[v4,2/2] examples/vhost: refactor vhost data path

  Change the vm2vm data path to batch enqueue for better performance.
Support latest async vhost API, refactor vhost async data path,
replase rte_atomicNN_xxx to atomic_XXX and clean some codes.

Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com>
---
 examples/vhost/main.c | 202 +++++++++++++++++++++++++++++++-----------
 examples/vhost/main.h |   7 +-
 2 files changed, 154 insertions(+), 55 deletions(-)
  

Hi Cheng,

Some comments are inline.

Thanks,
Jiayu
> -----Original Message-----
> From: Jiang, Cheng1 <cheng1.jiang@intel.com>
> Sent: Friday, December 25, 2020 4:07 PM
> To: maxime.coquelin@redhat.com; Xia, Chenbo <chenbo.xia@intel.com>
> Cc: dev@dpdk.org; Hu, Jiayu <jiayu.hu@intel.com>; Yang, YvonneX
> <yvonnex.yang@intel.com>; Jiang, Cheng1 <cheng1.jiang@intel.com>
> Subject: [PATCH v4 2/2] examples/vhost: refactor vhost data path
> 
> Change the vm2vm data path to batch enqueue for better performance.
> Support latest async vhost API, refactor vhost async data path,
> replase rte_atomicNN_xxx to atomic_XXX and clean some codes.

Typo: replase -> replace

> 
> Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com>
> ---
>  examples/vhost/main.c | 202 +++++++++++++++++++++++++++++++-----------
>  examples/vhost/main.h |   7 +-
>  2 files changed, 154 insertions(+), 55 deletions(-)
> 
> diff --git a/examples/vhost/main.c b/examples/vhost/main.c
> index 8d8c3038b..3ea12a474 100644
> --- a/examples/vhost/main.c
> +++ b/examples/vhost/main.c
> @@ -179,9 +179,18 @@ struct mbuf_table {
>  	struct rte_mbuf *m_table[MAX_PKT_BURST];
>  };
> 
> +struct vhost_bufftable {
> +	uint32_t len;
> +	uint64_t pre_tsc;
> +	struct rte_mbuf *m_table[MAX_PKT_BURST];
> +};
> +
>  /* TX queue for each data core. */
>  struct mbuf_table lcore_tx_queue[RTE_MAX_LCORE];
> 
> +/* TX queue for each vhost device. */

Every lcore maintains a TX buffer for every vhost device,
which is to batch pkts to enqueue for higher performance.
I suggest you to update the description of vhost_txbuff above,
as it is not very clear.

> +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)
>  #define VLAN_HLEN       4
> @@ -804,39 +813,114 @@ unlink_vmdq(struct vhost_dev *vdev)
>  	}
>  }
> 
> +static inline void
> +free_pkts(struct rte_mbuf **pkts, uint16_t n)
> +{
> +	while (n--)
> +		rte_pktmbuf_free(pkts[n]);
> +}
> +
>  static __rte_always_inline void
> -virtio_xmit(struct vhost_dev *dst_vdev, struct vhost_dev *src_vdev,
> +complete_async_pkts(struct vhost_dev *vdev)
> +{
> +	struct rte_mbuf *p_cpl[MAX_PKT_BURST];
> +	uint16_t complete_count;
> +
> +	complete_count = rte_vhost_poll_enqueue_completed(vdev->vid,
> +					VIRTIO_RXQ, p_cpl,
> MAX_PKT_BURST);
> +	if (complete_count) {
> +		atomic_fetch_sub(&vdev->nr_async_pkts, complete_count);
> +		free_pkts(p_cpl, complete_count);
> +	}
> +}
> +
> +static __rte_always_inline void
> +sync_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++;
> -
> -		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--;
> -		}
>  	} else {
>  		ret = rte_vhost_enqueue_burst(dst_vdev->vid, VIRTIO_RXQ,
> &m, 1);
>  	}
> 
>  	if (enable_stats) {
> -		rte_atomic64_inc(&dst_vdev->stats.rx_total_atomic);
> -		rte_atomic64_add(&dst_vdev->stats.rx_atomic, ret);
> +		atomic_fetch_add(&dst_vdev->stats.rx_total_atomic, 1);
> +		atomic_fetch_add(&dst_vdev->stats.rx_atomic, ret);
>  		src_vdev->stats.tx_total++;
>  		src_vdev->stats.tx += ret;
>  	}
>  }
> 
> +static __rte_always_inline void
> +drain_vhost(struct vhost_dev *vdev)
> +{
> +	uint16_t ret;
> +	uint64_t queue_id = rte_lcore_id() * MAX_VHOST_DEVICE + vdev-
> >vid;
> +	uint16_t nr_xmit = vhost_txbuff[queue_id]->len;
> +	struct rte_mbuf **m = vhost_txbuff[queue_id]->m_table;

"queue_id" is not a very good name, as it's not the queue id of vhost device,
but a buffer index which holds pkts to enqueue.

> +
> +	if (builtin_net_driver) {
> +		ret = vs_enqueue_pkts(vdev, VIRTIO_RXQ, m, nr_xmit);
> +	} else if (async_vhost_driver) {
> +		uint32_t cpu_cpl_nr = 0;
> +		uint16_t enqueue_fail = 0;
> +		struct rte_mbuf *m_cpu_cpl[nr_xmit];
> +
> +		complete_async_pkts(vdev);
> +		ret = rte_vhost_submit_enqueue_burst(vdev->vid,
> VIRTIO_RXQ,
> +					m, nr_xmit, m_cpu_cpl, &cpu_cpl_nr);
> +		atomic_fetch_add(&vdev->nr_async_pkts, ret - cpu_cpl_nr);
> +
> +		if (cpu_cpl_nr)
> +			free_pkts(m_cpu_cpl, cpu_cpl_nr);
> +
> +		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);
> +	}
> +
> +	if (enable_stats) {
> +		atomic_fetch_add(&vdev->stats.rx_total_atomic, nr_xmit);
> +		atomic_fetch_add(&vdev->stats.rx_atomic, ret);
> +	}
> +
> +	if (!async_vhost_driver)
> +		free_pkts(m, nr_xmit);
> +}
> +
> +static __rte_always_inline void
> +drain_vhost_table(void)
> +{
> +	const uint16_t lcore_id = rte_lcore_id();
> +	struct vhost_bufftable *vhost_txq;
> +	struct vhost_dev *vdev;
> +	uint64_t cur_tsc;
> +
> +	TAILQ_FOREACH(vdev, &lcore_info[lcore_id].vdev_list,
> lcore_vdev_entry) {

A lcore may have pkts to enqueue for any vhost device, as it's
decided by mac address. So drain_vhost_table() shouldn't just
process vhost ports allocated to its lcore, but all vhost ports that
have un-sent packets.

> +		if (!vdev->remove) {
> +			vhost_txq = vhost_txbuff[lcore_id *
> MAX_VHOST_DEVICE
> +					+ vdev->vid];
> +			cur_tsc = rte_rdtsc();
> +
> +			if (unlikely(cur_tsc - vhost_txq->pre_tsc
> +					> MBUF_TABLE_DRAIN_TSC)) {
> +				RTE_LOG_DP(DEBUG, VHOST_DATA,
> +					"Vhost tX queue drained after

"tX" -> "TX"

> timeout with burst size %u\n",
> +					vhost_txq->len);
> +				drain_vhost(vdev);
> +				vhost_txq->len = 0;
> +				vhost_txq->pre_tsc = cur_tsc;
> +			}
> +		}
> +	}
> +}
> +
>  /*
>   * Check if the packet destination MAC address is for a local device. If so then
> put
>   * the packet on that devices RX queue. If not then return.
> @@ -846,7 +930,8 @@ virtio_tx_local(struct vhost_dev *vdev, struct
> rte_mbuf *m)
>  {
>  	struct rte_ether_hdr *pkt_hdr;
>  	struct vhost_dev *dst_vdev;
> -
> +	struct vhost_bufftable *vhost_txq;
> +	const uint16_t lcore_id = rte_lcore_id();

Why use "const"?

>  	pkt_hdr = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
> 
>  	dst_vdev = find_vhost_dev(&pkt_hdr->d_addr);
> @@ -869,7 +954,19 @@ virtio_tx_local(struct vhost_dev *vdev, struct
> rte_mbuf *m)
>  		return 0;
>  	}
> 
> -	virtio_xmit(dst_vdev, vdev, m);
> +	vhost_txq = vhost_txbuff[lcore_id * MAX_VHOST_DEVICE + dst_vdev-
> >vid];
> +	vhost_txq->m_table[vhost_txq->len++] = m;
> +
> +	if (enable_stats) {
> +		vdev->stats.tx_total++;
> +		vdev->stats.tx++;
> +	}
> +
> +	if (unlikely(vhost_txq->len == MAX_PKT_BURST)) {
> +		drain_vhost(dst_vdev);
> +		vhost_txq->len = 0;
> +		vhost_txq->pre_tsc = rte_rdtsc();
> +	}
>  	return 0;
>  }
> 
> @@ -940,13 +1037,6 @@ static void virtio_tx_offload(struct rte_mbuf *m)
>  	tcp_hdr->cksum = get_psd_sum(l3_hdr, m->ol_flags);
>  }
> 
> -static inline void
> -free_pkts(struct rte_mbuf **pkts, uint16_t n)
> -{
> -	while (n--)
> -		rte_pktmbuf_free(pkts[n]);
> -}
> -
>  static __rte_always_inline void
>  do_drain_mbuf_table(struct mbuf_table *tx_q)
>  {
> @@ -979,16 +1069,14 @@ virtio_tx_route(struct vhost_dev *vdev, struct
> rte_mbuf *m, uint16_t vlan_tag)
> 
>  		TAILQ_FOREACH(vdev2, &vhost_dev_list, global_vdev_entry)
> {
>  			if (vdev2 != vdev)
> -				virtio_xmit(vdev2, vdev, m);
> +				sync_virtio_xmit(vdev2, vdev, m);
>  		}
>  		goto queue2nic;
>  	}
> 
>  	/*check if destination is local VM*/
> -	if ((vm2vm_mode == VM2VM_SOFTWARE) && (virtio_tx_local(vdev,
> m) == 0)) {
> -		rte_pktmbuf_free(m);
> +	if ((vm2vm_mode == VM2VM_SOFTWARE) && (virtio_tx_local(vdev,
> m) == 0))
>  		return;
> -	}
> 
>  	if (unlikely(vm2vm_mode == VM2VM_HARDWARE)) {
>  		if (unlikely(find_local_dest(vdev, m, &offset,
> @@ -1073,19 +1161,6 @@ 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)
>  {
> @@ -1095,9 +1170,6 @@ 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;
> 
> @@ -1123,17 +1195,31 @@ drain_eth_rx(struct vhost_dev *vdev)
>  		enqueue_count = vs_enqueue_pkts(vdev, VIRTIO_RXQ,
>  						pkts, rx_count);
>  	} else if (async_vhost_driver) {
> +		uint32_t cpu_cpl_nr = 0;
> +		uint16_t enqueue_fail = 0;
> +		struct rte_mbuf *m_cpu_cpl[MAX_PKT_BURST];
> +
> +		complete_async_pkts(vdev);
>  		enqueue_count = rte_vhost_submit_enqueue_burst(vdev-
> >vid,
> -					VIRTIO_RXQ, pkts, rx_count);
> -		vdev->nr_async_pkts += enqueue_count;
> +					VIRTIO_RXQ, pkts, rx_count,
> +					m_cpu_cpl, &cpu_cpl_nr);
> +		atomic_fetch_add(&vdev->nr_async_pkts,
> +					enqueue_count - cpu_cpl_nr);
> +		if (cpu_cpl_nr)
> +			free_pkts(m_cpu_cpl, cpu_cpl_nr);
> +
> +		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);
>  	}
> 
>  	if (enable_stats) {
> -		rte_atomic64_add(&vdev->stats.rx_total_atomic, rx_count);
> -		rte_atomic64_add(&vdev->stats.rx_atomic, enqueue_count);
> +		atomic_fetch_add(&vdev->stats.rx_total_atomic, rx_count);
> +		atomic_fetch_add(&vdev->stats.rx_atomic, enqueue_count);
>  	}
> 
>  	if (!async_vhost_driver)
> @@ -1202,7 +1288,7 @@ switch_worker(void *arg __rte_unused)
> 
>  	while(1) {
>  		drain_mbuf_table(tx_q);
> -
> +		drain_vhost_table();
>  		/*
>  		 * Inform the configuration core that we have exited the
>  		 * linked list and that no devices are in use if requested.
> @@ -1298,6 +1384,7 @@ static int
>  new_device(int vid)
>  {
>  	int lcore, core_add = 0;
> +	uint16_t i;
>  	uint32_t device_num_min = num_devices;
>  	struct vhost_dev *vdev;
>  	vdev = rte_zmalloc("vhost device", sizeof(*vdev),
> RTE_CACHE_LINE_SIZE);
> @@ -1309,6 +1396,13 @@ new_device(int vid)
>  	}
>  	vdev->vid = vid;
> 
> +	for (i = 0; i < RTE_MAX_LCORE; i++) {
> +		vhost_txbuff[i * MAX_VHOST_DEVICE + vid]
> +			= rte_zmalloc("vhost bufftable",
> +				sizeof(struct vhost_bufftable),
> +				RTE_CACHE_LINE_SIZE);

Rte_zmalloc() may fail. Need to handle failure.

> +	}
> +
>  	if (builtin_net_driver)
>  		vs_vhost_net_setup(vdev);
> 
> @@ -1343,12 +1437,15 @@ new_device(int vid)
>  	if (async_vhost_driver) {
>  		struct rte_vhost_async_features f;
>  		struct rte_vhost_async_channel_ops channel_ops;
> +
>  		if (strncmp(dma_type, "ioat", 4) == 0) {
>  			channel_ops.transfer_data = ioat_transfer_data_cb;
>  			channel_ops.check_completed_copies =
>  				ioat_check_completed_copies_cb;
> +
>  			f.async_inorder = 1;
>  			f.async_threshold = 256;
> +
>  			return rte_vhost_async_channel_register(vid,
> VIRTIO_RXQ,
>  				f.intval, &channel_ops);
>  		}
> @@ -1392,8 +1489,8 @@ print_stats(__rte_unused void *arg)
>  			tx         = vdev->stats.tx;
>  			tx_dropped = tx_total - tx;
> 
> -			rx_total   = rte_atomic64_read(&vdev-
> >stats.rx_total_atomic);
> -			rx         = rte_atomic64_read(&vdev->stats.rx_atomic);
> +			rx_total   = atomic_load(&vdev-
> >stats.rx_total_atomic);
> +			rx         = atomic_load(&vdev->stats.rx_atomic);
>  			rx_dropped = rx_total - rx;
> 
>  			printf("Statistics for device %d\n"
> @@ -1592,6 +1689,7 @@ 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;
> 
> diff --git a/examples/vhost/main.h b/examples/vhost/main.h
> index 4317b6ae8..6aa798a3e 100644
> --- a/examples/vhost/main.h
> +++ b/examples/vhost/main.h
> @@ -8,6 +8,7 @@
>  #include <sys/queue.h>
> 
>  #include <rte_ether.h>
> +#include <stdatomic.h>
> 
>  /* Macros for printing using RTE_LOG */
>  #define RTE_LOGTYPE_VHOST_CONFIG RTE_LOGTYPE_USER1
> @@ -21,8 +22,8 @@ enum {VIRTIO_RXQ, VIRTIO_TXQ, VIRTIO_QNUM};
>  struct device_statistics {
>  	uint64_t	tx;
>  	uint64_t	tx_total;
> -	rte_atomic64_t	rx_atomic;
> -	rte_atomic64_t	rx_total_atomic;
> +	atomic_int_least64_t	rx_atomic;
> +	atomic_int_least64_t	rx_total_atomic;
>  };
> 
>  struct vhost_queue {
> @@ -51,7 +52,7 @@ struct vhost_dev {
>  	uint64_t features;
>  	size_t hdr_len;
>  	uint16_t nr_vrings;
> -	uint16_t nr_async_pkts;
> +	atomic_int_least16_t nr_async_pkts;
>  	struct rte_vhost_memory *mem;
>  	struct device_statistics stats;
>  	TAILQ_ENTRY(vhost_dev) global_vdev_entry;
> --
> 2.29.2
  

Hi Jiayu,


> -----Original Message-----
> From: Hu, Jiayu <jiayu.hu@intel.com>
> Sent: Monday, December 28, 2020 12:04 PM
> To: Jiang, Cheng1 <cheng1.jiang@intel.com>; maxime.coquelin@redhat.com;
> Xia, Chenbo <chenbo.xia@intel.com>
> Cc: dev@dpdk.org; Yang, YvonneX <yvonnex.yang@intel.com>
> Subject: RE: [PATCH v4 2/2] examples/vhost: refactor vhost data path
> 
> Hi Cheng,
> 
> Some comments are inline.
> 
> Thanks,
> Jiayu
> > -----Original Message-----
> > From: Jiang, Cheng1 <cheng1.jiang@intel.com>
> > Sent: Friday, December 25, 2020 4:07 PM
> > To: maxime.coquelin@redhat.com; Xia, Chenbo <chenbo.xia@intel.com>
> > Cc: dev@dpdk.org; Hu, Jiayu <jiayu.hu@intel.com>; Yang, YvonneX
> > <yvonnex.yang@intel.com>; Jiang, Cheng1 <cheng1.jiang@intel.com>
> > Subject: [PATCH v4 2/2] examples/vhost: refactor vhost data path
> >
> > Change the vm2vm data path to batch enqueue for better performance.
> > Support latest async vhost API, refactor vhost async data path,
> > replase rte_atomicNN_xxx to atomic_XXX and clean some codes.
> 
> Typo: replase -> replace

I'll fix it in the next version.

> 
> >
> > Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com>
> > ---
> >  examples/vhost/main.c | 202 +++++++++++++++++++++++++++++++-----
> ------
> >  examples/vhost/main.h |   7 +-
> >  2 files changed, 154 insertions(+), 55 deletions(-)
> >
> > diff --git a/examples/vhost/main.c b/examples/vhost/main.c index
> > 8d8c3038b..3ea12a474 100644
> > --- a/examples/vhost/main.c
> > +++ b/examples/vhost/main.c
> > @@ -179,9 +179,18 @@ struct mbuf_table {  struct rte_mbuf
> > *m_table[MAX_PKT_BURST];  };
> >
> > +struct vhost_bufftable {
> > +uint32_t len;
> > +uint64_t pre_tsc;
> > +struct rte_mbuf *m_table[MAX_PKT_BURST]; };
> > +
> >  /* TX queue for each data core. */
> >  struct mbuf_table lcore_tx_queue[RTE_MAX_LCORE];
> >
> > +/* TX queue for each vhost device. */
> 
> Every lcore maintains a TX buffer for every vhost device, which is to batch
> pkts to enqueue for higher performance.
> I suggest you to update the description of vhost_txbuff above, as it is not
> very clear.

Sure, will add some comments in the next version.

> 
> > +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)
> >  #define VLAN_HLEN       4
> > @@ -804,39 +813,114 @@ unlink_vmdq(struct vhost_dev *vdev)  }  }
> >
> > +static inline void
> > +free_pkts(struct rte_mbuf **pkts, uint16_t n) { while (n--)
> > +rte_pktmbuf_free(pkts[n]); }
> > +
> >  static __rte_always_inline void
> > -virtio_xmit(struct vhost_dev *dst_vdev, struct vhost_dev *src_vdev,
> > +complete_async_pkts(struct vhost_dev *vdev) { struct rte_mbuf
> > +*p_cpl[MAX_PKT_BURST]; uint16_t complete_count;
> > +
> > +complete_count = rte_vhost_poll_enqueue_completed(vdev->vid,
> > +VIRTIO_RXQ, p_cpl,
> > MAX_PKT_BURST);
> > +if (complete_count) {
> > +atomic_fetch_sub(&vdev->nr_async_pkts, complete_count);
> > +free_pkts(p_cpl, complete_count); } }
> > +
> > +static __rte_always_inline void
> > +sync_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++;
> > -
> > -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--;
> > -}
> >  } else {
> >  ret = rte_vhost_enqueue_burst(dst_vdev->vid, VIRTIO_RXQ, &m, 1);  }
> >
> >  if (enable_stats) {
> > -rte_atomic64_inc(&dst_vdev->stats.rx_total_atomic);
> > -rte_atomic64_add(&dst_vdev->stats.rx_atomic, ret);
> > +atomic_fetch_add(&dst_vdev->stats.rx_total_atomic, 1);
> > +atomic_fetch_add(&dst_vdev->stats.rx_atomic, ret);
> >  src_vdev->stats.tx_total++;
> >  src_vdev->stats.tx += ret;
> >  }
> >  }
> >
> > +static __rte_always_inline void
> > +drain_vhost(struct vhost_dev *vdev)
> > +{
> > +uint16_t ret;
> > +uint64_t queue_id = rte_lcore_id() * MAX_VHOST_DEVICE + vdev-
> > >vid;
> > +uint16_t nr_xmit = vhost_txbuff[queue_id]->len; struct rte_mbuf **m =
> > +vhost_txbuff[queue_id]->m_table;
> 
> "queue_id" is not a very good name, as it's not the queue id of vhost device,
> but a buffer index which holds pkts to enqueue.

Sure, I will change it to buff_idx.

> 
> > +
> > +if (builtin_net_driver) {
> > +ret = vs_enqueue_pkts(vdev, VIRTIO_RXQ, m, nr_xmit); } else if
> > +(async_vhost_driver) { uint32_t cpu_cpl_nr = 0; uint16_t enqueue_fail
> > += 0; struct rte_mbuf *m_cpu_cpl[nr_xmit];
> > +
> > +complete_async_pkts(vdev);
> > +ret = rte_vhost_submit_enqueue_burst(vdev->vid,
> > VIRTIO_RXQ,
> > +m, nr_xmit, m_cpu_cpl, &cpu_cpl_nr);
> > +atomic_fetch_add(&vdev->nr_async_pkts, ret - cpu_cpl_nr);
> > +
> > +if (cpu_cpl_nr)
> > +free_pkts(m_cpu_cpl, cpu_cpl_nr);
> > +
> > +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); }
> > +
> > +if (enable_stats) {
> > +atomic_fetch_add(&vdev->stats.rx_total_atomic, nr_xmit);
> > +atomic_fetch_add(&vdev->stats.rx_atomic, ret); }
> > +
> > +if (!async_vhost_driver)
> > +free_pkts(m, nr_xmit);
> > +}
> > +
> > +static __rte_always_inline void
> > +drain_vhost_table(void)
> > +{
> > +const uint16_t lcore_id = rte_lcore_id(); struct vhost_bufftable
> > +*vhost_txq; struct vhost_dev *vdev; uint64_t cur_tsc;
> > +
> > +TAILQ_FOREACH(vdev, &lcore_info[lcore_id].vdev_list,
> > lcore_vdev_entry) {
> 
> A lcore may have pkts to enqueue for any vhost device, as it's decided by
> mac address. So drain_vhost_table() shouldn't just process vhost ports
> allocated to its lcore, but all vhost ports that have un-sent packets.

Sure, I will fix it in the next version.

> 
> > +if (!vdev->remove) {
> > +vhost_txq = vhost_txbuff[lcore_id *
> > MAX_VHOST_DEVICE
> > ++ vdev->vid];
> > +cur_tsc = rte_rdtsc();
> > +
> > +if (unlikely(cur_tsc - vhost_txq->pre_tsc
> > +> MBUF_TABLE_DRAIN_TSC)) {
> > +RTE_LOG_DP(DEBUG, VHOST_DATA,
> > +"Vhost tX queue drained after
> 
> "tX" -> "TX"

I will fix it in the next version.

> 
> > timeout with burst size %u\n",
> > +vhost_txq->len);
> > +drain_vhost(vdev);
> > +vhost_txq->len = 0;
> > +vhost_txq->pre_tsc = cur_tsc;
> > +}
> > +}
> > +}
> > +}
> > +
> >  /*
> >   * Check if the packet destination MAC address is for a local device.
> > If so then put
> >   * the packet on that devices RX queue. If not then return.
> > @@ -846,7 +930,8 @@ virtio_tx_local(struct vhost_dev *vdev, struct
> > rte_mbuf *m)  {  struct rte_ether_hdr *pkt_hdr;  struct vhost_dev
> > *dst_vdev;
> > -
> > +struct vhost_bufftable *vhost_txq;
> > +const uint16_t lcore_id = rte_lcore_id();
> 
> Why use "const"?

No particular reason, maybe I just forget to delete it. I will fix it in the next version.

> 
> >  pkt_hdr = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
> >
> >  dst_vdev = find_vhost_dev(&pkt_hdr->d_addr); @@ -869,7 +954,19 @@
> > virtio_tx_local(struct vhost_dev *vdev, struct rte_mbuf *m)  return 0;
> > }
> >
> > -virtio_xmit(dst_vdev, vdev, m);
> > +vhost_txq = vhost_txbuff[lcore_id * MAX_VHOST_DEVICE + dst_vdev-
> > >vid];
> > +vhost_txq->m_table[vhost_txq->len++] = m;
> > +
> > +if (enable_stats) {
> > +vdev->stats.tx_total++;
> > +vdev->stats.tx++;
> > +}
> > +
> > +if (unlikely(vhost_txq->len == MAX_PKT_BURST)) {
> > +drain_vhost(dst_vdev); vhost_txq->len = 0; vhost_txq->pre_tsc =
> > +rte_rdtsc(); }
> >  return 0;
> >  }
> >
> > @@ -940,13 +1037,6 @@ static void virtio_tx_offload(struct rte_mbuf
> > *m)  tcp_hdr->cksum = get_psd_sum(l3_hdr, m->ol_flags);  }
> >
> > -static inline void
> > -free_pkts(struct rte_mbuf **pkts, uint16_t n) -{ -while (n--)
> > -rte_pktmbuf_free(pkts[n]); -}
> > -
> >  static __rte_always_inline void
> >  do_drain_mbuf_table(struct mbuf_table *tx_q)  { @@ -979,16 +1069,14
> > @@ virtio_tx_route(struct vhost_dev *vdev, struct rte_mbuf *m,
> > uint16_t vlan_tag)
> >
> >  TAILQ_FOREACH(vdev2, &vhost_dev_list, global_vdev_entry) {  if (vdev2
> > != vdev) -virtio_xmit(vdev2, vdev, m);
> > +sync_virtio_xmit(vdev2, vdev, m);
> >  }
> >  goto queue2nic;
> >  }
> >
> >  /*check if destination is local VM*/
> > -if ((vm2vm_mode == VM2VM_SOFTWARE) && (virtio_tx_local(vdev,
> > m) == 0)) {
> > -rte_pktmbuf_free(m);
> > +if ((vm2vm_mode == VM2VM_SOFTWARE) && (virtio_tx_local(vdev,
> > m) == 0))
> >  return;
> > -}
> >
> >  if (unlikely(vm2vm_mode == VM2VM_HARDWARE)) {  if
> > (unlikely(find_local_dest(vdev, m, &offset, @@ -1073,19 +1161,6 @@
> > 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)
> >  {
> > @@ -1095,9 +1170,6 @@ 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;
> >
> > @@ -1123,17 +1195,31 @@ drain_eth_rx(struct vhost_dev *vdev)
> > enqueue_count = vs_enqueue_pkts(vdev, VIRTIO_RXQ,  pkts, rx_count);  }
> > else if (async_vhost_driver) {
> > +uint32_t cpu_cpl_nr = 0;
> > +uint16_t enqueue_fail = 0;
> > +struct rte_mbuf *m_cpu_cpl[MAX_PKT_BURST];
> > +
> > +complete_async_pkts(vdev);
> >  enqueue_count = rte_vhost_submit_enqueue_burst(vdev-
> > >vid,
> > -VIRTIO_RXQ, pkts, rx_count);
> > -vdev->nr_async_pkts += enqueue_count;
> > +VIRTIO_RXQ, pkts, rx_count,
> > +m_cpu_cpl, &cpu_cpl_nr);
> > +atomic_fetch_add(&vdev->nr_async_pkts,
> > +enqueue_count - cpu_cpl_nr);
> > +if (cpu_cpl_nr)
> > +free_pkts(m_cpu_cpl, cpu_cpl_nr);
> > +
> > +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);
> >  }
> >
> >  if (enable_stats) {
> > -rte_atomic64_add(&vdev->stats.rx_total_atomic, rx_count);
> > -rte_atomic64_add(&vdev->stats.rx_atomic, enqueue_count);
> > +atomic_fetch_add(&vdev->stats.rx_total_atomic, rx_count);
> > +atomic_fetch_add(&vdev->stats.rx_atomic, enqueue_count);
> >  }
> >
> >  if (!async_vhost_driver)
> > @@ -1202,7 +1288,7 @@ switch_worker(void *arg __rte_unused)
> >
> >  while(1) {
> >  drain_mbuf_table(tx_q);
> > -
> > +drain_vhost_table();
> >  /*
> >   * Inform the configuration core that we have exited the
> >   * linked list and that no devices are in use if requested.
> > @@ -1298,6 +1384,7 @@ static int
> >  new_device(int vid)
> >  {
> >  int lcore, core_add = 0;
> > +uint16_t i;
> >  uint32_t device_num_min = num_devices;  struct vhost_dev *vdev;  vdev
> > = rte_zmalloc("vhost device", sizeof(*vdev), RTE_CACHE_LINE_SIZE); @@
> > -1309,6 +1396,13 @@ new_device(int vid)  }  vdev->vid = vid;
> >
> > +for (i = 0; i < RTE_MAX_LCORE; i++) { vhost_txbuff[i *
> > +MAX_VHOST_DEVICE + vid] = rte_zmalloc("vhost bufftable",
> > +sizeof(struct vhost_bufftable), RTE_CACHE_LINE_SIZE);
> 
> Rte_zmalloc() may fail. Need to handle failure.

Sure, I will add failure handler in the next version.

Thanks.
Cheng

> 
> > +}
> > +
> >  if (builtin_net_driver)
> >  vs_vhost_net_setup(vdev);
> >
> > @@ -1343,12 +1437,15 @@ new_device(int vid)  if (async_vhost_driver) {
> > struct rte_vhost_async_features f;  struct rte_vhost_async_channel_ops
> > channel_ops;
> > +
> >  if (strncmp(dma_type, "ioat", 4) == 0) {  channel_ops.transfer_data =
> > ioat_transfer_data_cb;  channel_ops.check_completed_copies =
> > ioat_check_completed_copies_cb;
> > +
> >  f.async_inorder = 1;
> >  f.async_threshold = 256;
> > +
> >  return rte_vhost_async_channel_register(vid,
> > VIRTIO_RXQ,
> >  f.intval, &channel_ops);
> >  }
> > @@ -1392,8 +1489,8 @@ print_stats(__rte_unused void *arg)
> >  tx         = vdev->stats.tx;
> >  tx_dropped = tx_total - tx;
> >
> > -rx_total   = rte_atomic64_read(&vdev-
> > >stats.rx_total_atomic);
> > -rx         = rte_atomic64_read(&vdev->stats.rx_atomic);
> > +rx_total   = atomic_load(&vdev-
> > >stats.rx_total_atomic);
> > +rx         = atomic_load(&vdev->stats.rx_atomic);
> >  rx_dropped = rx_total - rx;
> >
> >  printf("Statistics for device %d\n"
> > @@ -1592,6 +1689,7 @@ 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;
> >
> > diff --git a/examples/vhost/main.h b/examples/vhost/main.h index
> > 4317b6ae8..6aa798a3e 100644
> > --- a/examples/vhost/main.h
> > +++ b/examples/vhost/main.h
> > @@ -8,6 +8,7 @@
> >  #include <sys/queue.h>
> >
> >  #include <rte_ether.h>
> > +#include <stdatomic.h>
> >
> >  /* Macros for printing using RTE_LOG */  #define
> > RTE_LOGTYPE_VHOST_CONFIG RTE_LOGTYPE_USER1 @@ -21,8 +22,8 @@
> enum
> > {VIRTIO_RXQ, VIRTIO_TXQ, VIRTIO_QNUM};  struct device_statistics {
> > uint64_ttx;  uint64_ttx_total; -rte_atomic64_trx_atomic;
> > -rte_atomic64_trx_total_atomic;
> > +atomic_int_least64_trx_atomic;
> > +atomic_int_least64_trx_total_atomic;
> >  };
> >
> >  struct vhost_queue {
> > @@ -51,7 +52,7 @@ struct vhost_dev {
> >  uint64_t features;
> >  size_t hdr_len;
> >  uint16_t nr_vrings;
> > -uint16_t nr_async_pkts;
> > +atomic_int_least16_t nr_async_pkts;
> >  struct rte_vhost_memory *mem;
> >  struct device_statistics stats;
> >  TAILQ_ENTRY(vhost_dev) global_vdev_entry;
> > --
> > 2.29.2
>