + async_iter_finalize(async);
> + if (hdr)
> + *nethdr = *hdr;
> +
> + return 0;
> +
> +error:
> + async_iter_cancel(async);
> + return -1;
> +}
You can do here the same refactoring I did for the enqueue path, i.e.
merging copy_desc_to_mbuf and async_desc_to_mbuf in a single function.
> +static __rte_always_inline uint16_t
> +async_poll_dequeue_completed_split(struct virtio_net *dev, uint16_t queue_id,
> + struct rte_mbuf **pkts, uint16_t count, uint16_t dma_id,
> + uint16_t vchan_id, bool legacy_ol_flags)
> +{
> + uint16_t start_idx, from, i;
> + uint16_t nr_cpl_pkts = 0;
> + struct async_inflight_info *pkts_info;
> + struct vhost_virtqueue *vq = dev->virtqueue[queue_id];
> +
> + pkts_info = vq->async->pkts_info;
> +
> + vhost_async_dma_check_completed(dev, dma_id, vchan_id, VHOST_DMA_MAX_COPY_COMPLETE);
> +
> + start_idx = async_get_first_inflight_pkt_idx(vq);
> +
> + from = start_idx;
> + while (vq->async->pkts_cmpl_flag[from] && count--) {
> + vq->async->pkts_cmpl_flag[from] = false;
> + from = (from + 1) & (vq->size - 1);
> + nr_cpl_pkts++;
> + }
> +
> + if (nr_cpl_pkts == 0)
> + return 0;
> +
> + for (i = 0; i < nr_cpl_pkts; i++) {
> + from = (start_idx + i) & (vq->size - 1);
> + pkts[i] = pkts_info[from].mbuf;
> +
> + if (virtio_net_with_host_offload(dev))
> + vhost_dequeue_offload(dev, &pkts_info[from].nethdr, pkts[i],
> + legacy_ol_flags);
> + }
> +
> + /* write back completed descs to used ring and update used idx */
> + write_back_completed_descs_split(vq, nr_cpl_pkts);
> + __atomic_add_fetch(&vq->used->idx, nr_cpl_pkts, __ATOMIC_RELEASE);
> + vhost_vring_call_split(dev, vq);
> +
> + vq->async->pkts_inflight_n -= nr_cpl_pkts;
> +
> + return nr_cpl_pkts;
> +}
> +
> +static __rte_always_inline uint16_t
> +virtio_dev_tx_async_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
> + uint16_t queue_id, struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts,
> + uint16_t count, uint16_t dma_id, uint16_t vchan_id, bool legacy_ol_flags)
> +{
> + static bool allocerr_warned;
> + bool dropped = false;
> + uint16_t free_entries;
> + uint16_t pkt_idx, slot_idx = 0;
> + uint16_t nr_done_pkts = 0;
> + uint16_t pkt_err = 0;
> + uint16_t n_xfer;
> + struct vhost_async *async = vq->async;
> + struct async_inflight_info *pkts_info = async->pkts_info;
> + struct rte_mbuf *pkts_prealloc[MAX_PKT_BURST];
> + uint16_t pkts_size = count;
> +
> + /**
> + * The ordering between avail index and
> + * desc reads needs to be enforced.
> + */
> + free_entries = __atomic_load_n(&vq->avail->idx, __ATOMIC_ACQUIRE) - vq->last_avail_idx;
> + if (free_entries == 0)
> + goto out;
> +
> + rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
> +
> + async_iter_reset(async);
> +
> + count = RTE_MIN(count, MAX_PKT_BURST);
> + count = RTE_MIN(count, free_entries);
> + VHOST_LOG_DATA(DEBUG, "(%s) about to dequeue %u buffers\n", dev->ifname, count);
> +
> + if (rte_pktmbuf_alloc_bulk(mbuf_pool, pkts_prealloc, count))
> + goto out;
> +
> + for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
> + uint16_t head_idx = 0;
> + uint16_t nr_vec = 0;
> + uint16_t to;
> + uint32_t buf_len;
> + int err;
> + struct buf_vector buf_vec[BUF_VECTOR_MAX];
> + struct rte_mbuf *pkt = pkts_prealloc[pkt_idx];
> +
> + if (unlikely(fill_vec_buf_split(dev, vq, vq->last_avail_idx,
> + &nr_vec, buf_vec,
> + &head_idx, &buf_len,
> + VHOST_ACCESS_RO) < 0)) {
> + dropped = true;
> + break;
> + }
> +
> + err = virtio_dev_pktmbuf_prep(dev, pkt, buf_len);
> + if (unlikely(err)) {
> + /**
> + * mbuf allocation fails for jumbo packets when external
> + * buffer allocation is not allowed and linear buffer
> + * is required. Drop this packet.
> + */
> + if (!allocerr_warned) {
> + VHOST_LOG_DATA(ERR,
> + "(%s) %s: Failed mbuf alloc of size %d from %s\n",
> + dev->ifname, __func__, buf_len, mbuf_pool->name);
> + allocerr_warned = true;
> + }
> + dropped = true;
> + break;
> + }
> +
> + slot_idx = (async->pkts_idx + pkt_idx) & (vq->size - 1);
> + err = async_desc_to_mbuf(dev, vq, buf_vec, nr_vec, pkt, mbuf_pool,
> + &pkts_info[slot_idx].nethdr);
> + if (unlikely(err)) {
> + if (!allocerr_warned) {
> + VHOST_LOG_DATA(ERR,
> + "(%s) %s: Failed to offload copies to async channel.\n",
> + dev->ifname, __func__);
> + allocerr_warned = true;
> + }
> + dropped = true;
> + break;
> + }
> +
> + pkts_info[slot_idx].mbuf = pkt;
> +
> + /* store used descs */
> + to = async->desc_idx_split & (vq->size - 1);
> + async->descs_split[to].id = head_idx;
> + async->descs_split[to].len = 0;
> + async->desc_idx_split++;
> +
> + vq->last_avail_idx++;
> + }
> +
> + if (unlikely(dropped))
> + rte_pktmbuf_free_bulk(&pkts_prealloc[pkt_idx], count - pkt_idx);
> +
> + n_xfer = vhost_async_dma_transfer(dev, vq, dma_id, vchan_id, async->pkts_idx,
> + async->iov_iter, pkt_idx);
> +
> + async->pkts_inflight_n += n_xfer;
> +
> + pkt_err = pkt_idx - n_xfer;
> + if (unlikely(pkt_err)) {
> + VHOST_LOG_DATA(DEBUG,
> + "(%s) %s: failed to transfer data for queue id %d.\n",
> + dev->ifname, __func__, queue_id);
> +
> + pkt_idx = n_xfer;
> + /* recover available ring */
> + vq->last_avail_idx -= pkt_err;
> +
> + /**
> + * recover async channel copy related structures and free pktmbufs
> + * for error pkts.
> + */
> + async->desc_idx_split -= pkt_err;
> + while (pkt_err-- > 0) {
> + rte_pktmbuf_free(pkts_info[slot_idx & (vq->size - 1)].mbuf);
> + slot_idx--;
> + }
> + }
> +
> + async->pkts_idx += pkt_idx;
> + if (async->pkts_idx >= vq->size)
> + async->pkts_idx -= vq->size;
> +
> +out:
> + /* DMA device may serve other queues, unconditionally check completed. */
> + nr_done_pkts = async_poll_dequeue_completed_split(dev, queue_id, pkts, pkts_size,
> + dma_id, vchan_id, legacy_ol_flags);
> +
> + return nr_done_pkts;
> +}
> +
> +__rte_noinline
> +static uint16_t
> +virtio_dev_tx_async_split_legacy(struct virtio_net *dev,
> + struct vhost_virtqueue *vq, uint16_t queue_id,
> + struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts,
> + uint16_t count, uint16_t dma_id, uint16_t vchan_id)
> +{
> + return virtio_dev_tx_async_split(dev, vq, queue_id, mbuf_pool,
> + pkts, count, dma_id, vchan_id, true);
> +}
> +
> +__rte_noinline
> +static uint16_t
> +virtio_dev_tx_async_split_compliant(struct virtio_net *dev,
> + struct vhost_virtqueue *vq, uint16_t queue_id,
> + struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts,
> + uint16_t count, uint16_t dma_id, uint16_t vchan_id)
> +{
> + return virtio_dev_tx_async_split(dev, vq, queue_id, mbuf_pool,
> + pkts, count, dma_id, vchan_id, false);
> +}
> +
> +uint16_t
> +rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id,
> + struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count,
> + int *nr_inflight, uint16_t dma_id, uint16_t vchan_id)
> +{
> + struct virtio_net *dev;
> + struct rte_mbuf *rarp_mbuf = NULL;
> + struct vhost_virtqueue *vq;
> + int16_t success = 1;
> +
> + *nr_inflight = -1;
> +
> + dev = get_device(vid);
> + if (!dev)
> + return 0;
> +
> + if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) {
> + VHOST_LOG_DATA(ERR,
> + "(%s) %s: built-in vhost net backend is disabled.\n",
> + dev->ifname, __func__);
> + return 0;
> + }
> +
> + if (unlikely(!is_valid_virt_queue_idx(queue_id, 1, dev->nr_vring))) {
> + VHOST_LOG_DATA(ERR,
> + "(%s) %s: invalid virtqueue idx %d.\n",
> + dev->ifname, __func__, queue_id);
> + return 0;
> + }
> +
> + if (unlikely(!dma_copy_track[dma_id].vchans ||
> + !dma_copy_track[dma_id].vchans[vchan_id].pkts_cmpl_flag_addr)) {
> + VHOST_LOG_DATA(ERR, "(%s) %s: invalid channel %d:%u.\n", dev->ifname, __func__,
> + dma_id, vchan_id);
> + return 0;
> + }
> +
> + vq = dev->virtqueue[queue_id];
> +
> + if (unlikely(rte_spinlock_trylock(&vq->access_lock) == 0))
> + return 0;
> +
> + if (unlikely(vq->enabled == 0)) {
> + count = 0;
> + goto out_access_unlock;
> + }
> +
> + if (unlikely(!vq->async)) {
> + VHOST_LOG_DATA(ERR, "(%s) %s: async not registered for queue id %d.\n",
> + dev->ifname, __func__, queue_id);
> + count = 0;
> + goto out_access_unlock;
> + }
> +
> + if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
> + vhost_user_iotlb_rd_lock(vq);
> +
> + if (unlikely(vq->access_ok == 0))
> + if (unlikely(vring_translate(dev, vq) < 0)) {
> + count = 0;
> + goto out;
> + }
> +
> + /*
> + * Construct a RARP broadcast packet, and inject it to the "pkts"
> + * array, to looks like that guest actually send such packet.
> + *
> + * Check user_send_rarp() for more information.
> + *
> + * broadcast_rarp shares a cacheline in the virtio_net structure
> + * with some fields that are accessed during enqueue and
> + * __atomic_compare_exchange_n causes a write if performed compare
> + * and exchange. This could result in false sharing between enqueue
> + * and dequeue.
> + *
> + * Prevent unnecessary false sharing by reading broadcast_rarp first
> + * and only performing compare and exchange if the read indicates it
> + * is likely to be set.
> + */
> + if (unlikely(__atomic_load_n(&dev->broadcast_rarp, __ATOMIC_ACQUIRE) &&
> + __atomic_compare_exchange_n(&dev->broadcast_rarp,
> + &success, 0, 0, __ATOMIC_RELEASE, __ATOMIC_RELAXED))) {
> +
> + rarp_mbuf = rte_net_make_rarp_packet(mbuf_pool, &dev->mac);
> + if (rarp_mbuf == NULL) {
> + VHOST_LOG_DATA(ERR, "Failed to make RARP packet.\n");
> + count = 0;
> + goto out;
> + }
> + /*
> + * Inject it to the head of "pkts" array, so that switch's mac
> + * learning table will get updated first.
> + */
> + pkts[0] = rarp_mbuf;
> + pkts++;
> + count -= 1;
> + }
> +
> + if (unlikely(vq_is_packed(dev))) {
> + static bool not_support_pack_log;
> + if (!not_support_pack_log) {
> + VHOST_LOG_DATA(ERR,
> + "(%s) %s: async dequeue does not support packed ring.\n",
> + dev->ifname, __func__);
> + not_support_pack_log = true;
> + }
> + count = 0;
> + goto out;
> + }
> +
> + if (dev->flags & VIRTIO_DEV_LEGACY_OL_FLAGS)
> + count = virtio_dev_tx_async_split_legacy(dev, vq, queue_id,
> + mbuf_pool, pkts, count, dma_id, vchan_id);
> + else
> + count = virtio_dev_tx_async_split_compliant(dev, vq, queue_id,
> + mbuf_pool, pkts, count, dma_id, vchan_id);
> +
> + *nr_inflight = vq->async->pkts_inflight_n;
> +
> +out:
> + if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
> + vhost_user_iotlb_rd_unlock(vq);
> +
> +out_access_unlock:
> + rte_spinlock_unlock(&vq->access_lock);
> +
> + if (unlikely(rarp_mbuf != NULL))
> + count += 1;
> +
> + return count;
> +}
^ permalink raw reply [flat|nested] 11+ messages in thread
* RE: [RFC,v3 1/2] vhost: support async dequeue for split ring
2022-03-31 9:15 ` Maxime Coquelin
@ 2022-03-31 11:20 ` Ding, Xuan
0 siblings, 0 replies; 11+ messages in thread
From: Ding, Xuan @ 2022-03-31 11:20 UTC (permalink / raw)
To: Maxime Coquelin, Xia, Chenbo
Cc: dev, Hu, Jiayu, Jiang, Cheng1, Pai G, Sunil, liangma, Wang, YuanX
Hi Maxime,
> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Thursday, March 31, 2022 5:15 PM
> To: Ding, Xuan <xuan.ding@intel.com>; Xia, Chenbo <chenbo.xia@intel.com>
> Cc: dev@dpdk.org; Hu, Jiayu <jiayu.hu@intel.com>; Jiang, Cheng1
> <cheng1.jiang@intel.com>; Pai G, Sunil <sunil.pai.g@intel.com>;
> liangma@liangbit.com; Wang, YuanX <yuanx.wang@intel.com>
> Subject: Re: [RFC,v3 1/2] vhost: support async dequeue for split ring
>
>
>
> On 3/10/22 07:54, xuan.ding@intel.com wrote:
> > From: Xuan Ding <xuan.ding@intel.com>
> >
> > This patch implements asynchronous dequeue data path for vhost split
> > ring, with dmadev library integrated.
> >
> > Signed-off-by: Xuan Ding <xuan.ding@intel.com>
> > Signed-off-by: Yuan Wang <yuanx.wang@intel.com>
> > ---
> > lib/vhost/rte_vhost_async.h | 37 ++-
> > lib/vhost/version.map | 1 +
> > lib/vhost/vhost.h | 1 +
> > lib/vhost/virtio_net.c | 504 ++++++++++++++++++++++++++++++++++++
> > 4 files changed, 541 insertions(+), 2 deletions(-)
> >
> > diff --git a/lib/vhost/rte_vhost_async.h b/lib/vhost/rte_vhost_async.h
> > index f1293c6a9d..b6ab0b06a2 100644
> > --- a/lib/vhost/rte_vhost_async.h
> > +++ b/lib/vhost/rte_vhost_async.h
> > @@ -155,9 +155,9 @@ int rte_vhost_async_get_inflight(int vid, uint16_t
> queue_id);
> > * @param count
> > * Size of the packet array
> > * @param dma_id
> > - * the identifier of DMA device
> > + * The identifier of DMA device
> > * @param vchan_id
> > - * the identifier of virtual DMA channel
> > + * The identifier of virtual DMA channel
>
> This is unrelated to the purpose of this patch, it can be moved in a dedicated
> trivial patch.
Okay, I will remove it from this patch set.
>
> > * @return
> > * Number of packets returned
> > */
> > @@ -187,6 +187,39 @@ uint16_t
> rte_vhost_clear_queue_thread_unsafe(int vid, uint16_t queue_id,
> > __rte_experimental
> > int rte_vhost_async_dma_configure(int16_t dma_id, uint16_t
> > vchan_id);
> >
> > +/**
> > + * This function tries to receive packets from the guest with
> > +offloading
> > + * copies to the async channel. The packets that are transfer
> > +completed
> > + * are returned in "pkts". The other packets that their copies are
> > +submitted to
> > + * the async channel but not completed are called "in-flight packets".
> > + * This function will not return in-flight packets until their copies
> > +are
> > + * completed by the async channel.
> > + *
> > + * @param vid
> > + * ID of vhost device to dequeue data
> > + * @param queue_id
> > + * ID of virtqueue to dequeue data
> > + * @param mbuf_pool
> > + * Mbuf_pool where host mbuf is allocated
> > + * @param pkts
> > + * Blank array to keep successfully dequeued packets
> > + * @param count
> > + * Size of the packet array
> > + * @param nr_inflight
> > + * The amount of in-flight packets. If error occurred, its value is set to -1.
> > + * @param dma_id
> > + * The identifier of DMA device
> > + * @param vchan_id
> > + * The identifier of virtual DMA channel
> > + * @return
> > + * Number of successfully dequeued packets */ __rte_experimental
> > +uint16_t rte_vhost_async_try_dequeue_burst(int vid, uint16_t
> > +queue_id,
> > + struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t
> count,
> > + int *nr_inflight, uint16_t dma_id, uint16_t vchan_id);
> > +
> > #ifdef __cplusplus
> > }
> > #endif
> > diff --git a/lib/vhost/version.map b/lib/vhost/version.map index
> > 0a66c5840c..968d6d4290 100644
> > --- a/lib/vhost/version.map
> > +++ b/lib/vhost/version.map
> > @@ -87,6 +87,7 @@ EXPERIMENTAL {
> >
> > # added in 22.03
> > rte_vhost_async_dma_configure;
>
> # added in 22.07
Sure, I will add in 22.07 in new version.
>
> > + rte_vhost_async_try_dequeue_burst;
> > };
> >
> > INTERNAL {
> > diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h index
> > a9edc271aa..3799d41089 100644
> > --- a/lib/vhost/vhost.h
> > +++ b/lib/vhost/vhost.h
> > @@ -178,6 +178,7 @@ extern struct async_dma_info
> dma_copy_track[RTE_DMADEV_DEFAULT_MAX];
> > */
> > struct async_inflight_info {
> > struct rte_mbuf *mbuf;
> > + struct virtio_net_hdr nethdr;
> > uint16_t descs; /* num of descs inflight */
> > uint16_t nr_buffers; /* num of buffers inflight for packed ring */
> > };
> > diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c index
> > 5f432b0d77..3816caca79 100644
> > --- a/lib/vhost/virtio_net.c
> > +++ b/lib/vhost/virtio_net.c
> > @@ -3141,3 +3141,507 @@ rte_vhost_dequeue_burst(int vid, uint16_t
> > queue_id,
> >
> > return count;
> > }
> > +
> > +static __rte_always_inline int
> > +async_desc_to_mbuf_seg(struct virtio_net *dev, struct vhost_virtqueue
> *vq,
> > + struct rte_mbuf *m, uint32_t mbuf_offset,
> > + uint64_t buf_iova, uint32_t cpy_len) {
> > + struct vhost_async *async = vq->async;
> > + uint64_t mapped_len;
> > + uint32_t buf_offset = 0;
> > + void *host_iova;
> > +
> > + while (cpy_len) {
> > + host_iova = (void *)(uintptr_t)gpa_to_first_hpa(dev,
> > + buf_iova + buf_offset, cpy_len,
> > + &mapped_len);
> > + if (unlikely(!host_iova)) {
> > + VHOST_LOG_DATA(ERR, "(%s) %s: failed to get
> host_iova.\n",
> > + dev->ifname, __func__);
> > + return -1;
> > + }
> > +
> > + if (unlikely(async_iter_add_iovec(dev, async, host_iova,
> > + (void *)(uintptr_t)rte_pktmbuf_iova_offset(m,
> mbuf_offset),
> > + (size_t)mapped_len)))
> > + return -1;
> > +
> > + cpy_len -= (uint32_t)mapped_len;
> > + mbuf_offset += (uint32_t)mapped_len;
> > + buf_offset += (uint32_t)mapped_len;
> > + }
> > +
> > + return 0;
> > +}
>
> It looks really similar to async_mbuf_to_desc_seg(), just the direction of the
> DMA copoy is changed.
>
> Maybe we could refactor the two functions in a single one with adding a
> parameter for the direction. Something like this:
>
> static __rte_always_inline int
> async_fill_seg(struct virtio_net *dev, struct vhost_virtqueue *vq,
> struct rte_mbuf *m, uint32_t mbuf_offset,
> uint64_t buf_iova, uint32_t cpy_len, bool to_desc) {
> struct vhost_async *async = vq->async;
> uint64_t mapped_len;
> uint32_t buf_offset = 0;
> void *src, *dst
> void *host_iova;
>
> while (cpy_len) {
> host_iova = (void *)(uintptr_t)gpa_to_first_hpa(dev,
> buf_iova + buf_offset, cpy_len,
> &mapped_len);
> if (unlikely(!host_iova)) {
> VHOST_LOG_DATA(ERR, "(%s) %s: failed to get host
> iova.\n",
> dev->ifname, __func__);
> return -1;
> }
>
> if (to_desc) {
> src = (void *)(uintptr_t)rte_pktmbuf_iova_offset(m,
> mbuff_offset);
> dst = host_iova
> } else {
> dst = host_iova
> src = (void *)(uintptr_t)rte_pktmbuf_iova_offset(m,
> mbuff_offset);
> }
>
> if (unlikely(async_iter_add_iovec(dev, async, src, dst,
> (size_t)mapped_len)))
> return -1;
>
> cpy_len -= (uint32_t)mapped_len;
> mbuf_offset += (uint32_t)mapped_len;
> buf_offset += (uint32_t)mapped_len;
> }
>
> return 0;
> }
>
>
> Then if you don't pass a variable but a static true/false value for to_desc, the
> compiler should generate the same code, so no performance degradation.
Thanks so much for the suggestion.
I noticed the async_mbuf_to_desc_seg() refactoring in enqueue path,
so I refactored the previous dequeue code to async_desc_to_mbuf_seg().
These two functions can indeed be combined into one, it is a good idea.
>
> > +
> > +static __rte_always_inline int
> > +async_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
> > + struct buf_vector *buf_vec, uint16_t nr_vec,
> > + struct rte_mbuf *m, struct rte_mempool *mbuf_pool,
> > + struct virtio_net_hdr *nethdr)
> > +{
> > + uint64_t buf_addr, buf_iova;
> > + uint32_t buf_avail, buf_offset, buf_len;
> > + uint32_t mbuf_avail, mbuf_offset;
> > + uint32_t cpy_len;
> > + /* A counter to avoid desc dead loop chain */
> > + uint16_t vec_idx = 0;
> > + struct rte_mbuf *cur = m, *prev = m;
> > + struct virtio_net_hdr tmp_hdr;
> > + struct virtio_net_hdr *hdr = NULL;
> > + struct vhost_async *async = vq->async;
> > +
> > + buf_addr = buf_vec[vec_idx].buf_addr;
> > + buf_len = buf_vec[vec_idx].buf_len;
> > + buf_iova = buf_vec[vec_idx].buf_iova;
> > +
> > + if (unlikely(buf_len < dev->vhost_hlen && nr_vec <= 1))
> > + return -1;
> > +
> > + if (virtio_net_with_host_offload(dev)) {
> > + if (unlikely(buf_len < sizeof(struct virtio_net_hdr))) {
> > + /*
> > + * No luck, the virtio-net header doesn't fit
> > + * in a contiguous virtual area.
> > + */
> > + copy_vnet_hdr_from_desc(&tmp_hdr, buf_vec);
> > + hdr = &tmp_hdr;
> > + } else {
> > + hdr = (struct virtio_net_hdr *)((uintptr_t)buf_addr);
> > + }
> > + }
> > +
> > + /*
> > + * A virtio driver normally uses at least 2 desc buffers
> > + * for Tx: the first for storing the header, and others
> > + * for storing the data.
> > + */
> > + if (unlikely(buf_len < dev->vhost_hlen)) {
> > + buf_offset = dev->vhost_hlen - buf_len;
> > + vec_idx++;
> > + buf_addr = buf_vec[vec_idx].buf_addr;
> > + buf_iova = buf_vec[vec_idx].buf_iova;
> > + buf_len = buf_vec[vec_idx].buf_len;
> > + buf_avail = buf_len - buf_offset;
> > + } else if (buf_len == dev->vhost_hlen) {
> > + if (unlikely(++vec_idx >= nr_vec))
> > + return -1;
> > + buf_addr = buf_vec[vec_idx].buf_addr;
> > + buf_iova = buf_vec[vec_idx].buf_iova;
> > + buf_len = buf_vec[vec_idx].buf_len;
> > +
> > + buf_offset = 0;
> > + buf_avail = buf_len;
> > + } else {
> > + buf_offset = dev->vhost_hlen;
> > + buf_avail = buf_vec[vec_idx].buf_len - dev->vhost_hlen;
> > + }
> > +
> > + PRINT_PACKET(dev, (uintptr_t)(buf_addr + buf_offset),
> > +(uint32_t)buf_avail, 0);
> > +
> > + mbuf_offset = 0;
> > + mbuf_avail = m->buf_len - RTE_PKTMBUF_HEADROOM;
> > +
> > + if (async_iter_initialize(dev, async))
> > + return -1;
> > +
> > + while (1) {
> > + cpy_len = RTE_MIN(buf_avail, mbuf_avail);
> > +
> > + if (async_desc_to_mbuf_seg(dev, vq, cur, mbuf_offset,
> buf_iova + buf_offset,
> > + cpy_len) < 0)
> > + goto error;
> > +
> > + mbuf_avail -= cpy_len;
> > + buf_avail -= cpy_len;
> > + mbuf_offset += cpy_len;
> > + buf_offset += cpy_len;
> > +
> > + /* This buf reaches to its end, get the next one */
> > + if (buf_avail == 0) {
> > + if (++vec_idx >= nr_vec)
> > + break;
> > +
> > + buf_addr = buf_vec[vec_idx].buf_addr;
> > + buf_iova = buf_vec[vec_idx].buf_iova;
> > + buf_len = buf_vec[vec_idx].buf_len;
> > +
> > + buf_offset = 0;
> > + buf_avail = buf_len;
> > +
> > + PRINT_PACKET(dev, (uintptr_t)buf_addr,
> (uint32_t)buf_avail, 0);
> > + }
> > +
> > + /*
> > + * This mbuf reaches to its end, get a new one
> > + * to hold more data.
> > + */
> > + if (mbuf_avail == 0) {
> > + cur = rte_pktmbuf_alloc(mbuf_pool);
> > + if (unlikely(cur == NULL)) {
> > + VHOST_LOG_DATA(ERR,
> > + "(%s) %s: failed to allocate memory
> for mbuf.\n",
> > + dev->ifname, __func__);
> > + goto error;
> > + }
> > +
> > + prev->next = cur;
> > + prev->data_len = mbuf_offset;
> > + m->nb_segs += 1;
> > + m->pkt_len += mbuf_offset;
> > + prev = cur;
> > +
> > + mbuf_offset = 0;
> > + mbuf_avail = cur->buf_len -
> RTE_PKTMBUF_HEADROOM;
> > + }
> > + }
> > +
> > + prev->data_len = mbuf_offset;
> > + m->pkt_len += mbuf_offset;
> > +
> > + async_iter_finalize(async);
> > + if (hdr)
> > + *nethdr = *hdr;
> > +
> > + return 0;
> > +
> > +error:
> > + async_iter_cancel(async);
> > + return -1;
> > +}
>
>
> You can do here the same refactoring I did for the enqueue path, i.e.
> merging copy_desc_to_mbuf and async_desc_to_mbuf in a single function.
Yes, I am preparing the v1 patch in 22.07, including the refactoring here.
Please see next version.
Thanks,
Xuan
>
> > +static __rte_always_inline uint16_t
> > +async_poll_dequeue_completed_split(struct virtio_net *dev, uint16_t
> queue_id,
> > + struct rte_mbuf **pkts, uint16_t count, uint16_t dma_id,
> > + uint16_t vchan_id, bool legacy_ol_flags) {
> > + uint16_t start_idx, from, i;
> > + uint16_t nr_cpl_pkts = 0;
> > + struct async_inflight_info *pkts_info;
> > + struct vhost_virtqueue *vq = dev->virtqueue[queue_id];
> > +
> > + pkts_info = vq->async->pkts_info;
> > +
> > + vhost_async_dma_check_completed(dev, dma_id, vchan_id,
> > +VHOST_DMA_MAX_COPY_COMPLETE);
> > +
> > + start_idx = async_get_first_inflight_pkt_idx(vq);
> > +
> > + from = start_idx;
> > + while (vq->async->pkts_cmpl_flag[from] && count--) {
> > + vq->async->pkts_cmpl_flag[from] = false;
> > + from = (from + 1) & (vq->size - 1);
> > + nr_cpl_pkts++;
> > + }
> > +
> > + if (nr_cpl_pkts == 0)
> > + return 0;
> > +
> > + for (i = 0; i < nr_cpl_pkts; i++) {
> > + from = (start_idx + i) & (vq->size - 1);
> > + pkts[i] = pkts_info[from].mbuf;
> > +
> > + if (virtio_net_with_host_offload(dev))
> > + vhost_dequeue_offload(dev,
> &pkts_info[from].nethdr, pkts[i],
> > + legacy_ol_flags);
> > + }
> > +
> > + /* write back completed descs to used ring and update used idx */
> > + write_back_completed_descs_split(vq, nr_cpl_pkts);
> > + __atomic_add_fetch(&vq->used->idx, nr_cpl_pkts,
> __ATOMIC_RELEASE);
> > + vhost_vring_call_split(dev, vq);
> > +
> > + vq->async->pkts_inflight_n -= nr_cpl_pkts;
> > +
> > + return nr_cpl_pkts;
> > +}
> > +
> > +static __rte_always_inline uint16_t
> > +virtio_dev_tx_async_split(struct virtio_net *dev, struct vhost_virtqueue
> *vq,
> > + uint16_t queue_id, struct rte_mempool *mbuf_pool, struct
> rte_mbuf **pkts,
> > + uint16_t count, uint16_t dma_id, uint16_t vchan_id, bool
> > +legacy_ol_flags) {
> > + static bool allocerr_warned;
> > + bool dropped = false;
> > + uint16_t free_entries;
> > + uint16_t pkt_idx, slot_idx = 0;
> > + uint16_t nr_done_pkts = 0;
> > + uint16_t pkt_err = 0;
> > + uint16_t n_xfer;
> > + struct vhost_async *async = vq->async;
> > + struct async_inflight_info *pkts_info = async->pkts_info;
> > + struct rte_mbuf *pkts_prealloc[MAX_PKT_BURST];
> > + uint16_t pkts_size = count;
> > +
> > + /**
> > + * The ordering between avail index and
> > + * desc reads needs to be enforced.
> > + */
> > + free_entries = __atomic_load_n(&vq->avail->idx,
> __ATOMIC_ACQUIRE) - vq->last_avail_idx;
> > + if (free_entries == 0)
> > + goto out;
> > +
> > + rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size -
> > +1)]);
> > +
> > + async_iter_reset(async);
> > +
> > + count = RTE_MIN(count, MAX_PKT_BURST);
> > + count = RTE_MIN(count, free_entries);
> > + VHOST_LOG_DATA(DEBUG, "(%s) about to dequeue %u buffers\n",
> > +dev->ifname, count);
> > +
> > + if (rte_pktmbuf_alloc_bulk(mbuf_pool, pkts_prealloc, count))
> > + goto out;
> > +
> > + for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
> > + uint16_t head_idx = 0;
> > + uint16_t nr_vec = 0;
> > + uint16_t to;
> > + uint32_t buf_len;
> > + int err;
> > + struct buf_vector buf_vec[BUF_VECTOR_MAX];
> > + struct rte_mbuf *pkt = pkts_prealloc[pkt_idx];
> > +
> > + if (unlikely(fill_vec_buf_split(dev, vq, vq->last_avail_idx,
> > + &nr_vec, buf_vec,
> > + &head_idx, &buf_len,
> > + VHOST_ACCESS_RO) < 0)) {
> > + dropped = true;
> > + break;
> > + }
> > +
> > + err = virtio_dev_pktmbuf_prep(dev, pkt, buf_len);
> > + if (unlikely(err)) {
> > + /**
> > + * mbuf allocation fails for jumbo packets when
> external
> > + * buffer allocation is not allowed and linear buffer
> > + * is required. Drop this packet.
> > + */
> > + if (!allocerr_warned) {
> > + VHOST_LOG_DATA(ERR,
> > + "(%s) %s: Failed mbuf alloc of size %d
> from %s\n",
> > + dev->ifname, __func__, buf_len,
> mbuf_pool->name);
> > + allocerr_warned = true;
> > + }
> > + dropped = true;
> > + break;
> > + }
> > +
> > + slot_idx = (async->pkts_idx + pkt_idx) & (vq->size - 1);
> > + err = async_desc_to_mbuf(dev, vq, buf_vec, nr_vec, pkt,
> mbuf_pool,
> > + &pkts_info[slot_idx].nethdr);
> > + if (unlikely(err)) {
> > + if (!allocerr_warned) {
> > + VHOST_LOG_DATA(ERR,
> > + "(%s) %s: Failed to offload copies to
> async channel.\n",
> > + dev->ifname, __func__);
> > + allocerr_warned = true;
> > + }
> > + dropped = true;
> > + break;
> > + }
> > +
> > + pkts_info[slot_idx].mbuf = pkt;
> > +
> > + /* store used descs */
> > + to = async->desc_idx_split & (vq->size - 1);
> > + async->descs_split[to].id = head_idx;
> > + async->descs_split[to].len = 0;
> > + async->desc_idx_split++;
> > +
> > + vq->last_avail_idx++;
> > + }
> > +
> > + if (unlikely(dropped))
> > + rte_pktmbuf_free_bulk(&pkts_prealloc[pkt_idx], count -
> pkt_idx);
> > +
> > + n_xfer = vhost_async_dma_transfer(dev, vq, dma_id, vchan_id,
> async->pkts_idx,
> > + async->iov_iter, pkt_idx);
> > +
> > + async->pkts_inflight_n += n_xfer;
> > +
> > + pkt_err = pkt_idx - n_xfer;
> > + if (unlikely(pkt_err)) {
> > + VHOST_LOG_DATA(DEBUG,
> > + "(%s) %s: failed to transfer data for queue id %d.\n",
> > + dev->ifname, __func__, queue_id);
> > +
> > + pkt_idx = n_xfer;
> > + /* recover available ring */
> > + vq->last_avail_idx -= pkt_err;
> > +
> > + /**
> > + * recover async channel copy related structures and free
> pktmbufs
> > + * for error pkts.
> > + */
> > + async->desc_idx_split -= pkt_err;
> > + while (pkt_err-- > 0) {
> > + rte_pktmbuf_free(pkts_info[slot_idx & (vq->size -
> 1)].mbuf);
> > + slot_idx--;
> > + }
> > + }
> > +
> > + async->pkts_idx += pkt_idx;
> > + if (async->pkts_idx >= vq->size)
> > + async->pkts_idx -= vq->size;
> > +
> > +out:
> > + /* DMA device may serve other queues, unconditionally check
> completed. */
> > + nr_done_pkts = async_poll_dequeue_completed_split(dev, queue_id,
> pkts, pkts_size,
> > + dma_id, vchan_id,
> legacy_ol_flags);
> > +
> > + return nr_done_pkts;
> > +}
> > +
> > +__rte_noinline
> > +static uint16_t
> > +virtio_dev_tx_async_split_legacy(struct virtio_net *dev,
> > + struct vhost_virtqueue *vq, uint16_t queue_id,
> > + struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts,
> > + uint16_t count, uint16_t dma_id, uint16_t vchan_id) {
> > + return virtio_dev_tx_async_split(dev, vq, queue_id, mbuf_pool,
> > + pkts, count, dma_id, vchan_id, true); }
> > +
> > +__rte_noinline
> > +static uint16_t
> > +virtio_dev_tx_async_split_compliant(struct virtio_net *dev,
> > + struct vhost_virtqueue *vq, uint16_t queue_id,
> > + struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts,
> > + uint16_t count, uint16_t dma_id, uint16_t vchan_id) {
> > + return virtio_dev_tx_async_split(dev, vq, queue_id, mbuf_pool,
> > + pkts, count, dma_id, vchan_id, false); }
> > +
> > +uint16_t
> > +rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id,
> > + struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t
> count,
> > + int *nr_inflight, uint16_t dma_id, uint16_t vchan_id) {
> > + struct virtio_net *dev;
> > + struct rte_mbuf *rarp_mbuf = NULL;
> > + struct vhost_virtqueue *vq;
> > + int16_t success = 1;
> > +
> > + *nr_inflight = -1;
> > +
> > + dev = get_device(vid);
> > + if (!dev)
> > + return 0;
> > +
> > + if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) {
> > + VHOST_LOG_DATA(ERR,
> > + "(%s) %s: built-in vhost net backend is disabled.\n",
> > + dev->ifname, __func__);
> > + return 0;
> > + }
> > +
> > + if (unlikely(!is_valid_virt_queue_idx(queue_id, 1, dev->nr_vring))) {
> > + VHOST_LOG_DATA(ERR,
> > + "(%s) %s: invalid virtqueue idx %d.\n",
> > + dev->ifname, __func__, queue_id);
> > + return 0;
> > + }
> > +
> > + if (unlikely(!dma_copy_track[dma_id].vchans ||
> > +
> !dma_copy_track[dma_id].vchans[vchan_id].pkts_cmpl_flag_addr)) {
> > + VHOST_LOG_DATA(ERR, "(%s) %s: invalid channel %d:%u.\n",
> dev->ifname, __func__,
> > + dma_id, vchan_id);
> > + return 0;
> > + }
> > +
> > + vq = dev->virtqueue[queue_id];
> > +
> > + if (unlikely(rte_spinlock_trylock(&vq->access_lock) == 0))
> > + return 0;
> > +
> > + if (unlikely(vq->enabled == 0)) {
> > + count = 0;
> > + goto out_access_unlock;
> > + }
> > +
> > + if (unlikely(!vq->async)) {
> > + VHOST_LOG_DATA(ERR, "(%s) %s: async not registered for
> queue id %d.\n",
> > + dev->ifname, __func__, queue_id);
> > + count = 0;
> > + goto out_access_unlock;
> > + }
> > +
> > + if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
> > + vhost_user_iotlb_rd_lock(vq);
> > +
> > + if (unlikely(vq->access_ok == 0))
> > + if (unlikely(vring_translate(dev, vq) < 0)) {
> > + count = 0;
> > + goto out;
> > + }
> > +
> > + /*
> > + * Construct a RARP broadcast packet, and inject it to the "pkts"
> > + * array, to looks like that guest actually send such packet.
> > + *
> > + * Check user_send_rarp() for more information.
> > + *
> > + * broadcast_rarp shares a cacheline in the virtio_net structure
> > + * with some fields that are accessed during enqueue and
> > + * __atomic_compare_exchange_n causes a write if performed
> compare
> > + * and exchange. This could result in false sharing between enqueue
> > + * and dequeue.
> > + *
> > + * Prevent unnecessary false sharing by reading broadcast_rarp first
> > + * and only performing compare and exchange if the read indicates it
> > + * is likely to be set.
> > + */
> > + if (unlikely(__atomic_load_n(&dev->broadcast_rarp,
> __ATOMIC_ACQUIRE) &&
> > + __atomic_compare_exchange_n(&dev-
> >broadcast_rarp,
> > + &success, 0, 0, __ATOMIC_RELEASE,
> __ATOMIC_RELAXED))) {
> > +
> > + rarp_mbuf = rte_net_make_rarp_packet(mbuf_pool, &dev-
> >mac);
> > + if (rarp_mbuf == NULL) {
> > + VHOST_LOG_DATA(ERR, "Failed to make RARP
> packet.\n");
> > + count = 0;
> > + goto out;
> > + }
> > + /*
> > + * Inject it to the head of "pkts" array, so that switch's mac
> > + * learning table will get updated first.
> > + */
> > + pkts[0] = rarp_mbuf;
> > + pkts++;
> > + count -= 1;
> > + }
> > +
> > + if (unlikely(vq_is_packed(dev))) {
> > + static bool not_support_pack_log;
> > + if (!not_support_pack_log) {
> > + VHOST_LOG_DATA(ERR,
> > + "(%s) %s: async dequeue does not support
> packed ring.\n",
> > + dev->ifname, __func__);
> > + not_support_pack_log = true;
> > + }
> > + count = 0;
> > + goto out;
> > + }
> > +
> > + if (dev->flags & VIRTIO_DEV_LEGACY_OL_FLAGS)
> > + count = virtio_dev_tx_async_split_legacy(dev, vq, queue_id,
> > + mbuf_pool, pkts, count, dma_id, vchan_id);
> > + else
> > + count = virtio_dev_tx_async_split_compliant(dev, vq,
> queue_id,
> > + mbuf_pool, pkts, count, dma_id, vchan_id);
> > +
> > + *nr_inflight = vq->async->pkts_inflight_n;
> > +
> > +out:
> > + if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
> > + vhost_user_iotlb_rd_unlock(vq);
> > +
> > +out_access_unlock:
> > + rte_spinlock_unlock(&vq->access_lock);
> > +
> > + if (unlikely(rarp_mbuf != NULL))
> > + count += 1;
> > +
> > + return count;
> > +}
^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2022-03-31 11:20 UTC | newest]
Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-01-01 0:12 [RFC 0/2] vhost: support async dequeue data path xuan.ding
2022-01-01 0:12 ` [RFC 1/2] vhost: support async dequeue for split ring xuan.ding
2022-01-01 0:12 ` [RFC 2/2] examples/vhost: support async dequeue data path xuan.ding
2022-02-24 11:03 ` [RFC,v2 0/2] vhost: " xuan.ding
2022-02-24 11:03 ` [RFC,v2 1/2] vhost: support async dequeue for split ring xuan.ding
2022-02-24 11:04 ` [RFC,v2 2/2] examples/vhost: support async dequeue data path xuan.ding
2022-03-10 6:54 ` [RFC,v3 0/2] vhost: " xuan.ding
2022-03-10 6:54 ` [RFC,v3 1/2] vhost: support async dequeue for split ring xuan.ding
2022-03-31 9:15 ` Maxime Coquelin
2022-03-31 11:20 ` Ding, Xuan
2022-03-10 6:54 ` [RFC,v3 2/2] examples/vhost: support async dequeue data path xuan.ding
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