[dpdk-dev] [PATCH v1 1/2] vhost: introduce async data path registration API

Maxime Coquelin maxime.coquelin at redhat.com
Fri Jun 26 16:28:38 CEST 2020



On 6/11/20 12:02 PM, patrick.fu at intel.com wrote:
> From: Patrick <patrick.fu at intel.com>
> 
> This patch introduces registration/un-registration APIs
> for async data path together with all required data
> structures and DMA callback function proto-types.
> 
> Signed-off-by: Patrick <patrick.fu at intel.com>
> ---
>  lib/librte_vhost/Makefile          |   3 +-
>  lib/librte_vhost/rte_vhost.h       |   1 +
>  lib/librte_vhost/rte_vhost_async.h | 134 +++++++++++++++++++++++++++++++++++++
>  lib/librte_vhost/socket.c          |  20 ++++++
>  lib/librte_vhost/vhost.c           |  74 +++++++++++++++++++-
>  lib/librte_vhost/vhost.h           |  30 ++++++++-
>  lib/librte_vhost/vhost_user.c      |  28 ++++++--
>  7 files changed, 283 insertions(+), 7 deletions(-)
>  create mode 100644 lib/librte_vhost/rte_vhost_async.h
> 
> diff --git a/lib/librte_vhost/Makefile b/lib/librte_vhost/Makefile
> index e592795..3aed094 100644
> --- a/lib/librte_vhost/Makefile
> +++ b/lib/librte_vhost/Makefile
> @@ -41,7 +41,8 @@ SRCS-$(CONFIG_RTE_LIBRTE_VHOST) := fd_man.c iotlb.c socket.c vhost.c \
>  					vhost_user.c virtio_net.c vdpa.c
>  
>  # install includes
> -SYMLINK-$(CONFIG_RTE_LIBRTE_VHOST)-include += rte_vhost.h rte_vdpa.h
> +SYMLINK-$(CONFIG_RTE_LIBRTE_VHOST)-include += rte_vhost.h rte_vdpa.h \
> +						rte_vhost_async.h
>  
>  # only compile vhost crypto when cryptodev is enabled
>  ifeq ($(CONFIG_RTE_LIBRTE_CRYPTODEV),y)
> diff --git a/lib/librte_vhost/rte_vhost.h b/lib/librte_vhost/rte_vhost.h
> index d43669f..cec4d07 100644
> --- a/lib/librte_vhost/rte_vhost.h
> +++ b/lib/librte_vhost/rte_vhost.h
> @@ -35,6 +35,7 @@
>  #define RTE_VHOST_USER_EXTBUF_SUPPORT	(1ULL << 5)
>  /* support only linear buffers (no chained mbufs) */
>  #define RTE_VHOST_USER_LINEARBUF_SUPPORT	(1ULL << 6)
> +#define RTE_VHOST_USER_ASYNC_COPY	(1ULL << 7)
>  
>  /** Protocol features. */
>  #ifndef VHOST_USER_PROTOCOL_F_MQ
> diff --git a/lib/librte_vhost/rte_vhost_async.h b/lib/librte_vhost/rte_vhost_async.h
> new file mode 100644
> index 0000000..82f2ebe
> --- /dev/null
> +++ b/lib/librte_vhost/rte_vhost_async.h
> @@ -0,0 +1,134 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2018 Intel Corporation
> + */
> +
> +#ifndef _RTE_VHOST_ASYNC_H_
> +#define _RTE_VHOST_ASYNC_H_
> +
> +#include "rte_vhost.h"
> +
> +/**
> + * iovec iterator
> + */
> +struct iov_it {
> +	/** offset to the first byte of interesting data */
> +	size_t offset;
> +	/** total bytes of data in this iterator */
> +	size_t count;
> +	/** pointer to the iovec array */
> +	struct iovec *iov;
> +	/** number of iovec in this iterator */
> +	unsigned long nr_segs;
> +};
> +
> +/**
> + * dma transfer descriptor pair
> + */
> +struct dma_trans_desc {
> +	/** source memory iov_it */
> +	struct iov_it *src;
> +	/** destination memory iov_it */
> +	struct iov_it *dst;
> +};
> +
> +/**
> + * dma transfer status
> + */
> +struct dma_trans_status {
> +	/** An array of application specific data for source memory */
> +	uintptr_t *src_opaque_data;
> +	/** An array of application specific data for destination memory */
> +	uintptr_t *dst_opaque_data;
> +};
> +
> +/**
> + * dma operation callbacks to be implemented by applications
> + */
> +struct rte_vhost_async_channel_ops {
> +	/**
> +	 * instruct a DMA channel to perform copies for a batch of packets
> +	 *
> +	 * @param vid
> +	 *  id of vhost device to perform data copies
> +	 * @param queue_id
> +	 *  queue id to perform data copies
> +	 * @param descs
> +	 *  an array of DMA transfer memory descriptors
> +	 * @param opaque_data
> +	 *  opaque data pair sending to DMA engine
> +	 * @param count
> +	 *  number of elements in the "descs" array
> +	 * @return
> +	 *  -1 on failure, number of descs processed on success
> +	 */
> +	int (*transfer_data)(int vid, uint16_t queue_id,
> +		struct dma_trans_desc *descs,
> +		struct dma_trans_status *opaque_data,
> +		uint16_t count);
> +	/**
> +	 * check copy-completed packets from a DMA channel
> +	 * @param vid
> +	 *  id of vhost device to check copy completion
> +	 * @param queue_id
> +	 *  queue id to check copyp completion
> +	 * @param opaque_data
> +	 *  buffer to receive the opaque data pair from DMA engine
> +	 * @param max_packets
> +	 *  max number of packets could be completed
> +	 * @return
> +	 *  -1 on failure, number of iov segments completed on success
> +	 */
> +	int (*check_completed_copies)(int vid, uint16_t queue_id,
> +		struct dma_trans_status *opaque_data,
> +		uint16_t max_packets);
> +};
> +
> +/**
> + *  dma channel feature bit definition
> + */
> +struct dma_channel_features {
> +	union {
> +		uint32_t intval;
> +		struct {
> +			uint32_t inorder:1;
> +			uint32_t resvd0115:15;
> +			uint32_t threshold:12;
> +			uint32_t resvd2831:4;
> +		};
> +	};
> +};
> +
> +/**
> + * register a dma channel for vhost
> + *
> + * @param vid
> + *  vhost device id DMA channel to be attached to
> + * @param queue_id
> + *  vhost queue id DMA channel to be attached to
> + * @param features
> + *  DMA channel feature bit
> + *    b0       : DMA supports inorder data transfer
> + *    b1  - b15: reserved
> + *    b16 - b27: Packet length threshold for DMA transfer
> + *    b28 - b31: reserved
> + * @param ops
> + *  DMA operation callbacks
> + * @return
> + *  0 on success, -1 on failures
> + */
> +int rte_vhost_async_channel_register(int vid, uint16_t queue_id,
> +	uint32_t features, struct rte_vhost_async_channel_ops *ops);
> +
> +/**
> + * unregister a dma channel for vhost
> + *
> + * @param vid
> + *  vhost device id DMA channel to be detached
> + * @param queue_id
> + *  vhost queue id DMA channel to be detached
> + * @return
> + *  0 on success, -1 on failures
> + */
> +int rte_vhost_async_channel_unregister(int vid, uint16_t queue_id);
> +
> +#endif /* _RTE_VDPA_H_ */
> diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
> index 0a66ef9..f817783 100644
> --- a/lib/librte_vhost/socket.c
> +++ b/lib/librte_vhost/socket.c
> @@ -42,6 +42,7 @@ struct vhost_user_socket {
>  	bool use_builtin_virtio_net;
>  	bool extbuf;
>  	bool linearbuf;
> +	bool async_copy;
>  
>  	/*
>  	 * The "supported_features" indicates the feature bits the
> @@ -210,6 +211,7 @@ struct vhost_user {
>  	size_t size;
>  	struct vhost_user_connection *conn;
>  	int ret;
> +	struct virtio_net *dev;
>  
>  	if (vsocket == NULL)
>  		return;
> @@ -241,6 +243,13 @@ struct vhost_user {
>  	if (vsocket->linearbuf)
>  		vhost_enable_linearbuf(vid);
>  
> +	if (vsocket->async_copy) {
> +		dev = get_device(vid);
> +
> +		if (dev)
> +			dev->async_copy = 1;
> +	}
> +
>  	VHOST_LOG_CONFIG(INFO, "new device, handle is %d\n", vid);
>  
>  	if (vsocket->notify_ops->new_connection) {
> @@ -891,6 +900,17 @@ struct vhost_user_reconnect_list {
>  		goto out_mutex;
>  	}
>  
> +	vsocket->async_copy = flags & RTE_VHOST_USER_ASYNC_COPY;
> +
> +	if (vsocket->async_copy &&
> +		(flags & (RTE_VHOST_USER_IOMMU_SUPPORT |
> +		RTE_VHOST_USER_POSTCOPY_SUPPORT))) {
> +		VHOST_LOG_CONFIG(ERR, "error: enabling async copy and IOMMU "
> +			"or post-copy feature simultaneously is not "
> +			"supported\n");
> +		goto out_mutex;
> +	}
> +

Have you ensure compatibility with the linearbuf feature (TSO)?
You will want to do same kind of check if not compatible.

>  	/*
>  	 * Set the supported features correctly for the builtin vhost-user
>  	 * net driver.
> diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
> index 0266318..e6b688a 100644
> --- a/lib/librte_vhost/vhost.c
> +++ b/lib/librte_vhost/vhost.c
> @@ -332,8 +332,13 @@
>  {
>  	if (vq_is_packed(dev))
>  		rte_free(vq->shadow_used_packed);
> -	else
> +	else {
>  		rte_free(vq->shadow_used_split);
> +		if (vq->async_pkts_pending)
> +			rte_free(vq->async_pkts_pending);
> +		if (vq->async_pending_info)
> +			rte_free(vq->async_pending_info);
> +	}
>  	rte_free(vq->batch_copy_elems);
>  	rte_mempool_free(vq->iotlb_pool);
>  	rte_free(vq);
> @@ -1527,3 +1532,70 @@ int rte_vhost_extern_callback_register(int vid,
>  	if (vhost_data_log_level >= 0)
>  		rte_log_set_level(vhost_data_log_level, RTE_LOG_WARNING);
>  }
> +
> +int rte_vhost_async_channel_register(int vid, uint16_t queue_id,
> +					uint32_t features,
> +					struct rte_vhost_async_channel_ops *ops)
> +{
> +	struct vhost_virtqueue *vq;
> +	struct virtio_net *dev = get_device(vid);
> +	struct dma_channel_features f;
> +
> +	if (dev == NULL || ops == NULL)
> +		return -1;
> +
> +	f.intval = features;
> +
> +	vq = dev->virtqueue[queue_id];
> +
> +	if (vq == NULL)
> +		return -1;
> +
> +	/** packed queue is not supported */
> +	if (vq_is_packed(dev) || !f.inorder)
> +		return -1;

You might want to print an error message to help the user understanding
why it fails.

> +
> +	if (ops->check_completed_copies == NULL ||
> +		ops->transfer_data == NULL)
> +		return -1;
> +
> +	rte_spinlock_lock(&vq->access_lock);
> +
> +	vq->async_ops.check_completed_copies = ops->check_completed_copies;
> +	vq->async_ops.transfer_data = ops->transfer_data;
> +
> +	vq->async_inorder = f.inorder;
> +	vq->async_threshold = f.threshold;
> +
> +	vq->async_registered = true;
> +
> +	rte_spinlock_unlock(&vq->access_lock);
> +
> +	return 0;
> +}
> +
> +int rte_vhost_async_channel_unregister(int vid, uint16_t queue_id)
> +{
> +	struct vhost_virtqueue *vq;
> +	struct virtio_net *dev = get_device(vid);
> +
> +	if (dev == NULL)
> +		return -1;
> +
> +	vq = dev->virtqueue[queue_id];
> +
> +	if (vq == NULL)
> +		return -1;
> +
> +	rte_spinlock_lock(&vq->access_lock);

We might want to wait all async transfers are done berfore
unregistering?

> +
> +	vq->async_ops.transfer_data = NULL;
> +	vq->async_ops.check_completed_copies = NULL;
> +
> +	vq->async_registered = false;
> +
> +	rte_spinlock_unlock(&vq->access_lock);
> +
> +	return 0;
> +}
> +
> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
> index df98d15..a7fbe23 100644
> --- a/lib/librte_vhost/vhost.h
> +++ b/lib/librte_vhost/vhost.h
> @@ -23,6 +23,8 @@
>  #include "rte_vhost.h"
>  #include "rte_vdpa.h"
>  
> +#include "rte_vhost_async.h"
> +
>  /* Used to indicate that the device is running on a data core */
>  #define VIRTIO_DEV_RUNNING 1
>  /* Used to indicate that the device is ready to operate */
> @@ -39,6 +41,11 @@
>  
>  #define VHOST_LOG_CACHE_NR 32
>  
> +#define MAX_PKT_BURST 32
> +
> +#define VHOST_MAX_ASYNC_IT (MAX_PKT_BURST * 2)
> +#define VHOST_MAX_ASYNC_VEC (BUF_VECTOR_MAX * 2)
> +
>  #define PACKED_DESC_ENQUEUE_USED_FLAG(w)	\
>  	((w) ? (VRING_DESC_F_AVAIL | VRING_DESC_F_USED | VRING_DESC_F_WRITE) : \
>  		VRING_DESC_F_WRITE)
> @@ -200,6 +207,25 @@ struct vhost_virtqueue {
>  	TAILQ_HEAD(, vhost_iotlb_entry) iotlb_list;
>  	int				iotlb_cache_nr;
>  	TAILQ_HEAD(, vhost_iotlb_entry) iotlb_pending_list;
> +
> +	/* operation callbacks for async dma */
> +	struct rte_vhost_async_channel_ops	async_ops;
> +
> +	struct iov_it it_pool[VHOST_MAX_ASYNC_IT];
> +	struct iovec vec_pool[VHOST_MAX_ASYNC_VEC];
> +
> +	/* async data transfer status */
> +	uintptr_t	**async_pkts_pending;
> +	#define		ASYNC_PENDING_INFO_N_MSK 0xFFFF
> +	#define		ASYNC_PENDING_INFO_N_SFT 16
> +	uint64_t	*async_pending_info;
> +	uint16_t	async_pkts_idx;
> +	uint16_t	async_pkts_inflight_n;
> +
> +	/* vq async features */
> +	bool		async_inorder;
> +	bool		async_registered;
> +	uint16_t	async_threshold;
>  } __rte_cache_aligned;
>  
>  /* Old kernels have no such macros defined */
> @@ -353,6 +379,7 @@ struct virtio_net {
>  	int16_t			broadcast_rarp;
>  	uint32_t		nr_vring;
>  	int			dequeue_zero_copy;
> +	int			async_copy;
>  	int			extbuf;
>  	int			linearbuf;
>  	struct vhost_virtqueue	*virtqueue[VHOST_MAX_QUEUE_PAIRS * 2];
> @@ -702,7 +729,8 @@ uint64_t translate_log_addr(struct virtio_net *dev, struct vhost_virtqueue *vq,
>  	/* Don't kick guest if we don't reach index specified by guest. */
>  	if (dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX)) {
>  		uint16_t old = vq->signalled_used;
> -		uint16_t new = vq->last_used_idx;
> +		uint16_t new = vq->async_pkts_inflight_n ?
> +					vq->used->idx:vq->last_used_idx;
>  		bool signalled_used_valid = vq->signalled_used_valid;
>  
>  		vq->signalled_used = new;
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index 84bebad..d7600bf 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -464,12 +464,25 @@
>  	} else {
>  		if (vq->shadow_used_split)
>  			rte_free(vq->shadow_used_split);
> +		if (vq->async_pkts_pending)
> +			rte_free(vq->async_pkts_pending);
> +		if (vq->async_pending_info)
> +			rte_free(vq->async_pending_info);
> +
>  		vq->shadow_used_split = rte_malloc(NULL,
>  				vq->size * sizeof(struct vring_used_elem),
>  				RTE_CACHE_LINE_SIZE);
> -		if (!vq->shadow_used_split) {
> +		vq->async_pkts_pending = rte_malloc(NULL,
> +				vq->size * sizeof(uintptr_t),
> +				RTE_CACHE_LINE_SIZE);
> +		vq->async_pending_info = rte_malloc(NULL,
> +				vq->size * sizeof(uint64_t),
> +				RTE_CACHE_LINE_SIZE);
> +		if (!vq->shadow_used_split ||
> +			!vq->async_pkts_pending ||
> +			!vq->async_pending_info) {
>  			VHOST_LOG_CONFIG(ERR,
> -					"failed to allocate memory for shadow used ring.\n");
> +					"failed to allocate memory for vq internal data.\n");
>  			return RTE_VHOST_MSG_RESULT_ERR;
>  		}
>  	}
> @@ -1147,7 +1160,8 @@
>  			goto err_mmap;
>  		}
>  
> -		populate = (dev->dequeue_zero_copy) ? MAP_POPULATE : 0;
> +		populate = (dev->dequeue_zero_copy || dev->async_copy) ?
> +			MAP_POPULATE : 0;
>  		mmap_addr = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
>  				 MAP_SHARED | populate, fd, 0);
>  
> @@ -1162,7 +1176,7 @@
>  		reg->host_user_addr = (uint64_t)(uintptr_t)mmap_addr +
>  				      mmap_offset;
>  
> -		if (dev->dequeue_zero_copy)
> +		if (dev->dequeue_zero_copy || dev->async_copy)
>  			if (add_guest_pages(dev, reg, alignment) < 0) {
>  				VHOST_LOG_CONFIG(ERR,
>  					"adding guest pages to region %u failed.\n",
> @@ -1945,6 +1959,12 @@ static int vhost_user_set_vring_err(struct virtio_net **pdev __rte_unused,
>  	} else {
>  		rte_free(vq->shadow_used_split);
>  		vq->shadow_used_split = NULL;
> +		if (vq->async_pkts_pending)
> +			rte_free(vq->async_pkts_pending);
> +		if (vq->async_pending_info)
> +			rte_free(vq->async_pending_info);
> +		vq->async_pkts_pending = NULL;
> +		vq->async_pending_info = NULL;
>  	}
>  
>  	rte_free(vq->batch_copy_elems);
> 



More information about the dev mailing list