1 files changed, 857 insertions, 0 deletions

diff --git a/lib/librte_eal/linuxapp/kni/kni_vhost.c b/lib/librte_eal/linuxapp/kni/kni_vhost.c
new file mode 100644
index 00000000..a3ca8499
--- /dev/null
+++ b/lib/librte_eal/linuxapp/kni/kni_vhost.c
@@ -0,0 +1,857 @@
+/*-
+ * GPL LICENSE SUMMARY
+ *
+ *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of version 2 of the GNU General Public License as
+ *   published by the Free Software Foundation.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *   General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *   The full GNU General Public License is included in this distribution
+ *   in the file called LICENSE.GPL.
+ *
+ *   Contact Information:
+ *   Intel Corporation
+ */
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <net/sock.h>
+#include <linux/virtio_net.h>
+#include <linux/wait.h>
+#include <linux/mm.h>
+#include <linux/nsproxy.h>
+#include <linux/sched.h>
+#include <linux/if_tun.h>
+#include <linux/version.h>
+
+#include "compat.h"
+#include "kni_dev.h"
+#include "kni_fifo.h"
+
+#define RX_BURST_SZ 4
+
+extern void put_unused_fd(unsigned int fd);
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,7,0)
+extern struct file*
+sock_alloc_file(struct socket *sock,
+		int flags, const char *dname);
+
+extern int get_unused_fd_flags(unsigned flags);
+
+extern void fd_install(unsigned int fd, struct file *file);
+
+static int kni_sock_map_fd(struct socket *sock)
+{
+	struct file *file;
+	int fd = get_unused_fd_flags(0);
+	if (fd < 0)
+		return fd;
+
+	file = sock_alloc_file(sock, 0, NULL);
+	if (IS_ERR(file)) {
+		put_unused_fd(fd);
+		return PTR_ERR(file);
+	}
+	fd_install(fd, file);
+	return fd;
+}
+#else
+#define kni_sock_map_fd(s)             sock_map_fd(s, 0)
+#endif
+
+static struct proto kni_raw_proto = {
+	.name = "kni_vhost",
+	.owner = THIS_MODULE,
+	.obj_size = sizeof(struct kni_vhost_queue),
+};
+
+static inline int
+kni_vhost_net_tx(struct kni_dev *kni, struct msghdr *m,
+		 unsigned offset, unsigned len)
+{
+	struct rte_kni_mbuf *pkt_kva = NULL;
+	struct rte_kni_mbuf *pkt_va = NULL;
+	int ret;
+
+	KNI_DBG_TX("tx offset=%d, len=%d, iovlen=%d\n",
+#ifdef HAVE_IOV_ITER_MSGHDR
+		   offset, len, (int)m->msg_iter.iov->iov_len);
+#else
+		   offset, len, (int)m->msg_iov->iov_len);
+#endif
+
+	/**
+	 * Check if it has at least one free entry in tx_q and
+	 * one entry in alloc_q.
+	 */
+	if (kni_fifo_free_count(kni->tx_q) == 0 ||
+	    kni_fifo_count(kni->alloc_q) == 0) {
+		/**
+		 * If no free entry in tx_q or no entry in alloc_q,
+		 * drops skb and goes out.
+		 */
+		goto drop;
+	}
+
+	/* dequeue a mbuf from alloc_q */
+	ret = kni_fifo_get(kni->alloc_q, (void **)&pkt_va, 1);
+	if (likely(ret == 1)) {
+		void *data_kva;
+
+		pkt_kva = (void *)pkt_va - kni->mbuf_va + kni->mbuf_kva;
+		data_kva = pkt_kva->buf_addr + pkt_kva->data_off
+		           - kni->mbuf_va + kni->mbuf_kva;
+
+#ifdef HAVE_IOV_ITER_MSGHDR
+		copy_from_iter(data_kva, len, &m->msg_iter);
+#else
+		memcpy_fromiovecend(data_kva, m->msg_iov, offset, len);
+#endif
+
+		if (unlikely(len < ETH_ZLEN)) {
+			memset(data_kva + len, 0, ETH_ZLEN - len);
+			len = ETH_ZLEN;
+		}
+		pkt_kva->pkt_len = len;
+		pkt_kva->data_len = len;
+
+		/* enqueue mbuf into tx_q */
+		ret = kni_fifo_put(kni->tx_q, (void **)&pkt_va, 1);
+		if (unlikely(ret != 1)) {
+			/* Failing should not happen */
+			KNI_ERR("Fail to enqueue mbuf into tx_q\n");
+			goto drop;
+		}
+	} else {
+		/* Failing should not happen */
+		KNI_ERR("Fail to dequeue mbuf from alloc_q\n");
+		goto drop;
+	}
+
+	/* update statistics */
+	kni->stats.tx_bytes += len;
+	kni->stats.tx_packets++;
+
+	return 0;
+
+drop:
+	/* update statistics */
+	kni->stats.tx_dropped++;
+
+	return 0;
+}
+
+static inline int
+kni_vhost_net_rx(struct kni_dev *kni, struct msghdr *m,
+		 unsigned offset, unsigned len)
+{
+	uint32_t pkt_len;
+	struct rte_kni_mbuf *kva;
+	struct rte_kni_mbuf *va;
+	void * data_kva;
+	struct sk_buff *skb;
+	struct kni_vhost_queue *q = kni->vhost_queue;
+
+	if (unlikely(q == NULL))
+		return 0;
+
+	/* ensure at least one entry in free_q */
+	if (unlikely(kni_fifo_free_count(kni->free_q) == 0))
+		return 0;
+
+	skb = skb_dequeue(&q->sk.sk_receive_queue);
+	if (unlikely(skb == NULL))
+		return 0;
+
+	kva = (struct rte_kni_mbuf*)skb->data;
+
+	/* free skb to cache */
+	skb->data = NULL;
+	if (unlikely(1 != kni_fifo_put(q->fifo, (void **)&skb, 1)))
+		/* Failing should not happen */
+		KNI_ERR("Fail to enqueue entries into rx cache fifo\n");
+
+	pkt_len = kva->data_len;
+	if (unlikely(pkt_len > len))
+		goto drop;
+
+	KNI_DBG_RX("rx offset=%d, len=%d, pkt_len=%d, iovlen=%d\n",
+#ifdef HAVE_IOV_ITER_MSGHDR
+		   offset, len, pkt_len, (int)m->msg_iter.iov->iov_len);
+#else
+		   offset, len, pkt_len, (int)m->msg_iov->iov_len);
+#endif
+
+	data_kva = kva->buf_addr + kva->data_off - kni->mbuf_va + kni->mbuf_kva;
+#ifdef HAVE_IOV_ITER_MSGHDR
+	if (unlikely(copy_to_iter(data_kva, pkt_len, &m->msg_iter)))
+#else
+	if (unlikely(memcpy_toiovecend(m->msg_iov, data_kva, offset, pkt_len)))
+#endif
+		goto drop;
+
+	/* Update statistics */
+	kni->stats.rx_bytes += pkt_len;
+	kni->stats.rx_packets++;
+
+	/* enqueue mbufs into free_q */
+	va = (void*)kva - kni->mbuf_kva + kni->mbuf_va;
+	if (unlikely(1 != kni_fifo_put(kni->free_q, (void **)&va, 1)))
+		/* Failing should not happen */
+		KNI_ERR("Fail to enqueue entries into free_q\n");
+
+	KNI_DBG_RX("receive done %d\n", pkt_len);
+
+	return pkt_len;
+
+drop:
+	/* Update drop statistics */
+	kni->stats.rx_dropped++;
+
+	return 0;
+}
+
+static unsigned int
+kni_sock_poll(struct file *file, struct socket *sock, poll_table * wait)
+{
+	struct kni_vhost_queue *q =
+		container_of(sock->sk, struct kni_vhost_queue, sk);
+	struct kni_dev *kni;
+	unsigned int mask = 0;
+
+	if (unlikely(q == NULL || q->kni == NULL))
+		return POLLERR;
+
+	kni = q->kni;
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,35)
+	KNI_DBG("start kni_poll on group %d, wq 0x%16llx\n",
+		  kni->group_id, (uint64_t)sock->wq);
+#else
+	KNI_DBG("start kni_poll on group %d, wait at 0x%16llx\n",
+		  kni->group_id, (uint64_t)&sock->wait);
+#endif
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,35)
+	poll_wait(file, &sock->wq->wait, wait);
+#else
+	poll_wait(file, &sock->wait, wait);
+#endif
+
+	if (kni_fifo_count(kni->rx_q) > 0)
+		mask |= POLLIN | POLLRDNORM;
+
+	if (sock_writeable(&q->sk) ||
+#ifdef SOCKWQ_ASYNC_NOSPACE
+	    (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &q->sock->flags) &&
+#else
+	    (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &q->sock->flags) &&
+#endif
+	     sock_writeable(&q->sk)))
+		mask |= POLLOUT | POLLWRNORM;
+
+	return mask;
+}
+
+static inline void
+kni_vhost_enqueue(struct kni_dev *kni, struct kni_vhost_queue *q,
+		  struct sk_buff *skb, struct rte_kni_mbuf *va)
+{
+	struct rte_kni_mbuf *kva;
+
+	kva = (void *)(va) - kni->mbuf_va + kni->mbuf_kva;
+	(skb)->data = (unsigned char*)kva;
+	(skb)->len = kva->data_len;
+	skb_queue_tail(&q->sk.sk_receive_queue, skb);
+}
+
+static inline void
+kni_vhost_enqueue_burst(struct kni_dev *kni, struct kni_vhost_queue *q,
+	  struct sk_buff **skb, struct rte_kni_mbuf **va)
+{
+	int i;
+	for (i = 0; i < RX_BURST_SZ; skb++, va++, i++)
+		kni_vhost_enqueue(kni, q, *skb, *va);
+}
+
+int
+kni_chk_vhost_rx(struct kni_dev *kni)
+{
+	struct kni_vhost_queue *q = kni->vhost_queue;
+	unsigned nb_in, nb_mbuf, nb_skb;
+	const unsigned BURST_MASK = RX_BURST_SZ - 1;
+	unsigned nb_burst, nb_backlog, i;
+	struct sk_buff *skb[RX_BURST_SZ];
+	struct rte_kni_mbuf *va[RX_BURST_SZ];
+
+	if (unlikely(BE_STOP & kni->vq_status)) {
+		kni->vq_status |= BE_FINISH;
+		return 0;
+	}
+
+	if (unlikely(q == NULL))
+		return 0;
+
+	nb_skb = kni_fifo_count(q->fifo);
+	nb_mbuf = kni_fifo_count(kni->rx_q);
+
+	nb_in = min(nb_mbuf, nb_skb);
+	nb_in = min(nb_in, (unsigned)RX_BURST_SZ);
+	nb_burst   = (nb_in & ~BURST_MASK);
+	nb_backlog = (nb_in & BURST_MASK);
+
+	/* enqueue skb_queue per BURST_SIZE bulk */
+	if (0 != nb_burst) {
+		if (unlikely(RX_BURST_SZ != kni_fifo_get(
+				     kni->rx_q, (void **)&va,
+				     RX_BURST_SZ)))
+			goto except;
+
+		if (unlikely(RX_BURST_SZ != kni_fifo_get(
+				     q->fifo, (void **)&skb,
+				     RX_BURST_SZ)))
+			goto except;
+
+		kni_vhost_enqueue_burst(kni, q, skb, va);
+	}
+
+	/* all leftover, do one by one */
+	for (i = 0; i < nb_backlog; ++i) {
+		if (unlikely(1 != kni_fifo_get(
+				     kni->rx_q,(void **)&va, 1)))
+			goto except;
+
+		if (unlikely(1 != kni_fifo_get(
+				     q->fifo, (void **)&skb, 1)))
+			goto except;
+
+		kni_vhost_enqueue(kni, q, *skb, *va);
+	}
+
+	/* Ondemand wake up */
+	if ((nb_in == RX_BURST_SZ) || (nb_skb == 0) ||
+	    ((nb_mbuf < RX_BURST_SZ) && (nb_mbuf != 0))) {
+		wake_up_interruptible_poll(sk_sleep(&q->sk),
+				   POLLIN | POLLRDNORM | POLLRDBAND);
+		KNI_DBG_RX("RX CHK KICK nb_mbuf %d, nb_skb %d, nb_in %d\n",
+			   nb_mbuf, nb_skb, nb_in);
+	}
+
+	return 0;
+
+except:
+	/* Failing should not happen */
+	KNI_ERR("Fail to enqueue fifo, it shouldn't happen \n");
+	BUG_ON(1);
+
+	return 0;
+}
+
+static int
+#ifdef HAVE_KIOCB_MSG_PARAM
+kni_sock_sndmsg(struct kiocb *iocb, struct socket *sock,
+	   struct msghdr *m, size_t total_len)
+#else
+kni_sock_sndmsg(struct socket *sock,
+	   struct msghdr *m, size_t total_len)
+#endif /* HAVE_KIOCB_MSG_PARAM */
+{
+	struct kni_vhost_queue *q =
+		container_of(sock->sk, struct kni_vhost_queue, sk);
+	int vnet_hdr_len = 0;
+	unsigned long len = total_len;
+
+	if (unlikely(q == NULL || q->kni == NULL))
+		return 0;
+
+	KNI_DBG_TX("kni_sndmsg len %ld, flags 0x%08x, nb_iov %d\n",
+#ifdef HAVE_IOV_ITER_MSGHDR
+		   len, q->flags, (int)m->msg_iter.iov->iov_len);
+#else
+		   len, q->flags, (int)m->msg_iovlen);
+#endif
+
+#ifdef RTE_KNI_VHOST_VNET_HDR_EN
+	if (likely(q->flags & IFF_VNET_HDR)) {
+		vnet_hdr_len = q->vnet_hdr_sz;
+		if (unlikely(len < vnet_hdr_len))
+			return -EINVAL;
+		len -= vnet_hdr_len;
+	}
+#endif
+
+	if (unlikely(len < ETH_HLEN + q->vnet_hdr_sz))
+		return -EINVAL;
+
+	return kni_vhost_net_tx(q->kni, m, vnet_hdr_len, len);
+}
+
+static int
+#ifdef HAVE_KIOCB_MSG_PARAM
+kni_sock_rcvmsg(struct kiocb *iocb, struct socket *sock,
+	   struct msghdr *m, size_t len, int flags)
+#else
+kni_sock_rcvmsg(struct socket *sock,
+	   struct msghdr *m, size_t len, int flags)
+#endif /* HAVE_KIOCB_MSG_PARAM */
+{
+	int vnet_hdr_len = 0;
+	int pkt_len = 0;
+	struct kni_vhost_queue *q =
+		container_of(sock->sk, struct kni_vhost_queue, sk);
+	static struct virtio_net_hdr
+		__attribute__ ((unused)) vnet_hdr = {
+		.flags = 0,
+		.gso_type = VIRTIO_NET_HDR_GSO_NONE
+	};
+
+	if (unlikely(q == NULL || q->kni == NULL))
+		return 0;
+
+#ifdef RTE_KNI_VHOST_VNET_HDR_EN
+	if (likely(q->flags & IFF_VNET_HDR)) {
+		vnet_hdr_len = q->vnet_hdr_sz;
+		if ((len -= vnet_hdr_len) < 0)
+			return -EINVAL;
+	}
+#endif
+
+	if (unlikely(0 == (pkt_len = kni_vhost_net_rx(q->kni,
+		m, vnet_hdr_len, len))))
+		return 0;
+
+#ifdef RTE_KNI_VHOST_VNET_HDR_EN
+	/* no need to copy hdr when no pkt received */
+#ifdef HAVE_IOV_ITER_MSGHDR
+	if (unlikely(copy_to_iter((void *)&vnet_hdr, vnet_hdr_len,
+		&m->msg_iter)))
+#else
+	if (unlikely(memcpy_toiovecend(m->msg_iov,
+		(void *)&vnet_hdr, 0, vnet_hdr_len)))
+#endif /* HAVE_IOV_ITER_MSGHDR */
+		return -EFAULT;
+#endif /* RTE_KNI_VHOST_VNET_HDR_EN */
+	KNI_DBG_RX("kni_rcvmsg expect_len %ld, flags 0x%08x, pkt_len %d\n",
+		   (unsigned long)len, q->flags, pkt_len);
+
+	return pkt_len + vnet_hdr_len;
+}
+
+/* dummy tap like ioctl */
+static int
+kni_sock_ioctl(struct socket *sock, unsigned int cmd,
+	      unsigned long arg)
+{
+	void __user *argp = (void __user *)arg;
+	struct ifreq __user *ifr = argp;
+	unsigned int __user *up = argp;
+	struct kni_vhost_queue *q =
+		container_of(sock->sk, struct kni_vhost_queue, sk);
+	struct kni_dev *kni;
+	unsigned int u;
+	int __user *sp = argp;
+	int s;
+	int ret;
+
+	KNI_DBG("tap ioctl cmd 0x%08x\n", cmd);
+
+	switch (cmd) {
+	case TUNSETIFF:
+		KNI_DBG("TUNSETIFF\n");
+		/* ignore the name, just look at flags */
+		if (get_user(u, &ifr->ifr_flags))
+			return -EFAULT;
+
+		ret = 0;
+		if ((u & ~IFF_VNET_HDR) != (IFF_NO_PI | IFF_TAP))
+			ret = -EINVAL;
+		else
+			q->flags = u;
+
+		return ret;
+
+	case TUNGETIFF:
+		KNI_DBG("TUNGETIFF\n");
+		rcu_read_lock_bh();
+		kni = rcu_dereference_bh(q->kni);
+		if (kni)
+			dev_hold(kni->net_dev);
+		rcu_read_unlock_bh();
+
+		if (!kni)
+			return -ENOLINK;
+
+		ret = 0;
+		if (copy_to_user(&ifr->ifr_name, kni->net_dev->name, IFNAMSIZ) ||
+		    put_user(q->flags, &ifr->ifr_flags))
+			ret = -EFAULT;
+		dev_put(kni->net_dev);
+		return ret;
+
+	case TUNGETFEATURES:
+		KNI_DBG("TUNGETFEATURES\n");
+		u = IFF_TAP | IFF_NO_PI;
+#ifdef RTE_KNI_VHOST_VNET_HDR_EN
+		u |= IFF_VNET_HDR;
+#endif
+		if (put_user(u, up))
+			return -EFAULT;
+		return 0;
+
+	case TUNSETSNDBUF:
+		KNI_DBG("TUNSETSNDBUF\n");
+		if (get_user(u, up))
+			return -EFAULT;
+
+		q->sk.sk_sndbuf = u;
+		return 0;
+
+	case TUNGETVNETHDRSZ:
+		s = q->vnet_hdr_sz;
+		if (put_user(s, sp))
+			return -EFAULT;
+		KNI_DBG("TUNGETVNETHDRSZ %d\n", s);
+		return 0;
+
+	case TUNSETVNETHDRSZ:
+		if (get_user(s, sp))
+			return -EFAULT;
+		if (s < (int)sizeof(struct virtio_net_hdr))
+			return -EINVAL;
+
+		KNI_DBG("TUNSETVNETHDRSZ %d\n", s);
+		q->vnet_hdr_sz = s;
+		return 0;
+
+	case TUNSETOFFLOAD:
+		KNI_DBG("TUNSETOFFLOAD %lx\n", arg);
+#ifdef RTE_KNI_VHOST_VNET_HDR_EN
+		/* not support any offload yet */
+		if (!(q->flags & IFF_VNET_HDR))
+			return  -EINVAL;
+
+		return 0;
+#else
+		return -EINVAL;
+#endif
+
+	default:
+		KNI_DBG("NOT SUPPORT\n");
+		return -EINVAL;
+	}
+}
+
+static int
+kni_sock_compat_ioctl(struct socket *sock, unsigned int cmd,
+		     unsigned long arg)
+{
+	/* 32 bits app on 64 bits OS to be supported later */
+	KNI_PRINT("Not implemented.\n");
+
+	return -EINVAL;
+}
+
+#define KNI_VHOST_WAIT_WQ_SAFE()                        \
+do {		                                	\
+	while ((BE_FINISH | BE_STOP) == kni->vq_status) \
+		msleep(1);                              \
+}while(0)                                               \
+
+
+static int
+kni_sock_release(struct socket *sock)
+{
+	struct kni_vhost_queue *q =
+		container_of(sock->sk, struct kni_vhost_queue, sk);
+	struct kni_dev *kni;
+
+	if (q == NULL)
+		return 0;
+
+	if (NULL != (kni = q->kni)) {
+		kni->vq_status = BE_STOP;
+		KNI_VHOST_WAIT_WQ_SAFE();
+		kni->vhost_queue = NULL;
+		q->kni = NULL;
+	}
+
+	if (q->sockfd != -1)
+		q->sockfd = -1;
+
+	sk_set_socket(&q->sk, NULL);
+	sock->sk = NULL;
+
+	sock_put(&q->sk);
+
+	KNI_DBG("dummy sock release done\n");
+
+	return 0;
+}
+
+int
+kni_sock_getname (struct socket *sock,
+		  struct sockaddr *addr,
+		  int *sockaddr_len, int peer)
+{
+	KNI_DBG("dummy sock getname\n");
+	((struct sockaddr_ll*)addr)->sll_family = AF_PACKET;
+	return 0;
+}
+
+static const struct proto_ops kni_socket_ops = {
+	.getname = kni_sock_getname,
+	.sendmsg = kni_sock_sndmsg,
+	.recvmsg = kni_sock_rcvmsg,
+	.release = kni_sock_release,
+	.poll    = kni_sock_poll,
+	.ioctl   = kni_sock_ioctl,
+	.compat_ioctl = kni_sock_compat_ioctl,
+};
+
+static void
+kni_sk_write_space(struct sock *sk)
+{
+	wait_queue_head_t *wqueue;
+
+	if (!sock_writeable(sk) ||
+#ifdef SOCKWQ_ASYNC_NOSPACE
+	    !test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags))
+#else
+	    !test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
+#endif
+		return;
+	wqueue = sk_sleep(sk);
+	if (wqueue && waitqueue_active(wqueue))
+		wake_up_interruptible_poll(
+			wqueue, POLLOUT | POLLWRNORM | POLLWRBAND);
+}
+
+static void
+kni_sk_destruct(struct sock *sk)
+{
+	struct kni_vhost_queue *q =
+		container_of(sk, struct kni_vhost_queue, sk);
+
+	if (!q)
+		return;
+
+	/* make sure there's no packet in buffer */
+	while (skb_dequeue(&sk->sk_receive_queue) != NULL)
+	       ;
+
+	mb();
+
+	if (q->fifo != NULL) {
+		kfree(q->fifo);
+		q->fifo = NULL;
+	}
+
+	if (q->cache != NULL) {
+		kfree(q->cache);
+		q->cache = NULL;
+	}
+}
+
+static int
+kni_vhost_backend_init(struct kni_dev *kni)
+{
+	struct kni_vhost_queue *q;
+	struct net *net = current->nsproxy->net_ns;
+	int err, i, sockfd;
+	struct rte_kni_fifo *fifo;
+	struct sk_buff *elem;
+
+	if (kni->vhost_queue != NULL)
+		return -1;
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 2, 0)
+	q = (struct kni_vhost_queue *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
+			&kni_raw_proto, 0);
+#else
+	q = (struct kni_vhost_queue *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
+			&kni_raw_proto);
+#endif
+	if (!q)
+		return -ENOMEM;
+
+	err = sock_create_lite(AF_UNSPEC, SOCK_RAW, IPPROTO_RAW, &q->sock);
+	if (err)
+		goto free_sk;
+
+	sockfd = kni_sock_map_fd(q->sock);
+	if (sockfd < 0) {
+		err = sockfd;
+		goto free_sock;
+	}
+
+	/* cache init */
+	q->cache = kzalloc(RTE_KNI_VHOST_MAX_CACHE_SIZE * sizeof(struct sk_buff),
+			   GFP_KERNEL);
+	if (!q->cache)
+		goto free_fd;
+
+	fifo = kzalloc(RTE_KNI_VHOST_MAX_CACHE_SIZE * sizeof(void *)
+			+ sizeof(struct rte_kni_fifo), GFP_KERNEL);
+	if (!fifo)
+		goto free_cache;
+
+	kni_fifo_init(fifo, RTE_KNI_VHOST_MAX_CACHE_SIZE);
+
+	for (i = 0; i < RTE_KNI_VHOST_MAX_CACHE_SIZE; i++) {
+		elem = &q->cache[i];
+		kni_fifo_put(fifo, (void**)&elem, 1);
+	}
+	q->fifo = fifo;
+
+	/* store sockfd in vhost_queue */
+	q->sockfd = sockfd;
+
+	/* init socket */
+	q->sock->type = SOCK_RAW;
+	q->sock->state = SS_CONNECTED;
+	q->sock->ops = &kni_socket_ops;
+	sock_init_data(q->sock, &q->sk);
+
+	/* init sock data */
+	q->sk.sk_write_space = kni_sk_write_space;
+	q->sk.sk_destruct = kni_sk_destruct;
+	q->flags = IFF_NO_PI | IFF_TAP;
+	q->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
+#ifdef RTE_KNI_VHOST_VNET_HDR_EN
+	q->flags |= IFF_VNET_HDR;
+#endif
+
+	/* bind kni_dev with vhost_queue */
+	q->kni = kni;
+	kni->vhost_queue = q;
+
+	wmb();
+
+	kni->vq_status = BE_START;
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,35)
+	KNI_DBG("backend init sockfd=%d, sock->wq=0x%16llx,"
+		  "sk->sk_wq=0x%16llx",
+		  q->sockfd, (uint64_t)q->sock->wq,
+		  (uint64_t)q->sk.sk_wq);
+#else
+	KNI_DBG("backend init sockfd=%d, sock->wait at 0x%16llx,"
+		  "sk->sk_sleep=0x%16llx",
+		  q->sockfd, (uint64_t)&q->sock->wait,
+		  (uint64_t)q->sk.sk_sleep);
+#endif
+
+	return 0;
+
+free_cache:
+	kfree(q->cache);
+	q->cache = NULL;
+
+free_fd:
+	put_unused_fd(sockfd);
+
+free_sock:
+	q->kni = NULL;
+	kni->vhost_queue = NULL;
+	kni->vq_status |= BE_FINISH;
+	sock_release(q->sock);
+	q->sock->ops = NULL;
+	q->sock = NULL;
+
+free_sk:
+	sk_free((struct sock*)q);
+
+	return err;
+}
+
+/* kni vhost sock sysfs */
+static ssize_t
+show_sock_fd(struct device *dev, struct device_attribute *attr,
+	     char *buf)
+{
+	struct net_device *net_dev = container_of(dev, struct net_device, dev);
+	struct kni_dev *kni = netdev_priv(net_dev);
+	int sockfd = -1;
+	if (kni->vhost_queue != NULL)
+		sockfd = kni->vhost_queue->sockfd;
+	return snprintf(buf, 10, "%d\n", sockfd);
+}
+
+static ssize_t
+show_sock_en(struct device *dev, struct device_attribute *attr,
+	     char *buf)
+{
+	struct net_device *net_dev = container_of(dev, struct net_device, dev);
+	struct kni_dev *kni = netdev_priv(net_dev);
+	return snprintf(buf, 10, "%u\n", (kni->vhost_queue == NULL ? 0 : 1));
+}
+
+static ssize_t
+set_sock_en(struct device *dev, struct device_attribute *attr,
+	      const char *buf, size_t count)
+{
+	struct net_device *net_dev = container_of(dev, struct net_device, dev);
+	struct kni_dev *kni = netdev_priv(net_dev);
+	unsigned long en;
+	int err = 0;
+
+	if (0 != kstrtoul(buf, 0, &en))
+		return -EINVAL;
+
+	if (en)
+		err = kni_vhost_backend_init(kni);
+
+	return err ? err : count;
+}
+
+static DEVICE_ATTR(sock_fd, S_IRUGO | S_IRUSR, show_sock_fd, NULL);
+static DEVICE_ATTR(sock_en, S_IRUGO | S_IWUSR, show_sock_en, set_sock_en);
+static struct attribute *dev_attrs[] = {
+	&dev_attr_sock_fd.attr,
+	&dev_attr_sock_en.attr,
+        NULL,
+};
+
+static const struct attribute_group dev_attr_grp = {
+	.attrs = dev_attrs,
+};
+
+int
+kni_vhost_backend_release(struct kni_dev *kni)
+{
+	struct kni_vhost_queue *q = kni->vhost_queue;
+
+	if (q == NULL)
+		return 0;
+
+	/* dettach from kni */
+	q->kni = NULL;
+
+	KNI_DBG("release backend done\n");
+
+	return 0;
+}
+
+int
+kni_vhost_init(struct kni_dev *kni)
+{
+	struct net_device *dev = kni->net_dev;
+
+	if (sysfs_create_group(&dev->dev.kobj, &dev_attr_grp))
+		sysfs_remove_group(&dev->dev.kobj, &dev_attr_grp);
+
+	kni->vq_status = BE_STOP;
+
+	KNI_DBG("kni_vhost_init done\n");
+
+	return 0;
+}