[dpdk-dev] [PATCH v1 2/4] example/vhost: add support for vhost async data path

[Cheng Jiang <Cheng1.jiang@intel.com>]

This patch is to implement vhost DMA operation callbacks for CBDMA
PMD and add vhost async data-path in vhost sample. With providing
callback implementation for CBDMA, vhost sample can leverage
CBDMA to accelerate vhost async data-path.

Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com>
---
 examples/vhost/main.c | 129 ++++++++++++++++++++++++++++++++++++++++--
 examples/vhost/main.h |   1 +
 2 files changed, 124 insertions(+), 6 deletions(-)

diff --git a/examples/vhost/main.c b/examples/vhost/main.c
index 011e3da21..b2a4e4370 100644
--- a/examples/vhost/main.c
+++ b/examples/vhost/main.c
@@ -24,6 +24,7 @@
 #include <rte_ip.h>
 #include <rte_tcp.h>
 #include <rte_pause.h>
+#include <rte_vhost_async.h>
 #include <rte_rawdev.h>
 #include <rte_ioat_rawdev.h>
 #include <rte_pci.h>
@@ -31,7 +32,7 @@
 #include "main.h"
 
 #ifndef MAX_QUEUES
-#define MAX_QUEUES 128
+#define MAX_QUEUES 512
 #endif
 
 /* the maximum number of external ports supported */
@@ -165,6 +166,62 @@ static struct rte_eth_conf vmdq_conf_default = {
 	},
 };
 
+static uint32_t
+ioat_transfer_data_cb(int vid, uint16_t queue_id,
+		struct rte_vhost_async_desc *descs,
+		struct rte_vhost_async_status *opaque_data, uint16_t count)
+{
+	int ret;
+	uint32_t i_desc;
+
+	struct rte_vhost_iov_iter *src = NULL;
+	struct rte_vhost_iov_iter *dst = NULL;
+	unsigned long i_seg;
+
+	int dev_id = dma_bind[vid].dmas[queue_id * 2 + VIRTIO_RXQ].dev_id;
+	if (likely(!opaque_data)) {
+		for (i_desc = 0; i_desc < count; i_desc++) {
+			src = descs[i_desc].src;
+			dst = descs[i_desc].dst;
+			i_seg = 0;
+			while (i_seg < src->nr_segs) {
+				ret = rte_ioat_enqueue_copy(dev_id,
+					(uintptr_t)(src->iov[i_seg].iov_base)
+						+ src->offset,
+					(uintptr_t)(dst->iov[i_seg].iov_base)
+						+ dst->offset,
+					src->iov[i_seg].iov_len,
+					0,
+					0,
+					0);
+				if (ret != 1)
+					break;
+				i_seg++;
+			}
+		}
+	} else {
+		/* Opaque data is not supported */
+		return -1;
+	}
+	/* ring the doorbell */
+	rte_ioat_do_copies(dev_id);
+	return i_desc;
+}
+
+static uint32_t
+ioat_check_completed_copies_cb(int vid, uint16_t queue_id,
+		struct rte_vhost_async_status *opaque_data,
+		uint16_t max_packets __rte_unused)
+{
+	if (!opaque_data) {
+		uintptr_t dump[255];
+		return rte_ioat_completed_copies(dma_bind[vid].dmas[queue_id * 2
+			+ VIRTIO_RXQ].dev_id, 255, dump, dump);
+	} else {
+		/* Opaque data is not supported */
+		return -1;
+	}
+}
 
 static unsigned lcore_ids[RTE_MAX_LCORE];
 static uint16_t ports[RTE_MAX_ETHPORTS];
@@ -206,6 +263,11 @@ struct mbuf_table lcore_tx_queue[RTE_MAX_LCORE];
 				 / US_PER_S * BURST_TX_DRAIN_US)
 #define VLAN_HLEN       4
 
+/*
+ * Builds up the correct configuration for VMDQ VLAN pool map
+ * according to the pool & queue limits.
+ */
+
 static inline int
 open_dma(const char *value, void *dma_bind_info)
 {
@@ -297,10 +359,6 @@ open_dma(const char *value, void *dma_bind_info)
 	return ret;
 }
 
-/*
- * Builds up the correct configuration for VMDQ VLAN pool map
- * according to the pool & queue limits.
- */
 static inline int
 get_eth_conf(struct rte_eth_conf *eth_conf, uint32_t num_devices)
 {
@@ -911,9 +969,26 @@ virtio_xmit(struct vhost_dev *dst_vdev, struct vhost_dev *src_vdev,
 	    struct rte_mbuf *m)
 {
 	uint16_t ret;
+	struct rte_mbuf *m_cpl[1];
 
 	if (builtin_net_driver) {
 		ret = vs_enqueue_pkts(dst_vdev, VIRTIO_RXQ, &m, 1);
+	} else if (async_vhost_driver) {
+		ret = rte_vhost_submit_enqueue_burst(dst_vdev->vid, VIRTIO_RXQ,
+						&m, 1);
+
+		if (likely(ret)) {
+			dst_vdev->nr_async_pkts++;
+			rte_mbuf_refcnt_update(m, 1);
+		}
+
+		while (likely(dst_vdev->nr_async_pkts)) {
+			if (rte_vhost_poll_enqueue_completed(dst_vdev->vid,
+					VIRTIO_RXQ, m_cpl, 1)) {
+				dst_vdev->nr_async_pkts--;
+				rte_pktmbuf_free(*m_cpl);
+			}
+		}
 	} else {
 		ret = rte_vhost_enqueue_burst(dst_vdev->vid, VIRTIO_RXQ, &m, 1);
 	}
@@ -1162,6 +1237,19 @@ drain_mbuf_table(struct mbuf_table *tx_q)
 	}
 }
 
+static __rte_always_inline void
+complete_async_pkts(struct vhost_dev *vdev, uint16_t qid)
+{
+	struct rte_mbuf *p_cpl[MAX_PKT_BURST];
+	uint16_t complete_count;
+
+	complete_count = rte_vhost_poll_enqueue_completed(vdev->vid,
+						qid, p_cpl, MAX_PKT_BURST);
+	vdev->nr_async_pkts -= complete_count;
+	if (complete_count)
+		free_pkts(p_cpl, complete_count);
+}
+
 static __rte_always_inline void
 drain_eth_rx(struct vhost_dev *vdev)
 {
@@ -1170,6 +1258,10 @@ drain_eth_rx(struct vhost_dev *vdev)
 
 	rx_count = rte_eth_rx_burst(ports[0], vdev->vmdq_rx_q,
 				    pkts, MAX_PKT_BURST);
+
+	while (likely(vdev->nr_async_pkts))
+		complete_async_pkts(vdev, VIRTIO_RXQ);
+
 	if (!rx_count)
 		return;
 
@@ -1194,16 +1286,22 @@ drain_eth_rx(struct vhost_dev *vdev)
 	if (builtin_net_driver) {
 		enqueue_count = vs_enqueue_pkts(vdev, VIRTIO_RXQ,
 						pkts, rx_count);
+	} else if (async_vhost_driver) {
+		enqueue_count = rte_vhost_submit_enqueue_burst(vdev->vid,
+					VIRTIO_RXQ, pkts, rx_count);
+		vdev->nr_async_pkts += enqueue_count;
 	} else {
 		enqueue_count = rte_vhost_enqueue_burst(vdev->vid, VIRTIO_RXQ,
 						pkts, rx_count);
 	}
+
 	if (enable_stats) {
 		rte_atomic64_add(&vdev->stats.rx_total_atomic, rx_count);
 		rte_atomic64_add(&vdev->stats.rx_atomic, enqueue_count);
 	}
 
-	free_pkts(pkts, rx_count);
+	if (!async_vhost_driver)
+		free_pkts(pkts, rx_count);
 }
 
 static __rte_always_inline void
@@ -1350,6 +1448,9 @@ destroy_device(int vid)
 		"(%d) device has been removed from data core\n",
 		vdev->vid);
 
+	if (async_vhost_driver)
+		rte_vhost_async_channel_unregister(vid, VIRTIO_RXQ);
+
 	rte_free(vdev);
 }
 
@@ -1364,6 +1465,12 @@ new_device(int vid)
 	uint32_t device_num_min = num_devices;
 	struct vhost_dev *vdev;
 
+	struct rte_vhost_async_channel_ops channel_ops = {
+		.transfer_data = ioat_transfer_data_cb,
+		.check_completed_copies = ioat_check_completed_copies_cb
+	};
+	struct rte_vhost_async_features f;
+
 	vdev = rte_zmalloc("vhost device", sizeof(*vdev), RTE_CACHE_LINE_SIZE);
 	if (vdev == NULL) {
 		RTE_LOG(INFO, VHOST_DATA,
@@ -1404,6 +1511,13 @@ new_device(int vid)
 		"(%d) device has been added to data core %d\n",
 		vid, vdev->coreid);
 
+	if (async_vhost_driver) {
+		f.async_inorder = 1;
+		f.async_threshold = 256;
+		return rte_vhost_async_channel_register(vid, VIRTIO_RXQ,
+			f.intval, &channel_ops);
+	}
+
 	return 0;
 }
 
@@ -1645,6 +1759,9 @@ main(int argc, char *argv[])
 	/* Register vhost user driver to handle vhost messages. */
 	for (i = 0; i < nb_sockets; i++) {
 		char *file = socket_files + i * PATH_MAX;
+		if (async_vhost_driver)
+			flags = flags | RTE_VHOST_USER_ASYNC_COPY;
+
 		ret = rte_vhost_driver_register(file, flags);
 		if (ret != 0) {
 			unregister_drivers(i);
diff --git a/examples/vhost/main.h b/examples/vhost/main.h
index 7cba0edbf..4317b6ae8 100644
--- a/examples/vhost/main.h
+++ b/examples/vhost/main.h
@@ -51,6 +51,7 @@ struct vhost_dev {
 	uint64_t features;
 	size_t hdr_len;
 	uint16_t nr_vrings;
+	uint16_t nr_async_pkts;
 	struct rte_vhost_memory *mem;
 	struct device_statistics stats;
 	TAILQ_ENTRY(vhost_dev) global_vdev_entry;
-- 
2.27.0