Re: [dpdk-dev] [PATCH v2 29/44] net/virtio: add Virtio-user memory tables ops

["Xia, Chenbo" <chenbo.xia@intel.com>]

Hi Maxime,

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Wednesday, January 20, 2021 5:25 AM
> To: dev@dpdk.org; Xia, Chenbo <chenbo.xia@intel.com>; olivier.matz@6wind.com;
> amorenoz@redhat.com; david.marchand@redhat.com
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
> Subject: [PATCH v2 29/44] net/virtio: add Virtio-user memory tables ops
> 
> This patch implements a dedicated callback for
> preparing and sending memory table to the backends.
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  drivers/net/virtio/virtio_user/vhost.h        |  1 +
>  drivers/net/virtio/virtio_user/vhost_kernel.c | 60 ++++++-------
>  drivers/net/virtio/virtio_user/vhost_user.c   | 86 ++++++++++++++-----
>  drivers/net/virtio/virtio_user/vhost_vdpa.c   |  8 +-
>  .../net/virtio/virtio_user/virtio_user_dev.c  |  4 +-
>  5 files changed, 101 insertions(+), 58 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_user/vhost.h
> b/drivers/net/virtio/virtio_user/vhost.h
> index d805526130..463801f563 100644
> --- a/drivers/net/virtio/virtio_user/vhost.h
> +++ b/drivers/net/virtio/virtio_user/vhost.h
> @@ -114,6 +114,7 @@ struct virtio_user_backend_ops {
>  	int (*set_features)(struct virtio_user_dev *dev, uint64_t features);
>  	int (*get_protocol_features)(struct virtio_user_dev *dev, uint64_t
> *features);
>  	int (*set_protocol_features)(struct virtio_user_dev *dev, uint64_t
> features);
> +	int (*set_memory_table)(struct virtio_user_dev *dev);
>  	int (*send_request)(struct virtio_user_dev *dev,
>  			    enum vhost_user_request req,
>  			    void *arg);
> diff --git a/drivers/net/virtio/virtio_user/vhost_kernel.c
> b/drivers/net/virtio/virtio_user/vhost_kernel.c
> index f44df8ef1f..2d30f572b6 100644
> --- a/drivers/net/virtio/virtio_user/vhost_kernel.c
> +++ b/drivers/net/virtio/virtio_user/vhost_kernel.c
> @@ -148,17 +148,6 @@ vhost_kernel_set_features(struct virtio_user_dev *dev,
> uint64_t features)
>  	return vhost_kernel_ioctl(dev->vhostfds[0], VHOST_SET_FEATURES,
> &features);
>  }
> 
> -static uint64_t vhost_req_user_to_kernel[] = {
> -	[VHOST_USER_RESET_OWNER] = VHOST_RESET_OWNER,
> -	[VHOST_USER_SET_VRING_CALL] = VHOST_SET_VRING_CALL,
> -	[VHOST_USER_SET_VRING_NUM] = VHOST_SET_VRING_NUM,
> -	[VHOST_USER_SET_VRING_BASE] = VHOST_SET_VRING_BASE,
> -	[VHOST_USER_GET_VRING_BASE] = VHOST_GET_VRING_BASE,
> -	[VHOST_USER_SET_VRING_ADDR] = VHOST_SET_VRING_ADDR,
> -	[VHOST_USER_SET_VRING_KICK] = VHOST_SET_VRING_KICK,
> -	[VHOST_USER_SET_MEM_TABLE] = VHOST_SET_MEM_TABLE,
> -};
> -
>  static int
>  add_memseg_list(const struct rte_memseg_list *msl, void *arg)
>  {
> @@ -193,16 +182,17 @@ add_memseg_list(const struct rte_memseg_list *msl, void
> *arg)
>   * have much more memory regions. Below function will treat each
>   * contiguous memory space reserved by DPDK as one region.
>   */
> -static struct vhost_memory_kernel *
> -prepare_vhost_memory_kernel(void)
> +static int
> +vhost_kernel_set_memory_table(struct virtio_user_dev *dev)
>  {
>  	struct vhost_memory_kernel *vm;
> +	int ret;
> 
>  	vm = malloc(sizeof(struct vhost_memory_kernel) +
>  			max_regions *
>  			sizeof(struct vhost_memory_region));
>  	if (!vm)
> -		return NULL;
> +		goto err;
> 
>  	vm->nregions = 0;
>  	vm->padding = 0;
> @@ -211,14 +201,34 @@ prepare_vhost_memory_kernel(void)
>  	 * The memory lock has already been taken by memory subsystem
>  	 * or virtio_user_start_device().
>  	 */
> -	if (rte_memseg_list_walk_thread_unsafe(add_memseg_list, vm) < 0) {
> -		free(vm);
> -		return NULL;
> -	}
> +	ret = rte_memseg_list_walk_thread_unsafe(add_memseg_list, vm);
> +	if (ret < 0)
> +		goto err_free;
> +
> +	ret = vhost_kernel_ioctl(dev->vhostfds[0], VHOST_SET_MEM_TABLE, vm);
> +	if (ret < 0)
> +		goto err_free;
> 
> -	return vm;
> +	free(vm);
> +
> +	return 0;
> +err_free:
> +	free(vm);
> +err:
> +	PMD_DRV_LOG(ERR, "Failed to set memory table");
> +	return -1;
>  }
> 
> +static uint64_t vhost_req_user_to_kernel[] = {
> +	[VHOST_USER_RESET_OWNER] = VHOST_RESET_OWNER,
> +	[VHOST_USER_SET_VRING_CALL] = VHOST_SET_VRING_CALL,
> +	[VHOST_USER_SET_VRING_NUM] = VHOST_SET_VRING_NUM,
> +	[VHOST_USER_SET_VRING_BASE] = VHOST_SET_VRING_BASE,
> +	[VHOST_USER_GET_VRING_BASE] = VHOST_GET_VRING_BASE,
> +	[VHOST_USER_SET_VRING_ADDR] = VHOST_SET_VRING_ADDR,
> +	[VHOST_USER_SET_VRING_KICK] = VHOST_SET_VRING_KICK,
> +};
> +
>  static int
>  vhost_kernel_send_request(struct virtio_user_dev *dev,
>  		   enum vhost_user_request req,
> @@ -227,7 +237,6 @@ vhost_kernel_send_request(struct virtio_user_dev *dev,
>  	int ret = -1;
>  	unsigned int i;
>  	uint64_t req_kernel;
> -	struct vhost_memory_kernel *vm = NULL;
>  	int vhostfd;
>  	unsigned int queue_sel;
> 
> @@ -235,13 +244,6 @@ vhost_kernel_send_request(struct virtio_user_dev *dev,
> 
>  	req_kernel = vhost_req_user_to_kernel[req];
> 
> -	if (req_kernel == VHOST_SET_MEM_TABLE) {
> -		vm = prepare_vhost_memory_kernel();
> -		if (!vm)
> -			return -1;
> -		arg = (void *)vm;
> -	}
> -
>  	switch (req_kernel) {
>  	case VHOST_SET_VRING_NUM:
>  	case VHOST_SET_VRING_ADDR:
> @@ -271,9 +273,6 @@ vhost_kernel_send_request(struct virtio_user_dev *dev,
>  		ret = ioctl(vhostfd, req_kernel, arg);
>  	}
> 
> -	if (vm)
> -		free(vm);
> -
>  	if (ret < 0)
>  		PMD_DRV_LOG(ERR, "%s failed: %s",
>  			    vhost_msg_strings[req], strerror(errno));
> @@ -403,6 +402,7 @@ struct virtio_user_backend_ops virtio_ops_kernel = {
>  	.set_owner = vhost_kernel_set_owner,
>  	.get_features = vhost_kernel_get_features,
>  	.set_features = vhost_kernel_set_features,
> +	.set_memory_table = vhost_kernel_set_memory_table,
>  	.send_request = vhost_kernel_send_request,
>  	.enable_qp = vhost_kernel_enable_queue_pair
>  };
> diff --git a/drivers/net/virtio/virtio_user/vhost_user.c
> b/drivers/net/virtio/virtio_user/vhost_user.c
> index 4877574f72..94533e31ce 100644
> --- a/drivers/net/virtio/virtio_user/vhost_user.c
> +++ b/drivers/net/virtio/virtio_user/vhost_user.c
> @@ -81,6 +81,9 @@ vhost_user_write(int fd, struct vhost_user_msg *msg, int
> *fds, int fd_num)
>  		r = sendmsg(fd, &msgh, 0);
>  	} while (r < 0 && errno == EINTR);
> 
> +	if (r < 0)
> +		PMD_DRV_LOG(ERR, "Failed to send msg: %s", strerror(errno));
> +
>  	return r;
>  }
> 
> @@ -125,6 +128,39 @@ vhost_user_read(int fd, struct vhost_user_msg *msg)
>  	return -1;
>  }
> 
> +static int
> +vhost_user_check_reply_ack(struct virtio_user_dev *dev, struct vhost_user_msg
> *msg)
> +{
> +	enum vhost_user_request req = msg->request;
> +	int ret;
> +
> +	if (!(msg->flags & VHOST_USER_NEED_REPLY_MASK))
> +		return 0;
> +
> +	ret = vhost_user_read(dev->vhostfd, msg);
> +	if (ret < 0) {
> +		PMD_DRV_LOG(ERR, "Failed to read reply-ack");
> +		return -1;
> +	}
> +
> +	if (req != msg->request) {
> +		PMD_DRV_LOG(ERR, "Unexpected reply-ack request type (%d)", msg-
> >request);
> +		return -1;
> +	}
> +
> +	if (msg->size != sizeof(msg->payload.u64)) {
> +		PMD_DRV_LOG(ERR, "Unexpected reply-ack payload size (%d)", msg-
> >size);

Better to use '%u'?

> +		return -1;
> +	}
> +
> +	if (msg->payload.u64) {
> +		PMD_DRV_LOG(ERR, "Slave replied NACK to request type %d", msg-
> >request);

Replace '%d' with '(%d)' to align with the above style? :P

Thanks,
Chenbo

> +		return -1;
> +	}
> +
> +	return 0;
> +}
> +
>  static int
>  vhost_user_set_owner(struct virtio_user_dev *dev)
>  {
> @@ -338,25 +374,47 @@ update_memory_region(const struct rte_memseg_list *msl
> __rte_unused,
>  }
> 
>  static int
> -prepare_vhost_memory_user(struct vhost_user_msg *msg, int fds[])
> +vhost_user_set_memory_table(struct virtio_user_dev *dev)
>  {
>  	struct walk_arg wa;
> +	int fds[VHOST_MEMORY_MAX_NREGIONS];
> +	int ret, fd_num;
> +	struct vhost_user_msg msg = {
> +		.request = VHOST_USER_SET_MEM_TABLE,
> +		.flags = VHOST_USER_VERSION,
> +	};
> +
> +	if (dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK))
> +		msg.flags |= VHOST_USER_NEED_REPLY_MASK;
> 
>  	wa.region_nr = 0;
> -	wa.vm = &msg->payload.memory;
> +	wa.vm = &msg.payload.memory;
>  	wa.fds = fds;
> 
>  	/*
>  	 * The memory lock has already been taken by memory subsystem
>  	 * or virtio_user_start_device().
>  	 */
> -	if (rte_memseg_walk_thread_unsafe(update_memory_region, &wa) < 0)
> -		return -1;
> +	ret = rte_memseg_walk_thread_unsafe(update_memory_region, &wa);
> +	if (ret < 0)
> +		goto err;
> 
> -	msg->payload.memory.nregions = wa.region_nr;
> -	msg->payload.memory.padding = 0;
> +	fd_num = wa.region_nr;
> +	msg.payload.memory.nregions = wa.region_nr;
> +	msg.payload.memory.padding = 0;
> 
> -	return 0;
> +	msg.size = sizeof(msg.payload.memory.nregions);
> +	msg.size += sizeof(msg.payload.memory.padding);
> +	msg.size += fd_num * sizeof(struct vhost_memory_region);
> +
> +	ret = vhost_user_write(dev->vhostfd, &msg, fds, fd_num);
> +	if (ret < 0)
> +		goto err;
> +
> +	return vhost_user_check_reply_ack(dev, &msg);
> +err:
> +	PMD_DRV_LOG(ERR, "Failed to set memory table");
> +	return -1;
>  }
> 
>  static struct vhost_user_msg m;
> @@ -369,7 +427,6 @@ const char * const vhost_msg_strings[] = {
>  	[VHOST_USER_GET_VRING_BASE] = "VHOST_GET_VRING_BASE",
>  	[VHOST_USER_SET_VRING_ADDR] = "VHOST_SET_VRING_ADDR",
>  	[VHOST_USER_SET_VRING_KICK] = "VHOST_SET_VRING_KICK",
> -	[VHOST_USER_SET_MEM_TABLE] = "VHOST_SET_MEM_TABLE",
>  	[VHOST_USER_SET_VRING_ENABLE] = "VHOST_SET_VRING_ENABLE",
>  	[VHOST_USER_SET_STATUS] = "VHOST_SET_STATUS",
>  	[VHOST_USER_GET_STATUS] = "VHOST_GET_STATUS",
> @@ -434,18 +491,6 @@ vhost_user_sock(struct virtio_user_dev *dev,
>  	case VHOST_USER_RESET_OWNER:
>  		break;
> 
> -	case VHOST_USER_SET_MEM_TABLE:
> -		if (prepare_vhost_memory_user(&msg, fds) < 0)
> -			return -1;
> -		fd_num = msg.payload.memory.nregions;
> -		msg.size = sizeof(m.payload.memory.nregions);
> -		msg.size += sizeof(m.payload.memory.padding);
> -		msg.size += fd_num * sizeof(struct vhost_memory_region);
> -
> -		if (has_reply_ack)
> -			msg.flags |= VHOST_USER_NEED_REPLY_MASK;
> -		break;
> -
>  	case VHOST_USER_SET_LOG_FD:
>  		fds[fd_num++] = *((int *)arg);
>  		break;
> @@ -644,6 +689,7 @@ struct virtio_user_backend_ops virtio_ops_user = {
>  	.set_features = vhost_user_set_features,
>  	.get_protocol_features = vhost_user_get_protocol_features,
>  	.set_protocol_features = vhost_user_set_protocol_features,
> +	.set_memory_table = vhost_user_set_memory_table,
>  	.send_request = vhost_user_sock,
>  	.enable_qp = vhost_user_enable_queue_pair
>  };
> diff --git a/drivers/net/virtio/virtio_user/vhost_vdpa.c
> b/drivers/net/virtio/virtio_user/vhost_vdpa.c
> index f627afbcfc..bd7daebf0c 100644
> --- a/drivers/net/virtio/virtio_user/vhost_vdpa.c
> +++ b/drivers/net/virtio/virtio_user/vhost_vdpa.c
> @@ -19,7 +19,6 @@
>  #define VHOST_SET_FEATURES _IOW(VHOST_VIRTIO, 0x00, __u64)
>  #define VHOST_SET_OWNER _IO(VHOST_VIRTIO, 0x01)
>  #define VHOST_RESET_OWNER _IO(VHOST_VIRTIO, 0x02)
> -#define VHOST_SET_MEM_TABLE _IOW(VHOST_VIRTIO, 0x03, void *)
>  #define VHOST_SET_LOG_BASE _IOW(VHOST_VIRTIO, 0x04, __u64)
>  #define VHOST_SET_LOG_FD _IOW(VHOST_VIRTIO, 0x07, int)
>  #define VHOST_SET_VRING_NUM _IOW(VHOST_VIRTIO, 0x10, struct vhost_vring_state)
> @@ -46,7 +45,6 @@ static uint64_t vhost_req_user_to_vdpa[] = {
>  	[VHOST_USER_GET_VRING_BASE] = VHOST_GET_VRING_BASE,
>  	[VHOST_USER_SET_VRING_ADDR] = VHOST_SET_VRING_ADDR,
>  	[VHOST_USER_SET_VRING_KICK] = VHOST_SET_VRING_KICK,
> -	[VHOST_USER_SET_MEM_TABLE] = VHOST_SET_MEM_TABLE,
>  	[VHOST_USER_SET_STATUS] = VHOST_VDPA_SET_STATUS,
>  	[VHOST_USER_GET_STATUS] = VHOST_VDPA_GET_STATUS,
>  	[VHOST_USER_SET_VRING_ENABLE] = VHOST_VDPA_SET_VRING_ENABLE,
> @@ -319,7 +317,7 @@ vhost_vdpa_map(const struct rte_memseg_list *msl, const
> struct rte_memseg *ms,
>  }
> 
>  static int
> -vhost_vdpa_dma_map_all(struct virtio_user_dev *dev)
> +vhost_vdpa_set_memory_table(struct virtio_user_dev *dev)
>  {
>  	int ret;
> 
> @@ -376,9 +374,6 @@ vhost_vdpa_send_request(struct virtio_user_dev *dev,
> 
>  	req_vdpa = vhost_req_user_to_vdpa[req];
> 
> -	if (req_vdpa == VHOST_SET_MEM_TABLE)
> -		return vhost_vdpa_dma_map_all(dev);
> -
>  	switch (req_vdpa) {
>  	case VHOST_SET_VRING_NUM:
>  	case VHOST_SET_VRING_ADDR:
> @@ -461,6 +456,7 @@ struct virtio_user_backend_ops virtio_ops_vdpa = {
>  	.set_features = vhost_vdpa_set_features,
>  	.get_protocol_features = vhost_vdpa_get_backend_features,
>  	.set_protocol_features = vhost_vdpa_set_backend_features,
> +	.set_memory_table = vhost_vdpa_set_memory_table,
>  	.send_request = vhost_vdpa_send_request,
>  	.enable_qp = vhost_vdpa_enable_queue_pair,
>  	.dma_map = vhost_vdpa_dma_map_batch,
> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c
> b/drivers/net/virtio/virtio_user/virtio_user_dev.c
> index 45417bbc5d..cb8f8a872c 100644
> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
> @@ -177,7 +177,7 @@ virtio_user_start_device(struct virtio_user_dev *dev)
>  		goto error;
> 
>  	/* Step 2: share memory regions */
> -	ret = dev->ops->send_request(dev, VHOST_USER_SET_MEM_TABLE, NULL);
> +	ret = dev->ops->set_memory_table(dev);
>  	if (ret < 0)
>  		goto error;
> 
> @@ -352,7 +352,7 @@ virtio_user_mem_event_cb(enum rte_mem_event type
> __rte_unused,
>  		dev->ops->enable_qp(dev, i, 0);
> 
>  	/* Step 2: update memory regions */
> -	dev->ops->send_request(dev, VHOST_USER_SET_MEM_TABLE, NULL);
> +	dev->ops->set_memory_table(dev);
> 
>  	/* Step 3: resume the active queues */
>  	for (i = 0; i < dev->queue_pairs; i++)
> --
> 2.29.2