Re: [dpdk-dev] [PATCH v2 40/44] net/virtio: move Vhost-user specifics to its backend

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

> -----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 40/44] net/virtio: move Vhost-user specifics to its backend
> 
> This patch moves all the Vhost-user backend specific
> logic like Vhost FD, listen FD and interrupt handling
> to the vhost-user backend implementation.
> 
> In order to achieve that, new ops are created to update
> the link status, disconnect and reconnect the server,
> and fetch the link state interrupt FD.
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  drivers/net/virtio/virtio_user/vhost.h        |   4 +
>  drivers/net/virtio/virtio_user/vhost_kernel.c |  18 +-
>  drivers/net/virtio/virtio_user/vhost_user.c   | 176 ++++++++++++++---
>  drivers/net/virtio/virtio_user/vhost_vdpa.c   |  16 ++
>  .../net/virtio/virtio_user/virtio_user_dev.c  | 181 +++++++++++++++---
>  .../net/virtio/virtio_user/virtio_user_dev.h  |   9 +-
>  drivers/net/virtio/virtio_user_ethdev.c       | 179 +----------------
>  7 files changed, 350 insertions(+), 233 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_user/vhost.h
> b/drivers/net/virtio/virtio_user/vhost.h
> index fc4f059c02..c49e88036d 100644
> --- a/drivers/net/virtio/virtio_user/vhost.h
> +++ b/drivers/net/virtio/virtio_user/vhost.h
> @@ -82,6 +82,10 @@ struct virtio_user_backend_ops {
>  	int (*enable_qp)(struct virtio_user_dev *dev, uint16_t pair_idx, int
> enable);
>  	int (*dma_map)(struct virtio_user_dev *dev, void *addr, uint64_t iova,
> size_t len);
>  	int (*dma_unmap)(struct virtio_user_dev *dev, void *addr, uint64_t iova,
> size_t len);
> +	int (*update_link_state)(struct virtio_user_dev *dev);
> +	int (*server_disconnect)(struct virtio_user_dev *dev);
> +	int (*server_reconnect)(struct virtio_user_dev *dev);
> +	int (*get_intr_fd)(struct virtio_user_dev *dev);
>  };
> 
>  extern struct virtio_user_backend_ops virtio_ops_user;
> diff --git a/drivers/net/virtio/virtio_user/vhost_kernel.c
> b/drivers/net/virtio/virtio_user/vhost_kernel.c
> index 47fb4427be..aa1f9ece5e 100644
> --- a/drivers/net/virtio/virtio_user/vhost_kernel.c
> +++ b/drivers/net/virtio/virtio_user/vhost_kernel.c
> @@ -459,6 +459,20 @@ vhost_kernel_get_backend_features(uint64_t *features)
>  	return 0;
>  }
> 
> +static int
> +vhost_kernel_update_link_state(struct virtio_user_dev *dev __rte_unused)
> +{
> +	/* Nothing to update (Maybe get TAP interface link state?) */
> +	return 0;
> +}
> +
> +static int
> +vhost_kernel_get_intr_fd(struct virtio_user_dev *dev __rte_unused)
> +{
> +	/* No link state interrupt with Vhost-kernel */
> +	return -1;
> +}
> +
>  struct virtio_user_backend_ops virtio_ops_kernel = {
>  	.setup = vhost_kernel_setup,
>  	.destroy = vhost_kernel_destroy,
> @@ -475,5 +489,7 @@ struct virtio_user_backend_ops virtio_ops_kernel = {
>  	.set_vring_addr = vhost_kernel_set_vring_addr,
>  	.get_status = vhost_kernel_get_status,
>  	.set_status = vhost_kernel_set_status,
> -	.enable_qp = vhost_kernel_enable_queue_pair
> +	.enable_qp = vhost_kernel_enable_queue_pair,
> +	.update_link_state = vhost_kernel_update_link_state,
> +	.get_intr_fd = vhost_kernel_get_intr_fd,
>  };
> diff --git a/drivers/net/virtio/virtio_user/vhost_user.c
> b/drivers/net/virtio/virtio_user/vhost_user.c
> index 0147b6d963..f046655af6 100644
> --- a/drivers/net/virtio/virtio_user/vhost_user.c
> +++ b/drivers/net/virtio/virtio_user/vhost_user.c
> @@ -11,6 +11,7 @@
>  #include <string.h>
>  #include <errno.h>
> 
> +#include <rte_alarm.h>
>  #include <rte_string_fns.h>
>  #include <rte_fbarray.h>
> 
> @@ -18,6 +19,8 @@
>  #include "virtio_user_dev.h"
> 
>  struct vhost_user_data {
> +	int vhostfd;
> +	int listenfd;
>  	uint64_t protocol_features;
>  };
> 
> @@ -182,13 +185,14 @@ vhost_user_read(int fd, struct vhost_user_msg *msg)
>  static int
>  vhost_user_check_reply_ack(struct virtio_user_dev *dev, struct vhost_user_msg
> *msg)
>  {
> +	struct vhost_user_data *data = dev->backend_data;
>  	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);
> +	ret = vhost_user_read(data->vhostfd, msg);
>  	if (ret < 0) {
>  		PMD_DRV_LOG(ERR, "Failed to read reply-ack");
>  		return -1;
> @@ -216,12 +220,13 @@ static int
>  vhost_user_set_owner(struct virtio_user_dev *dev)
>  {
>  	int ret;
> +	struct vhost_user_data *data = dev->backend_data;
>  	struct vhost_user_msg msg = {
>  		.request = VHOST_USER_SET_OWNER,
>  		.flags = VHOST_USER_VERSION,
>  	};
> 
> -	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
> +	ret = vhost_user_write(data->vhostfd, &msg, NULL, 0);
>  	if (ret < 0) {
>  		PMD_DRV_LOG(ERR, "Failed to set owner");
>  		return -1;
> @@ -234,16 +239,17 @@ static int
>  vhost_user_get_protocol_features(struct virtio_user_dev *dev, uint64_t
> *features)
>  {
>  	int ret;
> +	struct vhost_user_data *data = dev->backend_data;
>  	struct vhost_user_msg msg = {
>  		.request = VHOST_USER_GET_PROTOCOL_FEATURES,
>  		.flags = VHOST_USER_VERSION,
>  	};
> 
> -	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
> +	ret = vhost_user_write(data->vhostfd, &msg, NULL, 0);
>  	if (ret < 0)
>  		goto err;
> 
> -	ret = vhost_user_read(dev->vhostfd, &msg);
> +	ret = vhost_user_read(data->vhostfd, &msg);
>  	if (ret < 0)
>  		goto err;
> 
> @@ -270,6 +276,7 @@ static int
>  vhost_user_set_protocol_features(struct virtio_user_dev *dev, uint64_t
> features)
>  {
>  	int ret;
> +	struct vhost_user_data *data = dev->backend_data;
>  	struct vhost_user_msg msg = {
>  		.request = VHOST_USER_SET_PROTOCOL_FEATURES,
>  		.flags = VHOST_USER_VERSION,
> @@ -277,7 +284,7 @@ vhost_user_set_protocol_features(struct virtio_user_dev
> *dev, uint64_t features)
>  		.payload.u64 = features,
>  	};
> 
> -	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
> +	ret = vhost_user_write(data->vhostfd, &msg, NULL, 0);
>  	if (ret < 0) {
>  		PMD_DRV_LOG(ERR, "Failed to set protocol features");
>  		return -1;
> @@ -296,11 +303,11 @@ vhost_user_get_features(struct virtio_user_dev *dev,
> uint64_t *features)
>  		.flags = VHOST_USER_VERSION,
>  	};
> 
> -	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
> +	ret = vhost_user_write(data->vhostfd, &msg, NULL, 0);
>  	if (ret < 0)
>  		goto err;
> 
> -	ret = vhost_user_read(dev->vhostfd, &msg);
> +	ret = vhost_user_read(data->vhostfd, &msg);
>  	if (ret < 0)
>  		goto err;
> 
> @@ -344,6 +351,7 @@ static int
>  vhost_user_set_features(struct virtio_user_dev *dev, uint64_t features)
>  {
>  	int ret;
> +	struct vhost_user_data *data = dev->backend_data;
>  	struct vhost_user_msg msg = {
>  		.request = VHOST_USER_SET_FEATURES,
>  		.flags = VHOST_USER_VERSION,
> @@ -353,7 +361,7 @@ vhost_user_set_features(struct virtio_user_dev *dev,
> uint64_t features)
> 
>  	msg.payload.u64 |= dev->device_features & (1ULL <<
> VHOST_USER_F_PROTOCOL_FEATURES);
> 
> -	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
> +	ret = vhost_user_write(data->vhostfd, &msg, NULL, 0);
>  	if (ret < 0) {
>  		PMD_DRV_LOG(ERR, "Failed to set features");
>  		return -1;
> @@ -477,7 +485,7 @@ vhost_user_set_memory_table(struct virtio_user_dev *dev)
>  	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);
> +	ret = vhost_user_write(data->vhostfd, &msg, fds, fd_num);
>  	if (ret < 0)
>  		goto err;
> 
> @@ -492,6 +500,7 @@ vhost_user_set_vring(struct virtio_user_dev *dev, enum
> vhost_user_request req,
>  		struct vhost_vring_state *state)
>  {
>  	int ret;
> +	struct vhost_user_data *data = dev->backend_data;
>  	struct vhost_user_msg msg = {
>  		.request = req,
>  		.flags = VHOST_USER_VERSION,
> @@ -499,7 +508,7 @@ vhost_user_set_vring(struct virtio_user_dev *dev, enum
> vhost_user_request req,
>  		.payload.state = *state,
>  	};
> 
> -	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
> +	ret = vhost_user_write(data->vhostfd, &msg, NULL, 0);
>  	if (ret < 0) {
>  		PMD_DRV_LOG(ERR, "Failed to set vring state (request %d)", req);
>  		return -1;
> @@ -531,6 +540,7 @@ vhost_user_get_vring_base(struct virtio_user_dev *dev,
> struct vhost_vring_state
>  {
>  	int ret;
>  	struct vhost_user_msg msg;
> +	struct vhost_user_data *data = dev->backend_data;
>  	unsigned int index = state->index;
> 
>  	ret = vhost_user_set_vring(dev, VHOST_USER_GET_VRING_BASE, state);
> @@ -539,7 +549,7 @@ vhost_user_get_vring_base(struct virtio_user_dev *dev,
> struct vhost_vring_state
>  		goto err;
>  	}
> 
> -	ret = vhost_user_read(dev->vhostfd, &msg);
> +	ret = vhost_user_read(data->vhostfd, &msg);
>  	if (ret < 0) {
>  		PMD_DRV_LOG(ERR, "Failed to read reply");
>  		goto err;
> @@ -575,6 +585,7 @@ vhost_user_set_vring_file(struct virtio_user_dev *dev,
> enum vhost_user_request r
>  	int ret;
>  	int fd = file->fd;
>  	int num_fd = 0;
> +	struct vhost_user_data *data = dev->backend_data;
>  	struct vhost_user_msg msg = {
>  		.request = req,
>  		.flags = VHOST_USER_VERSION,
> @@ -587,7 +598,7 @@ vhost_user_set_vring_file(struct virtio_user_dev *dev,
> enum vhost_user_request r
>  	else
>  		msg.payload.u64 |= VHOST_USER_VRING_NOFD_MASK;
> 
> -	ret = vhost_user_write(dev->vhostfd, &msg, &fd, num_fd);
> +	ret = vhost_user_write(data->vhostfd, &msg, &fd, num_fd);
>  	if (ret < 0) {
>  		PMD_DRV_LOG(ERR, "Failed to set vring file (request %d)", req);
>  		return -1;
> @@ -613,6 +624,7 @@ static int
>  vhost_user_set_vring_addr(struct virtio_user_dev *dev, struct
> vhost_vring_addr *addr)
>  {
>  	int ret;
> +	struct vhost_user_data *data = dev->backend_data;
>  	struct vhost_user_msg msg = {
>  		.request = VHOST_USER_SET_VRING_ADDR,
>  		.flags = VHOST_USER_VERSION,
> @@ -620,7 +632,7 @@ vhost_user_set_vring_addr(struct virtio_user_dev *dev,
> struct vhost_vring_addr *
>  		.payload.addr = *addr,
>  	};
> 
> -	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
> +	ret = vhost_user_write(data->vhostfd, &msg, NULL, 0);
>  	if (ret < 0) {
>  		PMD_DRV_LOG(ERR, "Failed to send vring addresses");
>  		return -1;
> @@ -653,13 +665,13 @@ vhost_user_get_status(struct virtio_user_dev *dev,
> uint8_t *status)
>  	if (!(data->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_STATUS)))
>  		return -ENOTSUP;
> 
> -	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
> +	ret = vhost_user_write(data->vhostfd, &msg, NULL, 0);
>  	if (ret < 0) {
>  		PMD_DRV_LOG(ERR, "Failed to send request");
>  		goto err;
>  	}
> 
> -	ret = vhost_user_read(dev->vhostfd, &msg);
> +	ret = vhost_user_read(data->vhostfd, &msg);
>  	if (ret < 0) {
>  		PMD_DRV_LOG(ERR, "Failed to recv request");
>  		goto err;
> @@ -712,7 +724,7 @@ vhost_user_set_status(struct virtio_user_dev *dev, uint8_t
> status)
>  	if (data->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK))
>  		msg.flags |= VHOST_USER_NEED_REPLY_MASK;
> 
> -	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
> +	ret = vhost_user_write(data->vhostfd, &msg, NULL, 0);
>  	if (ret < 0) {
>  		PMD_DRV_LOG(ERR, "Failed to send get status request");
>  		return -1;
> @@ -723,11 +735,12 @@ vhost_user_set_status(struct virtio_user_dev *dev,
> uint8_t status)
> 
>  #define MAX_VIRTIO_USER_BACKLOG 1
>  static int
> -virtio_user_start_server(struct virtio_user_dev *dev, struct sockaddr_un *un)
> +vhost_user_start_server(struct virtio_user_dev *dev, struct sockaddr_un *un)
>  {
>  	int ret;
>  	int flag;
> -	int fd = dev->listenfd;
> +	struct vhost_user_data *data = dev->backend_data;
> +	int fd = data->listenfd;
> 
>  	ret = bind(fd, (struct sockaddr *)un, sizeof(*un));
>  	if (ret < 0) {
> @@ -740,8 +753,8 @@ virtio_user_start_server(struct virtio_user_dev *dev,
> struct sockaddr_un *un)
>  		return -1;
> 
>  	PMD_DRV_LOG(NOTICE, "(%s) waiting for client connection...", dev->path);
> -	dev->vhostfd = accept(fd, NULL, NULL);
> -	if (dev->vhostfd < 0) {
> +	data->vhostfd = accept(fd, NULL, NULL);
> +	if (data->vhostfd < 0) {
>  		PMD_DRV_LOG(ERR, "Failed to accept initial client connection (%s)",
>  				strerror(errno));
>  		return -1;
> @@ -756,6 +769,37 @@ virtio_user_start_server(struct virtio_user_dev *dev,
> struct sockaddr_un *un)
>  	return 0;
>  }
> 
> +static int
> +vhost_user_server_disconnect(struct virtio_user_dev *dev)
> +{
> +	struct vhost_user_data *data = dev->backend_data;
> +
> +	if (data->vhostfd < 0) {
> +		PMD_DRV_LOG(ERR, "(%s) Expected valid Vhost FD", dev->path);
> +		return -1;
> +	}
> +
> +	close(data->vhostfd);
> +	data->vhostfd = -1;
> +
> +	return 0;
> +}
> +
> +static int
> +vhost_user_server_reconnect(struct virtio_user_dev *dev)
> +{
> +	struct vhost_user_data *data = dev->backend_data;
> +	int fd;
> +
> +	fd = accept(data->listenfd, NULL, NULL);
> +	if (fd < 0)
> +		return -1;
> +
> +	data->vhostfd = fd;
> +
> +	return 0;
> +}
> +
>  /**
>   * Set up environment to talk with a vhost user backend.
>   *
> @@ -781,6 +825,8 @@ vhost_user_setup(struct virtio_user_dev *dev)
> 
>  	dev->backend_data = data;
> 
> +	data->vhostfd = -1;
> +
>  	fd = socket(AF_UNIX, SOCK_STREAM, 0);
>  	if (fd < 0) {
>  		PMD_DRV_LOG(ERR, "socket() error, %s", strerror(errno));
> @@ -796,8 +842,8 @@ vhost_user_setup(struct virtio_user_dev *dev)
>  	strlcpy(un.sun_path, dev->path, sizeof(un.sun_path));
> 
>  	if (dev->is_server) {
> -		dev->listenfd = fd;
> -		if (virtio_user_start_server(dev, &un) < 0) {
> +		data->listenfd = fd;
> +		if (vhost_user_start_server(dev, &un) < 0) {
>  			PMD_DRV_LOG(ERR, "virtio-user startup fails in server mode");
>  			goto err_socket;
>  		}
> @@ -806,7 +852,7 @@ vhost_user_setup(struct virtio_user_dev *dev)
>  			PMD_DRV_LOG(ERR, "connect error, %s", strerror(errno));
>  			goto err_socket;
>  		}
> -		dev->vhostfd = fd;
> +		data->vhostfd = fd;
>  	}
> 
>  	return 0;
> @@ -823,11 +869,24 @@ vhost_user_setup(struct virtio_user_dev *dev)
>  static int
>  vhost_user_destroy(struct virtio_user_dev *dev)
>  {
> -	if (dev->backend_data) {
> -		free(dev->backend_data);
> -		dev->backend_data = NULL;
> +	struct vhost_user_data *data = dev->backend_data;
> +
> +	if (!data)
> +		return 0;
> +
> +	if (data->vhostfd >= 0) {
> +		close(data->vhostfd);
> +		data->vhostfd = -1;
>  	}
> 
> +	if (data->listenfd >= 0) {
> +		close(data->listenfd);
> +		data->listenfd = -1;
> +	}
> +
> +	free(data);
> +	dev->backend_data = NULL;
> +
>  	return 0;
>  }
> 
> @@ -836,8 +895,12 @@ vhost_user_enable_queue_pair(struct virtio_user_dev *dev,
>  			     uint16_t pair_idx,
>  			     int enable)
>  {
> +	struct vhost_user_data *data = dev->backend_data;
>  	int i;
> 
> +	if (data->vhostfd < 0)
> +		return 0;
> +
>  	if (dev->qp_enabled[pair_idx] == enable)
>  		return 0;
> 
> @@ -863,6 +926,61 @@ vhost_user_get_backend_features(uint64_t *features)
>  	return 0;
>  }
> 
> +static int
> +vhost_user_update_link_state(struct virtio_user_dev *dev)
> +{
> +	struct vhost_user_data *data = dev->backend_data;
> +	char buf[128];
> +
> +	if (data->vhostfd >= 0) {
> +		int r;
> +		int flags;
> +
> +		flags = fcntl(data->vhostfd, F_GETFL);
> +		if (fcntl(data->vhostfd, F_SETFL, flags | O_NONBLOCK) == -1) {
> +			PMD_DRV_LOG(ERR, "error setting O_NONBLOCK flag");
> +			return -1;
> +		}
> +
> +		r = recv(data->vhostfd, buf, 128, MSG_PEEK);
> +		if (r == 0 || (r < 0 && errno != EAGAIN)) {
> +			dev->net_status &= (~VIRTIO_NET_S_LINK_UP);
> +			PMD_DRV_LOG(ERR, "virtio-user port %u is down", dev-
> >port_id);
> +
> +			/* This function could be called in the process
> +			 * of interrupt handling, callback cannot be
> +			 * unregistered here, set an alarm to do it.
> +			 */
> +			rte_eal_alarm_set(1, virtio_user_dev_delayed_handler, (void
> *)dev);
> +		} else {
> +			dev->net_status |= VIRTIO_NET_S_LINK_UP;
> +		}
> +
> +		if (fcntl(data->vhostfd, F_SETFL,
> +					flags & ~O_NONBLOCK) == -1) {
> +			PMD_DRV_LOG(ERR, "error clearing O_NONBLOCK flag");
> +			return -1;
> +		}
> +	} else if (dev->is_server) {
> +		dev->net_status &= (~VIRTIO_NET_S_LINK_UP);
> +		if (virtio_user_dev_server_reconnect(dev) >= 0)
> +			dev->net_status |= VIRTIO_NET_S_LINK_UP;
> +	}
> +
> +	return 0;
> +}
> +
> +static int
> +vhost_user_get_intr_fd(struct virtio_user_dev *dev)
> +{
> +	struct vhost_user_data *data = dev->backend_data;
> +
> +	if (dev->is_server && data->vhostfd == -1)
> +		return data->listenfd;
> +
> +	return data->vhostfd;
> +}
> +
>  struct virtio_user_backend_ops virtio_ops_user = {
>  	.setup = vhost_user_setup,
>  	.destroy = vhost_user_destroy,
> @@ -879,5 +997,9 @@ struct virtio_user_backend_ops virtio_ops_user = {
>  	.set_vring_addr = vhost_user_set_vring_addr,
>  	.get_status = vhost_user_get_status,
>  	.set_status = vhost_user_set_status,
> -	.enable_qp = vhost_user_enable_queue_pair
> +	.enable_qp = vhost_user_enable_queue_pair,
> +	.update_link_state = vhost_user_update_link_state,
> +	.server_disconnect = vhost_user_server_disconnect,
> +	.server_reconnect = vhost_user_server_reconnect,
> +	.get_intr_fd = vhost_user_get_intr_fd,
>  };
> diff --git a/drivers/net/virtio/virtio_user/vhost_vdpa.c
> b/drivers/net/virtio/virtio_user/vhost_vdpa.c
> index f5a8943993..5e3778b682 100644
> --- a/drivers/net/virtio/virtio_user/vhost_vdpa.c
> +++ b/drivers/net/virtio/virtio_user/vhost_vdpa.c
> @@ -471,6 +471,20 @@ vhost_vdpa_get_backend_features(uint64_t *features)
>  	return 0;
>  }
> 
> +static int
> +vhost_vdpa_update_link_state(struct virtio_user_dev *dev __rte_unused)
> +{
> +	/* Nothing to update (for now?) */
> +	return 0;
> +}
> +
> +static int
> +vhost_vdpa_get_intr_fd(struct virtio_user_dev *dev __rte_unused)
> +{
> +	/* No link state interrupt with Vhost-vDPA */
> +	return -1;
> +}
> +
>  struct virtio_user_backend_ops virtio_ops_vdpa = {
>  	.setup = vhost_vdpa_setup,
>  	.destroy = vhost_vdpa_destroy,
> @@ -490,4 +504,6 @@ struct virtio_user_backend_ops virtio_ops_vdpa = {
>  	.enable_qp = vhost_vdpa_enable_queue_pair,
>  	.dma_map = vhost_vdpa_dma_map_batch,
>  	.dma_unmap = vhost_vdpa_dma_unmap_batch,
> +	.update_link_state = vhost_vdpa_update_link_state,
> +	.get_intr_fd = vhost_vdpa_get_intr_fd,
>  };
> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c
> b/drivers/net/virtio/virtio_user/virtio_user_dev.c
> index 215819d46d..7128457e32 100644
> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
> @@ -343,11 +343,7 @@ virtio_user_fill_intr_handle(struct virtio_user_dev *dev)
>  	eth_dev->intr_handle->type = RTE_INTR_HANDLE_VDEV;
>  	/* For virtio vdev, no need to read counter for clean */
>  	eth_dev->intr_handle->efd_counter_size = 0;
> -	eth_dev->intr_handle->fd = -1;
> -	if (dev->vhostfd >= 0)
> -		eth_dev->intr_handle->fd = dev->vhostfd;
> -	else if (dev->is_server)
> -		eth_dev->intr_handle->fd = dev->listenfd;
> +	eth_dev->intr_handle->fd = dev->ops->get_intr_fd(dev);
> 
>  	return 0;
>  }
> @@ -404,7 +400,6 @@ virtio_user_dev_setup(struct virtio_user_dev *dev)
>  {
>  	uint32_t q;
> 
> -	dev->vhostfd = -1;
>  	dev->vhostfds = NULL;
>  	dev->tapfds = NULL;
> 
> @@ -598,15 +593,6 @@ virtio_user_dev_uninit(struct virtio_user_dev *dev)
>  		close(dev->callfds[i]);
>  		close(dev->kickfds[i]);
>  	}
> -
> -	if (dev->vhostfd >= 0)
> -		close(dev->vhostfd);
> -
> -	if (dev->is_server && dev->listenfd >= 0) {
> -		close(dev->listenfd);
> -		dev->listenfd = -1;
> -	}
> -
>  	if (dev->vhostfds) {
>  		for (i = 0; i < dev->max_queue_pairs; ++i) {
>  			close(dev->vhostfds[i]);
> @@ -637,15 +623,11 @@ virtio_user_handle_mq(struct virtio_user_dev *dev,
> uint16_t q_pairs)
>  		return -1;
>  	}
> 
> -	/* Server mode can't enable queue pairs if vhostfd is invalid,
> -	 * always return 0 in this case.
> -	 */
> -	if (!dev->is_server || dev->vhostfd >= 0) {
> -		for (i = 0; i < q_pairs; ++i)
> -			ret |= dev->ops->enable_qp(dev, i, 1);
> -		for (i = q_pairs; i < dev->max_queue_pairs; ++i)
> -			ret |= dev->ops->enable_qp(dev, i, 0);
> -	}
> +	for (i = 0; i < q_pairs; ++i)
> +		ret |= dev->ops->enable_qp(dev, i, 1);
> +	for (i = q_pairs; i < dev->max_queue_pairs; ++i)
> +		ret |= dev->ops->enable_qp(dev, i, 0);
> +
>  	dev->queue_pairs = q_pairs;
> 
>  	return ret;
> @@ -860,3 +842,154 @@ virtio_user_dev_update_status(struct virtio_user_dev
> *dev)
>  	pthread_mutex_unlock(&dev->mutex);
>  	return ret;
>  }
> +
> +int
> +virtio_user_dev_update_link_state(struct virtio_user_dev *dev)
> +{
> +	if (dev->ops->update_link_state)
> +		return dev->ops->update_link_state(dev);
> +
> +	return 0;
> +}
> +
> +static void
> +virtio_user_dev_reset_queues_packed(struct rte_eth_dev *eth_dev)
> +{
> +	struct virtio_user_dev *dev = eth_dev->data->dev_private;
> +	struct virtio_hw *hw = &dev->hw;
> +	struct virtnet_rx *rxvq;
> +	struct virtnet_tx *txvq;
> +	uint16_t i;
> +
> +	/* Add lock to avoid queue contention. */
> +	rte_spinlock_lock(&hw->state_lock);
> +	hw->started = 0;
> +
> +	/*
> +	 * Waiting for datapath to complete before resetting queues.
> +	 * 1 ms should be enough for the ongoing Tx/Rx function to finish.
> +	 */
> +	rte_delay_ms(1);
> +
> +	/* Vring reset for each Tx queue and Rx queue. */
> +	for (i = 0; i < eth_dev->data->nb_rx_queues; i++) {
> +		rxvq = eth_dev->data->rx_queues[i];
> +		virtqueue_rxvq_reset_packed(rxvq->vq);
> +		virtio_dev_rx_queue_setup_finish(eth_dev, i);
> +	}
> +
> +	for (i = 0; i < eth_dev->data->nb_tx_queues; i++) {
> +		txvq = eth_dev->data->tx_queues[i];
> +		virtqueue_txvq_reset_packed(txvq->vq);
> +	}
> +
> +	hw->started = 1;
> +	rte_spinlock_unlock(&hw->state_lock);
> +}
> +
> +void
> +virtio_user_dev_delayed_handler(void *param)
> +{
> +	struct virtio_user_dev *dev = param;
> +	struct rte_eth_dev *eth_dev = &rte_eth_devices[dev->port_id];
> +
> +	if (rte_intr_disable(eth_dev->intr_handle) < 0) {
> +		PMD_DRV_LOG(ERR, "interrupt disable failed");
> +		return;
> +	}
> +	rte_intr_callback_unregister(eth_dev->intr_handle,
> +				     virtio_interrupt_handler, eth_dev);
> +	if (dev->is_server) {
> +		if (dev->ops->server_disconnect)
> +			dev->ops->server_disconnect(dev);
> +		eth_dev->intr_handle->fd = dev->ops->get_intr_fd(dev);
> +		rte_intr_callback_register(eth_dev->intr_handle,
> +					   virtio_interrupt_handler, eth_dev);
> +		if (rte_intr_enable(eth_dev->intr_handle) < 0) {
> +			PMD_DRV_LOG(ERR, "interrupt enable failed");
> +			return;
> +		}
> +	}
> +}
> +
> +int
> +virtio_user_dev_server_reconnect(struct virtio_user_dev *dev)
> +{
> +	int ret, old_status;
> +	struct rte_eth_dev *eth_dev = &rte_eth_devices[dev->port_id];
> +	struct virtio_hw *hw = &dev->hw;
> +
> +	if (!dev->ops->server_reconnect) {
> +		PMD_DRV_LOG(ERR, "(%s) Missing server reconnect callback", dev-
> >path);
> +		return -1;
> +	}
> +
> +	if (dev->ops->server_reconnect(dev)) {
> +		PMD_DRV_LOG(ERR, "(%s) Reconnect callback call failed", dev->path);
> +		return -1;
> +	}
> +
> +	old_status = dev->status;
> +
> +	virtio_reset(hw);
> +
> +	virtio_set_status(hw, VIRTIO_CONFIG_STATUS_ACK);
> +
> +	virtio_set_status(hw, VIRTIO_CONFIG_STATUS_DRIVER);
> +
> +	if (dev->ops->get_features(dev, &dev->device_features) < 0) {
> +		PMD_INIT_LOG(ERR, "get_features failed: %s",
> +			     strerror(errno));
> +		return -1;
> +	}
> +
> +	dev->device_features |= dev->frontend_features;
> +
> +	/* unmask vhost-user unsupported features */
> +	dev->device_features &= ~(dev->unsupported_features);
> +
> +	dev->features &= dev->device_features;
> +
> +	/* For packed ring, resetting queues is required in reconnection. */
> +	if (virtio_with_packed_queue(hw) &&
> +	   (old_status & VIRTIO_CONFIG_STATUS_DRIVER_OK)) {
> +		PMD_INIT_LOG(NOTICE, "Packets on the fly will be dropped"
> +				" when packed ring reconnecting.");
> +		virtio_user_dev_reset_queues_packed(eth_dev);
> +	}
> +
> +	virtio_set_status(hw, VIRTIO_CONFIG_STATUS_FEATURES_OK);
> +
> +	/* Start the device */
> +	virtio_set_status(hw, VIRTIO_CONFIG_STATUS_DRIVER_OK);
> +	if (!dev->started)
> +		return -1;
> +
> +	if (dev->queue_pairs > 1) {
> +		ret = virtio_user_handle_mq(dev, dev->queue_pairs);
> +		if (ret != 0) {
> +			PMD_INIT_LOG(ERR, "Fails to enable multi-queue pairs!");
> +			return -1;
> +		}
> +	}
> +	if (eth_dev->data->dev_flags & RTE_ETH_DEV_INTR_LSC) {
> +		if (rte_intr_disable(eth_dev->intr_handle) < 0) {
> +			PMD_DRV_LOG(ERR, "interrupt disable failed");
> +			return -1;
> +		}
> +		rte_intr_callback_unregister(eth_dev->intr_handle,
> +					     virtio_interrupt_handler,
> +					     eth_dev);
> +
> +		eth_dev->intr_handle->fd = dev->ops->get_intr_fd(dev);
> +		rte_intr_callback_register(eth_dev->intr_handle,
> +					   virtio_interrupt_handler, eth_dev);
> +
> +		if (rte_intr_enable(eth_dev->intr_handle) < 0) {
> +			PMD_DRV_LOG(ERR, "interrupt enable failed");
> +			return -1;
> +		}
> +	}
> +	PMD_INIT_LOG(NOTICE, "server mode virtio-user reconnection succeeds!");
> +	return 0;
> +}
> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.h
> b/drivers/net/virtio/virtio_user/virtio_user_dev.h
> index 7650097b6d..36d2410546 100644
> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
> @@ -27,11 +27,11 @@ struct virtio_user_queue {
>  struct virtio_user_dev {
>  	struct virtio_hw hw;
>  	enum virtio_user_backend_type backend_type;
> -	/* for vhost_user backend */
> -	int		vhostfd;
> -	int		listenfd;   /* listening fd */
>  	bool		is_server;  /* server or client mode */
> 
> +	/* for vhost_vdpa backend */
> +	int		vhostfd;
> +
>  	/* for vhost_kernel backend */
>  	char		*ifname;
>  	int		*vhostfds;
> @@ -85,5 +85,8 @@ void virtio_user_handle_cq_packed(struct virtio_user_dev
> *dev,
>  uint8_t virtio_user_handle_mq(struct virtio_user_dev *dev, uint16_t q_pairs);
>  int virtio_user_dev_set_status(struct virtio_user_dev *dev, uint8_t status);
>  int virtio_user_dev_update_status(struct virtio_user_dev *dev);
> +int virtio_user_dev_update_link_state(struct virtio_user_dev *dev);
> +void virtio_user_dev_delayed_handler(void *param);
> +int virtio_user_dev_server_reconnect(struct virtio_user_dev *dev);
>  extern const char * const virtio_user_backend_strings[];
>  #endif
> diff --git a/drivers/net/virtio/virtio_user_ethdev.c
> b/drivers/net/virtio/virtio_user_ethdev.c
> index e2c606a838..063a723872 100644
> --- a/drivers/net/virtio/virtio_user_ethdev.c
> +++ b/drivers/net/virtio/virtio_user_ethdev.c
> @@ -28,146 +28,6 @@
> 
>  #define virtio_user_get_dev(hwp) container_of(hwp, struct virtio_user_dev, hw)
> 
> -static void
> -virtio_user_reset_queues_packed(struct rte_eth_dev *eth_dev)
> -{
> -	struct virtio_user_dev *dev = eth_dev->data->dev_private;
> -	struct virtio_hw *hw = &dev->hw;
> -	struct virtnet_rx *rxvq;
> -	struct virtnet_tx *txvq;
> -	uint16_t i;
> -
> -	/* Add lock to avoid queue contention. */
> -	rte_spinlock_lock(&hw->state_lock);
> -	hw->started = 0;
> -
> -	/*
> -	 * Waitting for datapath to complete before resetting queues.
> -	 * 1 ms should be enough for the ongoing Tx/Rx function to finish.
> -	 */
> -	rte_delay_ms(1);
> -
> -	/* Vring reset for each Tx queue and Rx queue. */
> -	for (i = 0; i < eth_dev->data->nb_rx_queues; i++) {
> -		rxvq = eth_dev->data->rx_queues[i];
> -		virtqueue_rxvq_reset_packed(rxvq->vq);
> -		virtio_dev_rx_queue_setup_finish(eth_dev, i);
> -	}
> -
> -	for (i = 0; i < eth_dev->data->nb_tx_queues; i++) {
> -		txvq = eth_dev->data->tx_queues[i];
> -		virtqueue_txvq_reset_packed(txvq->vq);
> -	}
> -
> -	hw->started = 1;
> -	rte_spinlock_unlock(&hw->state_lock);
> -}
> -
> -
> -static int
> -virtio_user_server_reconnect(struct virtio_user_dev *dev)
> -{
> -	int ret, connectfd, old_status;
> -	struct rte_eth_dev *eth_dev = &rte_eth_devices[dev->port_id];
> -	struct virtio_hw *hw = &dev->hw;
> -
> -	connectfd = accept(dev->listenfd, NULL, NULL);
> -	if (connectfd < 0)
> -		return -1;
> -
> -	dev->vhostfd = connectfd;
> -	old_status = dev->status;
> -
> -	virtio_reset(hw);
> -
> -	virtio_set_status(hw, VIRTIO_CONFIG_STATUS_ACK);
> -
> -	virtio_set_status(hw, VIRTIO_CONFIG_STATUS_DRIVER);
> -
> -	if (dev->ops->get_features(dev, &dev->device_features) < 0) {
> -		PMD_INIT_LOG(ERR, "get_features failed: %s",
> -			     strerror(errno));
> -		return -1;
> -	}
> -
> -	dev->device_features |= dev->frontend_features;
> -
> -	/* umask vhost-user unsupported features */
> -	dev->device_features &= ~(dev->unsupported_features);
> -
> -	dev->features &= dev->device_features;
> -
> -	/* For packed ring, resetting queues is required in reconnection. */
> -	if (virtio_with_packed_queue(hw) &&
> -	   (old_status & VIRTIO_CONFIG_STATUS_DRIVER_OK)) {
> -		PMD_INIT_LOG(NOTICE, "Packets on the fly will be dropped"
> -				" when packed ring reconnecting.");
> -		virtio_user_reset_queues_packed(eth_dev);
> -	}
> -
> -	virtio_set_status(hw, VIRTIO_CONFIG_STATUS_FEATURES_OK);
> -
> -	/* Start the device */
> -	virtio_set_status(hw, VIRTIO_CONFIG_STATUS_DRIVER_OK);
> -	if (!dev->started)
> -		return -1;
> -
> -	if (dev->queue_pairs > 1) {
> -		ret = virtio_user_handle_mq(dev, dev->queue_pairs);
> -		if (ret != 0) {
> -			PMD_INIT_LOG(ERR, "Fails to enable multi-queue pairs!");
> -			return -1;
> -		}
> -	}
> -	if (eth_dev->data->dev_flags & RTE_ETH_DEV_INTR_LSC) {
> -		if (rte_intr_disable(eth_dev->intr_handle) < 0) {
> -			PMD_DRV_LOG(ERR, "interrupt disable failed");
> -			return -1;
> -		}
> -		rte_intr_callback_unregister(eth_dev->intr_handle,
> -					     virtio_interrupt_handler,
> -					     eth_dev);
> -		eth_dev->intr_handle->fd = connectfd;
> -		rte_intr_callback_register(eth_dev->intr_handle,
> -					   virtio_interrupt_handler, eth_dev);
> -
> -		if (rte_intr_enable(eth_dev->intr_handle) < 0) {
> -			PMD_DRV_LOG(ERR, "interrupt enable failed");
> -			return -1;
> -		}
> -	}
> -	PMD_INIT_LOG(NOTICE, "server mode virtio-user reconnection succeeds!");
> -	return 0;
> -}
> -
> -static void
> -virtio_user_delayed_handler(void *param)
> -{
> -	struct virtio_hw *hw = (struct virtio_hw *)param;
> -	struct rte_eth_dev *eth_dev = &rte_eth_devices[hw->port_id];
> -	struct virtio_user_dev *dev = virtio_user_get_dev(hw);
> -
> -	if (rte_intr_disable(eth_dev->intr_handle) < 0) {
> -		PMD_DRV_LOG(ERR, "interrupt disable failed");
> -		return;
> -	}
> -	rte_intr_callback_unregister(eth_dev->intr_handle,
> -				     virtio_interrupt_handler, eth_dev);
> -	if (dev->is_server) {
> -		if (dev->vhostfd >= 0) {
> -			close(dev->vhostfd);
> -			dev->vhostfd = -1;
> -		}
> -		eth_dev->intr_handle->fd = dev->listenfd;
> -		rte_intr_callback_register(eth_dev->intr_handle,
> -					   virtio_interrupt_handler, eth_dev);
> -		if (rte_intr_enable(eth_dev->intr_handle) < 0) {
> -			PMD_DRV_LOG(ERR, "interrupt enable failed");
> -			return;
> -		}
> -	}
> -}
> -
>  static void
>  virtio_user_read_dev_config(struct virtio_hw *hw, size_t offset,
>  		     void *dst, int length)
> @@ -183,44 +43,7 @@ virtio_user_read_dev_config(struct virtio_hw *hw, size_t
> offset,
>  	}
> 
>  	if (offset == offsetof(struct virtio_net_config, status)) {
> -		char buf[128];
> -
> -		if (dev->vhostfd >= 0) {
> -			int r;
> -			int flags;
> -
> -			flags = fcntl(dev->vhostfd, F_GETFL);
> -			if (fcntl(dev->vhostfd, F_SETFL,
> -					flags | O_NONBLOCK) == -1) {
> -				PMD_DRV_LOG(ERR, "error setting O_NONBLOCK flag");
> -				return;
> -			}
> -			r = recv(dev->vhostfd, buf, 128, MSG_PEEK);
> -			if (r == 0 || (r < 0 && errno != EAGAIN)) {
> -				dev->net_status &= (~VIRTIO_NET_S_LINK_UP);
> -				PMD_DRV_LOG(ERR, "virtio-user port %u is down",
> -					    hw->port_id);
> -
> -				/* This function could be called in the process
> -				 * of interrupt handling, callback cannot be
> -				 * unregistered here, set an alarm to do it.
> -				 */
> -				rte_eal_alarm_set(1,
> -						  virtio_user_delayed_handler,
> -						  (void *)hw);
> -			} else {
> -				dev->net_status |= VIRTIO_NET_S_LINK_UP;
> -			}
> -			if (fcntl(dev->vhostfd, F_SETFL,
> -					flags & ~O_NONBLOCK) == -1) {
> -				PMD_DRV_LOG(ERR, "error clearing O_NONBLOCK flag");
> -				return;
> -			}
> -		} else if (dev->is_server) {
> -			dev->net_status &= (~VIRTIO_NET_S_LINK_UP);
> -			if (virtio_user_server_reconnect(dev) >= 0)
> -				dev->net_status |= VIRTIO_NET_S_LINK_UP;
> -		}
> +		virtio_user_dev_update_link_state(dev);
> 
>  		*(uint16_t *)dst = dev->net_status;
>  	}
> --
> 2.29.2

Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>