1 files changed, 1123 insertions, 0 deletions

diff --git a/src/seastar/dpdk/lib/librte_vhost/socket.c b/src/seastar/dpdk/lib/librte_vhost/socket.c
new file mode 100644
index 000000000..274988c4d
--- /dev/null
+++ b/src/seastar/dpdk/lib/librte_vhost/socket.c
@@ -0,0 +1,1123 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2016 Intel Corporation
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/queue.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <pthread.h>
+
+#include <rte_log.h>
+
+#include "fd_man.h"
+#include "vhost.h"
+#include "vhost_user.h"
+
+
+TAILQ_HEAD(vhost_user_connection_list, vhost_user_connection);
+
+/*
+ * Every time rte_vhost_driver_register() is invoked, an associated
+ * vhost_user_socket struct will be created.
+ */
+struct vhost_user_socket {
+	struct vhost_user_connection_list conn_list;
+	pthread_mutex_t conn_mutex;
+	char *path;
+	int socket_fd;
+	struct sockaddr_un un;
+	bool is_server;
+	bool reconnect;
+	bool dequeue_zero_copy;
+	bool iommu_support;
+	bool use_builtin_virtio_net;
+
+	/*
+	 * The "supported_features" indicates the feature bits the
+	 * vhost driver supports. The "features" indicates the feature
+	 * bits after the rte_vhost_driver_features_disable/enable().
+	 * It is also the final feature bits used for vhost-user
+	 * features negotiation.
+	 */
+	uint64_t supported_features;
+	uint64_t features;
+
+	uint64_t protocol_features;
+
+	/*
+	 * Device id to identify a specific backend device.
+	 * It's set to -1 for the default software implementation.
+	 * If valid, one socket can have 1 connection only.
+	 */
+	int vdpa_dev_id;
+
+	struct vhost_device_ops const *notify_ops;
+};
+
+struct vhost_user_connection {
+	struct vhost_user_socket *vsocket;
+	int connfd;
+	int vid;
+
+	TAILQ_ENTRY(vhost_user_connection) next;
+};
+
+#define MAX_VHOST_SOCKET 1024
+struct vhost_user {
+	struct vhost_user_socket *vsockets[MAX_VHOST_SOCKET];
+	struct fdset fdset;
+	int vsocket_cnt;
+	pthread_mutex_t mutex;
+};
+
+#define MAX_VIRTIO_BACKLOG 128
+
+static void vhost_user_server_new_connection(int fd, void *data, int *remove);
+static void vhost_user_read_cb(int fd, void *dat, int *remove);
+static int create_unix_socket(struct vhost_user_socket *vsocket);
+static int vhost_user_start_client(struct vhost_user_socket *vsocket);
+
+static struct vhost_user vhost_user = {
+	.fdset = {
+		.fd = { [0 ... MAX_FDS - 1] = {-1, NULL, NULL, NULL, 0} },
+		.fd_mutex = PTHREAD_MUTEX_INITIALIZER,
+		.fd_pooling_mutex = PTHREAD_MUTEX_INITIALIZER,
+		.num = 0
+	},
+	.vsocket_cnt = 0,
+	.mutex = PTHREAD_MUTEX_INITIALIZER,
+};
+
+/*
+ * return bytes# of read on success or negative val on failure. Update fdnum
+ * with number of fds read.
+ */
+int
+read_fd_message(int sockfd, char *buf, int buflen, int *fds, int max_fds,
+		int *fd_num)
+{
+	struct iovec iov;
+	struct msghdr msgh;
+	char control[CMSG_SPACE(max_fds * sizeof(int))];
+	struct cmsghdr *cmsg;
+	int got_fds = 0;
+	int ret;
+
+	*fd_num = 0;
+
+	memset(&msgh, 0, sizeof(msgh));
+	iov.iov_base = buf;
+	iov.iov_len  = buflen;
+
+	msgh.msg_iov = &iov;
+	msgh.msg_iovlen = 1;
+	msgh.msg_control = control;
+	msgh.msg_controllen = sizeof(control);
+
+	ret = recvmsg(sockfd, &msgh, 0);
+	if (ret <= 0) {
+		RTE_LOG(ERR, VHOST_CONFIG, "recvmsg failed\n");
+		return ret;
+	}
+
+	if (msgh.msg_flags & (MSG_TRUNC | MSG_CTRUNC)) {
+		RTE_LOG(ERR, VHOST_CONFIG, "truncted msg\n");
+		return -1;
+	}
+
+	for (cmsg = CMSG_FIRSTHDR(&msgh); cmsg != NULL;
+		cmsg = CMSG_NXTHDR(&msgh, cmsg)) {
+		if ((cmsg->cmsg_level == SOL_SOCKET) &&
+			(cmsg->cmsg_type == SCM_RIGHTS)) {
+			got_fds = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
+			*fd_num = got_fds;
+			memcpy(fds, CMSG_DATA(cmsg), got_fds * sizeof(int));
+			break;
+		}
+	}
+
+	/* Clear out unused file descriptors */
+	while (got_fds < max_fds)
+		fds[got_fds++] = -1;
+
+	return ret;
+}
+
+int
+send_fd_message(int sockfd, char *buf, int buflen, int *fds, int fd_num)
+{
+
+	struct iovec iov;
+	struct msghdr msgh;
+	size_t fdsize = fd_num * sizeof(int);
+	char control[CMSG_SPACE(fdsize)];
+	struct cmsghdr *cmsg;
+	int ret;
+
+	memset(&msgh, 0, sizeof(msgh));
+	iov.iov_base = buf;
+	iov.iov_len = buflen;
+
+	msgh.msg_iov = &iov;
+	msgh.msg_iovlen = 1;
+
+	if (fds && fd_num > 0) {
+		msgh.msg_control = control;
+		msgh.msg_controllen = sizeof(control);
+		cmsg = CMSG_FIRSTHDR(&msgh);
+		if (cmsg == NULL) {
+			RTE_LOG(ERR, VHOST_CONFIG, "cmsg == NULL\n");
+			errno = EINVAL;
+			return -1;
+		}
+		cmsg->cmsg_len = CMSG_LEN(fdsize);
+		cmsg->cmsg_level = SOL_SOCKET;
+		cmsg->cmsg_type = SCM_RIGHTS;
+		memcpy(CMSG_DATA(cmsg), fds, fdsize);
+	} else {
+		msgh.msg_control = NULL;
+		msgh.msg_controllen = 0;
+	}
+
+	do {
+		ret = sendmsg(sockfd, &msgh, MSG_NOSIGNAL);
+	} while (ret < 0 && errno == EINTR);
+
+	if (ret < 0) {
+		RTE_LOG(ERR, VHOST_CONFIG,  "sendmsg error\n");
+		return ret;
+	}
+
+	return ret;
+}
+
+static void
+vhost_user_add_connection(int fd, struct vhost_user_socket *vsocket)
+{
+	int vid;
+	size_t size;
+	struct vhost_user_connection *conn;
+	int ret;
+
+	if (vsocket == NULL)
+		return;
+
+	conn = malloc(sizeof(*conn));
+	if (conn == NULL) {
+		close(fd);
+		return;
+	}
+
+	vid = vhost_new_device();
+	if (vid == -1) {
+		goto err;
+	}
+
+	size = strnlen(vsocket->path, PATH_MAX);
+	vhost_set_ifname(vid, vsocket->path, size);
+
+	vhost_set_builtin_virtio_net(vid, vsocket->use_builtin_virtio_net);
+
+	vhost_attach_vdpa_device(vid, vsocket->vdpa_dev_id);
+
+	if (vsocket->dequeue_zero_copy)
+		vhost_enable_dequeue_zero_copy(vid);
+
+	RTE_LOG(INFO, VHOST_CONFIG, "new device, handle is %d\n", vid);
+
+	if (vsocket->notify_ops->new_connection) {
+		ret = vsocket->notify_ops->new_connection(vid);
+		if (ret < 0) {
+			RTE_LOG(ERR, VHOST_CONFIG,
+				"failed to add vhost user connection with fd %d\n",
+				fd);
+			goto err_cleanup;
+		}
+	}
+
+	conn->connfd = fd;
+	conn->vsocket = vsocket;
+	conn->vid = vid;
+	ret = fdset_add(&vhost_user.fdset, fd, vhost_user_read_cb,
+			NULL, conn);
+	if (ret < 0) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"failed to add fd %d into vhost server fdset\n",
+			fd);
+
+		if (vsocket->notify_ops->destroy_connection)
+			vsocket->notify_ops->destroy_connection(conn->vid);
+
+		goto err_cleanup;
+	}
+
+	pthread_mutex_lock(&vsocket->conn_mutex);
+	TAILQ_INSERT_TAIL(&vsocket->conn_list, conn, next);
+	pthread_mutex_unlock(&vsocket->conn_mutex);
+
+	fdset_pipe_notify(&vhost_user.fdset);
+	return;
+
+err_cleanup:
+	vhost_destroy_device(vid);
+err:
+	free(conn);
+	close(fd);
+}
+
+/* call back when there is new vhost-user connection from client  */
+static void
+vhost_user_server_new_connection(int fd, void *dat, int *remove __rte_unused)
+{
+	struct vhost_user_socket *vsocket = dat;
+
+	fd = accept(fd, NULL, NULL);
+	if (fd < 0)
+		return;
+
+	RTE_LOG(INFO, VHOST_CONFIG, "new vhost user connection is %d\n", fd);
+	vhost_user_add_connection(fd, vsocket);
+}
+
+static void
+vhost_user_read_cb(int connfd, void *dat, int *remove)
+{
+	struct vhost_user_connection *conn = dat;
+	struct vhost_user_socket *vsocket = conn->vsocket;
+	int ret;
+
+	ret = vhost_user_msg_handler(conn->vid, connfd);
+	if (ret < 0) {
+		struct virtio_net *dev = get_device(conn->vid);
+
+		close(connfd);
+		*remove = 1;
+
+		if (dev)
+			vhost_destroy_device_notify(dev);
+
+		if (vsocket->notify_ops->destroy_connection)
+			vsocket->notify_ops->destroy_connection(conn->vid);
+
+		vhost_destroy_device(conn->vid);
+
+		pthread_mutex_lock(&vsocket->conn_mutex);
+		TAILQ_REMOVE(&vsocket->conn_list, conn, next);
+		pthread_mutex_unlock(&vsocket->conn_mutex);
+
+		free(conn);
+
+		if (vsocket->reconnect) {
+			create_unix_socket(vsocket);
+			vhost_user_start_client(vsocket);
+		}
+	}
+}
+
+static int
+create_unix_socket(struct vhost_user_socket *vsocket)
+{
+	int fd;
+	struct sockaddr_un *un = &vsocket->un;
+
+	fd = socket(AF_UNIX, SOCK_STREAM, 0);
+	if (fd < 0)
+		return -1;
+	RTE_LOG(INFO, VHOST_CONFIG, "vhost-user %s: socket created, fd: %d\n",
+		vsocket->is_server ? "server" : "client", fd);
+
+	if (!vsocket->is_server && fcntl(fd, F_SETFL, O_NONBLOCK)) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"vhost-user: can't set nonblocking mode for socket, fd: "
+			"%d (%s)\n", fd, strerror(errno));
+		close(fd);
+		return -1;
+	}
+
+	memset(un, 0, sizeof(*un));
+	un->sun_family = AF_UNIX;
+	strncpy(un->sun_path, vsocket->path, sizeof(un->sun_path));
+	un->sun_path[sizeof(un->sun_path) - 1] = '\0';
+
+	vsocket->socket_fd = fd;
+	return 0;
+}
+
+static int
+vhost_user_start_server(struct vhost_user_socket *vsocket)
+{
+	int ret;
+	int fd = vsocket->socket_fd;
+	const char *path = vsocket->path;
+
+	/*
+	 * bind () may fail if the socket file with the same name already
+	 * exists. But the library obviously should not delete the file
+	 * provided by the user, since we can not be sure that it is not
+	 * being used by other applications. Moreover, many applications form
+	 * socket names based on user input, which is prone to errors.
+	 *
+	 * The user must ensure that the socket does not exist before
+	 * registering the vhost driver in server mode.
+	 */
+	ret = bind(fd, (struct sockaddr *)&vsocket->un, sizeof(vsocket->un));
+	if (ret < 0) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"failed to bind to %s: %s; remove it and try again\n",
+			path, strerror(errno));
+		goto err;
+	}
+	RTE_LOG(INFO, VHOST_CONFIG, "bind to %s\n", path);
+
+	ret = listen(fd, MAX_VIRTIO_BACKLOG);
+	if (ret < 0)
+		goto err;
+
+	ret = fdset_add(&vhost_user.fdset, fd, vhost_user_server_new_connection,
+		  NULL, vsocket);
+	if (ret < 0) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"failed to add listen fd %d to vhost server fdset\n",
+			fd);
+		goto err;
+	}
+
+	return 0;
+
+err:
+	close(fd);
+	return -1;
+}
+
+struct vhost_user_reconnect {
+	struct sockaddr_un un;
+	int fd;
+	struct vhost_user_socket *vsocket;
+
+	TAILQ_ENTRY(vhost_user_reconnect) next;
+};
+
+TAILQ_HEAD(vhost_user_reconnect_tailq_list, vhost_user_reconnect);
+struct vhost_user_reconnect_list {
+	struct vhost_user_reconnect_tailq_list head;
+	pthread_mutex_t mutex;
+};
+
+static struct vhost_user_reconnect_list reconn_list;
+static pthread_t reconn_tid;
+
+static int
+vhost_user_connect_nonblock(int fd, struct sockaddr *un, size_t sz)
+{
+	int ret, flags;
+
+	ret = connect(fd, un, sz);
+	if (ret < 0 && errno != EISCONN)
+		return -1;
+
+	flags = fcntl(fd, F_GETFL, 0);
+	if (flags < 0) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"can't get flags for connfd %d\n", fd);
+		return -2;
+	}
+	if ((flags & O_NONBLOCK) && fcntl(fd, F_SETFL, flags & ~O_NONBLOCK)) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+				"can't disable nonblocking on fd %d\n", fd);
+		return -2;
+	}
+	return 0;
+}
+
+static void *
+vhost_user_client_reconnect(void *arg __rte_unused)
+{
+	int ret;
+	struct vhost_user_reconnect *reconn, *next;
+
+	while (1) {
+		pthread_mutex_lock(&reconn_list.mutex);
+
+		/*
+		 * An equal implementation of TAILQ_FOREACH_SAFE,
+		 * which does not exist on all platforms.
+		 */
+		for (reconn = TAILQ_FIRST(&reconn_list.head);
+		     reconn != NULL; reconn = next) {
+			next = TAILQ_NEXT(reconn, next);
+
+			ret = vhost_user_connect_nonblock(reconn->fd,
+						(struct sockaddr *)&reconn->un,
+						sizeof(reconn->un));
+			if (ret == -2) {
+				close(reconn->fd);
+				RTE_LOG(ERR, VHOST_CONFIG,
+					"reconnection for fd %d failed\n",
+					reconn->fd);
+				goto remove_fd;
+			}
+			if (ret == -1)
+				continue;
+
+			RTE_LOG(INFO, VHOST_CONFIG,
+				"%s: connected\n", reconn->vsocket->path);
+			vhost_user_add_connection(reconn->fd, reconn->vsocket);
+remove_fd:
+			TAILQ_REMOVE(&reconn_list.head, reconn, next);
+			free(reconn);
+		}
+
+		pthread_mutex_unlock(&reconn_list.mutex);
+		sleep(1);
+	}
+
+	return NULL;
+}
+
+static int
+vhost_user_reconnect_init(void)
+{
+	int ret;
+
+	ret = pthread_mutex_init(&reconn_list.mutex, NULL);
+	if (ret < 0) {
+		RTE_LOG(ERR, VHOST_CONFIG, "failed to initialize mutex");
+		return ret;
+	}
+	TAILQ_INIT(&reconn_list.head);
+
+	ret = rte_ctrl_thread_create(&reconn_tid, "vhost_reconn", NULL,
+			     vhost_user_client_reconnect, NULL);
+	if (ret != 0) {
+		RTE_LOG(ERR, VHOST_CONFIG, "failed to create reconnect thread");
+		if (pthread_mutex_destroy(&reconn_list.mutex)) {
+			RTE_LOG(ERR, VHOST_CONFIG,
+				"failed to destroy reconnect mutex");
+		}
+	}
+
+	return ret;
+}
+
+static int
+vhost_user_start_client(struct vhost_user_socket *vsocket)
+{
+	int ret;
+	int fd = vsocket->socket_fd;
+	const char *path = vsocket->path;
+	struct vhost_user_reconnect *reconn;
+
+	ret = vhost_user_connect_nonblock(fd, (struct sockaddr *)&vsocket->un,
+					  sizeof(vsocket->un));
+	if (ret == 0) {
+		vhost_user_add_connection(fd, vsocket);
+		return 0;
+	}
+
+	RTE_LOG(WARNING, VHOST_CONFIG,
+		"failed to connect to %s: %s\n",
+		path, strerror(errno));
+
+	if (ret == -2 || !vsocket->reconnect) {
+		close(fd);
+		return -1;
+	}
+
+	RTE_LOG(INFO, VHOST_CONFIG, "%s: reconnecting...\n", path);
+	reconn = malloc(sizeof(*reconn));
+	if (reconn == NULL) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"failed to allocate memory for reconnect\n");
+		close(fd);
+		return -1;
+	}
+	reconn->un = vsocket->un;
+	reconn->fd = fd;
+	reconn->vsocket = vsocket;
+	pthread_mutex_lock(&reconn_list.mutex);
+	TAILQ_INSERT_TAIL(&reconn_list.head, reconn, next);
+	pthread_mutex_unlock(&reconn_list.mutex);
+
+	return 0;
+}
+
+static struct vhost_user_socket *
+find_vhost_user_socket(const char *path)
+{
+	int i;
+
+	if (path == NULL)
+		return NULL;
+
+	for (i = 0; i < vhost_user.vsocket_cnt; i++) {
+		struct vhost_user_socket *vsocket = vhost_user.vsockets[i];
+
+		if (!strcmp(vsocket->path, path))
+			return vsocket;
+	}
+
+	return NULL;
+}
+
+int
+rte_vhost_driver_attach_vdpa_device(const char *path, int did)
+{
+	struct vhost_user_socket *vsocket;
+
+	if (rte_vdpa_get_device(did) == NULL || path == NULL)
+		return -1;
+
+	pthread_mutex_lock(&vhost_user.mutex);
+	vsocket = find_vhost_user_socket(path);
+	if (vsocket)
+		vsocket->vdpa_dev_id = did;
+	pthread_mutex_unlock(&vhost_user.mutex);
+
+	return vsocket ? 0 : -1;
+}
+
+int
+rte_vhost_driver_detach_vdpa_device(const char *path)
+{
+	struct vhost_user_socket *vsocket;
+
+	pthread_mutex_lock(&vhost_user.mutex);
+	vsocket = find_vhost_user_socket(path);
+	if (vsocket)
+		vsocket->vdpa_dev_id = -1;
+	pthread_mutex_unlock(&vhost_user.mutex);
+
+	return vsocket ? 0 : -1;
+}
+
+int
+rte_vhost_driver_get_vdpa_device_id(const char *path)
+{
+	struct vhost_user_socket *vsocket;
+	int did = -1;
+
+	pthread_mutex_lock(&vhost_user.mutex);
+	vsocket = find_vhost_user_socket(path);
+	if (vsocket)
+		did = vsocket->vdpa_dev_id;
+	pthread_mutex_unlock(&vhost_user.mutex);
+
+	return did;
+}
+
+int
+rte_vhost_driver_disable_features(const char *path, uint64_t features)
+{
+	struct vhost_user_socket *vsocket;
+
+	pthread_mutex_lock(&vhost_user.mutex);
+	vsocket = find_vhost_user_socket(path);
+
+	/* Note that use_builtin_virtio_net is not affected by this function
+	 * since callers may want to selectively disable features of the
+	 * built-in vhost net device backend.
+	 */
+
+	if (vsocket)
+		vsocket->features &= ~features;
+	pthread_mutex_unlock(&vhost_user.mutex);
+
+	return vsocket ? 0 : -1;
+}
+
+int
+rte_vhost_driver_enable_features(const char *path, uint64_t features)
+{
+	struct vhost_user_socket *vsocket;
+
+	pthread_mutex_lock(&vhost_user.mutex);
+	vsocket = find_vhost_user_socket(path);
+	if (vsocket) {
+		if ((vsocket->supported_features & features) != features) {
+			/*
+			 * trying to enable features the driver doesn't
+			 * support.
+			 */
+			pthread_mutex_unlock(&vhost_user.mutex);
+			return -1;
+		}
+		vsocket->features |= features;
+	}
+	pthread_mutex_unlock(&vhost_user.mutex);
+
+	return vsocket ? 0 : -1;
+}
+
+int
+rte_vhost_driver_set_features(const char *path, uint64_t features)
+{
+	struct vhost_user_socket *vsocket;
+
+	pthread_mutex_lock(&vhost_user.mutex);
+	vsocket = find_vhost_user_socket(path);
+	if (vsocket) {
+		vsocket->supported_features = features;
+		vsocket->features = features;
+
+		/* Anyone setting feature bits is implementing their own vhost
+		 * device backend.
+		 */
+		vsocket->use_builtin_virtio_net = false;
+	}
+	pthread_mutex_unlock(&vhost_user.mutex);
+
+	return vsocket ? 0 : -1;
+}
+
+int
+rte_vhost_driver_get_features(const char *path, uint64_t *features)
+{
+	struct vhost_user_socket *vsocket;
+	uint64_t vdpa_features;
+	struct rte_vdpa_device *vdpa_dev;
+	int did = -1;
+	int ret = 0;
+
+	pthread_mutex_lock(&vhost_user.mutex);
+	vsocket = find_vhost_user_socket(path);
+	if (!vsocket) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"socket file %s is not registered yet.\n", path);
+		ret = -1;
+		goto unlock_exit;
+	}
+
+	did = vsocket->vdpa_dev_id;
+	vdpa_dev = rte_vdpa_get_device(did);
+	if (!vdpa_dev || !vdpa_dev->ops->get_features) {
+		*features = vsocket->features;
+		goto unlock_exit;
+	}
+
+	if (vdpa_dev->ops->get_features(did, &vdpa_features) < 0) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+				"failed to get vdpa features "
+				"for socket file %s.\n", path);
+		ret = -1;
+		goto unlock_exit;
+	}
+
+	*features = vsocket->features & vdpa_features;
+
+unlock_exit:
+	pthread_mutex_unlock(&vhost_user.mutex);
+	return ret;
+}
+
+int
+rte_vhost_driver_set_protocol_features(const char *path,
+		uint64_t protocol_features)
+{
+	struct vhost_user_socket *vsocket;
+
+	pthread_mutex_lock(&vhost_user.mutex);
+	vsocket = find_vhost_user_socket(path);
+	if (vsocket)
+		vsocket->protocol_features = protocol_features;
+	pthread_mutex_unlock(&vhost_user.mutex);
+	return vsocket ? 0 : -1;
+}
+
+int
+rte_vhost_driver_get_protocol_features(const char *path,
+		uint64_t *protocol_features)
+{
+	struct vhost_user_socket *vsocket;
+	uint64_t vdpa_protocol_features;
+	struct rte_vdpa_device *vdpa_dev;
+	int did = -1;
+	int ret = 0;
+
+	pthread_mutex_lock(&vhost_user.mutex);
+	vsocket = find_vhost_user_socket(path);
+	if (!vsocket) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"socket file %s is not registered yet.\n", path);
+		ret = -1;
+		goto unlock_exit;
+	}
+
+	did = vsocket->vdpa_dev_id;
+	vdpa_dev = rte_vdpa_get_device(did);
+	if (!vdpa_dev || !vdpa_dev->ops->get_protocol_features) {
+		*protocol_features = vsocket->protocol_features;
+		goto unlock_exit;
+	}
+
+	if (vdpa_dev->ops->get_protocol_features(did,
+				&vdpa_protocol_features) < 0) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+				"failed to get vdpa protocol features "
+				"for socket file %s.\n", path);
+		ret = -1;
+		goto unlock_exit;
+	}
+
+	*protocol_features = vsocket->protocol_features
+		& vdpa_protocol_features;
+
+unlock_exit:
+	pthread_mutex_unlock(&vhost_user.mutex);
+	return ret;
+}
+
+int
+rte_vhost_driver_get_queue_num(const char *path, uint32_t *queue_num)
+{
+	struct vhost_user_socket *vsocket;
+	uint32_t vdpa_queue_num;
+	struct rte_vdpa_device *vdpa_dev;
+	int did = -1;
+	int ret = 0;
+
+	pthread_mutex_lock(&vhost_user.mutex);
+	vsocket = find_vhost_user_socket(path);
+	if (!vsocket) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"socket file %s is not registered yet.\n", path);
+		ret = -1;
+		goto unlock_exit;
+	}
+
+	did = vsocket->vdpa_dev_id;
+	vdpa_dev = rte_vdpa_get_device(did);
+	if (!vdpa_dev || !vdpa_dev->ops->get_queue_num) {
+		*queue_num = VHOST_MAX_QUEUE_PAIRS;
+		goto unlock_exit;
+	}
+
+	if (vdpa_dev->ops->get_queue_num(did, &vdpa_queue_num) < 0) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+				"failed to get vdpa queue number "
+				"for socket file %s.\n", path);
+		ret = -1;
+		goto unlock_exit;
+	}
+
+	*queue_num = RTE_MIN((uint32_t)VHOST_MAX_QUEUE_PAIRS, vdpa_queue_num);
+
+unlock_exit:
+	pthread_mutex_unlock(&vhost_user.mutex);
+	return ret;
+}
+
+static void
+vhost_user_socket_mem_free(struct vhost_user_socket *vsocket)
+{
+	if (vsocket && vsocket->path) {
+		free(vsocket->path);
+		vsocket->path = NULL;
+	}
+
+	if (vsocket) {
+		free(vsocket);
+		vsocket = NULL;
+	}
+}
+
+/*
+ * Register a new vhost-user socket; here we could act as server
+ * (the default case), or client (when RTE_VHOST_USER_CLIENT) flag
+ * is set.
+ */
+int
+rte_vhost_driver_register(const char *path, uint64_t flags)
+{
+	int ret = -1;
+	struct vhost_user_socket *vsocket;
+
+	if (!path)
+		return -1;
+
+	pthread_mutex_lock(&vhost_user.mutex);
+
+	if (vhost_user.vsocket_cnt == MAX_VHOST_SOCKET) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"error: the number of vhost sockets reaches maximum\n");
+		goto out;
+	}
+
+	vsocket = malloc(sizeof(struct vhost_user_socket));
+	if (!vsocket)
+		goto out;
+	memset(vsocket, 0, sizeof(struct vhost_user_socket));
+	vsocket->path = strdup(path);
+	if (vsocket->path == NULL) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"error: failed to copy socket path string\n");
+		vhost_user_socket_mem_free(vsocket);
+		goto out;
+	}
+	TAILQ_INIT(&vsocket->conn_list);
+	ret = pthread_mutex_init(&vsocket->conn_mutex, NULL);
+	if (ret) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"error: failed to init connection mutex\n");
+		goto out_free;
+	}
+	vsocket->dequeue_zero_copy = flags & RTE_VHOST_USER_DEQUEUE_ZERO_COPY;
+
+	/*
+	 * Set the supported features correctly for the builtin vhost-user
+	 * net driver.
+	 *
+	 * Applications know nothing about features the builtin virtio net
+	 * driver (virtio_net.c) supports, thus it's not possible for them
+	 * to invoke rte_vhost_driver_set_features(). To workaround it, here
+	 * we set it unconditionally. If the application want to implement
+	 * another vhost-user driver (say SCSI), it should call the
+	 * rte_vhost_driver_set_features(), which will overwrite following
+	 * two values.
+	 */
+	vsocket->use_builtin_virtio_net = true;
+	vsocket->supported_features = VIRTIO_NET_SUPPORTED_FEATURES;
+	vsocket->features           = VIRTIO_NET_SUPPORTED_FEATURES;
+	vsocket->protocol_features  = VHOST_USER_PROTOCOL_FEATURES;
+
+	/*
+	 * Dequeue zero copy can't assure descriptors returned in order.
+	 * Also, it requires that the guest memory is populated, which is
+	 * not compatible with postcopy.
+	 */
+	if (vsocket->dequeue_zero_copy) {
+		vsocket->supported_features &= ~(1ULL << VIRTIO_F_IN_ORDER);
+		vsocket->features &= ~(1ULL << VIRTIO_F_IN_ORDER);
+
+		RTE_LOG(INFO, VHOST_CONFIG,
+			"Dequeue zero copy requested, disabling postcopy support\n");
+		vsocket->protocol_features &=
+			~(1ULL << VHOST_USER_PROTOCOL_F_PAGEFAULT);
+	}
+
+	if (!(flags & RTE_VHOST_USER_IOMMU_SUPPORT)) {
+		vsocket->supported_features &= ~(1ULL << VIRTIO_F_IOMMU_PLATFORM);
+		vsocket->features &= ~(1ULL << VIRTIO_F_IOMMU_PLATFORM);
+	}
+
+	if (!(flags & RTE_VHOST_USER_POSTCOPY_SUPPORT)) {
+		vsocket->protocol_features &=
+			~(1ULL << VHOST_USER_PROTOCOL_F_PAGEFAULT);
+	} else {
+#ifndef RTE_LIBRTE_VHOST_POSTCOPY
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"Postcopy requested but not compiled\n");
+		ret = -1;
+		goto out_mutex;
+#endif
+	}
+
+	if ((flags & RTE_VHOST_USER_CLIENT) != 0) {
+		vsocket->reconnect = !(flags & RTE_VHOST_USER_NO_RECONNECT);
+		if (vsocket->reconnect && reconn_tid == 0) {
+			if (vhost_user_reconnect_init() != 0)
+				goto out_mutex;
+		}
+	} else {
+		vsocket->is_server = true;
+	}
+	ret = create_unix_socket(vsocket);
+	if (ret < 0) {
+		goto out_mutex;
+	}
+
+	vhost_user.vsockets[vhost_user.vsocket_cnt++] = vsocket;
+
+	pthread_mutex_unlock(&vhost_user.mutex);
+	return ret;
+
+out_mutex:
+	if (pthread_mutex_destroy(&vsocket->conn_mutex)) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"error: failed to destroy connection mutex\n");
+	}
+out_free:
+	vhost_user_socket_mem_free(vsocket);
+out:
+	pthread_mutex_unlock(&vhost_user.mutex);
+
+	return ret;
+}
+
+static bool
+vhost_user_remove_reconnect(struct vhost_user_socket *vsocket)
+{
+	int found = false;
+	struct vhost_user_reconnect *reconn, *next;
+
+	pthread_mutex_lock(&reconn_list.mutex);
+
+	for (reconn = TAILQ_FIRST(&reconn_list.head);
+	     reconn != NULL; reconn = next) {
+		next = TAILQ_NEXT(reconn, next);
+
+		if (reconn->vsocket == vsocket) {
+			TAILQ_REMOVE(&reconn_list.head, reconn, next);
+			close(reconn->fd);
+			free(reconn);
+			found = true;
+			break;
+		}
+	}
+	pthread_mutex_unlock(&reconn_list.mutex);
+	return found;
+}
+
+/**
+ * Unregister the specified vhost socket
+ */
+int
+rte_vhost_driver_unregister(const char *path)
+{
+	int i;
+	int count;
+	struct vhost_user_connection *conn, *next;
+
+	if (path == NULL)
+		return -1;
+
+again:
+	pthread_mutex_lock(&vhost_user.mutex);
+
+	for (i = 0; i < vhost_user.vsocket_cnt; i++) {
+		struct vhost_user_socket *vsocket = vhost_user.vsockets[i];
+
+		if (!strcmp(vsocket->path, path)) {
+			pthread_mutex_lock(&vsocket->conn_mutex);
+			for (conn = TAILQ_FIRST(&vsocket->conn_list);
+			     conn != NULL;
+			     conn = next) {
+				next = TAILQ_NEXT(conn, next);
+
+				/*
+				 * If r/wcb is executing, release the
+				 * conn_mutex lock, and try again since
+				 * the r/wcb may use the conn_mutex lock.
+				 */
+				if (fdset_try_del(&vhost_user.fdset,
+						  conn->connfd) == -1) {
+					pthread_mutex_unlock(
+							&vsocket->conn_mutex);
+					pthread_mutex_unlock(&vhost_user.mutex);
+					goto again;
+				}
+
+				RTE_LOG(INFO, VHOST_CONFIG,
+					"free connfd = %d for device '%s'\n",
+					conn->connfd, path);
+				close(conn->connfd);
+				vhost_destroy_device(conn->vid);
+				TAILQ_REMOVE(&vsocket->conn_list, conn, next);
+				free(conn);
+			}
+			pthread_mutex_unlock(&vsocket->conn_mutex);
+
+			if (vsocket->is_server) {
+				fdset_del(&vhost_user.fdset,
+						vsocket->socket_fd);
+				close(vsocket->socket_fd);
+				unlink(path);
+			} else if (vsocket->reconnect) {
+				vhost_user_remove_reconnect(vsocket);
+			}
+
+			pthread_mutex_destroy(&vsocket->conn_mutex);
+			vhost_user_socket_mem_free(vsocket);
+
+			count = --vhost_user.vsocket_cnt;
+			vhost_user.vsockets[i] = vhost_user.vsockets[count];
+			vhost_user.vsockets[count] = NULL;
+			pthread_mutex_unlock(&vhost_user.mutex);
+
+			return 0;
+		}
+	}
+	pthread_mutex_unlock(&vhost_user.mutex);
+
+	return -1;
+}
+
+/*
+ * Register ops so that we can add/remove device to data core.
+ */
+int
+rte_vhost_driver_callback_register(const char *path,
+	struct vhost_device_ops const * const ops)
+{
+	struct vhost_user_socket *vsocket;
+
+	pthread_mutex_lock(&vhost_user.mutex);
+	vsocket = find_vhost_user_socket(path);
+	if (vsocket)
+		vsocket->notify_ops = ops;
+	pthread_mutex_unlock(&vhost_user.mutex);
+
+	return vsocket ? 0 : -1;
+}
+
+struct vhost_device_ops const *
+vhost_driver_callback_get(const char *path)
+{
+	struct vhost_user_socket *vsocket;
+
+	pthread_mutex_lock(&vhost_user.mutex);
+	vsocket = find_vhost_user_socket(path);
+	pthread_mutex_unlock(&vhost_user.mutex);
+
+	return vsocket ? vsocket->notify_ops : NULL;
+}
+
+int
+rte_vhost_driver_start(const char *path)
+{
+	struct vhost_user_socket *vsocket;
+	static pthread_t fdset_tid;
+
+	pthread_mutex_lock(&vhost_user.mutex);
+	vsocket = find_vhost_user_socket(path);
+	pthread_mutex_unlock(&vhost_user.mutex);
+
+	if (!vsocket)
+		return -1;
+
+	if (fdset_tid == 0) {
+		/**
+		 * create a pipe which will be waited by poll and notified to
+		 * rebuild the wait list of poll.
+		 */
+		if (fdset_pipe_init(&vhost_user.fdset) < 0) {
+			RTE_LOG(ERR, VHOST_CONFIG,
+				"failed to create pipe for vhost fdset\n");
+			return -1;
+		}
+
+		int ret = rte_ctrl_thread_create(&fdset_tid,
+			"vhost-events", NULL, fdset_event_dispatch,
+			&vhost_user.fdset);
+		if (ret != 0) {
+			RTE_LOG(ERR, VHOST_CONFIG,
+				"failed to create fdset handling thread");
+
+			fdset_pipe_uninit(&vhost_user.fdset);
+			return -1;
+		}
+	}
+
+	if (vsocket->is_server)
+		return vhost_user_start_server(vsocket);
+	else
+		return vhost_user_start_client(vsocket);
+}