Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

9 files changed, 5621 insertions, 0 deletions

diff --git a/kernel/net/vmw_vsock/Kconfig b/kernel/net/vmw_vsock/Kconfig
new file mode 100644
index 000000000..14810abed
--- /dev/null
+++ b/kernel/net/vmw_vsock/Kconfig
@@ -0,0 +1,28 @@
+#
+# Vsock protocol
+#
+
+config VSOCKETS
+	tristate "Virtual Socket protocol"
+	help
+	  Virtual Socket Protocol is a socket protocol similar to TCP/IP
+	  allowing communication between Virtual Machines and hypervisor
+	  or host.
+
+	  You should also select one or more hypervisor-specific transports
+	  below.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called vsock. If unsure, say N.
+
+config VMWARE_VMCI_VSOCKETS
+	tristate "VMware VMCI transport for Virtual Sockets"
+	depends on VSOCKETS && VMWARE_VMCI
+	help
+	  This module implements a VMCI transport for Virtual Sockets.
+
+	  Enable this transport if your Virtual Machine runs on a VMware
+	  hypervisor.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called vmw_vsock_vmci_transport. If unsure, say N.
diff --git a/kernel/net/vmw_vsock/Makefile b/kernel/net/vmw_vsock/Makefile
new file mode 100644
index 000000000..2ce52d70f
--- /dev/null
+++ b/kernel/net/vmw_vsock/Makefile
@@ -0,0 +1,7 @@
+obj-$(CONFIG_VSOCKETS) += vsock.o
+obj-$(CONFIG_VMWARE_VMCI_VSOCKETS) += vmw_vsock_vmci_transport.o
+
+vsock-y += af_vsock.o vsock_addr.o
+
+vmw_vsock_vmci_transport-y += vmci_transport.o vmci_transport_notify.o \
+	vmci_transport_notify_qstate.o
diff --git a/kernel/net/vmw_vsock/af_vsock.c b/kernel/net/vmw_vsock/af_vsock.c
new file mode 100644
index 000000000..2ec86e652
--- /dev/null
+++ b/kernel/net/vmw_vsock/af_vsock.c
@@ -0,0 +1,1999 @@
+/*
+ * VMware vSockets Driver
+ *
+ * Copyright (C) 2007-2013 VMware, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation version 2 and no later version.
+ *
+ * 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.
+ */
+
+/* Implementation notes:
+ *
+ * - There are two kinds of sockets: those created by user action (such as
+ * calling socket(2)) and those created by incoming connection request packets.
+ *
+ * - There are two "global" tables, one for bound sockets (sockets that have
+ * specified an address that they are responsible for) and one for connected
+ * sockets (sockets that have established a connection with another socket).
+ * These tables are "global" in that all sockets on the system are placed
+ * within them. - Note, though, that the bound table contains an extra entry
+ * for a list of unbound sockets and SOCK_DGRAM sockets will always remain in
+ * that list. The bound table is used solely for lookup of sockets when packets
+ * are received and that's not necessary for SOCK_DGRAM sockets since we create
+ * a datagram handle for each and need not perform a lookup.  Keeping SOCK_DGRAM
+ * sockets out of the bound hash buckets will reduce the chance of collisions
+ * when looking for SOCK_STREAM sockets and prevents us from having to check the
+ * socket type in the hash table lookups.
+ *
+ * - Sockets created by user action will either be "client" sockets that
+ * initiate a connection or "server" sockets that listen for connections; we do
+ * not support simultaneous connects (two "client" sockets connecting).
+ *
+ * - "Server" sockets are referred to as listener sockets throughout this
+ * implementation because they are in the SS_LISTEN state.  When a connection
+ * request is received (the second kind of socket mentioned above), we create a
+ * new socket and refer to it as a pending socket.  These pending sockets are
+ * placed on the pending connection list of the listener socket.  When future
+ * packets are received for the address the listener socket is bound to, we
+ * check if the source of the packet is from one that has an existing pending
+ * connection.  If it does, we process the packet for the pending socket.  When
+ * that socket reaches the connected state, it is removed from the listener
+ * socket's pending list and enqueued in the listener socket's accept queue.
+ * Callers of accept(2) will accept connected sockets from the listener socket's
+ * accept queue.  If the socket cannot be accepted for some reason then it is
+ * marked rejected.  Once the connection is accepted, it is owned by the user
+ * process and the responsibility for cleanup falls with that user process.
+ *
+ * - It is possible that these pending sockets will never reach the connected
+ * state; in fact, we may never receive another packet after the connection
+ * request.  Because of this, we must schedule a cleanup function to run in the
+ * future, after some amount of time passes where a connection should have been
+ * established.  This function ensures that the socket is off all lists so it
+ * cannot be retrieved, then drops all references to the socket so it is cleaned
+ * up (sock_put() -> sk_free() -> our sk_destruct implementation).  Note this
+ * function will also cleanup rejected sockets, those that reach the connected
+ * state but leave it before they have been accepted.
+ *
+ * - Sockets created by user action will be cleaned up when the user process
+ * calls close(2), causing our release implementation to be called. Our release
+ * implementation will perform some cleanup then drop the last reference so our
+ * sk_destruct implementation is invoked.  Our sk_destruct implementation will
+ * perform additional cleanup that's common for both types of sockets.
+ *
+ * - A socket's reference count is what ensures that the structure won't be
+ * freed.  Each entry in a list (such as the "global" bound and connected tables
+ * and the listener socket's pending list and connected queue) ensures a
+ * reference.  When we defer work until process context and pass a socket as our
+ * argument, we must ensure the reference count is increased to ensure the
+ * socket isn't freed before the function is run; the deferred function will
+ * then drop the reference.
+ */
+
+#include <linux/types.h>
+#include <linux/bitops.h>
+#include <linux/cred.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/kmod.h>
+#include <linux/list.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/net.h>
+#include <linux/poll.h>
+#include <linux/skbuff.h>
+#include <linux/smp.h>
+#include <linux/socket.h>
+#include <linux/stddef.h>
+#include <linux/unistd.h>
+#include <linux/wait.h>
+#include <linux/workqueue.h>
+#include <net/sock.h>
+#include <net/af_vsock.h>
+
+static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr);
+static void vsock_sk_destruct(struct sock *sk);
+static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
+
+/* Protocol family. */
+static struct proto vsock_proto = {
+	.name = "AF_VSOCK",
+	.owner = THIS_MODULE,
+	.obj_size = sizeof(struct vsock_sock),
+};
+
+/* The default peer timeout indicates how long we will wait for a peer response
+ * to a control message.
+ */
+#define VSOCK_DEFAULT_CONNECT_TIMEOUT (2 * HZ)
+
+#define SS_LISTEN 255
+
+static const struct vsock_transport *transport;
+static DEFINE_MUTEX(vsock_register_mutex);
+
+/**** EXPORTS ****/
+
+/* Get the ID of the local context.  This is transport dependent. */
+
+int vm_sockets_get_local_cid(void)
+{
+	return transport->get_local_cid();
+}
+EXPORT_SYMBOL_GPL(vm_sockets_get_local_cid);
+
+/**** UTILS ****/
+
+/* Each bound VSocket is stored in the bind hash table and each connected
+ * VSocket is stored in the connected hash table.
+ *
+ * Unbound sockets are all put on the same list attached to the end of the hash
+ * table (vsock_unbound_sockets).  Bound sockets are added to the hash table in
+ * the bucket that their local address hashes to (vsock_bound_sockets(addr)
+ * represents the list that addr hashes to).
+ *
+ * Specifically, we initialize the vsock_bind_table array to a size of
+ * VSOCK_HASH_SIZE + 1 so that vsock_bind_table[0] through
+ * vsock_bind_table[VSOCK_HASH_SIZE - 1] are for bound sockets and
+ * vsock_bind_table[VSOCK_HASH_SIZE] is for unbound sockets.  The hash function
+ * mods with VSOCK_HASH_SIZE to ensure this.
+ */
+#define VSOCK_HASH_SIZE         251
+#define MAX_PORT_RETRIES        24
+
+#define VSOCK_HASH(addr)        ((addr)->svm_port % VSOCK_HASH_SIZE)
+#define vsock_bound_sockets(addr) (&vsock_bind_table[VSOCK_HASH(addr)])
+#define vsock_unbound_sockets     (&vsock_bind_table[VSOCK_HASH_SIZE])
+
+/* XXX This can probably be implemented in a better way. */
+#define VSOCK_CONN_HASH(src, dst)				\
+	(((src)->svm_cid ^ (dst)->svm_port) % VSOCK_HASH_SIZE)
+#define vsock_connected_sockets(src, dst)		\
+	(&vsock_connected_table[VSOCK_CONN_HASH(src, dst)])
+#define vsock_connected_sockets_vsk(vsk)				\
+	vsock_connected_sockets(&(vsk)->remote_addr, &(vsk)->local_addr)
+
+static struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1];
+static struct list_head vsock_connected_table[VSOCK_HASH_SIZE];
+static DEFINE_SPINLOCK(vsock_table_lock);
+
+/* Autobind this socket to the local address if necessary. */
+static int vsock_auto_bind(struct vsock_sock *vsk)
+{
+	struct sock *sk = sk_vsock(vsk);
+	struct sockaddr_vm local_addr;
+
+	if (vsock_addr_bound(&vsk->local_addr))
+		return 0;
+	vsock_addr_init(&local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
+	return __vsock_bind(sk, &local_addr);
+}
+
+static void vsock_init_tables(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(vsock_bind_table); i++)
+		INIT_LIST_HEAD(&vsock_bind_table[i]);
+
+	for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++)
+		INIT_LIST_HEAD(&vsock_connected_table[i]);
+}
+
+static void __vsock_insert_bound(struct list_head *list,
+				 struct vsock_sock *vsk)
+{
+	sock_hold(&vsk->sk);
+	list_add(&vsk->bound_table, list);
+}
+
+static void __vsock_insert_connected(struct list_head *list,
+				     struct vsock_sock *vsk)
+{
+	sock_hold(&vsk->sk);
+	list_add(&vsk->connected_table, list);
+}
+
+static void __vsock_remove_bound(struct vsock_sock *vsk)
+{
+	list_del_init(&vsk->bound_table);
+	sock_put(&vsk->sk);
+}
+
+static void __vsock_remove_connected(struct vsock_sock *vsk)
+{
+	list_del_init(&vsk->connected_table);
+	sock_put(&vsk->sk);
+}
+
+static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
+{
+	struct vsock_sock *vsk;
+
+	list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table)
+		if (addr->svm_port == vsk->local_addr.svm_port)
+			return sk_vsock(vsk);
+
+	return NULL;
+}
+
+static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
+						  struct sockaddr_vm *dst)
+{
+	struct vsock_sock *vsk;
+
+	list_for_each_entry(vsk, vsock_connected_sockets(src, dst),
+			    connected_table) {
+		if (vsock_addr_equals_addr(src, &vsk->remote_addr) &&
+		    dst->svm_port == vsk->local_addr.svm_port) {
+			return sk_vsock(vsk);
+		}
+	}
+
+	return NULL;
+}
+
+static bool __vsock_in_bound_table(struct vsock_sock *vsk)
+{
+	return !list_empty(&vsk->bound_table);
+}
+
+static bool __vsock_in_connected_table(struct vsock_sock *vsk)
+{
+	return !list_empty(&vsk->connected_table);
+}
+
+static void vsock_insert_unbound(struct vsock_sock *vsk)
+{
+	spin_lock_bh(&vsock_table_lock);
+	__vsock_insert_bound(vsock_unbound_sockets, vsk);
+	spin_unlock_bh(&vsock_table_lock);
+}
+
+void vsock_insert_connected(struct vsock_sock *vsk)
+{
+	struct list_head *list = vsock_connected_sockets(
+		&vsk->remote_addr, &vsk->local_addr);
+
+	spin_lock_bh(&vsock_table_lock);
+	__vsock_insert_connected(list, vsk);
+	spin_unlock_bh(&vsock_table_lock);
+}
+EXPORT_SYMBOL_GPL(vsock_insert_connected);
+
+void vsock_remove_bound(struct vsock_sock *vsk)
+{
+	spin_lock_bh(&vsock_table_lock);
+	__vsock_remove_bound(vsk);
+	spin_unlock_bh(&vsock_table_lock);
+}
+EXPORT_SYMBOL_GPL(vsock_remove_bound);
+
+void vsock_remove_connected(struct vsock_sock *vsk)
+{
+	spin_lock_bh(&vsock_table_lock);
+	__vsock_remove_connected(vsk);
+	spin_unlock_bh(&vsock_table_lock);
+}
+EXPORT_SYMBOL_GPL(vsock_remove_connected);
+
+struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
+{
+	struct sock *sk;
+
+	spin_lock_bh(&vsock_table_lock);
+	sk = __vsock_find_bound_socket(addr);
+	if (sk)
+		sock_hold(sk);
+
+	spin_unlock_bh(&vsock_table_lock);
+
+	return sk;
+}
+EXPORT_SYMBOL_GPL(vsock_find_bound_socket);
+
+struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
+					 struct sockaddr_vm *dst)
+{
+	struct sock *sk;
+
+	spin_lock_bh(&vsock_table_lock);
+	sk = __vsock_find_connected_socket(src, dst);
+	if (sk)
+		sock_hold(sk);
+
+	spin_unlock_bh(&vsock_table_lock);
+
+	return sk;
+}
+EXPORT_SYMBOL_GPL(vsock_find_connected_socket);
+
+static bool vsock_in_bound_table(struct vsock_sock *vsk)
+{
+	bool ret;
+
+	spin_lock_bh(&vsock_table_lock);
+	ret = __vsock_in_bound_table(vsk);
+	spin_unlock_bh(&vsock_table_lock);
+
+	return ret;
+}
+
+static bool vsock_in_connected_table(struct vsock_sock *vsk)
+{
+	bool ret;
+
+	spin_lock_bh(&vsock_table_lock);
+	ret = __vsock_in_connected_table(vsk);
+	spin_unlock_bh(&vsock_table_lock);
+
+	return ret;
+}
+
+void vsock_for_each_connected_socket(void (*fn)(struct sock *sk))
+{
+	int i;
+
+	spin_lock_bh(&vsock_table_lock);
+
+	for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++) {
+		struct vsock_sock *vsk;
+		list_for_each_entry(vsk, &vsock_connected_table[i],
+				    connected_table)
+			fn(sk_vsock(vsk));
+	}
+
+	spin_unlock_bh(&vsock_table_lock);
+}
+EXPORT_SYMBOL_GPL(vsock_for_each_connected_socket);
+
+void vsock_add_pending(struct sock *listener, struct sock *pending)
+{
+	struct vsock_sock *vlistener;
+	struct vsock_sock *vpending;
+
+	vlistener = vsock_sk(listener);
+	vpending = vsock_sk(pending);
+
+	sock_hold(pending);
+	sock_hold(listener);
+	list_add_tail(&vpending->pending_links, &vlistener->pending_links);
+}
+EXPORT_SYMBOL_GPL(vsock_add_pending);
+
+void vsock_remove_pending(struct sock *listener, struct sock *pending)
+{
+	struct vsock_sock *vpending = vsock_sk(pending);
+
+	list_del_init(&vpending->pending_links);
+	sock_put(listener);
+	sock_put(pending);
+}
+EXPORT_SYMBOL_GPL(vsock_remove_pending);
+
+void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
+{
+	struct vsock_sock *vlistener;
+	struct vsock_sock *vconnected;
+
+	vlistener = vsock_sk(listener);
+	vconnected = vsock_sk(connected);
+
+	sock_hold(connected);
+	sock_hold(listener);
+	list_add_tail(&vconnected->accept_queue, &vlistener->accept_queue);
+}
+EXPORT_SYMBOL_GPL(vsock_enqueue_accept);
+
+static struct sock *vsock_dequeue_accept(struct sock *listener)
+{
+	struct vsock_sock *vlistener;
+	struct vsock_sock *vconnected;
+
+	vlistener = vsock_sk(listener);
+
+	if (list_empty(&vlistener->accept_queue))
+		return NULL;
+
+	vconnected = list_entry(vlistener->accept_queue.next,
+				struct vsock_sock, accept_queue);
+
+	list_del_init(&vconnected->accept_queue);
+	sock_put(listener);
+	/* The caller will need a reference on the connected socket so we let
+	 * it call sock_put().
+	 */
+
+	return sk_vsock(vconnected);
+}
+
+static bool vsock_is_accept_queue_empty(struct sock *sk)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+	return list_empty(&vsk->accept_queue);
+}
+
+static bool vsock_is_pending(struct sock *sk)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+	return !list_empty(&vsk->pending_links);
+}
+
+static int vsock_send_shutdown(struct sock *sk, int mode)
+{
+	return transport->shutdown(vsock_sk(sk), mode);
+}
+
+void vsock_pending_work(struct work_struct *work)
+{
+	struct sock *sk;
+	struct sock *listener;
+	struct vsock_sock *vsk;
+	bool cleanup;
+
+	vsk = container_of(work, struct vsock_sock, dwork.work);
+	sk = sk_vsock(vsk);
+	listener = vsk->listener;
+	cleanup = true;
+
+	lock_sock(listener);
+	lock_sock(sk);
+
+	if (vsock_is_pending(sk)) {
+		vsock_remove_pending(listener, sk);
+	} else if (!vsk->rejected) {
+		/* We are not on the pending list and accept() did not reject
+		 * us, so we must have been accepted by our user process.  We
+		 * just need to drop our references to the sockets and be on
+		 * our way.
+		 */
+		cleanup = false;
+		goto out;
+	}
+
+	listener->sk_ack_backlog--;
+
+	/* We need to remove ourself from the global connected sockets list so
+	 * incoming packets can't find this socket, and to reduce the reference
+	 * count.
+	 */
+	if (vsock_in_connected_table(vsk))
+		vsock_remove_connected(vsk);
+
+	sk->sk_state = SS_FREE;
+
+out:
+	release_sock(sk);
+	release_sock(listener);
+	if (cleanup)
+		sock_put(sk);
+
+	sock_put(sk);
+	sock_put(listener);
+}
+EXPORT_SYMBOL_GPL(vsock_pending_work);
+
+/**** SOCKET OPERATIONS ****/
+
+static int __vsock_bind_stream(struct vsock_sock *vsk,
+			       struct sockaddr_vm *addr)
+{
+	static u32 port = LAST_RESERVED_PORT + 1;
+	struct sockaddr_vm new_addr;
+
+	vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
+
+	if (addr->svm_port == VMADDR_PORT_ANY) {
+		bool found = false;
+		unsigned int i;
+
+		for (i = 0; i < MAX_PORT_RETRIES; i++) {
+			if (port <= LAST_RESERVED_PORT)
+				port = LAST_RESERVED_PORT + 1;
+
+			new_addr.svm_port = port++;
+
+			if (!__vsock_find_bound_socket(&new_addr)) {
+				found = true;
+				break;
+			}
+		}
+
+		if (!found)
+			return -EADDRNOTAVAIL;
+	} else {
+		/* If port is in reserved range, ensure caller
+		 * has necessary privileges.
+		 */
+		if (addr->svm_port <= LAST_RESERVED_PORT &&
+		    !capable(CAP_NET_BIND_SERVICE)) {
+			return -EACCES;
+		}
+
+		if (__vsock_find_bound_socket(&new_addr))
+			return -EADDRINUSE;
+	}
+
+	vsock_addr_init(&vsk->local_addr, new_addr.svm_cid, new_addr.svm_port);
+
+	/* Remove stream sockets from the unbound list and add them to the hash
+	 * table for easy lookup by its address.  The unbound list is simply an
+	 * extra entry at the end of the hash table, a trick used by AF_UNIX.
+	 */
+	__vsock_remove_bound(vsk);
+	__vsock_insert_bound(vsock_bound_sockets(&vsk->local_addr), vsk);
+
+	return 0;
+}
+
+static int __vsock_bind_dgram(struct vsock_sock *vsk,
+			      struct sockaddr_vm *addr)
+{
+	return transport->dgram_bind(vsk, addr);
+}
+
+static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+	u32 cid;
+	int retval;
+
+	/* First ensure this socket isn't already bound. */
+	if (vsock_addr_bound(&vsk->local_addr))
+		return -EINVAL;
+
+	/* Now bind to the provided address or select appropriate values if
+	 * none are provided (VMADDR_CID_ANY and VMADDR_PORT_ANY).  Note that
+	 * like AF_INET prevents binding to a non-local IP address (in most
+	 * cases), we only allow binding to the local CID.
+	 */
+	cid = transport->get_local_cid();
+	if (addr->svm_cid != cid && addr->svm_cid != VMADDR_CID_ANY)
+		return -EADDRNOTAVAIL;
+
+	switch (sk->sk_socket->type) {
+	case SOCK_STREAM:
+		spin_lock_bh(&vsock_table_lock);
+		retval = __vsock_bind_stream(vsk, addr);
+		spin_unlock_bh(&vsock_table_lock);
+		break;
+
+	case SOCK_DGRAM:
+		retval = __vsock_bind_dgram(vsk, addr);
+		break;
+
+	default:
+		retval = -EINVAL;
+		break;
+	}
+
+	return retval;
+}
+
+struct sock *__vsock_create(struct net *net,
+			    struct socket *sock,
+			    struct sock *parent,
+			    gfp_t priority,
+			    unsigned short type)
+{
+	struct sock *sk;
+	struct vsock_sock *psk;
+	struct vsock_sock *vsk;
+
+	sk = sk_alloc(net, AF_VSOCK, priority, &vsock_proto);
+	if (!sk)
+		return NULL;
+
+	sock_init_data(sock, sk);
+
+	/* sk->sk_type is normally set in sock_init_data, but only if sock is
+	 * non-NULL. We make sure that our sockets always have a type by
+	 * setting it here if needed.
+	 */
+	if (!sock)
+		sk->sk_type = type;
+
+	vsk = vsock_sk(sk);
+	vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
+	vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
+
+	sk->sk_destruct = vsock_sk_destruct;
+	sk->sk_backlog_rcv = vsock_queue_rcv_skb;
+	sk->sk_state = 0;
+	sock_reset_flag(sk, SOCK_DONE);
+
+	INIT_LIST_HEAD(&vsk->bound_table);
+	INIT_LIST_HEAD(&vsk->connected_table);
+	vsk->listener = NULL;
+	INIT_LIST_HEAD(&vsk->pending_links);
+	INIT_LIST_HEAD(&vsk->accept_queue);
+	vsk->rejected = false;
+	vsk->sent_request = false;
+	vsk->ignore_connecting_rst = false;
+	vsk->peer_shutdown = 0;
+
+	psk = parent ? vsock_sk(parent) : NULL;
+	if (parent) {
+		vsk->trusted = psk->trusted;
+		vsk->owner = get_cred(psk->owner);
+		vsk->connect_timeout = psk->connect_timeout;
+	} else {
+		vsk->trusted = capable(CAP_NET_ADMIN);
+		vsk->owner = get_current_cred();
+		vsk->connect_timeout = VSOCK_DEFAULT_CONNECT_TIMEOUT;
+	}
+
+	if (transport->init(vsk, psk) < 0) {
+		sk_free(sk);
+		return NULL;
+	}
+
+	if (sock)
+		vsock_insert_unbound(vsk);
+
+	return sk;
+}
+EXPORT_SYMBOL_GPL(__vsock_create);
+
+static void __vsock_release(struct sock *sk)
+{
+	if (sk) {
+		struct sk_buff *skb;
+		struct sock *pending;
+		struct vsock_sock *vsk;
+
+		vsk = vsock_sk(sk);
+		pending = NULL;	/* Compiler warning. */
+
+		if (vsock_in_bound_table(vsk))
+			vsock_remove_bound(vsk);
+
+		if (vsock_in_connected_table(vsk))
+			vsock_remove_connected(vsk);
+
+		transport->release(vsk);
+
+		lock_sock(sk);
+		sock_orphan(sk);
+		sk->sk_shutdown = SHUTDOWN_MASK;
+
+		while ((skb = skb_dequeue(&sk->sk_receive_queue)))
+			kfree_skb(skb);
+
+		/* Clean up any sockets that never were accepted. */
+		while ((pending = vsock_dequeue_accept(sk)) != NULL) {
+			__vsock_release(pending);
+			sock_put(pending);
+		}
+
+		release_sock(sk);
+		sock_put(sk);
+	}
+}
+
+static void vsock_sk_destruct(struct sock *sk)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+	transport->destruct(vsk);
+
+	/* When clearing these addresses, there's no need to set the family and
+	 * possibly register the address family with the kernel.
+	 */
+	vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
+	vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
+
+	put_cred(vsk->owner);
+}
+
+static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+	int err;
+
+	err = sock_queue_rcv_skb(sk, skb);
+	if (err)
+		kfree_skb(skb);
+
+	return err;
+}
+
+s64 vsock_stream_has_data(struct vsock_sock *vsk)
+{
+	return transport->stream_has_data(vsk);
+}
+EXPORT_SYMBOL_GPL(vsock_stream_has_data);
+
+s64 vsock_stream_has_space(struct vsock_sock *vsk)
+{
+	return transport->stream_has_space(vsk);
+}
+EXPORT_SYMBOL_GPL(vsock_stream_has_space);
+
+static int vsock_release(struct socket *sock)
+{
+	__vsock_release(sock->sk);
+	sock->sk = NULL;
+	sock->state = SS_FREE;
+
+	return 0;
+}
+
+static int
+vsock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
+{
+	int err;
+	struct sock *sk;
+	struct sockaddr_vm *vm_addr;
+
+	sk = sock->sk;
+
+	if (vsock_addr_cast(addr, addr_len, &vm_addr) != 0)
+		return -EINVAL;
+
+	lock_sock(sk);
+	err = __vsock_bind(sk, vm_addr);
+	release_sock(sk);
+
+	return err;
+}
+
+static int vsock_getname(struct socket *sock,
+			 struct sockaddr *addr, int *addr_len, int peer)
+{
+	int err;
+	struct sock *sk;
+	struct vsock_sock *vsk;
+	struct sockaddr_vm *vm_addr;
+
+	sk = sock->sk;
+	vsk = vsock_sk(sk);
+	err = 0;
+
+	lock_sock(sk);
+
+	if (peer) {
+		if (sock->state != SS_CONNECTED) {
+			err = -ENOTCONN;
+			goto out;
+		}
+		vm_addr = &vsk->remote_addr;
+	} else {
+		vm_addr = &vsk->local_addr;
+	}
+
+	if (!vm_addr) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	/* sys_getsockname() and sys_getpeername() pass us a
+	 * MAX_SOCK_ADDR-sized buffer and don't set addr_len.  Unfortunately
+	 * that macro is defined in socket.c instead of .h, so we hardcode its
+	 * value here.
+	 */
+	BUILD_BUG_ON(sizeof(*vm_addr) > 128);
+	memcpy(addr, vm_addr, sizeof(*vm_addr));
+	*addr_len = sizeof(*vm_addr);
+
+out:
+	release_sock(sk);
+	return err;
+}
+
+static int vsock_shutdown(struct socket *sock, int mode)
+{
+	int err;
+	struct sock *sk;
+
+	/* User level uses SHUT_RD (0) and SHUT_WR (1), but the kernel uses
+	 * RCV_SHUTDOWN (1) and SEND_SHUTDOWN (2), so we must increment mode
+	 * here like the other address families do.  Note also that the
+	 * increment makes SHUT_RDWR (2) into RCV_SHUTDOWN | SEND_SHUTDOWN (3),
+	 * which is what we want.
+	 */
+	mode++;
+
+	if ((mode & ~SHUTDOWN_MASK) || !mode)
+		return -EINVAL;
+
+	/* If this is a STREAM socket and it is not connected then bail out
+	 * immediately.  If it is a DGRAM socket then we must first kick the
+	 * socket so that it wakes up from any sleeping calls, for example
+	 * recv(), and then afterwards return the error.
+	 */
+
+	sk = sock->sk;
+	if (sock->state == SS_UNCONNECTED) {
+		err = -ENOTCONN;
+		if (sk->sk_type == SOCK_STREAM)
+			return err;
+	} else {
+		sock->state = SS_DISCONNECTING;
+		err = 0;
+	}
+
+	/* Receive and send shutdowns are treated alike. */
+	mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN);
+	if (mode) {
+		lock_sock(sk);
+		sk->sk_shutdown |= mode;
+		sk->sk_state_change(sk);
+		release_sock(sk);
+
+		if (sk->sk_type == SOCK_STREAM) {
+			sock_reset_flag(sk, SOCK_DONE);
+			vsock_send_shutdown(sk, mode);
+		}
+	}
+
+	return err;
+}
+
+static unsigned int vsock_poll(struct file *file, struct socket *sock,
+			       poll_table *wait)
+{
+	struct sock *sk;
+	unsigned int mask;
+	struct vsock_sock *vsk;
+
+	sk = sock->sk;
+	vsk = vsock_sk(sk);
+
+	poll_wait(file, sk_sleep(sk), wait);
+	mask = 0;
+
+	if (sk->sk_err)
+		/* Signify that there has been an error on this socket. */
+		mask |= POLLERR;
+
+	/* INET sockets treat local write shutdown and peer write shutdown as a
+	 * case of POLLHUP set.
+	 */
+	if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
+	    ((sk->sk_shutdown & SEND_SHUTDOWN) &&
+	     (vsk->peer_shutdown & SEND_SHUTDOWN))) {
+		mask |= POLLHUP;
+	}
+
+	if (sk->sk_shutdown & RCV_SHUTDOWN ||
+	    vsk->peer_shutdown & SEND_SHUTDOWN) {
+		mask |= POLLRDHUP;
+	}
+
+	if (sock->type == SOCK_DGRAM) {
+		/* For datagram sockets we can read if there is something in
+		 * the queue and write as long as the socket isn't shutdown for
+		 * sending.
+		 */
+		if (!skb_queue_empty(&sk->sk_receive_queue) ||
+		    (sk->sk_shutdown & RCV_SHUTDOWN)) {
+			mask |= POLLIN | POLLRDNORM;
+		}
+
+		if (!(sk->sk_shutdown & SEND_SHUTDOWN))
+			mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
+
+	} else if (sock->type == SOCK_STREAM) {
+		lock_sock(sk);
+
+		/* Listening sockets that have connections in their accept
+		 * queue can be read.
+		 */
+		if (sk->sk_state == SS_LISTEN
+		    && !vsock_is_accept_queue_empty(sk))
+			mask |= POLLIN | POLLRDNORM;
+
+		/* If there is something in the queue then we can read. */
+		if (transport->stream_is_active(vsk) &&
+		    !(sk->sk_shutdown & RCV_SHUTDOWN)) {
+			bool data_ready_now = false;
+			int ret = transport->notify_poll_in(
+					vsk, 1, &data_ready_now);
+			if (ret < 0) {
+				mask |= POLLERR;
+			} else {
+				if (data_ready_now)
+					mask |= POLLIN | POLLRDNORM;
+
+			}
+		}
+
+		/* Sockets whose connections have been closed, reset, or
+		 * terminated should also be considered read, and we check the
+		 * shutdown flag for that.
+		 */
+		if (sk->sk_shutdown & RCV_SHUTDOWN ||
+		    vsk->peer_shutdown & SEND_SHUTDOWN) {
+			mask |= POLLIN | POLLRDNORM;
+		}
+
+		/* Connected sockets that can produce data can be written. */
+		if (sk->sk_state == SS_CONNECTED) {
+			if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
+				bool space_avail_now = false;
+				int ret = transport->notify_poll_out(
+						vsk, 1, &space_avail_now);
+				if (ret < 0) {
+					mask |= POLLERR;
+				} else {
+					if (space_avail_now)
+						/* Remove POLLWRBAND since INET
+						 * sockets are not setting it.
+						 */
+						mask |= POLLOUT | POLLWRNORM;
+
+				}
+			}
+		}
+
+		/* Simulate INET socket poll behaviors, which sets
+		 * POLLOUT|POLLWRNORM when peer is closed and nothing to read,
+		 * but local send is not shutdown.
+		 */
+		if (sk->sk_state == SS_UNCONNECTED) {
+			if (!(sk->sk_shutdown & SEND_SHUTDOWN))
+				mask |= POLLOUT | POLLWRNORM;
+
+		}
+
+		release_sock(sk);
+	}
+
+	return mask;
+}
+
+static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
+			       size_t len)
+{
+	int err;
+	struct sock *sk;
+	struct vsock_sock *vsk;
+	struct sockaddr_vm *remote_addr;
+
+	if (msg->msg_flags & MSG_OOB)
+		return -EOPNOTSUPP;
+
+	/* For now, MSG_DONTWAIT is always assumed... */
+	err = 0;
+	sk = sock->sk;
+	vsk = vsock_sk(sk);
+
+	lock_sock(sk);
+
+	err = vsock_auto_bind(vsk);
+	if (err)
+		goto out;
+
+
+	/* If the provided message contains an address, use that.  Otherwise
+	 * fall back on the socket's remote handle (if it has been connected).
+	 */
+	if (msg->msg_name &&
+	    vsock_addr_cast(msg->msg_name, msg->msg_namelen,
+			    &remote_addr) == 0) {
+		/* Ensure this address is of the right type and is a valid
+		 * destination.
+		 */
+
+		if (remote_addr->svm_cid == VMADDR_CID_ANY)
+			remote_addr->svm_cid = transport->get_local_cid();
+
+		if (!vsock_addr_bound(remote_addr)) {
+			err = -EINVAL;
+			goto out;
+		}
+	} else if (sock->state == SS_CONNECTED) {
+		remote_addr = &vsk->remote_addr;
+
+		if (remote_addr->svm_cid == VMADDR_CID_ANY)
+			remote_addr->svm_cid = transport->get_local_cid();
+
+		/* XXX Should connect() or this function ensure remote_addr is
+		 * bound?
+		 */
+		if (!vsock_addr_bound(&vsk->remote_addr)) {
+			err = -EINVAL;
+			goto out;
+		}
+	} else {
+		err = -EINVAL;
+		goto out;
+	}
+
+	if (!transport->dgram_allow(remote_addr->svm_cid,
+				    remote_addr->svm_port)) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	err = transport->dgram_enqueue(vsk, remote_addr, msg, len);
+
+out:
+	release_sock(sk);
+	return err;
+}
+
+static int vsock_dgram_connect(struct socket *sock,
+			       struct sockaddr *addr, int addr_len, int flags)
+{
+	int err;
+	struct sock *sk;
+	struct vsock_sock *vsk;
+	struct sockaddr_vm *remote_addr;
+
+	sk = sock->sk;
+	vsk = vsock_sk(sk);
+
+	err = vsock_addr_cast(addr, addr_len, &remote_addr);
+	if (err == -EAFNOSUPPORT && remote_addr->svm_family == AF_UNSPEC) {
+		lock_sock(sk);
+		vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY,
+				VMADDR_PORT_ANY);
+		sock->state = SS_UNCONNECTED;
+		release_sock(sk);
+		return 0;
+	} else if (err != 0)
+		return -EINVAL;
+
+	lock_sock(sk);
+
+	err = vsock_auto_bind(vsk);
+	if (err)
+		goto out;
+
+	if (!transport->dgram_allow(remote_addr->svm_cid,
+				    remote_addr->svm_port)) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	memcpy(&vsk->remote_addr, remote_addr, sizeof(vsk->remote_addr));
+	sock->state = SS_CONNECTED;
+
+out:
+	release_sock(sk);
+	return err;
+}
+
+static int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
+			       size_t len, int flags)
+{
+	return transport->dgram_dequeue(vsock_sk(sock->sk), msg, len, flags);
+}
+
+static const struct proto_ops vsock_dgram_ops = {
+	.family = PF_VSOCK,
+	.owner = THIS_MODULE,
+	.release = vsock_release,
+	.bind = vsock_bind,
+	.connect = vsock_dgram_connect,
+	.socketpair = sock_no_socketpair,
+	.accept = sock_no_accept,
+	.getname = vsock_getname,
+	.poll = vsock_poll,
+	.ioctl = sock_no_ioctl,
+	.listen = sock_no_listen,
+	.shutdown = vsock_shutdown,
+	.setsockopt = sock_no_setsockopt,
+	.getsockopt = sock_no_getsockopt,
+	.sendmsg = vsock_dgram_sendmsg,
+	.recvmsg = vsock_dgram_recvmsg,
+	.mmap = sock_no_mmap,
+	.sendpage = sock_no_sendpage,
+};
+
+static void vsock_connect_timeout(struct work_struct *work)
+{
+	struct sock *sk;
+	struct vsock_sock *vsk;
+
+	vsk = container_of(work, struct vsock_sock, dwork.work);
+	sk = sk_vsock(vsk);
+
+	lock_sock(sk);
+	if (sk->sk_state == SS_CONNECTING &&
+	    (sk->sk_shutdown != SHUTDOWN_MASK)) {
+		sk->sk_state = SS_UNCONNECTED;
+		sk->sk_err = ETIMEDOUT;
+		sk->sk_error_report(sk);
+	}
+	release_sock(sk);
+
+	sock_put(sk);
+}
+
+static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr,
+				int addr_len, int flags)
+{
+	int err;
+	struct sock *sk;
+	struct vsock_sock *vsk;
+	struct sockaddr_vm *remote_addr;
+	long timeout;
+	DEFINE_WAIT(wait);
+
+	err = 0;
+	sk = sock->sk;
+	vsk = vsock_sk(sk);
+
+	lock_sock(sk);
+
+	/* XXX AF_UNSPEC should make us disconnect like AF_INET. */
+	switch (sock->state) {
+	case SS_CONNECTED:
+		err = -EISCONN;
+		goto out;
+	case SS_DISCONNECTING:
+		err = -EINVAL;
+		goto out;
+	case SS_CONNECTING:
+		/* This continues on so we can move sock into the SS_CONNECTED
+		 * state once the connection has completed (at which point err
+		 * will be set to zero also).  Otherwise, we will either wait
+		 * for the connection or return -EALREADY should this be a
+		 * non-blocking call.
+		 */
+		err = -EALREADY;
+		break;
+	default:
+		if ((sk->sk_state == SS_LISTEN) ||
+		    vsock_addr_cast(addr, addr_len, &remote_addr) != 0) {
+			err = -EINVAL;
+			goto out;
+		}
+
+		/* The hypervisor and well-known contexts do not have socket
+		 * endpoints.
+		 */
+		if (!transport->stream_allow(remote_addr->svm_cid,
+					     remote_addr->svm_port)) {
+			err = -ENETUNREACH;
+			goto out;
+		}
+
+		/* Set the remote address that we are connecting to. */
+		memcpy(&vsk->remote_addr, remote_addr,
+		       sizeof(vsk->remote_addr));
+
+		err = vsock_auto_bind(vsk);
+		if (err)
+			goto out;
+
+		sk->sk_state = SS_CONNECTING;
+
+		err = transport->connect(vsk);
+		if (err < 0)
+			goto out;
+
+		/* Mark sock as connecting and set the error code to in
+		 * progress in case this is a non-blocking connect.
+		 */
+		sock->state = SS_CONNECTING;
+		err = -EINPROGRESS;
+	}
+
+	/* The receive path will handle all communication until we are able to
+	 * enter the connected state.  Here we wait for the connection to be
+	 * completed or a notification of an error.
+	 */
+	timeout = vsk->connect_timeout;
+	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+
+	while (sk->sk_state != SS_CONNECTED && sk->sk_err == 0) {
+		if (flags & O_NONBLOCK) {
+			/* If we're not going to block, we schedule a timeout
+			 * function to generate a timeout on the connection
+			 * attempt, in case the peer doesn't respond in a
+			 * timely manner. We hold on to the socket until the
+			 * timeout fires.
+			 */
+			sock_hold(sk);
+			INIT_DELAYED_WORK(&vsk->dwork,
+					  vsock_connect_timeout);
+			schedule_delayed_work(&vsk->dwork, timeout);
+
+			/* Skip ahead to preserve error code set above. */
+			goto out_wait;
+		}
+
+		release_sock(sk);
+		timeout = schedule_timeout(timeout);
+		lock_sock(sk);
+
+		if (signal_pending(current)) {
+			err = sock_intr_errno(timeout);
+			goto out_wait_error;
+		} else if (timeout == 0) {
+			err = -ETIMEDOUT;
+			goto out_wait_error;
+		}
+
+		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+	}
+
+	if (sk->sk_err) {
+		err = -sk->sk_err;
+		goto out_wait_error;
+	} else
+		err = 0;
+
+out_wait:
+	finish_wait(sk_sleep(sk), &wait);
+out:
+	release_sock(sk);
+	return err;
+
+out_wait_error:
+	sk->sk_state = SS_UNCONNECTED;
+	sock->state = SS_UNCONNECTED;
+	goto out_wait;
+}
+
+static int vsock_accept(struct socket *sock, struct socket *newsock, int flags)
+{
+	struct sock *listener;
+	int err;
+	struct sock *connected;
+	struct vsock_sock *vconnected;
+	long timeout;
+	DEFINE_WAIT(wait);
+
+	err = 0;
+	listener = sock->sk;
+
+	lock_sock(listener);
+
+	if (sock->type != SOCK_STREAM) {
+		err = -EOPNOTSUPP;
+		goto out;
+	}
+
+	if (listener->sk_state != SS_LISTEN) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	/* Wait for children sockets to appear; these are the new sockets
+	 * created upon connection establishment.
+	 */
+	timeout = sock_sndtimeo(listener, flags & O_NONBLOCK);
+	prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
+
+	while ((connected = vsock_dequeue_accept(listener)) == NULL &&
+	       listener->sk_err == 0) {
+		release_sock(listener);
+		timeout = schedule_timeout(timeout);
+		lock_sock(listener);
+
+		if (signal_pending(current)) {
+			err = sock_intr_errno(timeout);
+			goto out_wait;
+		} else if (timeout == 0) {
+			err = -EAGAIN;
+			goto out_wait;
+		}
+
+		prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
+	}
+
+	if (listener->sk_err)
+		err = -listener->sk_err;
+
+	if (connected) {
+		listener->sk_ack_backlog--;
+
+		lock_sock(connected);
+		vconnected = vsock_sk(connected);
+
+		/* If the listener socket has received an error, then we should
+		 * reject this socket and return.  Note that we simply mark the
+		 * socket rejected, drop our reference, and let the cleanup
+		 * function handle the cleanup; the fact that we found it in
+		 * the listener's accept queue guarantees that the cleanup
+		 * function hasn't run yet.
+		 */
+		if (err) {
+			vconnected->rejected = true;
+			release_sock(connected);
+			sock_put(connected);
+			goto out_wait;
+		}
+
+		newsock->state = SS_CONNECTED;
+		sock_graft(connected, newsock);
+		release_sock(connected);
+		sock_put(connected);
+	}
+
+out_wait:
+	finish_wait(sk_sleep(listener), &wait);
+out:
+	release_sock(listener);
+	return err;
+}
+
+static int vsock_listen(struct socket *sock, int backlog)
+{
+	int err;
+	struct sock *sk;
+	struct vsock_sock *vsk;
+
+	sk = sock->sk;
+
+	lock_sock(sk);
+
+	if (sock->type != SOCK_STREAM) {
+		err = -EOPNOTSUPP;
+		goto out;
+	}
+
+	if (sock->state != SS_UNCONNECTED) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	vsk = vsock_sk(sk);
+
+	if (!vsock_addr_bound(&vsk->local_addr)) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	sk->sk_max_ack_backlog = backlog;
+	sk->sk_state = SS_LISTEN;
+
+	err = 0;
+
+out:
+	release_sock(sk);
+	return err;
+}
+
+static int vsock_stream_setsockopt(struct socket *sock,
+				   int level,
+				   int optname,
+				   char __user *optval,
+				   unsigned int optlen)
+{
+	int err;
+	struct sock *sk;
+	struct vsock_sock *vsk;
+	u64 val;
+
+	if (level != AF_VSOCK)
+		return -ENOPROTOOPT;
+
+#define COPY_IN(_v)                                       \
+	do {						  \
+		if (optlen < sizeof(_v)) {		  \
+			err = -EINVAL;			  \
+			goto exit;			  \
+		}					  \
+		if (copy_from_user(&_v, optval, sizeof(_v)) != 0) {	\
+			err = -EFAULT;					\
+			goto exit;					\
+		}							\
+	} while (0)
+
+	err = 0;
+	sk = sock->sk;
+	vsk = vsock_sk(sk);
+
+	lock_sock(sk);
+
+	switch (optname) {
+	case SO_VM_SOCKETS_BUFFER_SIZE:
+		COPY_IN(val);
+		transport->set_buffer_size(vsk, val);
+		break;
+
+	case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
+		COPY_IN(val);
+		transport->set_max_buffer_size(vsk, val);
+		break;
+
+	case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
+		COPY_IN(val);
+		transport->set_min_buffer_size(vsk, val);
+		break;
+
+	case SO_VM_SOCKETS_CONNECT_TIMEOUT: {
+		struct timeval tv;
+		COPY_IN(tv);
+		if (tv.tv_sec >= 0 && tv.tv_usec < USEC_PER_SEC &&
+		    tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)) {
+			vsk->connect_timeout = tv.tv_sec * HZ +
+			    DIV_ROUND_UP(tv.tv_usec, (1000000 / HZ));
+			if (vsk->connect_timeout == 0)
+				vsk->connect_timeout =
+				    VSOCK_DEFAULT_CONNECT_TIMEOUT;
+
+		} else {
+			err = -ERANGE;
+		}
+		break;
+	}
+
+	default:
+		err = -ENOPROTOOPT;
+		break;
+	}
+
+#undef COPY_IN
+
+exit:
+	release_sock(sk);
+	return err;
+}
+
+static int vsock_stream_getsockopt(struct socket *sock,
+				   int level, int optname,
+				   char __user *optval,
+				   int __user *optlen)
+{
+	int err;
+	int len;
+	struct sock *sk;
+	struct vsock_sock *vsk;
+	u64 val;
+
+	if (level != AF_VSOCK)
+		return -ENOPROTOOPT;
+
+	err = get_user(len, optlen);
+	if (err != 0)
+		return err;
+
+#define COPY_OUT(_v)                            \
+	do {					\
+		if (len < sizeof(_v))		\
+			return -EINVAL;		\
+						\
+		len = sizeof(_v);		\
+		if (copy_to_user(optval, &_v, len) != 0)	\
+			return -EFAULT;				\
+								\
+	} while (0)
+
+	err = 0;
+	sk = sock->sk;
+	vsk = vsock_sk(sk);
+
+	switch (optname) {
+	case SO_VM_SOCKETS_BUFFER_SIZE:
+		val = transport->get_buffer_size(vsk);
+		COPY_OUT(val);
+		break;
+
+	case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
+		val = transport->get_max_buffer_size(vsk);
+		COPY_OUT(val);
+		break;
+
+	case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
+		val = transport->get_min_buffer_size(vsk);
+		COPY_OUT(val);
+		break;
+
+	case SO_VM_SOCKETS_CONNECT_TIMEOUT: {
+		struct timeval tv;
+		tv.tv_sec = vsk->connect_timeout / HZ;
+		tv.tv_usec =
+		    (vsk->connect_timeout -
+		     tv.tv_sec * HZ) * (1000000 / HZ);
+		COPY_OUT(tv);
+		break;
+	}
+	default:
+		return -ENOPROTOOPT;
+	}
+
+	err = put_user(len, optlen);
+	if (err != 0)
+		return -EFAULT;
+
+#undef COPY_OUT
+
+	return 0;
+}
+
+static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,
+				size_t len)
+{
+	struct sock *sk;
+	struct vsock_sock *vsk;
+	ssize_t total_written;
+	long timeout;
+	int err;
+	struct vsock_transport_send_notify_data send_data;
+
+	DEFINE_WAIT(wait);
+
+	sk = sock->sk;
+	vsk = vsock_sk(sk);
+	total_written = 0;
+	err = 0;
+
+	if (msg->msg_flags & MSG_OOB)
+		return -EOPNOTSUPP;
+
+	lock_sock(sk);
+
+	/* Callers should not provide a destination with stream sockets. */
+	if (msg->msg_namelen) {
+		err = sk->sk_state == SS_CONNECTED ? -EISCONN : -EOPNOTSUPP;
+		goto out;
+	}
+
+	/* Send data only if both sides are not shutdown in the direction. */
+	if (sk->sk_shutdown & SEND_SHUTDOWN ||
+	    vsk->peer_shutdown & RCV_SHUTDOWN) {
+		err = -EPIPE;
+		goto out;
+	}
+
+	if (sk->sk_state != SS_CONNECTED ||
+	    !vsock_addr_bound(&vsk->local_addr)) {
+		err = -ENOTCONN;
+		goto out;
+	}
+
+	if (!vsock_addr_bound(&vsk->remote_addr)) {
+		err = -EDESTADDRREQ;
+		goto out;
+	}
+
+	/* Wait for room in the produce queue to enqueue our user's data. */
+	timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
+
+	err = transport->notify_send_init(vsk, &send_data);
+	if (err < 0)
+		goto out;
+
+	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+
+	while (total_written < len) {
+		ssize_t written;
+
+		while (vsock_stream_has_space(vsk) == 0 &&
+		       sk->sk_err == 0 &&
+		       !(sk->sk_shutdown & SEND_SHUTDOWN) &&
+		       !(vsk->peer_shutdown & RCV_SHUTDOWN)) {
+
+			/* Don't wait for non-blocking sockets. */
+			if (timeout == 0) {
+				err = -EAGAIN;
+				goto out_wait;
+			}
+
+			err = transport->notify_send_pre_block(vsk, &send_data);
+			if (err < 0)
+				goto out_wait;
+
+			release_sock(sk);
+			timeout = schedule_timeout(timeout);
+			lock_sock(sk);
+			if (signal_pending(current)) {
+				err = sock_intr_errno(timeout);
+				goto out_wait;
+			} else if (timeout == 0) {
+				err = -EAGAIN;
+				goto out_wait;
+			}
+
+			prepare_to_wait(sk_sleep(sk), &wait,
+					TASK_INTERRUPTIBLE);
+		}
+
+		/* These checks occur both as part of and after the loop
+		 * conditional since we need to check before and after
+		 * sleeping.
+		 */
+		if (sk->sk_err) {
+			err = -sk->sk_err;
+			goto out_wait;
+		} else if ((sk->sk_shutdown & SEND_SHUTDOWN) ||
+			   (vsk->peer_shutdown & RCV_SHUTDOWN)) {
+			err = -EPIPE;
+			goto out_wait;
+		}
+
+		err = transport->notify_send_pre_enqueue(vsk, &send_data);
+		if (err < 0)
+			goto out_wait;
+
+		/* Note that enqueue will only write as many bytes as are free
+		 * in the produce queue, so we don't need to ensure len is
+		 * smaller than the queue size.  It is the caller's
+		 * responsibility to check how many bytes we were able to send.
+		 */
+
+		written = transport->stream_enqueue(
+				vsk, msg,
+				len - total_written);
+		if (written < 0) {
+			err = -ENOMEM;
+			goto out_wait;
+		}
+
+		total_written += written;
+
+		err = transport->notify_send_post_enqueue(
+				vsk, written, &send_data);
+		if (err < 0)
+			goto out_wait;
+
+	}
+
+out_wait:
+	if (total_written > 0)
+		err = total_written;
+	finish_wait(sk_sleep(sk), &wait);
+out:
+	release_sock(sk);
+	return err;
+}
+
+
+static int
+vsock_stream_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
+		     int flags)
+{
+	struct sock *sk;
+	struct vsock_sock *vsk;
+	int err;
+	size_t target;
+	ssize_t copied;
+	long timeout;
+	struct vsock_transport_recv_notify_data recv_data;
+
+	DEFINE_WAIT(wait);
+
+	sk = sock->sk;
+	vsk = vsock_sk(sk);
+	err = 0;
+
+	lock_sock(sk);
+
+	if (sk->sk_state != SS_CONNECTED) {
+		/* Recvmsg is supposed to return 0 if a peer performs an
+		 * orderly shutdown. Differentiate between that case and when a
+		 * peer has not connected or a local shutdown occured with the
+		 * SOCK_DONE flag.
+		 */
+		if (sock_flag(sk, SOCK_DONE))
+			err = 0;
+		else
+			err = -ENOTCONN;
+
+		goto out;
+	}
+
+	if (flags & MSG_OOB) {
+		err = -EOPNOTSUPP;
+		goto out;
+	}
+
+	/* We don't check peer_shutdown flag here since peer may actually shut
+	 * down, but there can be data in the queue that a local socket can
+	 * receive.
+	 */
+	if (sk->sk_shutdown & RCV_SHUTDOWN) {
+		err = 0;
+		goto out;
+	}
+
+	/* It is valid on Linux to pass in a zero-length receive buffer.  This
+	 * is not an error.  We may as well bail out now.
+	 */
+	if (!len) {
+		err = 0;
+		goto out;
+	}
+
+	/* We must not copy less than target bytes into the user's buffer
+	 * before returning successfully, so we wait for the consume queue to
+	 * have that much data to consume before dequeueing.  Note that this
+	 * makes it impossible to handle cases where target is greater than the
+	 * queue size.
+	 */
+	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
+	if (target >= transport->stream_rcvhiwat(vsk)) {
+		err = -ENOMEM;
+		goto out;
+	}
+	timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
+	copied = 0;
+
+	err = transport->notify_recv_init(vsk, target, &recv_data);
+	if (err < 0)
+		goto out;
+
+	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+
+	while (1) {
+		s64 ready = vsock_stream_has_data(vsk);
+
+		if (ready < 0) {
+			/* Invalid queue pair content. XXX This should be
+			 * changed to a connection reset in a later change.
+			 */
+
+			err = -ENOMEM;
+			goto out_wait;
+		} else if (ready > 0) {
+			ssize_t read;
+
+			err = transport->notify_recv_pre_dequeue(
+					vsk, target, &recv_data);
+			if (err < 0)
+				break;
+
+			read = transport->stream_dequeue(
+					vsk, msg,
+					len - copied, flags);
+			if (read < 0) {
+				err = -ENOMEM;
+				break;
+			}
+
+			copied += read;
+
+			err = transport->notify_recv_post_dequeue(
+					vsk, target, read,
+					!(flags & MSG_PEEK), &recv_data);
+			if (err < 0)
+				goto out_wait;
+
+			if (read >= target || flags & MSG_PEEK)
+				break;
+
+			target -= read;
+		} else {
+			if (sk->sk_err != 0 || (sk->sk_shutdown & RCV_SHUTDOWN)
+			    || (vsk->peer_shutdown & SEND_SHUTDOWN)) {
+				break;
+			}
+			/* Don't wait for non-blocking sockets. */
+			if (timeout == 0) {
+				err = -EAGAIN;
+				break;
+			}
+
+			err = transport->notify_recv_pre_block(
+					vsk, target, &recv_data);
+			if (err < 0)
+				break;
+
+			release_sock(sk);
+			timeout = schedule_timeout(timeout);
+			lock_sock(sk);
+
+			if (signal_pending(current)) {
+				err = sock_intr_errno(timeout);
+				break;
+			} else if (timeout == 0) {
+				err = -EAGAIN;
+				break;
+			}
+
+			prepare_to_wait(sk_sleep(sk), &wait,
+					TASK_INTERRUPTIBLE);
+		}
+	}
+
+	if (sk->sk_err)
+		err = -sk->sk_err;
+	else if (sk->sk_shutdown & RCV_SHUTDOWN)
+		err = 0;
+
+	if (copied > 0) {
+		/* We only do these additional bookkeeping/notification steps
+		 * if we actually copied something out of the queue pair
+		 * instead of just peeking ahead.
+		 */
+
+		if (!(flags & MSG_PEEK)) {
+			/* If the other side has shutdown for sending and there
+			 * is nothing more to read, then modify the socket
+			 * state.
+			 */
+			if (vsk->peer_shutdown & SEND_SHUTDOWN) {
+				if (vsock_stream_has_data(vsk) <= 0) {
+					sk->sk_state = SS_UNCONNECTED;
+					sock_set_flag(sk, SOCK_DONE);
+					sk->sk_state_change(sk);
+				}
+			}
+		}
+		err = copied;
+	}
+
+out_wait:
+	finish_wait(sk_sleep(sk), &wait);
+out:
+	release_sock(sk);
+	return err;
+}
+
+static const struct proto_ops vsock_stream_ops = {
+	.family = PF_VSOCK,
+	.owner = THIS_MODULE,
+	.release = vsock_release,
+	.bind = vsock_bind,
+	.connect = vsock_stream_connect,
+	.socketpair = sock_no_socketpair,
+	.accept = vsock_accept,
+	.getname = vsock_getname,
+	.poll = vsock_poll,
+	.ioctl = sock_no_ioctl,
+	.listen = vsock_listen,
+	.shutdown = vsock_shutdown,
+	.setsockopt = vsock_stream_setsockopt,
+	.getsockopt = vsock_stream_getsockopt,
+	.sendmsg = vsock_stream_sendmsg,
+	.recvmsg = vsock_stream_recvmsg,
+	.mmap = sock_no_mmap,
+	.sendpage = sock_no_sendpage,
+};
+
+static int vsock_create(struct net *net, struct socket *sock,
+			int protocol, int kern)
+{
+	if (!sock)
+		return -EINVAL;
+
+	if (protocol && protocol != PF_VSOCK)
+		return -EPROTONOSUPPORT;
+
+	switch (sock->type) {
+	case SOCK_DGRAM:
+		sock->ops = &vsock_dgram_ops;
+		break;
+	case SOCK_STREAM:
+		sock->ops = &vsock_stream_ops;
+		break;
+	default:
+		return -ESOCKTNOSUPPORT;
+	}
+
+	sock->state = SS_UNCONNECTED;
+
+	return __vsock_create(net, sock, NULL, GFP_KERNEL, 0) ? 0 : -ENOMEM;
+}
+
+static const struct net_proto_family vsock_family_ops = {
+	.family = AF_VSOCK,
+	.create = vsock_create,
+	.owner = THIS_MODULE,
+};
+
+static long vsock_dev_do_ioctl(struct file *filp,
+			       unsigned int cmd, void __user *ptr)
+{
+	u32 __user *p = ptr;
+	int retval = 0;
+
+	switch (cmd) {
+	case IOCTL_VM_SOCKETS_GET_LOCAL_CID:
+		if (put_user(transport->get_local_cid(), p) != 0)
+			retval = -EFAULT;
+		break;
+
+	default:
+		pr_err("Unknown ioctl %d\n", cmd);
+		retval = -EINVAL;
+	}
+
+	return retval;
+}
+
+static long vsock_dev_ioctl(struct file *filp,
+			    unsigned int cmd, unsigned long arg)
+{
+	return vsock_dev_do_ioctl(filp, cmd, (void __user *)arg);
+}
+
+#ifdef CONFIG_COMPAT
+static long vsock_dev_compat_ioctl(struct file *filp,
+				   unsigned int cmd, unsigned long arg)
+{
+	return vsock_dev_do_ioctl(filp, cmd, compat_ptr(arg));
+}
+#endif
+
+static const struct file_operations vsock_device_ops = {
+	.owner		= THIS_MODULE,
+	.unlocked_ioctl	= vsock_dev_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= vsock_dev_compat_ioctl,
+#endif
+	.open		= nonseekable_open,
+};
+
+static struct miscdevice vsock_device = {
+	.name		= "vsock",
+	.fops		= &vsock_device_ops,
+};
+
+int __vsock_core_init(const struct vsock_transport *t, struct module *owner)
+{
+	int err = mutex_lock_interruptible(&vsock_register_mutex);
+
+	if (err)
+		return err;
+
+	if (transport) {
+		err = -EBUSY;
+		goto err_busy;
+	}
+
+	/* Transport must be the owner of the protocol so that it can't
+	 * unload while there are open sockets.
+	 */
+	vsock_proto.owner = owner;
+	transport = t;
+
+	vsock_init_tables();
+
+	vsock_device.minor = MISC_DYNAMIC_MINOR;
+	err = misc_register(&vsock_device);
+	if (err) {
+		pr_err("Failed to register misc device\n");
+		return -ENOENT;
+	}
+
+	err = proto_register(&vsock_proto, 1);	/* we want our slab */
+	if (err) {
+		pr_err("Cannot register vsock protocol\n");
+		goto err_misc_deregister;
+	}
+
+	err = sock_register(&vsock_family_ops);
+	if (err) {
+		pr_err("could not register af_vsock (%d) address family: %d\n",
+		       AF_VSOCK, err);
+		goto err_unregister_proto;
+	}
+
+	mutex_unlock(&vsock_register_mutex);
+	return 0;
+
+err_unregister_proto:
+	proto_unregister(&vsock_proto);
+err_misc_deregister:
+	misc_deregister(&vsock_device);
+	transport = NULL;
+err_busy:
+	mutex_unlock(&vsock_register_mutex);
+	return err;
+}
+EXPORT_SYMBOL_GPL(__vsock_core_init);
+
+void vsock_core_exit(void)
+{
+	mutex_lock(&vsock_register_mutex);
+
+	misc_deregister(&vsock_device);
+	sock_unregister(AF_VSOCK);
+	proto_unregister(&vsock_proto);
+
+	/* We do not want the assignment below re-ordered. */
+	mb();
+	transport = NULL;
+
+	mutex_unlock(&vsock_register_mutex);
+}
+EXPORT_SYMBOL_GPL(vsock_core_exit);
+
+MODULE_AUTHOR("VMware, Inc.");
+MODULE_DESCRIPTION("VMware Virtual Socket Family");
+MODULE_VERSION("1.0.1.0-k");
+MODULE_LICENSE("GPL v2");
diff --git a/kernel/net/vmw_vsock/vmci_transport.c b/kernel/net/vmw_vsock/vmci_transport.c
new file mode 100644
index 000000000..c294da095
--- /dev/null
+++ b/kernel/net/vmw_vsock/vmci_transport.c
@@ -0,0 +1,2169 @@
+/*
+ * VMware vSockets Driver
+ *
+ * Copyright (C) 2007-2013 VMware, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation version 2 and no later version.
+ *
+ * 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.
+ */
+
+#include <linux/types.h>
+#include <linux/bitops.h>
+#include <linux/cred.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/kmod.h>
+#include <linux/list.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/net.h>
+#include <linux/poll.h>
+#include <linux/skbuff.h>
+#include <linux/smp.h>
+#include <linux/socket.h>
+#include <linux/stddef.h>
+#include <linux/unistd.h>
+#include <linux/wait.h>
+#include <linux/workqueue.h>
+#include <net/sock.h>
+#include <net/af_vsock.h>
+
+#include "vmci_transport_notify.h"
+
+static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg);
+static int vmci_transport_recv_stream_cb(void *data, struct vmci_datagram *dg);
+static void vmci_transport_peer_attach_cb(u32 sub_id,
+					  const struct vmci_event_data *ed,
+					  void *client_data);
+static void vmci_transport_peer_detach_cb(u32 sub_id,
+					  const struct vmci_event_data *ed,
+					  void *client_data);
+static void vmci_transport_recv_pkt_work(struct work_struct *work);
+static int vmci_transport_recv_listen(struct sock *sk,
+				      struct vmci_transport_packet *pkt);
+static int vmci_transport_recv_connecting_server(
+					struct sock *sk,
+					struct sock *pending,
+					struct vmci_transport_packet *pkt);
+static int vmci_transport_recv_connecting_client(
+					struct sock *sk,
+					struct vmci_transport_packet *pkt);
+static int vmci_transport_recv_connecting_client_negotiate(
+					struct sock *sk,
+					struct vmci_transport_packet *pkt);
+static int vmci_transport_recv_connecting_client_invalid(
+					struct sock *sk,
+					struct vmci_transport_packet *pkt);
+static int vmci_transport_recv_connected(struct sock *sk,
+					 struct vmci_transport_packet *pkt);
+static bool vmci_transport_old_proto_override(bool *old_pkt_proto);
+static u16 vmci_transport_new_proto_supported_versions(void);
+static bool vmci_transport_proto_to_notify_struct(struct sock *sk, u16 *proto,
+						  bool old_pkt_proto);
+
+struct vmci_transport_recv_pkt_info {
+	struct work_struct work;
+	struct sock *sk;
+	struct vmci_transport_packet pkt;
+};
+
+static struct vmci_handle vmci_transport_stream_handle = { VMCI_INVALID_ID,
+							   VMCI_INVALID_ID };
+static u32 vmci_transport_qp_resumed_sub_id = VMCI_INVALID_ID;
+
+static int PROTOCOL_OVERRIDE = -1;
+
+#define VMCI_TRANSPORT_DEFAULT_QP_SIZE_MIN   128
+#define VMCI_TRANSPORT_DEFAULT_QP_SIZE       262144
+#define VMCI_TRANSPORT_DEFAULT_QP_SIZE_MAX   262144
+
+/* The default peer timeout indicates how long we will wait for a peer response
+ * to a control message.
+ */
+#define VSOCK_DEFAULT_CONNECT_TIMEOUT (2 * HZ)
+
+#define SS_LISTEN 255
+
+/* Helper function to convert from a VMCI error code to a VSock error code. */
+
+static s32 vmci_transport_error_to_vsock_error(s32 vmci_error)
+{
+	int err;
+
+	switch (vmci_error) {
+	case VMCI_ERROR_NO_MEM:
+		err = ENOMEM;
+		break;
+	case VMCI_ERROR_DUPLICATE_ENTRY:
+	case VMCI_ERROR_ALREADY_EXISTS:
+		err = EADDRINUSE;
+		break;
+	case VMCI_ERROR_NO_ACCESS:
+		err = EPERM;
+		break;
+	case VMCI_ERROR_NO_RESOURCES:
+		err = ENOBUFS;
+		break;
+	case VMCI_ERROR_INVALID_RESOURCE:
+		err = EHOSTUNREACH;
+		break;
+	case VMCI_ERROR_INVALID_ARGS:
+	default:
+		err = EINVAL;
+	}
+
+	return err > 0 ? -err : err;
+}
+
+static u32 vmci_transport_peer_rid(u32 peer_cid)
+{
+	if (VMADDR_CID_HYPERVISOR == peer_cid)
+		return VMCI_TRANSPORT_HYPERVISOR_PACKET_RID;
+
+	return VMCI_TRANSPORT_PACKET_RID;
+}
+
+static inline void
+vmci_transport_packet_init(struct vmci_transport_packet *pkt,
+			   struct sockaddr_vm *src,
+			   struct sockaddr_vm *dst,
+			   u8 type,
+			   u64 size,
+			   u64 mode,
+			   struct vmci_transport_waiting_info *wait,
+			   u16 proto,
+			   struct vmci_handle handle)
+{
+	/* We register the stream control handler as an any cid handle so we
+	 * must always send from a source address of VMADDR_CID_ANY
+	 */
+	pkt->dg.src = vmci_make_handle(VMADDR_CID_ANY,
+				       VMCI_TRANSPORT_PACKET_RID);
+	pkt->dg.dst = vmci_make_handle(dst->svm_cid,
+				       vmci_transport_peer_rid(dst->svm_cid));
+	pkt->dg.payload_size = sizeof(*pkt) - sizeof(pkt->dg);
+	pkt->version = VMCI_TRANSPORT_PACKET_VERSION;
+	pkt->type = type;
+	pkt->src_port = src->svm_port;
+	pkt->dst_port = dst->svm_port;
+	memset(&pkt->proto, 0, sizeof(pkt->proto));
+	memset(&pkt->_reserved2, 0, sizeof(pkt->_reserved2));
+
+	switch (pkt->type) {
+	case VMCI_TRANSPORT_PACKET_TYPE_INVALID:
+		pkt->u.size = 0;
+		break;
+
+	case VMCI_TRANSPORT_PACKET_TYPE_REQUEST:
+	case VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE:
+		pkt->u.size = size;
+		break;
+
+	case VMCI_TRANSPORT_PACKET_TYPE_OFFER:
+	case VMCI_TRANSPORT_PACKET_TYPE_ATTACH:
+		pkt->u.handle = handle;
+		break;
+
+	case VMCI_TRANSPORT_PACKET_TYPE_WROTE:
+	case VMCI_TRANSPORT_PACKET_TYPE_READ:
+	case VMCI_TRANSPORT_PACKET_TYPE_RST:
+		pkt->u.size = 0;
+		break;
+
+	case VMCI_TRANSPORT_PACKET_TYPE_SHUTDOWN:
+		pkt->u.mode = mode;
+		break;
+
+	case VMCI_TRANSPORT_PACKET_TYPE_WAITING_READ:
+	case VMCI_TRANSPORT_PACKET_TYPE_WAITING_WRITE:
+		memcpy(&pkt->u.wait, wait, sizeof(pkt->u.wait));
+		break;
+
+	case VMCI_TRANSPORT_PACKET_TYPE_REQUEST2:
+	case VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE2:
+		pkt->u.size = size;
+		pkt->proto = proto;
+		break;
+	}
+}
+
+static inline void
+vmci_transport_packet_get_addresses(struct vmci_transport_packet *pkt,
+				    struct sockaddr_vm *local,
+				    struct sockaddr_vm *remote)
+{
+	vsock_addr_init(local, pkt->dg.dst.context, pkt->dst_port);
+	vsock_addr_init(remote, pkt->dg.src.context, pkt->src_port);
+}
+
+static int
+__vmci_transport_send_control_pkt(struct vmci_transport_packet *pkt,
+				  struct sockaddr_vm *src,
+				  struct sockaddr_vm *dst,
+				  enum vmci_transport_packet_type type,
+				  u64 size,
+				  u64 mode,
+				  struct vmci_transport_waiting_info *wait,
+				  u16 proto,
+				  struct vmci_handle handle,
+				  bool convert_error)
+{
+	int err;
+
+	vmci_transport_packet_init(pkt, src, dst, type, size, mode, wait,
+				   proto, handle);
+	err = vmci_datagram_send(&pkt->dg);
+	if (convert_error && (err < 0))
+		return vmci_transport_error_to_vsock_error(err);
+
+	return err;
+}
+
+static int
+vmci_transport_reply_control_pkt_fast(struct vmci_transport_packet *pkt,
+				      enum vmci_transport_packet_type type,
+				      u64 size,
+				      u64 mode,
+				      struct vmci_transport_waiting_info *wait,
+				      struct vmci_handle handle)
+{
+	struct vmci_transport_packet reply;
+	struct sockaddr_vm src, dst;
+
+	if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST) {
+		return 0;
+	} else {
+		vmci_transport_packet_get_addresses(pkt, &src, &dst);
+		return __vmci_transport_send_control_pkt(&reply, &src, &dst,
+							 type,
+							 size, mode, wait,
+							 VSOCK_PROTO_INVALID,
+							 handle, true);
+	}
+}
+
+static int
+vmci_transport_send_control_pkt_bh(struct sockaddr_vm *src,
+				   struct sockaddr_vm *dst,
+				   enum vmci_transport_packet_type type,
+				   u64 size,
+				   u64 mode,
+				   struct vmci_transport_waiting_info *wait,
+				   struct vmci_handle handle)
+{
+	/* Note that it is safe to use a single packet across all CPUs since
+	 * two tasklets of the same type are guaranteed to not ever run
+	 * simultaneously. If that ever changes, or VMCI stops using tasklets,
+	 * we can use per-cpu packets.
+	 */
+	static struct vmci_transport_packet pkt;
+
+	return __vmci_transport_send_control_pkt(&pkt, src, dst, type,
+						 size, mode, wait,
+						 VSOCK_PROTO_INVALID, handle,
+						 false);
+}
+
+static int
+vmci_transport_send_control_pkt(struct sock *sk,
+				enum vmci_transport_packet_type type,
+				u64 size,
+				u64 mode,
+				struct vmci_transport_waiting_info *wait,
+				u16 proto,
+				struct vmci_handle handle)
+{
+	struct vmci_transport_packet *pkt;
+	struct vsock_sock *vsk;
+	int err;
+
+	vsk = vsock_sk(sk);
+
+	if (!vsock_addr_bound(&vsk->local_addr))
+		return -EINVAL;
+
+	if (!vsock_addr_bound(&vsk->remote_addr))
+		return -EINVAL;
+
+	pkt = kmalloc(sizeof(*pkt), GFP_KERNEL);
+	if (!pkt)
+		return -ENOMEM;
+
+	err = __vmci_transport_send_control_pkt(pkt, &vsk->local_addr,
+						&vsk->remote_addr, type, size,
+						mode, wait, proto, handle,
+						true);
+	kfree(pkt);
+
+	return err;
+}
+
+static int vmci_transport_send_reset_bh(struct sockaddr_vm *dst,
+					struct sockaddr_vm *src,
+					struct vmci_transport_packet *pkt)
+{
+	if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST)
+		return 0;
+	return vmci_transport_send_control_pkt_bh(
+					dst, src,
+					VMCI_TRANSPORT_PACKET_TYPE_RST, 0,
+					0, NULL, VMCI_INVALID_HANDLE);
+}
+
+static int vmci_transport_send_reset(struct sock *sk,
+				     struct vmci_transport_packet *pkt)
+{
+	if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST)
+		return 0;
+	return vmci_transport_send_control_pkt(sk,
+					VMCI_TRANSPORT_PACKET_TYPE_RST,
+					0, 0, NULL, VSOCK_PROTO_INVALID,
+					VMCI_INVALID_HANDLE);
+}
+
+static int vmci_transport_send_negotiate(struct sock *sk, size_t size)
+{
+	return vmci_transport_send_control_pkt(
+					sk,
+					VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE,
+					size, 0, NULL,
+					VSOCK_PROTO_INVALID,
+					VMCI_INVALID_HANDLE);
+}
+
+static int vmci_transport_send_negotiate2(struct sock *sk, size_t size,
+					  u16 version)
+{
+	return vmci_transport_send_control_pkt(
+					sk,
+					VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE2,
+					size, 0, NULL, version,
+					VMCI_INVALID_HANDLE);
+}
+
+static int vmci_transport_send_qp_offer(struct sock *sk,
+					struct vmci_handle handle)
+{
+	return vmci_transport_send_control_pkt(
+					sk, VMCI_TRANSPORT_PACKET_TYPE_OFFER, 0,
+					0, NULL,
+					VSOCK_PROTO_INVALID, handle);
+}
+
+static int vmci_transport_send_attach(struct sock *sk,
+				      struct vmci_handle handle)
+{
+	return vmci_transport_send_control_pkt(
+					sk, VMCI_TRANSPORT_PACKET_TYPE_ATTACH,
+					0, 0, NULL, VSOCK_PROTO_INVALID,
+					handle);
+}
+
+static int vmci_transport_reply_reset(struct vmci_transport_packet *pkt)
+{
+	return vmci_transport_reply_control_pkt_fast(
+						pkt,
+						VMCI_TRANSPORT_PACKET_TYPE_RST,
+						0, 0, NULL,
+						VMCI_INVALID_HANDLE);
+}
+
+static int vmci_transport_send_invalid_bh(struct sockaddr_vm *dst,
+					  struct sockaddr_vm *src)
+{
+	return vmci_transport_send_control_pkt_bh(
+					dst, src,
+					VMCI_TRANSPORT_PACKET_TYPE_INVALID,
+					0, 0, NULL, VMCI_INVALID_HANDLE);
+}
+
+int vmci_transport_send_wrote_bh(struct sockaddr_vm *dst,
+				 struct sockaddr_vm *src)
+{
+	return vmci_transport_send_control_pkt_bh(
+					dst, src,
+					VMCI_TRANSPORT_PACKET_TYPE_WROTE, 0,
+					0, NULL, VMCI_INVALID_HANDLE);
+}
+
+int vmci_transport_send_read_bh(struct sockaddr_vm *dst,
+				struct sockaddr_vm *src)
+{
+	return vmci_transport_send_control_pkt_bh(
+					dst, src,
+					VMCI_TRANSPORT_PACKET_TYPE_READ, 0,
+					0, NULL, VMCI_INVALID_HANDLE);
+}
+
+int vmci_transport_send_wrote(struct sock *sk)
+{
+	return vmci_transport_send_control_pkt(
+					sk, VMCI_TRANSPORT_PACKET_TYPE_WROTE, 0,
+					0, NULL, VSOCK_PROTO_INVALID,
+					VMCI_INVALID_HANDLE);
+}
+
+int vmci_transport_send_read(struct sock *sk)
+{
+	return vmci_transport_send_control_pkt(
+					sk, VMCI_TRANSPORT_PACKET_TYPE_READ, 0,
+					0, NULL, VSOCK_PROTO_INVALID,
+					VMCI_INVALID_HANDLE);
+}
+
+int vmci_transport_send_waiting_write(struct sock *sk,
+				      struct vmci_transport_waiting_info *wait)
+{
+	return vmci_transport_send_control_pkt(
+				sk, VMCI_TRANSPORT_PACKET_TYPE_WAITING_WRITE,
+				0, 0, wait, VSOCK_PROTO_INVALID,
+				VMCI_INVALID_HANDLE);
+}
+
+int vmci_transport_send_waiting_read(struct sock *sk,
+				     struct vmci_transport_waiting_info *wait)
+{
+	return vmci_transport_send_control_pkt(
+				sk, VMCI_TRANSPORT_PACKET_TYPE_WAITING_READ,
+				0, 0, wait, VSOCK_PROTO_INVALID,
+				VMCI_INVALID_HANDLE);
+}
+
+static int vmci_transport_shutdown(struct vsock_sock *vsk, int mode)
+{
+	return vmci_transport_send_control_pkt(
+					&vsk->sk,
+					VMCI_TRANSPORT_PACKET_TYPE_SHUTDOWN,
+					0, mode, NULL,
+					VSOCK_PROTO_INVALID,
+					VMCI_INVALID_HANDLE);
+}
+
+static int vmci_transport_send_conn_request(struct sock *sk, size_t size)
+{
+	return vmci_transport_send_control_pkt(sk,
+					VMCI_TRANSPORT_PACKET_TYPE_REQUEST,
+					size, 0, NULL,
+					VSOCK_PROTO_INVALID,
+					VMCI_INVALID_HANDLE);
+}
+
+static int vmci_transport_send_conn_request2(struct sock *sk, size_t size,
+					     u16 version)
+{
+	return vmci_transport_send_control_pkt(
+					sk, VMCI_TRANSPORT_PACKET_TYPE_REQUEST2,
+					size, 0, NULL, version,
+					VMCI_INVALID_HANDLE);
+}
+
+static struct sock *vmci_transport_get_pending(
+					struct sock *listener,
+					struct vmci_transport_packet *pkt)
+{
+	struct vsock_sock *vlistener;
+	struct vsock_sock *vpending;
+	struct sock *pending;
+	struct sockaddr_vm src;
+
+	vsock_addr_init(&src, pkt->dg.src.context, pkt->src_port);
+
+	vlistener = vsock_sk(listener);
+
+	list_for_each_entry(vpending, &vlistener->pending_links,
+			    pending_links) {
+		if (vsock_addr_equals_addr(&src, &vpending->remote_addr) &&
+		    pkt->dst_port == vpending->local_addr.svm_port) {
+			pending = sk_vsock(vpending);
+			sock_hold(pending);
+			goto found;
+		}
+	}
+
+	pending = NULL;
+found:
+	return pending;
+
+}
+
+static void vmci_transport_release_pending(struct sock *pending)
+{
+	sock_put(pending);
+}
+
+/* We allow two kinds of sockets to communicate with a restricted VM: 1)
+ * trusted sockets 2) sockets from applications running as the same user as the
+ * VM (this is only true for the host side and only when using hosted products)
+ */
+
+static bool vmci_transport_is_trusted(struct vsock_sock *vsock, u32 peer_cid)
+{
+	return vsock->trusted ||
+	       vmci_is_context_owner(peer_cid, vsock->owner->uid);
+}
+
+/* We allow sending datagrams to and receiving datagrams from a restricted VM
+ * only if it is trusted as described in vmci_transport_is_trusted.
+ */
+
+static bool vmci_transport_allow_dgram(struct vsock_sock *vsock, u32 peer_cid)
+{
+	if (VMADDR_CID_HYPERVISOR == peer_cid)
+		return true;
+
+	if (vsock->cached_peer != peer_cid) {
+		vsock->cached_peer = peer_cid;
+		if (!vmci_transport_is_trusted(vsock, peer_cid) &&
+		    (vmci_context_get_priv_flags(peer_cid) &
+		     VMCI_PRIVILEGE_FLAG_RESTRICTED)) {
+			vsock->cached_peer_allow_dgram = false;
+		} else {
+			vsock->cached_peer_allow_dgram = true;
+		}
+	}
+
+	return vsock->cached_peer_allow_dgram;
+}
+
+static int
+vmci_transport_queue_pair_alloc(struct vmci_qp **qpair,
+				struct vmci_handle *handle,
+				u64 produce_size,
+				u64 consume_size,
+				u32 peer, u32 flags, bool trusted)
+{
+	int err = 0;
+
+	if (trusted) {
+		/* Try to allocate our queue pair as trusted. This will only
+		 * work if vsock is running in the host.
+		 */
+
+		err = vmci_qpair_alloc(qpair, handle, produce_size,
+				       consume_size,
+				       peer, flags,
+				       VMCI_PRIVILEGE_FLAG_TRUSTED);
+		if (err != VMCI_ERROR_NO_ACCESS)
+			goto out;
+
+	}
+
+	err = vmci_qpair_alloc(qpair, handle, produce_size, consume_size,
+			       peer, flags, VMCI_NO_PRIVILEGE_FLAGS);
+out:
+	if (err < 0) {
+		pr_err("Could not attach to queue pair with %d\n",
+		       err);
+		err = vmci_transport_error_to_vsock_error(err);
+	}
+
+	return err;
+}
+
+static int
+vmci_transport_datagram_create_hnd(u32 resource_id,
+				   u32 flags,
+				   vmci_datagram_recv_cb recv_cb,
+				   void *client_data,
+				   struct vmci_handle *out_handle)
+{
+	int err = 0;
+
+	/* Try to allocate our datagram handler as trusted. This will only work
+	 * if vsock is running in the host.
+	 */
+
+	err = vmci_datagram_create_handle_priv(resource_id, flags,
+					       VMCI_PRIVILEGE_FLAG_TRUSTED,
+					       recv_cb,
+					       client_data, out_handle);
+
+	if (err == VMCI_ERROR_NO_ACCESS)
+		err = vmci_datagram_create_handle(resource_id, flags,
+						  recv_cb, client_data,
+						  out_handle);
+
+	return err;
+}
+
+/* This is invoked as part of a tasklet that's scheduled when the VMCI
+ * interrupt fires.  This is run in bottom-half context and if it ever needs to
+ * sleep it should defer that work to a work queue.
+ */
+
+static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg)
+{
+	struct sock *sk;
+	size_t size;
+	struct sk_buff *skb;
+	struct vsock_sock *vsk;
+
+	sk = (struct sock *)data;
+
+	/* This handler is privileged when this module is running on the host.
+	 * We will get datagrams from all endpoints (even VMs that are in a
+	 * restricted context). If we get one from a restricted context then
+	 * the destination socket must be trusted.
+	 *
+	 * NOTE: We access the socket struct without holding the lock here.
+	 * This is ok because the field we are interested is never modified
+	 * outside of the create and destruct socket functions.
+	 */
+	vsk = vsock_sk(sk);
+	if (!vmci_transport_allow_dgram(vsk, dg->src.context))
+		return VMCI_ERROR_NO_ACCESS;
+
+	size = VMCI_DG_SIZE(dg);
+
+	/* Attach the packet to the socket's receive queue as an sk_buff. */
+	skb = alloc_skb(size, GFP_ATOMIC);
+	if (!skb)
+		return VMCI_ERROR_NO_MEM;
+
+	/* sk_receive_skb() will do a sock_put(), so hold here. */
+	sock_hold(sk);
+	skb_put(skb, size);
+	memcpy(skb->data, dg, size);
+	sk_receive_skb(sk, skb, 0);
+
+	return VMCI_SUCCESS;
+}
+
+static bool vmci_transport_stream_allow(u32 cid, u32 port)
+{
+	static const u32 non_socket_contexts[] = {
+		VMADDR_CID_RESERVED,
+	};
+	int i;
+
+	BUILD_BUG_ON(sizeof(cid) != sizeof(*non_socket_contexts));
+
+	for (i = 0; i < ARRAY_SIZE(non_socket_contexts); i++) {
+		if (cid == non_socket_contexts[i])
+			return false;
+	}
+
+	return true;
+}
+
+/* This is invoked as part of a tasklet that's scheduled when the VMCI
+ * interrupt fires.  This is run in bottom-half context but it defers most of
+ * its work to the packet handling work queue.
+ */
+
+static int vmci_transport_recv_stream_cb(void *data, struct vmci_datagram *dg)
+{
+	struct sock *sk;
+	struct sockaddr_vm dst;
+	struct sockaddr_vm src;
+	struct vmci_transport_packet *pkt;
+	struct vsock_sock *vsk;
+	bool bh_process_pkt;
+	int err;
+
+	sk = NULL;
+	err = VMCI_SUCCESS;
+	bh_process_pkt = false;
+
+	/* Ignore incoming packets from contexts without sockets, or resources
+	 * that aren't vsock implementations.
+	 */
+
+	if (!vmci_transport_stream_allow(dg->src.context, -1)
+	    || vmci_transport_peer_rid(dg->src.context) != dg->src.resource)
+		return VMCI_ERROR_NO_ACCESS;
+
+	if (VMCI_DG_SIZE(dg) < sizeof(*pkt))
+		/* Drop datagrams that do not contain full VSock packets. */
+		return VMCI_ERROR_INVALID_ARGS;
+
+	pkt = (struct vmci_transport_packet *)dg;
+
+	/* Find the socket that should handle this packet.  First we look for a
+	 * connected socket and if there is none we look for a socket bound to
+	 * the destintation address.
+	 */
+	vsock_addr_init(&src, pkt->dg.src.context, pkt->src_port);
+	vsock_addr_init(&dst, pkt->dg.dst.context, pkt->dst_port);
+
+	sk = vsock_find_connected_socket(&src, &dst);
+	if (!sk) {
+		sk = vsock_find_bound_socket(&dst);
+		if (!sk) {
+			/* We could not find a socket for this specified
+			 * address.  If this packet is a RST, we just drop it.
+			 * If it is another packet, we send a RST.  Note that
+			 * we do not send a RST reply to RSTs so that we do not
+			 * continually send RSTs between two endpoints.
+			 *
+			 * Note that since this is a reply, dst is src and src
+			 * is dst.
+			 */
+			if (vmci_transport_send_reset_bh(&dst, &src, pkt) < 0)
+				pr_err("unable to send reset\n");
+
+			err = VMCI_ERROR_NOT_FOUND;
+			goto out;
+		}
+	}
+
+	/* If the received packet type is beyond all types known to this
+	 * implementation, reply with an invalid message.  Hopefully this will
+	 * help when implementing backwards compatibility in the future.
+	 */
+	if (pkt->type >= VMCI_TRANSPORT_PACKET_TYPE_MAX) {
+		vmci_transport_send_invalid_bh(&dst, &src);
+		err = VMCI_ERROR_INVALID_ARGS;
+		goto out;
+	}
+
+	/* This handler is privileged when this module is running on the host.
+	 * We will get datagram connect requests from all endpoints (even VMs
+	 * that are in a restricted context). If we get one from a restricted
+	 * context then the destination socket must be trusted.
+	 *
+	 * NOTE: We access the socket struct without holding the lock here.
+	 * This is ok because the field we are interested is never modified
+	 * outside of the create and destruct socket functions.
+	 */
+	vsk = vsock_sk(sk);
+	if (!vmci_transport_allow_dgram(vsk, pkt->dg.src.context)) {
+		err = VMCI_ERROR_NO_ACCESS;
+		goto out;
+	}
+
+	/* We do most everything in a work queue, but let's fast path the
+	 * notification of reads and writes to help data transfer performance.
+	 * We can only do this if there is no process context code executing
+	 * for this socket since that may change the state.
+	 */
+	bh_lock_sock(sk);
+
+	if (!sock_owned_by_user(sk)) {
+		/* The local context ID may be out of date, update it. */
+		vsk->local_addr.svm_cid = dst.svm_cid;
+
+		if (sk->sk_state == SS_CONNECTED)
+			vmci_trans(vsk)->notify_ops->handle_notify_pkt(
+					sk, pkt, true, &dst, &src,
+					&bh_process_pkt);
+	}
+
+	bh_unlock_sock(sk);
+
+	if (!bh_process_pkt) {
+		struct vmci_transport_recv_pkt_info *recv_pkt_info;
+
+		recv_pkt_info = kmalloc(sizeof(*recv_pkt_info), GFP_ATOMIC);
+		if (!recv_pkt_info) {
+			if (vmci_transport_send_reset_bh(&dst, &src, pkt) < 0)
+				pr_err("unable to send reset\n");
+
+			err = VMCI_ERROR_NO_MEM;
+			goto out;
+		}
+
+		recv_pkt_info->sk = sk;
+		memcpy(&recv_pkt_info->pkt, pkt, sizeof(recv_pkt_info->pkt));
+		INIT_WORK(&recv_pkt_info->work, vmci_transport_recv_pkt_work);
+
+		schedule_work(&recv_pkt_info->work);
+		/* Clear sk so that the reference count incremented by one of
+		 * the Find functions above is not decremented below.  We need
+		 * that reference count for the packet handler we've scheduled
+		 * to run.
+		 */
+		sk = NULL;
+	}
+
+out:
+	if (sk)
+		sock_put(sk);
+
+	return err;
+}
+
+static void vmci_transport_peer_attach_cb(u32 sub_id,
+					  const struct vmci_event_data *e_data,
+					  void *client_data)
+{
+	struct sock *sk = client_data;
+	const struct vmci_event_payload_qp *e_payload;
+	struct vsock_sock *vsk;
+
+	e_payload = vmci_event_data_const_payload(e_data);
+
+	vsk = vsock_sk(sk);
+
+	/* We don't ask for delayed CBs when we subscribe to this event (we
+	 * pass 0 as flags to vmci_event_subscribe()).  VMCI makes no
+	 * guarantees in that case about what context we might be running in,
+	 * so it could be BH or process, blockable or non-blockable.  So we
+	 * need to account for all possible contexts here.
+	 */
+	local_bh_disable();
+	bh_lock_sock(sk);
+
+	/* XXX This is lame, we should provide a way to lookup sockets by
+	 * qp_handle.
+	 */
+	if (vmci_handle_is_equal(vmci_trans(vsk)->qp_handle,
+				 e_payload->handle)) {
+		/* XXX This doesn't do anything, but in the future we may want
+		 * to set a flag here to verify the attach really did occur and
+		 * we weren't just sent a datagram claiming it was.
+		 */
+		goto out;
+	}
+
+out:
+	bh_unlock_sock(sk);
+	local_bh_enable();
+}
+
+static void vmci_transport_handle_detach(struct sock *sk)
+{
+	struct vsock_sock *vsk;
+
+	vsk = vsock_sk(sk);
+	if (!vmci_handle_is_invalid(vmci_trans(vsk)->qp_handle)) {
+		sock_set_flag(sk, SOCK_DONE);
+
+		/* On a detach the peer will not be sending or receiving
+		 * anymore.
+		 */
+		vsk->peer_shutdown = SHUTDOWN_MASK;
+
+		/* We should not be sending anymore since the peer won't be
+		 * there to receive, but we can still receive if there is data
+		 * left in our consume queue.
+		 */
+		if (vsock_stream_has_data(vsk) <= 0) {
+			if (sk->sk_state == SS_CONNECTING) {
+				/* The peer may detach from a queue pair while
+				 * we are still in the connecting state, i.e.,
+				 * if the peer VM is killed after attaching to
+				 * a queue pair, but before we complete the
+				 * handshake. In that case, we treat the detach
+				 * event like a reset.
+				 */
+
+				sk->sk_state = SS_UNCONNECTED;
+				sk->sk_err = ECONNRESET;
+				sk->sk_error_report(sk);
+				return;
+			}
+			sk->sk_state = SS_UNCONNECTED;
+		}
+		sk->sk_state_change(sk);
+	}
+}
+
+static void vmci_transport_peer_detach_cb(u32 sub_id,
+					  const struct vmci_event_data *e_data,
+					  void *client_data)
+{
+	struct sock *sk = client_data;
+	const struct vmci_event_payload_qp *e_payload;
+	struct vsock_sock *vsk;
+
+	e_payload = vmci_event_data_const_payload(e_data);
+	vsk = vsock_sk(sk);
+	if (vmci_handle_is_invalid(e_payload->handle))
+		return;
+
+	/* Same rules for locking as for peer_attach_cb(). */
+	local_bh_disable();
+	bh_lock_sock(sk);
+
+	/* XXX This is lame, we should provide a way to lookup sockets by
+	 * qp_handle.
+	 */
+	if (vmci_handle_is_equal(vmci_trans(vsk)->qp_handle,
+				 e_payload->handle))
+		vmci_transport_handle_detach(sk);
+
+	bh_unlock_sock(sk);
+	local_bh_enable();
+}
+
+static void vmci_transport_qp_resumed_cb(u32 sub_id,
+					 const struct vmci_event_data *e_data,
+					 void *client_data)
+{
+	vsock_for_each_connected_socket(vmci_transport_handle_detach);
+}
+
+static void vmci_transport_recv_pkt_work(struct work_struct *work)
+{
+	struct vmci_transport_recv_pkt_info *recv_pkt_info;
+	struct vmci_transport_packet *pkt;
+	struct sock *sk;
+
+	recv_pkt_info =
+		container_of(work, struct vmci_transport_recv_pkt_info, work);
+	sk = recv_pkt_info->sk;
+	pkt = &recv_pkt_info->pkt;
+
+	lock_sock(sk);
+
+	/* The local context ID may be out of date. */
+	vsock_sk(sk)->local_addr.svm_cid = pkt->dg.dst.context;
+
+	switch (sk->sk_state) {
+	case SS_LISTEN:
+		vmci_transport_recv_listen(sk, pkt);
+		break;
+	case SS_CONNECTING:
+		/* Processing of pending connections for servers goes through
+		 * the listening socket, so see vmci_transport_recv_listen()
+		 * for that path.
+		 */
+		vmci_transport_recv_connecting_client(sk, pkt);
+		break;
+	case SS_CONNECTED:
+		vmci_transport_recv_connected(sk, pkt);
+		break;
+	default:
+		/* Because this function does not run in the same context as
+		 * vmci_transport_recv_stream_cb it is possible that the
+		 * socket has closed. We need to let the other side know or it
+		 * could be sitting in a connect and hang forever. Send a
+		 * reset to prevent that.
+		 */
+		vmci_transport_send_reset(sk, pkt);
+		break;
+	}
+
+	release_sock(sk);
+	kfree(recv_pkt_info);
+	/* Release reference obtained in the stream callback when we fetched
+	 * this socket out of the bound or connected list.
+	 */
+	sock_put(sk);
+}
+
+static int vmci_transport_recv_listen(struct sock *sk,
+				      struct vmci_transport_packet *pkt)
+{
+	struct sock *pending;
+	struct vsock_sock *vpending;
+	int err;
+	u64 qp_size;
+	bool old_request = false;
+	bool old_pkt_proto = false;
+
+	err = 0;
+
+	/* Because we are in the listen state, we could be receiving a packet
+	 * for ourself or any previous connection requests that we received.
+	 * If it's the latter, we try to find a socket in our list of pending
+	 * connections and, if we do, call the appropriate handler for the
+	 * state that that socket is in.  Otherwise we try to service the
+	 * connection request.
+	 */
+	pending = vmci_transport_get_pending(sk, pkt);
+	if (pending) {
+		lock_sock(pending);
+
+		/* The local context ID may be out of date. */
+		vsock_sk(pending)->local_addr.svm_cid = pkt->dg.dst.context;
+
+		switch (pending->sk_state) {
+		case SS_CONNECTING:
+			err = vmci_transport_recv_connecting_server(sk,
+								    pending,
+								    pkt);
+			break;
+		default:
+			vmci_transport_send_reset(pending, pkt);
+			err = -EINVAL;
+		}
+
+		if (err < 0)
+			vsock_remove_pending(sk, pending);
+
+		release_sock(pending);
+		vmci_transport_release_pending(pending);
+
+		return err;
+	}
+
+	/* The listen state only accepts connection requests.  Reply with a
+	 * reset unless we received a reset.
+	 */
+
+	if (!(pkt->type == VMCI_TRANSPORT_PACKET_TYPE_REQUEST ||
+	      pkt->type == VMCI_TRANSPORT_PACKET_TYPE_REQUEST2)) {
+		vmci_transport_reply_reset(pkt);
+		return -EINVAL;
+	}
+
+	if (pkt->u.size == 0) {
+		vmci_transport_reply_reset(pkt);
+		return -EINVAL;
+	}
+
+	/* If this socket can't accommodate this connection request, we send a
+	 * reset.  Otherwise we create and initialize a child socket and reply
+	 * with a connection negotiation.
+	 */
+	if (sk->sk_ack_backlog >= sk->sk_max_ack_backlog) {
+		vmci_transport_reply_reset(pkt);
+		return -ECONNREFUSED;
+	}
+
+	pending = __vsock_create(sock_net(sk), NULL, sk, GFP_KERNEL,
+				 sk->sk_type);
+	if (!pending) {
+		vmci_transport_send_reset(sk, pkt);
+		return -ENOMEM;
+	}
+
+	vpending = vsock_sk(pending);
+
+	vsock_addr_init(&vpending->local_addr, pkt->dg.dst.context,
+			pkt->dst_port);
+	vsock_addr_init(&vpending->remote_addr, pkt->dg.src.context,
+			pkt->src_port);
+
+	/* If the proposed size fits within our min/max, accept it. Otherwise
+	 * propose our own size.
+	 */
+	if (pkt->u.size >= vmci_trans(vpending)->queue_pair_min_size &&
+	    pkt->u.size <= vmci_trans(vpending)->queue_pair_max_size) {
+		qp_size = pkt->u.size;
+	} else {
+		qp_size = vmci_trans(vpending)->queue_pair_size;
+	}
+
+	/* Figure out if we are using old or new requests based on the
+	 * overrides pkt types sent by our peer.
+	 */
+	if (vmci_transport_old_proto_override(&old_pkt_proto)) {
+		old_request = old_pkt_proto;
+	} else {
+		if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_REQUEST)
+			old_request = true;
+		else if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_REQUEST2)
+			old_request = false;
+
+	}
+
+	if (old_request) {
+		/* Handle a REQUEST (or override) */
+		u16 version = VSOCK_PROTO_INVALID;
+		if (vmci_transport_proto_to_notify_struct(
+			pending, &version, true))
+			err = vmci_transport_send_negotiate(pending, qp_size);
+		else
+			err = -EINVAL;
+
+	} else {
+		/* Handle a REQUEST2 (or override) */
+		int proto_int = pkt->proto;
+		int pos;
+		u16 active_proto_version = 0;
+
+		/* The list of possible protocols is the intersection of all
+		 * protocols the client supports ... plus all the protocols we
+		 * support.
+		 */
+		proto_int &= vmci_transport_new_proto_supported_versions();
+
+		/* We choose the highest possible protocol version and use that
+		 * one.
+		 */
+		pos = fls(proto_int);
+		if (pos) {
+			active_proto_version = (1 << (pos - 1));
+			if (vmci_transport_proto_to_notify_struct(
+				pending, &active_proto_version, false))
+				err = vmci_transport_send_negotiate2(pending,
+							qp_size,
+							active_proto_version);
+			else
+				err = -EINVAL;
+
+		} else {
+			err = -EINVAL;
+		}
+	}
+
+	if (err < 0) {
+		vmci_transport_send_reset(sk, pkt);
+		sock_put(pending);
+		err = vmci_transport_error_to_vsock_error(err);
+		goto out;
+	}
+
+	vsock_add_pending(sk, pending);
+	sk->sk_ack_backlog++;
+
+	pending->sk_state = SS_CONNECTING;
+	vmci_trans(vpending)->produce_size =
+		vmci_trans(vpending)->consume_size = qp_size;
+	vmci_trans(vpending)->queue_pair_size = qp_size;
+
+	vmci_trans(vpending)->notify_ops->process_request(pending);
+
+	/* We might never receive another message for this socket and it's not
+	 * connected to any process, so we have to ensure it gets cleaned up
+	 * ourself.  Our delayed work function will take care of that.  Note
+	 * that we do not ever cancel this function since we have few
+	 * guarantees about its state when calling cancel_delayed_work().
+	 * Instead we hold a reference on the socket for that function and make
+	 * it capable of handling cases where it needs to do nothing but
+	 * release that reference.
+	 */
+	vpending->listener = sk;
+	sock_hold(sk);
+	sock_hold(pending);
+	INIT_DELAYED_WORK(&vpending->dwork, vsock_pending_work);
+	schedule_delayed_work(&vpending->dwork, HZ);
+
+out:
+	return err;
+}
+
+static int
+vmci_transport_recv_connecting_server(struct sock *listener,
+				      struct sock *pending,
+				      struct vmci_transport_packet *pkt)
+{
+	struct vsock_sock *vpending;
+	struct vmci_handle handle;
+	struct vmci_qp *qpair;
+	bool is_local;
+	u32 flags;
+	u32 detach_sub_id;
+	int err;
+	int skerr;
+
+	vpending = vsock_sk(pending);
+	detach_sub_id = VMCI_INVALID_ID;
+
+	switch (pkt->type) {
+	case VMCI_TRANSPORT_PACKET_TYPE_OFFER:
+		if (vmci_handle_is_invalid(pkt->u.handle)) {
+			vmci_transport_send_reset(pending, pkt);
+			skerr = EPROTO;
+			err = -EINVAL;
+			goto destroy;
+		}
+		break;
+	default:
+		/* Close and cleanup the connection. */
+		vmci_transport_send_reset(pending, pkt);
+		skerr = EPROTO;
+		err = pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST ? 0 : -EINVAL;
+		goto destroy;
+	}
+
+	/* In order to complete the connection we need to attach to the offered
+	 * queue pair and send an attach notification.  We also subscribe to the
+	 * detach event so we know when our peer goes away, and we do that
+	 * before attaching so we don't miss an event.  If all this succeeds,
+	 * we update our state and wakeup anything waiting in accept() for a
+	 * connection.
+	 */
+
+	/* We don't care about attach since we ensure the other side has
+	 * attached by specifying the ATTACH_ONLY flag below.
+	 */
+	err = vmci_event_subscribe(VMCI_EVENT_QP_PEER_DETACH,
+				   vmci_transport_peer_detach_cb,
+				   pending, &detach_sub_id);
+	if (err < VMCI_SUCCESS) {
+		vmci_transport_send_reset(pending, pkt);
+		err = vmci_transport_error_to_vsock_error(err);
+		skerr = -err;
+		goto destroy;
+	}
+
+	vmci_trans(vpending)->detach_sub_id = detach_sub_id;
+
+	/* Now attach to the queue pair the client created. */
+	handle = pkt->u.handle;
+
+	/* vpending->local_addr always has a context id so we do not need to
+	 * worry about VMADDR_CID_ANY in this case.
+	 */
+	is_local =
+	    vpending->remote_addr.svm_cid == vpending->local_addr.svm_cid;
+	flags = VMCI_QPFLAG_ATTACH_ONLY;
+	flags |= is_local ? VMCI_QPFLAG_LOCAL : 0;
+
+	err = vmci_transport_queue_pair_alloc(
+					&qpair,
+					&handle,
+					vmci_trans(vpending)->produce_size,
+					vmci_trans(vpending)->consume_size,
+					pkt->dg.src.context,
+					flags,
+					vmci_transport_is_trusted(
+						vpending,
+						vpending->remote_addr.svm_cid));
+	if (err < 0) {
+		vmci_transport_send_reset(pending, pkt);
+		skerr = -err;
+		goto destroy;
+	}
+
+	vmci_trans(vpending)->qp_handle = handle;
+	vmci_trans(vpending)->qpair = qpair;
+
+	/* When we send the attach message, we must be ready to handle incoming
+	 * control messages on the newly connected socket. So we move the
+	 * pending socket to the connected state before sending the attach
+	 * message. Otherwise, an incoming packet triggered by the attach being
+	 * received by the peer may be processed concurrently with what happens
+	 * below after sending the attach message, and that incoming packet
+	 * will find the listening socket instead of the (currently) pending
+	 * socket. Note that enqueueing the socket increments the reference
+	 * count, so even if a reset comes before the connection is accepted,
+	 * the socket will be valid until it is removed from the queue.
+	 *
+	 * If we fail sending the attach below, we remove the socket from the
+	 * connected list and move the socket to SS_UNCONNECTED before
+	 * releasing the lock, so a pending slow path processing of an incoming
+	 * packet will not see the socket in the connected state in that case.
+	 */
+	pending->sk_state = SS_CONNECTED;
+
+	vsock_insert_connected(vpending);
+
+	/* Notify our peer of our attach. */
+	err = vmci_transport_send_attach(pending, handle);
+	if (err < 0) {
+		vsock_remove_connected(vpending);
+		pr_err("Could not send attach\n");
+		vmci_transport_send_reset(pending, pkt);
+		err = vmci_transport_error_to_vsock_error(err);
+		skerr = -err;
+		goto destroy;
+	}
+
+	/* We have a connection. Move the now connected socket from the
+	 * listener's pending list to the accept queue so callers of accept()
+	 * can find it.
+	 */
+	vsock_remove_pending(listener, pending);
+	vsock_enqueue_accept(listener, pending);
+
+	/* Callers of accept() will be be waiting on the listening socket, not
+	 * the pending socket.
+	 */
+	listener->sk_state_change(listener);
+
+	return 0;
+
+destroy:
+	pending->sk_err = skerr;
+	pending->sk_state = SS_UNCONNECTED;
+	/* As long as we drop our reference, all necessary cleanup will handle
+	 * when the cleanup function drops its reference and our destruct
+	 * implementation is called.  Note that since the listen handler will
+	 * remove pending from the pending list upon our failure, the cleanup
+	 * function won't drop the additional reference, which is why we do it
+	 * here.
+	 */
+	sock_put(pending);
+
+	return err;
+}
+
+static int
+vmci_transport_recv_connecting_client(struct sock *sk,
+				      struct vmci_transport_packet *pkt)
+{
+	struct vsock_sock *vsk;
+	int err;
+	int skerr;
+
+	vsk = vsock_sk(sk);
+
+	switch (pkt->type) {
+	case VMCI_TRANSPORT_PACKET_TYPE_ATTACH:
+		if (vmci_handle_is_invalid(pkt->u.handle) ||
+		    !vmci_handle_is_equal(pkt->u.handle,
+					  vmci_trans(vsk)->qp_handle)) {
+			skerr = EPROTO;
+			err = -EINVAL;
+			goto destroy;
+		}
+
+		/* Signify the socket is connected and wakeup the waiter in
+		 * connect(). Also place the socket in the connected table for
+		 * accounting (it can already be found since it's in the bound
+		 * table).
+		 */
+		sk->sk_state = SS_CONNECTED;
+		sk->sk_socket->state = SS_CONNECTED;
+		vsock_insert_connected(vsk);
+		sk->sk_state_change(sk);
+
+		break;
+	case VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE:
+	case VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE2:
+		if (pkt->u.size == 0
+		    || pkt->dg.src.context != vsk->remote_addr.svm_cid
+		    || pkt->src_port != vsk->remote_addr.svm_port
+		    || !vmci_handle_is_invalid(vmci_trans(vsk)->qp_handle)
+		    || vmci_trans(vsk)->qpair
+		    || vmci_trans(vsk)->produce_size != 0
+		    || vmci_trans(vsk)->consume_size != 0
+		    || vmci_trans(vsk)->attach_sub_id != VMCI_INVALID_ID
+		    || vmci_trans(vsk)->detach_sub_id != VMCI_INVALID_ID) {
+			skerr = EPROTO;
+			err = -EINVAL;
+
+			goto destroy;
+		}
+
+		err = vmci_transport_recv_connecting_client_negotiate(sk, pkt);
+		if (err) {
+			skerr = -err;
+			goto destroy;
+		}
+
+		break;
+	case VMCI_TRANSPORT_PACKET_TYPE_INVALID:
+		err = vmci_transport_recv_connecting_client_invalid(sk, pkt);
+		if (err) {
+			skerr = -err;
+			goto destroy;
+		}
+
+		break;
+	case VMCI_TRANSPORT_PACKET_TYPE_RST:
+		/* Older versions of the linux code (WS 6.5 / ESX 4.0) used to
+		 * continue processing here after they sent an INVALID packet.
+		 * This meant that we got a RST after the INVALID. We ignore a
+		 * RST after an INVALID. The common code doesn't send the RST
+		 * ... so we can hang if an old version of the common code
+		 * fails between getting a REQUEST and sending an OFFER back.
+		 * Not much we can do about it... except hope that it doesn't
+		 * happen.
+		 */
+		if (vsk->ignore_connecting_rst) {
+			vsk->ignore_connecting_rst = false;
+		} else {
+			skerr = ECONNRESET;
+			err = 0;
+			goto destroy;
+		}
+
+		break;
+	default:
+		/* Close and cleanup the connection. */
+		skerr = EPROTO;
+		err = -EINVAL;
+		goto destroy;
+	}
+
+	return 0;
+
+destroy:
+	vmci_transport_send_reset(sk, pkt);
+
+	sk->sk_state = SS_UNCONNECTED;
+	sk->sk_err = skerr;
+	sk->sk_error_report(sk);
+	return err;
+}
+
+static int vmci_transport_recv_connecting_client_negotiate(
+					struct sock *sk,
+					struct vmci_transport_packet *pkt)
+{
+	int err;
+	struct vsock_sock *vsk;
+	struct vmci_handle handle;
+	struct vmci_qp *qpair;
+	u32 attach_sub_id;
+	u32 detach_sub_id;
+	bool is_local;
+	u32 flags;
+	bool old_proto = true;
+	bool old_pkt_proto;
+	u16 version;
+
+	vsk = vsock_sk(sk);
+	handle = VMCI_INVALID_HANDLE;
+	attach_sub_id = VMCI_INVALID_ID;
+	detach_sub_id = VMCI_INVALID_ID;
+
+	/* If we have gotten here then we should be past the point where old
+	 * linux vsock could have sent the bogus rst.
+	 */
+	vsk->sent_request = false;
+	vsk->ignore_connecting_rst = false;
+
+	/* Verify that we're OK with the proposed queue pair size */
+	if (pkt->u.size < vmci_trans(vsk)->queue_pair_min_size ||
+	    pkt->u.size > vmci_trans(vsk)->queue_pair_max_size) {
+		err = -EINVAL;
+		goto destroy;
+	}
+
+	/* At this point we know the CID the peer is using to talk to us. */
+
+	if (vsk->local_addr.svm_cid == VMADDR_CID_ANY)
+		vsk->local_addr.svm_cid = pkt->dg.dst.context;
+
+	/* Setup the notify ops to be the highest supported version that both
+	 * the server and the client support.
+	 */
+
+	if (vmci_transport_old_proto_override(&old_pkt_proto)) {
+		old_proto = old_pkt_proto;
+	} else {
+		if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE)
+			old_proto = true;
+		else if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE2)
+			old_proto = false;
+
+	}
+
+	if (old_proto)
+		version = VSOCK_PROTO_INVALID;
+	else
+		version = pkt->proto;
+
+	if (!vmci_transport_proto_to_notify_struct(sk, &version, old_proto)) {
+		err = -EINVAL;
+		goto destroy;
+	}
+
+	/* Subscribe to attach and detach events first.
+	 *
+	 * XXX We attach once for each queue pair created for now so it is easy
+	 * to find the socket (it's provided), but later we should only
+	 * subscribe once and add a way to lookup sockets by queue pair handle.
+	 */
+	err = vmci_event_subscribe(VMCI_EVENT_QP_PEER_ATTACH,
+				   vmci_transport_peer_attach_cb,
+				   sk, &attach_sub_id);
+	if (err < VMCI_SUCCESS) {
+		err = vmci_transport_error_to_vsock_error(err);
+		goto destroy;
+	}
+
+	err = vmci_event_subscribe(VMCI_EVENT_QP_PEER_DETACH,
+				   vmci_transport_peer_detach_cb,
+				   sk, &detach_sub_id);
+	if (err < VMCI_SUCCESS) {
+		err = vmci_transport_error_to_vsock_error(err);
+		goto destroy;
+	}
+
+	/* Make VMCI select the handle for us. */
+	handle = VMCI_INVALID_HANDLE;
+	is_local = vsk->remote_addr.svm_cid == vsk->local_addr.svm_cid;
+	flags = is_local ? VMCI_QPFLAG_LOCAL : 0;
+
+	err = vmci_transport_queue_pair_alloc(&qpair,
+					      &handle,
+					      pkt->u.size,
+					      pkt->u.size,
+					      vsk->remote_addr.svm_cid,
+					      flags,
+					      vmci_transport_is_trusted(
+						  vsk,
+						  vsk->
+						  remote_addr.svm_cid));
+	if (err < 0)
+		goto destroy;
+
+	err = vmci_transport_send_qp_offer(sk, handle);
+	if (err < 0) {
+		err = vmci_transport_error_to_vsock_error(err);
+		goto destroy;
+	}
+
+	vmci_trans(vsk)->qp_handle = handle;
+	vmci_trans(vsk)->qpair = qpair;
+
+	vmci_trans(vsk)->produce_size = vmci_trans(vsk)->consume_size =
+		pkt->u.size;
+
+	vmci_trans(vsk)->attach_sub_id = attach_sub_id;
+	vmci_trans(vsk)->detach_sub_id = detach_sub_id;
+
+	vmci_trans(vsk)->notify_ops->process_negotiate(sk);
+
+	return 0;
+
+destroy:
+	if (attach_sub_id != VMCI_INVALID_ID)
+		vmci_event_unsubscribe(attach_sub_id);
+
+	if (detach_sub_id != VMCI_INVALID_ID)
+		vmci_event_unsubscribe(detach_sub_id);
+
+	if (!vmci_handle_is_invalid(handle))
+		vmci_qpair_detach(&qpair);
+
+	return err;
+}
+
+static int
+vmci_transport_recv_connecting_client_invalid(struct sock *sk,
+					      struct vmci_transport_packet *pkt)
+{
+	int err = 0;
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+	if (vsk->sent_request) {
+		vsk->sent_request = false;
+		vsk->ignore_connecting_rst = true;
+
+		err = vmci_transport_send_conn_request(
+			sk, vmci_trans(vsk)->queue_pair_size);
+		if (err < 0)
+			err = vmci_transport_error_to_vsock_error(err);
+		else
+			err = 0;
+
+	}
+
+	return err;
+}
+
+static int vmci_transport_recv_connected(struct sock *sk,
+					 struct vmci_transport_packet *pkt)
+{
+	struct vsock_sock *vsk;
+	bool pkt_processed = false;
+
+	/* In cases where we are closing the connection, it's sufficient to
+	 * mark the state change (and maybe error) and wake up any waiting
+	 * threads. Since this is a connected socket, it's owned by a user
+	 * process and will be cleaned up when the failure is passed back on
+	 * the current or next system call.  Our system call implementations
+	 * must therefore check for error and state changes on entry and when
+	 * being awoken.
+	 */
+	switch (pkt->type) {
+	case VMCI_TRANSPORT_PACKET_TYPE_SHUTDOWN:
+		if (pkt->u.mode) {
+			vsk = vsock_sk(sk);
+
+			vsk->peer_shutdown |= pkt->u.mode;
+			sk->sk_state_change(sk);
+		}
+		break;
+
+	case VMCI_TRANSPORT_PACKET_TYPE_RST:
+		vsk = vsock_sk(sk);
+		/* It is possible that we sent our peer a message (e.g a
+		 * WAITING_READ) right before we got notified that the peer had
+		 * detached. If that happens then we can get a RST pkt back
+		 * from our peer even though there is data available for us to
+		 * read. In that case, don't shutdown the socket completely but
+		 * instead allow the local client to finish reading data off
+		 * the queuepair. Always treat a RST pkt in connected mode like
+		 * a clean shutdown.
+		 */
+		sock_set_flag(sk, SOCK_DONE);
+		vsk->peer_shutdown = SHUTDOWN_MASK;
+		if (vsock_stream_has_data(vsk) <= 0)
+			sk->sk_state = SS_DISCONNECTING;
+
+		sk->sk_state_change(sk);
+		break;
+
+	default:
+		vsk = vsock_sk(sk);
+		vmci_trans(vsk)->notify_ops->handle_notify_pkt(
+				sk, pkt, false, NULL, NULL,
+				&pkt_processed);
+		if (!pkt_processed)
+			return -EINVAL;
+
+		break;
+	}
+
+	return 0;
+}
+
+static int vmci_transport_socket_init(struct vsock_sock *vsk,
+				      struct vsock_sock *psk)
+{
+	vsk->trans = kmalloc(sizeof(struct vmci_transport), GFP_KERNEL);
+	if (!vsk->trans)
+		return -ENOMEM;
+
+	vmci_trans(vsk)->dg_handle = VMCI_INVALID_HANDLE;
+	vmci_trans(vsk)->qp_handle = VMCI_INVALID_HANDLE;
+	vmci_trans(vsk)->qpair = NULL;
+	vmci_trans(vsk)->produce_size = vmci_trans(vsk)->consume_size = 0;
+	vmci_trans(vsk)->attach_sub_id = vmci_trans(vsk)->detach_sub_id =
+		VMCI_INVALID_ID;
+	vmci_trans(vsk)->notify_ops = NULL;
+	if (psk) {
+		vmci_trans(vsk)->queue_pair_size =
+			vmci_trans(psk)->queue_pair_size;
+		vmci_trans(vsk)->queue_pair_min_size =
+			vmci_trans(psk)->queue_pair_min_size;
+		vmci_trans(vsk)->queue_pair_max_size =
+			vmci_trans(psk)->queue_pair_max_size;
+	} else {
+		vmci_trans(vsk)->queue_pair_size =
+			VMCI_TRANSPORT_DEFAULT_QP_SIZE;
+		vmci_trans(vsk)->queue_pair_min_size =
+			 VMCI_TRANSPORT_DEFAULT_QP_SIZE_MIN;
+		vmci_trans(vsk)->queue_pair_max_size =
+			VMCI_TRANSPORT_DEFAULT_QP_SIZE_MAX;
+	}
+
+	return 0;
+}
+
+static void vmci_transport_destruct(struct vsock_sock *vsk)
+{
+	if (vmci_trans(vsk)->attach_sub_id != VMCI_INVALID_ID) {
+		vmci_event_unsubscribe(vmci_trans(vsk)->attach_sub_id);
+		vmci_trans(vsk)->attach_sub_id = VMCI_INVALID_ID;
+	}
+
+	if (vmci_trans(vsk)->detach_sub_id != VMCI_INVALID_ID) {
+		vmci_event_unsubscribe(vmci_trans(vsk)->detach_sub_id);
+		vmci_trans(vsk)->detach_sub_id = VMCI_INVALID_ID;
+	}
+
+	if (!vmci_handle_is_invalid(vmci_trans(vsk)->qp_handle)) {
+		vmci_qpair_detach(&vmci_trans(vsk)->qpair);
+		vmci_trans(vsk)->qp_handle = VMCI_INVALID_HANDLE;
+		vmci_trans(vsk)->produce_size = 0;
+		vmci_trans(vsk)->consume_size = 0;
+	}
+
+	if (vmci_trans(vsk)->notify_ops)
+		vmci_trans(vsk)->notify_ops->socket_destruct(vsk);
+
+	kfree(vsk->trans);
+	vsk->trans = NULL;
+}
+
+static void vmci_transport_release(struct vsock_sock *vsk)
+{
+	if (!vmci_handle_is_invalid(vmci_trans(vsk)->dg_handle)) {
+		vmci_datagram_destroy_handle(vmci_trans(vsk)->dg_handle);
+		vmci_trans(vsk)->dg_handle = VMCI_INVALID_HANDLE;
+	}
+}
+
+static int vmci_transport_dgram_bind(struct vsock_sock *vsk,
+				     struct sockaddr_vm *addr)
+{
+	u32 port;
+	u32 flags;
+	int err;
+
+	/* VMCI will select a resource ID for us if we provide
+	 * VMCI_INVALID_ID.
+	 */
+	port = addr->svm_port == VMADDR_PORT_ANY ?
+			VMCI_INVALID_ID : addr->svm_port;
+
+	if (port <= LAST_RESERVED_PORT && !capable(CAP_NET_BIND_SERVICE))
+		return -EACCES;
+
+	flags = addr->svm_cid == VMADDR_CID_ANY ?
+				VMCI_FLAG_ANYCID_DG_HND : 0;
+
+	err = vmci_transport_datagram_create_hnd(port, flags,
+						 vmci_transport_recv_dgram_cb,
+						 &vsk->sk,
+						 &vmci_trans(vsk)->dg_handle);
+	if (err < VMCI_SUCCESS)
+		return vmci_transport_error_to_vsock_error(err);
+	vsock_addr_init(&vsk->local_addr, addr->svm_cid,
+			vmci_trans(vsk)->dg_handle.resource);
+
+	return 0;
+}
+
+static int vmci_transport_dgram_enqueue(
+	struct vsock_sock *vsk,
+	struct sockaddr_vm *remote_addr,
+	struct msghdr *msg,
+	size_t len)
+{
+	int err;
+	struct vmci_datagram *dg;
+
+	if (len > VMCI_MAX_DG_PAYLOAD_SIZE)
+		return -EMSGSIZE;
+
+	if (!vmci_transport_allow_dgram(vsk, remote_addr->svm_cid))
+		return -EPERM;
+
+	/* Allocate a buffer for the user's message and our packet header. */
+	dg = kmalloc(len + sizeof(*dg), GFP_KERNEL);
+	if (!dg)
+		return -ENOMEM;
+
+	memcpy_from_msg(VMCI_DG_PAYLOAD(dg), msg, len);
+
+	dg->dst = vmci_make_handle(remote_addr->svm_cid,
+				   remote_addr->svm_port);
+	dg->src = vmci_make_handle(vsk->local_addr.svm_cid,
+				   vsk->local_addr.svm_port);
+	dg->payload_size = len;
+
+	err = vmci_datagram_send(dg);
+	kfree(dg);
+	if (err < 0)
+		return vmci_transport_error_to_vsock_error(err);
+
+	return err - sizeof(*dg);
+}
+
+static int vmci_transport_dgram_dequeue(struct vsock_sock *vsk,
+					struct msghdr *msg, size_t len,
+					int flags)
+{
+	int err;
+	int noblock;
+	struct vmci_datagram *dg;
+	size_t payload_len;
+	struct sk_buff *skb;
+
+	noblock = flags & MSG_DONTWAIT;
+
+	if (flags & MSG_OOB || flags & MSG_ERRQUEUE)
+		return -EOPNOTSUPP;
+
+	/* Retrieve the head sk_buff from the socket's receive queue. */
+	err = 0;
+	skb = skb_recv_datagram(&vsk->sk, flags, noblock, &err);
+	if (err)
+		return err;
+
+	if (!skb)
+		return -EAGAIN;
+
+	dg = (struct vmci_datagram *)skb->data;
+	if (!dg)
+		/* err is 0, meaning we read zero bytes. */
+		goto out;
+
+	payload_len = dg->payload_size;
+	/* Ensure the sk_buff matches the payload size claimed in the packet. */
+	if (payload_len != skb->len - sizeof(*dg)) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	if (payload_len > len) {
+		payload_len = len;
+		msg->msg_flags |= MSG_TRUNC;
+	}
+
+	/* Place the datagram payload in the user's iovec. */
+	err = skb_copy_datagram_msg(skb, sizeof(*dg), msg, payload_len);
+	if (err)
+		goto out;
+
+	if (msg->msg_name) {
+		/* Provide the address of the sender. */
+		DECLARE_SOCKADDR(struct sockaddr_vm *, vm_addr, msg->msg_name);
+		vsock_addr_init(vm_addr, dg->src.context, dg->src.resource);
+		msg->msg_namelen = sizeof(*vm_addr);
+	}
+	err = payload_len;
+
+out:
+	skb_free_datagram(&vsk->sk, skb);
+	return err;
+}
+
+static bool vmci_transport_dgram_allow(u32 cid, u32 port)
+{
+	if (cid == VMADDR_CID_HYPERVISOR) {
+		/* Registrations of PBRPC Servers do not modify VMX/Hypervisor
+		 * state and are allowed.
+		 */
+		return port == VMCI_UNITY_PBRPC_REGISTER;
+	}
+
+	return true;
+}
+
+static int vmci_transport_connect(struct vsock_sock *vsk)
+{
+	int err;
+	bool old_pkt_proto = false;
+	struct sock *sk = &vsk->sk;
+
+	if (vmci_transport_old_proto_override(&old_pkt_proto) &&
+		old_pkt_proto) {
+		err = vmci_transport_send_conn_request(
+			sk, vmci_trans(vsk)->queue_pair_size);
+		if (err < 0) {
+			sk->sk_state = SS_UNCONNECTED;
+			return err;
+		}
+	} else {
+		int supported_proto_versions =
+			vmci_transport_new_proto_supported_versions();
+		err = vmci_transport_send_conn_request2(
+				sk, vmci_trans(vsk)->queue_pair_size,
+				supported_proto_versions);
+		if (err < 0) {
+			sk->sk_state = SS_UNCONNECTED;
+			return err;
+		}
+
+		vsk->sent_request = true;
+	}
+
+	return err;
+}
+
+static ssize_t vmci_transport_stream_dequeue(
+	struct vsock_sock *vsk,
+	struct msghdr *msg,
+	size_t len,
+	int flags)
+{
+	if (flags & MSG_PEEK)
+		return vmci_qpair_peekv(vmci_trans(vsk)->qpair, msg, len, 0);
+	else
+		return vmci_qpair_dequev(vmci_trans(vsk)->qpair, msg, len, 0);
+}
+
+static ssize_t vmci_transport_stream_enqueue(
+	struct vsock_sock *vsk,
+	struct msghdr *msg,
+	size_t len)
+{
+	return vmci_qpair_enquev(vmci_trans(vsk)->qpair, msg, len, 0);
+}
+
+static s64 vmci_transport_stream_has_data(struct vsock_sock *vsk)
+{
+	return vmci_qpair_consume_buf_ready(vmci_trans(vsk)->qpair);
+}
+
+static s64 vmci_transport_stream_has_space(struct vsock_sock *vsk)
+{
+	return vmci_qpair_produce_free_space(vmci_trans(vsk)->qpair);
+}
+
+static u64 vmci_transport_stream_rcvhiwat(struct vsock_sock *vsk)
+{
+	return vmci_trans(vsk)->consume_size;
+}
+
+static bool vmci_transport_stream_is_active(struct vsock_sock *vsk)
+{
+	return !vmci_handle_is_invalid(vmci_trans(vsk)->qp_handle);
+}
+
+static u64 vmci_transport_get_buffer_size(struct vsock_sock *vsk)
+{
+	return vmci_trans(vsk)->queue_pair_size;
+}
+
+static u64 vmci_transport_get_min_buffer_size(struct vsock_sock *vsk)
+{
+	return vmci_trans(vsk)->queue_pair_min_size;
+}
+
+static u64 vmci_transport_get_max_buffer_size(struct vsock_sock *vsk)
+{
+	return vmci_trans(vsk)->queue_pair_max_size;
+}
+
+static void vmci_transport_set_buffer_size(struct vsock_sock *vsk, u64 val)
+{
+	if (val < vmci_trans(vsk)->queue_pair_min_size)
+		vmci_trans(vsk)->queue_pair_min_size = val;
+	if (val > vmci_trans(vsk)->queue_pair_max_size)
+		vmci_trans(vsk)->queue_pair_max_size = val;
+	vmci_trans(vsk)->queue_pair_size = val;
+}
+
+static void vmci_transport_set_min_buffer_size(struct vsock_sock *vsk,
+					       u64 val)
+{
+	if (val > vmci_trans(vsk)->queue_pair_size)
+		vmci_trans(vsk)->queue_pair_size = val;
+	vmci_trans(vsk)->queue_pair_min_size = val;
+}
+
+static void vmci_transport_set_max_buffer_size(struct vsock_sock *vsk,
+					       u64 val)
+{
+	if (val < vmci_trans(vsk)->queue_pair_size)
+		vmci_trans(vsk)->queue_pair_size = val;
+	vmci_trans(vsk)->queue_pair_max_size = val;
+}
+
+static int vmci_transport_notify_poll_in(
+	struct vsock_sock *vsk,
+	size_t target,
+	bool *data_ready_now)
+{
+	return vmci_trans(vsk)->notify_ops->poll_in(
+			&vsk->sk, target, data_ready_now);
+}
+
+static int vmci_transport_notify_poll_out(
+	struct vsock_sock *vsk,
+	size_t target,
+	bool *space_available_now)
+{
+	return vmci_trans(vsk)->notify_ops->poll_out(
+			&vsk->sk, target, space_available_now);
+}
+
+static int vmci_transport_notify_recv_init(
+	struct vsock_sock *vsk,
+	size_t target,
+	struct vsock_transport_recv_notify_data *data)
+{
+	return vmci_trans(vsk)->notify_ops->recv_init(
+			&vsk->sk, target,
+			(struct vmci_transport_recv_notify_data *)data);
+}
+
+static int vmci_transport_notify_recv_pre_block(
+	struct vsock_sock *vsk,
+	size_t target,
+	struct vsock_transport_recv_notify_data *data)
+{
+	return vmci_trans(vsk)->notify_ops->recv_pre_block(
+			&vsk->sk, target,
+			(struct vmci_transport_recv_notify_data *)data);
+}
+
+static int vmci_transport_notify_recv_pre_dequeue(
+	struct vsock_sock *vsk,
+	size_t target,
+	struct vsock_transport_recv_notify_data *data)
+{
+	return vmci_trans(vsk)->notify_ops->recv_pre_dequeue(
+			&vsk->sk, target,
+			(struct vmci_transport_recv_notify_data *)data);
+}
+
+static int vmci_transport_notify_recv_post_dequeue(
+	struct vsock_sock *vsk,
+	size_t target,
+	ssize_t copied,
+	bool data_read,
+	struct vsock_transport_recv_notify_data *data)
+{
+	return vmci_trans(vsk)->notify_ops->recv_post_dequeue(
+			&vsk->sk, target, copied, data_read,
+			(struct vmci_transport_recv_notify_data *)data);
+}
+
+static int vmci_transport_notify_send_init(
+	struct vsock_sock *vsk,
+	struct vsock_transport_send_notify_data *data)
+{
+	return vmci_trans(vsk)->notify_ops->send_init(
+			&vsk->sk,
+			(struct vmci_transport_send_notify_data *)data);
+}
+
+static int vmci_transport_notify_send_pre_block(
+	struct vsock_sock *vsk,
+	struct vsock_transport_send_notify_data *data)
+{
+	return vmci_trans(vsk)->notify_ops->send_pre_block(
+			&vsk->sk,
+			(struct vmci_transport_send_notify_data *)data);
+}
+
+static int vmci_transport_notify_send_pre_enqueue(
+	struct vsock_sock *vsk,
+	struct vsock_transport_send_notify_data *data)
+{
+	return vmci_trans(vsk)->notify_ops->send_pre_enqueue(
+			&vsk->sk,
+			(struct vmci_transport_send_notify_data *)data);
+}
+
+static int vmci_transport_notify_send_post_enqueue(
+	struct vsock_sock *vsk,
+	ssize_t written,
+	struct vsock_transport_send_notify_data *data)
+{
+	return vmci_trans(vsk)->notify_ops->send_post_enqueue(
+			&vsk->sk, written,
+			(struct vmci_transport_send_notify_data *)data);
+}
+
+static bool vmci_transport_old_proto_override(bool *old_pkt_proto)
+{
+	if (PROTOCOL_OVERRIDE != -1) {
+		if (PROTOCOL_OVERRIDE == 0)
+			*old_pkt_proto = true;
+		else
+			*old_pkt_proto = false;
+
+		pr_info("Proto override in use\n");
+		return true;
+	}
+
+	return false;
+}
+
+static bool vmci_transport_proto_to_notify_struct(struct sock *sk,
+						  u16 *proto,
+						  bool old_pkt_proto)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+	if (old_pkt_proto) {
+		if (*proto != VSOCK_PROTO_INVALID) {
+			pr_err("Can't set both an old and new protocol\n");
+			return false;
+		}
+		vmci_trans(vsk)->notify_ops = &vmci_transport_notify_pkt_ops;
+		goto exit;
+	}
+
+	switch (*proto) {
+	case VSOCK_PROTO_PKT_ON_NOTIFY:
+		vmci_trans(vsk)->notify_ops =
+			&vmci_transport_notify_pkt_q_state_ops;
+		break;
+	default:
+		pr_err("Unknown notify protocol version\n");
+		return false;
+	}
+
+exit:
+	vmci_trans(vsk)->notify_ops->socket_init(sk);
+	return true;
+}
+
+static u16 vmci_transport_new_proto_supported_versions(void)
+{
+	if (PROTOCOL_OVERRIDE != -1)
+		return PROTOCOL_OVERRIDE;
+
+	return VSOCK_PROTO_ALL_SUPPORTED;
+}
+
+static u32 vmci_transport_get_local_cid(void)
+{
+	return vmci_get_context_id();
+}
+
+static struct vsock_transport vmci_transport = {
+	.init = vmci_transport_socket_init,
+	.destruct = vmci_transport_destruct,
+	.release = vmci_transport_release,
+	.connect = vmci_transport_connect,
+	.dgram_bind = vmci_transport_dgram_bind,
+	.dgram_dequeue = vmci_transport_dgram_dequeue,
+	.dgram_enqueue = vmci_transport_dgram_enqueue,
+	.dgram_allow = vmci_transport_dgram_allow,
+	.stream_dequeue = vmci_transport_stream_dequeue,
+	.stream_enqueue = vmci_transport_stream_enqueue,
+	.stream_has_data = vmci_transport_stream_has_data,
+	.stream_has_space = vmci_transport_stream_has_space,
+	.stream_rcvhiwat = vmci_transport_stream_rcvhiwat,
+	.stream_is_active = vmci_transport_stream_is_active,
+	.stream_allow = vmci_transport_stream_allow,
+	.notify_poll_in = vmci_transport_notify_poll_in,
+	.notify_poll_out = vmci_transport_notify_poll_out,
+	.notify_recv_init = vmci_transport_notify_recv_init,
+	.notify_recv_pre_block = vmci_transport_notify_recv_pre_block,
+	.notify_recv_pre_dequeue = vmci_transport_notify_recv_pre_dequeue,
+	.notify_recv_post_dequeue = vmci_transport_notify_recv_post_dequeue,
+	.notify_send_init = vmci_transport_notify_send_init,
+	.notify_send_pre_block = vmci_transport_notify_send_pre_block,
+	.notify_send_pre_enqueue = vmci_transport_notify_send_pre_enqueue,
+	.notify_send_post_enqueue = vmci_transport_notify_send_post_enqueue,
+	.shutdown = vmci_transport_shutdown,
+	.set_buffer_size = vmci_transport_set_buffer_size,
+	.set_min_buffer_size = vmci_transport_set_min_buffer_size,
+	.set_max_buffer_size = vmci_transport_set_max_buffer_size,
+	.get_buffer_size = vmci_transport_get_buffer_size,
+	.get_min_buffer_size = vmci_transport_get_min_buffer_size,
+	.get_max_buffer_size = vmci_transport_get_max_buffer_size,
+	.get_local_cid = vmci_transport_get_local_cid,
+};
+
+static int __init vmci_transport_init(void)
+{
+	int err;
+
+	/* Create the datagram handle that we will use to send and receive all
+	 * VSocket control messages for this context.
+	 */
+	err = vmci_transport_datagram_create_hnd(VMCI_TRANSPORT_PACKET_RID,
+						 VMCI_FLAG_ANYCID_DG_HND,
+						 vmci_transport_recv_stream_cb,
+						 NULL,
+						 &vmci_transport_stream_handle);
+	if (err < VMCI_SUCCESS) {
+		pr_err("Unable to create datagram handle. (%d)\n", err);
+		return vmci_transport_error_to_vsock_error(err);
+	}
+
+	err = vmci_event_subscribe(VMCI_EVENT_QP_RESUMED,
+				   vmci_transport_qp_resumed_cb,
+				   NULL, &vmci_transport_qp_resumed_sub_id);
+	if (err < VMCI_SUCCESS) {
+		pr_err("Unable to subscribe to resumed event. (%d)\n", err);
+		err = vmci_transport_error_to_vsock_error(err);
+		vmci_transport_qp_resumed_sub_id = VMCI_INVALID_ID;
+		goto err_destroy_stream_handle;
+	}
+
+	err = vsock_core_init(&vmci_transport);
+	if (err < 0)
+		goto err_unsubscribe;
+
+	return 0;
+
+err_unsubscribe:
+	vmci_event_unsubscribe(vmci_transport_qp_resumed_sub_id);
+err_destroy_stream_handle:
+	vmci_datagram_destroy_handle(vmci_transport_stream_handle);
+	return err;
+}
+module_init(vmci_transport_init);
+
+static void __exit vmci_transport_exit(void)
+{
+	if (!vmci_handle_is_invalid(vmci_transport_stream_handle)) {
+		if (vmci_datagram_destroy_handle(
+			vmci_transport_stream_handle) != VMCI_SUCCESS)
+			pr_err("Couldn't destroy datagram handle\n");
+		vmci_transport_stream_handle = VMCI_INVALID_HANDLE;
+	}
+
+	if (vmci_transport_qp_resumed_sub_id != VMCI_INVALID_ID) {
+		vmci_event_unsubscribe(vmci_transport_qp_resumed_sub_id);
+		vmci_transport_qp_resumed_sub_id = VMCI_INVALID_ID;
+	}
+
+	vsock_core_exit();
+}
+module_exit(vmci_transport_exit);
+
+MODULE_AUTHOR("VMware, Inc.");
+MODULE_DESCRIPTION("VMCI transport for Virtual Sockets");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("vmware_vsock");
+MODULE_ALIAS_NETPROTO(PF_VSOCK);
diff --git a/kernel/net/vmw_vsock/vmci_transport.h b/kernel/net/vmw_vsock/vmci_transport.h
new file mode 100644
index 000000000..ce6c9623d
--- /dev/null
+++ b/kernel/net/vmw_vsock/vmci_transport.h
@@ -0,0 +1,142 @@
+/*
+ * VMware vSockets Driver
+ *
+ * Copyright (C) 2013 VMware, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation version 2 and no later version.
+ *
+ * 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.
+ */
+
+#ifndef _VMCI_TRANSPORT_H_
+#define _VMCI_TRANSPORT_H_
+
+#include <linux/vmw_vmci_defs.h>
+#include <linux/vmw_vmci_api.h>
+
+#include <net/vsock_addr.h>
+#include <net/af_vsock.h>
+
+/* If the packet format changes in a release then this should change too. */
+#define VMCI_TRANSPORT_PACKET_VERSION 1
+
+/* The resource ID on which control packets are sent. */
+#define VMCI_TRANSPORT_PACKET_RID 1
+
+/* The resource ID on which control packets are sent to the hypervisor. */
+#define VMCI_TRANSPORT_HYPERVISOR_PACKET_RID 15
+
+#define VSOCK_PROTO_INVALID        0
+#define VSOCK_PROTO_PKT_ON_NOTIFY (1 << 0)
+#define VSOCK_PROTO_ALL_SUPPORTED (VSOCK_PROTO_PKT_ON_NOTIFY)
+
+#define vmci_trans(_vsk) ((struct vmci_transport *)((_vsk)->trans))
+
+enum vmci_transport_packet_type {
+	VMCI_TRANSPORT_PACKET_TYPE_INVALID = 0,
+	VMCI_TRANSPORT_PACKET_TYPE_REQUEST,
+	VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE,
+	VMCI_TRANSPORT_PACKET_TYPE_OFFER,
+	VMCI_TRANSPORT_PACKET_TYPE_ATTACH,
+	VMCI_TRANSPORT_PACKET_TYPE_WROTE,
+	VMCI_TRANSPORT_PACKET_TYPE_READ,
+	VMCI_TRANSPORT_PACKET_TYPE_RST,
+	VMCI_TRANSPORT_PACKET_TYPE_SHUTDOWN,
+	VMCI_TRANSPORT_PACKET_TYPE_WAITING_WRITE,
+	VMCI_TRANSPORT_PACKET_TYPE_WAITING_READ,
+	VMCI_TRANSPORT_PACKET_TYPE_REQUEST2,
+	VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE2,
+	VMCI_TRANSPORT_PACKET_TYPE_MAX
+};
+
+struct vmci_transport_waiting_info {
+	u64 generation;
+	u64 offset;
+};
+
+/* Control packet type for STREAM sockets.  DGRAMs have no control packets nor
+ * special packet header for data packets, they are just raw VMCI DGRAM
+ * messages.  For STREAMs, control packets are sent over the control channel
+ * while data is written and read directly from queue pairs with no packet
+ * format.
+ */
+struct vmci_transport_packet {
+	struct vmci_datagram dg;
+	u8 version;
+	u8 type;
+	u16 proto;
+	u32 src_port;
+	u32 dst_port;
+	u32 _reserved2;
+	union {
+		u64 size;
+		u64 mode;
+		struct vmci_handle handle;
+		struct vmci_transport_waiting_info wait;
+	} u;
+};
+
+struct vmci_transport_notify_pkt {
+	u64 write_notify_window;
+	u64 write_notify_min_window;
+	bool peer_waiting_read;
+	bool peer_waiting_write;
+	bool peer_waiting_write_detected;
+	bool sent_waiting_read;
+	bool sent_waiting_write;
+	struct vmci_transport_waiting_info peer_waiting_read_info;
+	struct vmci_transport_waiting_info peer_waiting_write_info;
+	u64 produce_q_generation;
+	u64 consume_q_generation;
+};
+
+struct vmci_transport_notify_pkt_q_state {
+	u64 write_notify_window;
+	u64 write_notify_min_window;
+	bool peer_waiting_write;
+	bool peer_waiting_write_detected;
+};
+
+union vmci_transport_notify {
+	struct vmci_transport_notify_pkt pkt;
+	struct vmci_transport_notify_pkt_q_state pkt_q_state;
+};
+
+/* Our transport-specific data. */
+struct vmci_transport {
+	/* For DGRAMs. */
+	struct vmci_handle dg_handle;
+	/* For STREAMs. */
+	struct vmci_handle qp_handle;
+	struct vmci_qp *qpair;
+	u64 produce_size;
+	u64 consume_size;
+	u64 queue_pair_size;
+	u64 queue_pair_min_size;
+	u64 queue_pair_max_size;
+	u32 attach_sub_id;
+	u32 detach_sub_id;
+	union vmci_transport_notify notify;
+	struct vmci_transport_notify_ops *notify_ops;
+};
+
+int vmci_transport_register(void);
+void vmci_transport_unregister(void);
+
+int vmci_transport_send_wrote_bh(struct sockaddr_vm *dst,
+				 struct sockaddr_vm *src);
+int vmci_transport_send_read_bh(struct sockaddr_vm *dst,
+				struct sockaddr_vm *src);
+int vmci_transport_send_wrote(struct sock *sk);
+int vmci_transport_send_read(struct sock *sk);
+int vmci_transport_send_waiting_write(struct sock *sk,
+				      struct vmci_transport_waiting_info *wait);
+int vmci_transport_send_waiting_read(struct sock *sk,
+				     struct vmci_transport_waiting_info *wait);
+
+#endif
diff --git a/kernel/net/vmw_vsock/vmci_transport_notify.c b/kernel/net/vmw_vsock/vmci_transport_notify.c
new file mode 100644
index 000000000..9b7f207f2
--- /dev/null
+++ b/kernel/net/vmw_vsock/vmci_transport_notify.c
@@ -0,0 +1,680 @@
+/*
+ * VMware vSockets Driver
+ *
+ * Copyright (C) 2009-2013 VMware, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation version 2 and no later version.
+ *
+ * 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.
+ */
+
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/stddef.h>
+#include <net/sock.h>
+
+#include "vmci_transport_notify.h"
+
+#define PKT_FIELD(vsk, field_name) (vmci_trans(vsk)->notify.pkt.field_name)
+
+static bool vmci_transport_notify_waiting_write(struct vsock_sock *vsk)
+{
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+	bool retval;
+	u64 notify_limit;
+
+	if (!PKT_FIELD(vsk, peer_waiting_write))
+		return false;
+
+#ifdef VSOCK_OPTIMIZATION_FLOW_CONTROL
+	/* When the sender blocks, we take that as a sign that the sender is
+	 * faster than the receiver. To reduce the transmit rate of the sender,
+	 * we delay the sending of the read notification by decreasing the
+	 * write_notify_window. The notification is delayed until the number of
+	 * bytes used in the queue drops below the write_notify_window.
+	 */
+
+	if (!PKT_FIELD(vsk, peer_waiting_write_detected)) {
+		PKT_FIELD(vsk, peer_waiting_write_detected) = true;
+		if (PKT_FIELD(vsk, write_notify_window) < PAGE_SIZE) {
+			PKT_FIELD(vsk, write_notify_window) =
+			    PKT_FIELD(vsk, write_notify_min_window);
+		} else {
+			PKT_FIELD(vsk, write_notify_window) -= PAGE_SIZE;
+			if (PKT_FIELD(vsk, write_notify_window) <
+			    PKT_FIELD(vsk, write_notify_min_window))
+				PKT_FIELD(vsk, write_notify_window) =
+				    PKT_FIELD(vsk, write_notify_min_window);
+
+		}
+	}
+	notify_limit = vmci_trans(vsk)->consume_size -
+		PKT_FIELD(vsk, write_notify_window);
+#else
+	notify_limit = 0;
+#endif
+
+	/* For now we ignore the wait information and just see if the free
+	 * space exceeds the notify limit.  Note that improving this function
+	 * to be more intelligent will not require a protocol change and will
+	 * retain compatibility between endpoints with mixed versions of this
+	 * function.
+	 *
+	 * The notify_limit is used to delay notifications in the case where
+	 * flow control is enabled. Below the test is expressed in terms of
+	 * free space in the queue: if free_space > ConsumeSize -
+	 * write_notify_window then notify An alternate way of expressing this
+	 * is to rewrite the expression to use the data ready in the receive
+	 * queue: if write_notify_window > bufferReady then notify as
+	 * free_space == ConsumeSize - bufferReady.
+	 */
+	retval = vmci_qpair_consume_free_space(vmci_trans(vsk)->qpair) >
+		notify_limit;
+#ifdef VSOCK_OPTIMIZATION_FLOW_CONTROL
+	if (retval) {
+		/*
+		 * Once we notify the peer, we reset the detected flag so the
+		 * next wait will again cause a decrease in the window size.
+		 */
+
+		PKT_FIELD(vsk, peer_waiting_write_detected) = false;
+	}
+#endif
+	return retval;
+#else
+	return true;
+#endif
+}
+
+static bool vmci_transport_notify_waiting_read(struct vsock_sock *vsk)
+{
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+	if (!PKT_FIELD(vsk, peer_waiting_read))
+		return false;
+
+	/* For now we ignore the wait information and just see if there is any
+	 * data for our peer to read.  Note that improving this function to be
+	 * more intelligent will not require a protocol change and will retain
+	 * compatibility between endpoints with mixed versions of this
+	 * function.
+	 */
+	return vmci_qpair_produce_buf_ready(vmci_trans(vsk)->qpair) > 0;
+#else
+	return true;
+#endif
+}
+
+static void
+vmci_transport_handle_waiting_read(struct sock *sk,
+				   struct vmci_transport_packet *pkt,
+				   bool bottom_half,
+				   struct sockaddr_vm *dst,
+				   struct sockaddr_vm *src)
+{
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+	struct vsock_sock *vsk;
+
+	vsk = vsock_sk(sk);
+
+	PKT_FIELD(vsk, peer_waiting_read) = true;
+	memcpy(&PKT_FIELD(vsk, peer_waiting_read_info), &pkt->u.wait,
+	       sizeof(PKT_FIELD(vsk, peer_waiting_read_info)));
+
+	if (vmci_transport_notify_waiting_read(vsk)) {
+		bool sent;
+
+		if (bottom_half)
+			sent = vmci_transport_send_wrote_bh(dst, src) > 0;
+		else
+			sent = vmci_transport_send_wrote(sk) > 0;
+
+		if (sent)
+			PKT_FIELD(vsk, peer_waiting_read) = false;
+	}
+#endif
+}
+
+static void
+vmci_transport_handle_waiting_write(struct sock *sk,
+				    struct vmci_transport_packet *pkt,
+				    bool bottom_half,
+				    struct sockaddr_vm *dst,
+				    struct sockaddr_vm *src)
+{
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+	struct vsock_sock *vsk;
+
+	vsk = vsock_sk(sk);
+
+	PKT_FIELD(vsk, peer_waiting_write) = true;
+	memcpy(&PKT_FIELD(vsk, peer_waiting_write_info), &pkt->u.wait,
+	       sizeof(PKT_FIELD(vsk, peer_waiting_write_info)));
+
+	if (vmci_transport_notify_waiting_write(vsk)) {
+		bool sent;
+
+		if (bottom_half)
+			sent = vmci_transport_send_read_bh(dst, src) > 0;
+		else
+			sent = vmci_transport_send_read(sk) > 0;
+
+		if (sent)
+			PKT_FIELD(vsk, peer_waiting_write) = false;
+	}
+#endif
+}
+
+static void
+vmci_transport_handle_read(struct sock *sk,
+			   struct vmci_transport_packet *pkt,
+			   bool bottom_half,
+			   struct sockaddr_vm *dst, struct sockaddr_vm *src)
+{
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+	struct vsock_sock *vsk;
+
+	vsk = vsock_sk(sk);
+	PKT_FIELD(vsk, sent_waiting_write) = false;
+#endif
+
+	sk->sk_write_space(sk);
+}
+
+static bool send_waiting_read(struct sock *sk, u64 room_needed)
+{
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+	struct vsock_sock *vsk;
+	struct vmci_transport_waiting_info waiting_info;
+	u64 tail;
+	u64 head;
+	u64 room_left;
+	bool ret;
+
+	vsk = vsock_sk(sk);
+
+	if (PKT_FIELD(vsk, sent_waiting_read))
+		return true;
+
+	if (PKT_FIELD(vsk, write_notify_window) <
+			vmci_trans(vsk)->consume_size)
+		PKT_FIELD(vsk, write_notify_window) =
+		    min(PKT_FIELD(vsk, write_notify_window) + PAGE_SIZE,
+			vmci_trans(vsk)->consume_size);
+
+	vmci_qpair_get_consume_indexes(vmci_trans(vsk)->qpair, &tail, &head);
+	room_left = vmci_trans(vsk)->consume_size - head;
+	if (room_needed >= room_left) {
+		waiting_info.offset = room_needed - room_left;
+		waiting_info.generation =
+		    PKT_FIELD(vsk, consume_q_generation) + 1;
+	} else {
+		waiting_info.offset = head + room_needed;
+		waiting_info.generation = PKT_FIELD(vsk, consume_q_generation);
+	}
+
+	ret = vmci_transport_send_waiting_read(sk, &waiting_info) > 0;
+	if (ret)
+		PKT_FIELD(vsk, sent_waiting_read) = true;
+
+	return ret;
+#else
+	return true;
+#endif
+}
+
+static bool send_waiting_write(struct sock *sk, u64 room_needed)
+{
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+	struct vsock_sock *vsk;
+	struct vmci_transport_waiting_info waiting_info;
+	u64 tail;
+	u64 head;
+	u64 room_left;
+	bool ret;
+
+	vsk = vsock_sk(sk);
+
+	if (PKT_FIELD(vsk, sent_waiting_write))
+		return true;
+
+	vmci_qpair_get_produce_indexes(vmci_trans(vsk)->qpair, &tail, &head);
+	room_left = vmci_trans(vsk)->produce_size - tail;
+	if (room_needed + 1 >= room_left) {
+		/* Wraps around to current generation. */
+		waiting_info.offset = room_needed + 1 - room_left;
+		waiting_info.generation = PKT_FIELD(vsk, produce_q_generation);
+	} else {
+		waiting_info.offset = tail + room_needed + 1;
+		waiting_info.generation =
+		    PKT_FIELD(vsk, produce_q_generation) - 1;
+	}
+
+	ret = vmci_transport_send_waiting_write(sk, &waiting_info) > 0;
+	if (ret)
+		PKT_FIELD(vsk, sent_waiting_write) = true;
+
+	return ret;
+#else
+	return true;
+#endif
+}
+
+static int vmci_transport_send_read_notification(struct sock *sk)
+{
+	struct vsock_sock *vsk;
+	bool sent_read;
+	unsigned int retries;
+	int err;
+
+	vsk = vsock_sk(sk);
+	sent_read = false;
+	retries = 0;
+	err = 0;
+
+	if (vmci_transport_notify_waiting_write(vsk)) {
+		/* Notify the peer that we have read, retrying the send on
+		 * failure up to our maximum value.  XXX For now we just log
+		 * the failure, but later we should schedule a work item to
+		 * handle the resend until it succeeds.  That would require
+		 * keeping track of work items in the vsk and cleaning them up
+		 * upon socket close.
+		 */
+		while (!(vsk->peer_shutdown & RCV_SHUTDOWN) &&
+		       !sent_read &&
+		       retries < VMCI_TRANSPORT_MAX_DGRAM_RESENDS) {
+			err = vmci_transport_send_read(sk);
+			if (err >= 0)
+				sent_read = true;
+
+			retries++;
+		}
+
+		if (retries >= VMCI_TRANSPORT_MAX_DGRAM_RESENDS)
+			pr_err("%p unable to send read notify to peer\n", sk);
+		else
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+			PKT_FIELD(vsk, peer_waiting_write) = false;
+#endif
+
+	}
+	return err;
+}
+
+static void
+vmci_transport_handle_wrote(struct sock *sk,
+			    struct vmci_transport_packet *pkt,
+			    bool bottom_half,
+			    struct sockaddr_vm *dst, struct sockaddr_vm *src)
+{
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+	struct vsock_sock *vsk = vsock_sk(sk);
+	PKT_FIELD(vsk, sent_waiting_read) = false;
+#endif
+	sk->sk_data_ready(sk);
+}
+
+static void vmci_transport_notify_pkt_socket_init(struct sock *sk)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+	PKT_FIELD(vsk, write_notify_window) = PAGE_SIZE;
+	PKT_FIELD(vsk, write_notify_min_window) = PAGE_SIZE;
+	PKT_FIELD(vsk, peer_waiting_read) = false;
+	PKT_FIELD(vsk, peer_waiting_write) = false;
+	PKT_FIELD(vsk, peer_waiting_write_detected) = false;
+	PKT_FIELD(vsk, sent_waiting_read) = false;
+	PKT_FIELD(vsk, sent_waiting_write) = false;
+	PKT_FIELD(vsk, produce_q_generation) = 0;
+	PKT_FIELD(vsk, consume_q_generation) = 0;
+
+	memset(&PKT_FIELD(vsk, peer_waiting_read_info), 0,
+	       sizeof(PKT_FIELD(vsk, peer_waiting_read_info)));
+	memset(&PKT_FIELD(vsk, peer_waiting_write_info), 0,
+	       sizeof(PKT_FIELD(vsk, peer_waiting_write_info)));
+}
+
+static void vmci_transport_notify_pkt_socket_destruct(struct vsock_sock *vsk)
+{
+}
+
+static int
+vmci_transport_notify_pkt_poll_in(struct sock *sk,
+				  size_t target, bool *data_ready_now)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+	if (vsock_stream_has_data(vsk)) {
+		*data_ready_now = true;
+	} else {
+		/* We can't read right now because there is nothing in the
+		 * queue. Ask for notifications when there is something to
+		 * read.
+		 */
+		if (sk->sk_state == SS_CONNECTED) {
+			if (!send_waiting_read(sk, 1))
+				return -1;
+
+		}
+		*data_ready_now = false;
+	}
+
+	return 0;
+}
+
+static int
+vmci_transport_notify_pkt_poll_out(struct sock *sk,
+				   size_t target, bool *space_avail_now)
+{
+	s64 produce_q_free_space;
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+	produce_q_free_space = vsock_stream_has_space(vsk);
+	if (produce_q_free_space > 0) {
+		*space_avail_now = true;
+		return 0;
+	} else if (produce_q_free_space == 0) {
+		/* This is a connected socket but we can't currently send data.
+		 * Notify the peer that we are waiting if the queue is full. We
+		 * only send a waiting write if the queue is full because
+		 * otherwise we end up in an infinite WAITING_WRITE, READ,
+		 * WAITING_WRITE, READ, etc. loop. Treat failing to send the
+		 * notification as a socket error, passing that back through
+		 * the mask.
+		 */
+		if (!send_waiting_write(sk, 1))
+			return -1;
+
+		*space_avail_now = false;
+	}
+
+	return 0;
+}
+
+static int
+vmci_transport_notify_pkt_recv_init(
+			struct sock *sk,
+			size_t target,
+			struct vmci_transport_recv_notify_data *data)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+#ifdef VSOCK_OPTIMIZATION_WAITING_NOTIFY
+	data->consume_head = 0;
+	data->produce_tail = 0;
+#ifdef VSOCK_OPTIMIZATION_FLOW_CONTROL
+	data->notify_on_block = false;
+
+	if (PKT_FIELD(vsk, write_notify_min_window) < target + 1) {
+		PKT_FIELD(vsk, write_notify_min_window) = target + 1;
+		if (PKT_FIELD(vsk, write_notify_window) <
+		    PKT_FIELD(vsk, write_notify_min_window)) {
+			/* If the current window is smaller than the new
+			 * minimal window size, we need to reevaluate whether
+			 * we need to notify the sender. If the number of ready
+			 * bytes are smaller than the new window, we need to
+			 * send a notification to the sender before we block.
+			 */
+
+			PKT_FIELD(vsk, write_notify_window) =
+			    PKT_FIELD(vsk, write_notify_min_window);
+			data->notify_on_block = true;
+		}
+	}
+#endif
+#endif
+
+	return 0;
+}
+
+static int
+vmci_transport_notify_pkt_recv_pre_block(
+				struct sock *sk,
+				size_t target,
+				struct vmci_transport_recv_notify_data *data)
+{
+	int err = 0;
+
+	/* Notify our peer that we are waiting for data to read. */
+	if (!send_waiting_read(sk, target)) {
+		err = -EHOSTUNREACH;
+		return err;
+	}
+#ifdef VSOCK_OPTIMIZATION_FLOW_CONTROL
+	if (data->notify_on_block) {
+		err = vmci_transport_send_read_notification(sk);
+		if (err < 0)
+			return err;
+
+		data->notify_on_block = false;
+	}
+#endif
+
+	return err;
+}
+
+static int
+vmci_transport_notify_pkt_recv_pre_dequeue(
+				struct sock *sk,
+				size_t target,
+				struct vmci_transport_recv_notify_data *data)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+	/* Now consume up to len bytes from the queue.  Note that since we have
+	 * the socket locked we should copy at least ready bytes.
+	 */
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+	vmci_qpair_get_consume_indexes(vmci_trans(vsk)->qpair,
+				       &data->produce_tail,
+				       &data->consume_head);
+#endif
+
+	return 0;
+}
+
+static int
+vmci_transport_notify_pkt_recv_post_dequeue(
+				struct sock *sk,
+				size_t target,
+				ssize_t copied,
+				bool data_read,
+				struct vmci_transport_recv_notify_data *data)
+{
+	struct vsock_sock *vsk;
+	int err;
+
+	vsk = vsock_sk(sk);
+	err = 0;
+
+	if (data_read) {
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+		/* Detect a wrap-around to maintain queue generation.  Note
+		 * that this is safe since we hold the socket lock across the
+		 * two queue pair operations.
+		 */
+		if (copied >=
+			vmci_trans(vsk)->consume_size - data->consume_head)
+			PKT_FIELD(vsk, consume_q_generation)++;
+#endif
+
+		err = vmci_transport_send_read_notification(sk);
+		if (err < 0)
+			return err;
+
+	}
+	return err;
+}
+
+static int
+vmci_transport_notify_pkt_send_init(
+			struct sock *sk,
+			struct vmci_transport_send_notify_data *data)
+{
+#ifdef VSOCK_OPTIMIZATION_WAITING_NOTIFY
+	data->consume_head = 0;
+	data->produce_tail = 0;
+#endif
+
+	return 0;
+}
+
+static int
+vmci_transport_notify_pkt_send_pre_block(
+				struct sock *sk,
+				struct vmci_transport_send_notify_data *data)
+{
+	/* Notify our peer that we are waiting for room to write. */
+	if (!send_waiting_write(sk, 1))
+		return -EHOSTUNREACH;
+
+	return 0;
+}
+
+static int
+vmci_transport_notify_pkt_send_pre_enqueue(
+				struct sock *sk,
+				struct vmci_transport_send_notify_data *data)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+	vmci_qpair_get_produce_indexes(vmci_trans(vsk)->qpair,
+				       &data->produce_tail,
+				       &data->consume_head);
+#endif
+
+	return 0;
+}
+
+static int
+vmci_transport_notify_pkt_send_post_enqueue(
+				struct sock *sk,
+				ssize_t written,
+				struct vmci_transport_send_notify_data *data)
+{
+	int err = 0;
+	struct vsock_sock *vsk;
+	bool sent_wrote = false;
+	int retries = 0;
+
+	vsk = vsock_sk(sk);
+
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+	/* Detect a wrap-around to maintain queue generation.  Note that this
+	 * is safe since we hold the socket lock across the two queue pair
+	 * operations.
+	 */
+	if (written >= vmci_trans(vsk)->produce_size - data->produce_tail)
+		PKT_FIELD(vsk, produce_q_generation)++;
+
+#endif
+
+	if (vmci_transport_notify_waiting_read(vsk)) {
+		/* Notify the peer that we have written, retrying the send on
+		 * failure up to our maximum value. See the XXX comment for the
+		 * corresponding piece of code in StreamRecvmsg() for potential
+		 * improvements.
+		 */
+		while (!(vsk->peer_shutdown & RCV_SHUTDOWN) &&
+		       !sent_wrote &&
+		       retries < VMCI_TRANSPORT_MAX_DGRAM_RESENDS) {
+			err = vmci_transport_send_wrote(sk);
+			if (err >= 0)
+				sent_wrote = true;
+
+			retries++;
+		}
+
+		if (retries >= VMCI_TRANSPORT_MAX_DGRAM_RESENDS) {
+			pr_err("%p unable to send wrote notify to peer\n", sk);
+			return err;
+		} else {
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+			PKT_FIELD(vsk, peer_waiting_read) = false;
+#endif
+		}
+	}
+	return err;
+}
+
+static void
+vmci_transport_notify_pkt_handle_pkt(
+			struct sock *sk,
+			struct vmci_transport_packet *pkt,
+			bool bottom_half,
+			struct sockaddr_vm *dst,
+			struct sockaddr_vm *src, bool *pkt_processed)
+{
+	bool processed = false;
+
+	switch (pkt->type) {
+	case VMCI_TRANSPORT_PACKET_TYPE_WROTE:
+		vmci_transport_handle_wrote(sk, pkt, bottom_half, dst, src);
+		processed = true;
+		break;
+	case VMCI_TRANSPORT_PACKET_TYPE_READ:
+		vmci_transport_handle_read(sk, pkt, bottom_half, dst, src);
+		processed = true;
+		break;
+	case VMCI_TRANSPORT_PACKET_TYPE_WAITING_WRITE:
+		vmci_transport_handle_waiting_write(sk, pkt, bottom_half,
+						    dst, src);
+		processed = true;
+		break;
+
+	case VMCI_TRANSPORT_PACKET_TYPE_WAITING_READ:
+		vmci_transport_handle_waiting_read(sk, pkt, bottom_half,
+						   dst, src);
+		processed = true;
+		break;
+	}
+
+	if (pkt_processed)
+		*pkt_processed = processed;
+}
+
+static void vmci_transport_notify_pkt_process_request(struct sock *sk)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+	PKT_FIELD(vsk, write_notify_window) = vmci_trans(vsk)->consume_size;
+	if (vmci_trans(vsk)->consume_size <
+		PKT_FIELD(vsk, write_notify_min_window))
+		PKT_FIELD(vsk, write_notify_min_window) =
+			vmci_trans(vsk)->consume_size;
+}
+
+static void vmci_transport_notify_pkt_process_negotiate(struct sock *sk)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+	PKT_FIELD(vsk, write_notify_window) = vmci_trans(vsk)->consume_size;
+	if (vmci_trans(vsk)->consume_size <
+		PKT_FIELD(vsk, write_notify_min_window))
+		PKT_FIELD(vsk, write_notify_min_window) =
+			vmci_trans(vsk)->consume_size;
+}
+
+/* Socket control packet based operations. */
+struct vmci_transport_notify_ops vmci_transport_notify_pkt_ops = {
+	vmci_transport_notify_pkt_socket_init,
+	vmci_transport_notify_pkt_socket_destruct,
+	vmci_transport_notify_pkt_poll_in,
+	vmci_transport_notify_pkt_poll_out,
+	vmci_transport_notify_pkt_handle_pkt,
+	vmci_transport_notify_pkt_recv_init,
+	vmci_transport_notify_pkt_recv_pre_block,
+	vmci_transport_notify_pkt_recv_pre_dequeue,
+	vmci_transport_notify_pkt_recv_post_dequeue,
+	vmci_transport_notify_pkt_send_init,
+	vmci_transport_notify_pkt_send_pre_block,
+	vmci_transport_notify_pkt_send_pre_enqueue,
+	vmci_transport_notify_pkt_send_post_enqueue,
+	vmci_transport_notify_pkt_process_request,
+	vmci_transport_notify_pkt_process_negotiate,
+};
diff --git a/kernel/net/vmw_vsock/vmci_transport_notify.h b/kernel/net/vmw_vsock/vmci_transport_notify.h
new file mode 100644
index 000000000..7df793249
--- /dev/null
+++ b/kernel/net/vmw_vsock/vmci_transport_notify.h
@@ -0,0 +1,83 @@
+/*
+ * VMware vSockets Driver
+ *
+ * Copyright (C) 2009-2013 VMware, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation version 2 and no later version.
+ *
+ * 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.
+ */
+
+#ifndef __VMCI_TRANSPORT_NOTIFY_H__
+#define __VMCI_TRANSPORT_NOTIFY_H__
+
+#include <linux/types.h>
+#include <linux/vmw_vmci_defs.h>
+#include <linux/vmw_vmci_api.h>
+#include <linux/vm_sockets.h>
+
+#include "vmci_transport.h"
+
+/* Comment this out to compare with old protocol. */
+#define VSOCK_OPTIMIZATION_WAITING_NOTIFY 1
+#if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
+/* Comment this out to remove flow control for "new" protocol */
+#define VSOCK_OPTIMIZATION_FLOW_CONTROL 1
+#endif
+
+#define VMCI_TRANSPORT_MAX_DGRAM_RESENDS       10
+
+struct vmci_transport_recv_notify_data {
+	u64 consume_head;
+	u64 produce_tail;
+	bool notify_on_block;
+};
+
+struct vmci_transport_send_notify_data {
+	u64 consume_head;
+	u64 produce_tail;
+};
+
+/* Socket notification callbacks. */
+struct vmci_transport_notify_ops {
+	void (*socket_init) (struct sock *sk);
+	void (*socket_destruct) (struct vsock_sock *vsk);
+	int (*poll_in) (struct sock *sk, size_t target,
+			  bool *data_ready_now);
+	int (*poll_out) (struct sock *sk, size_t target,
+			   bool *space_avail_now);
+	void (*handle_notify_pkt) (struct sock *sk,
+				   struct vmci_transport_packet *pkt,
+				   bool bottom_half, struct sockaddr_vm *dst,
+				   struct sockaddr_vm *src,
+				   bool *pkt_processed);
+	int (*recv_init) (struct sock *sk, size_t target,
+			  struct vmci_transport_recv_notify_data *data);
+	int (*recv_pre_block) (struct sock *sk, size_t target,
+			       struct vmci_transport_recv_notify_data *data);
+	int (*recv_pre_dequeue) (struct sock *sk, size_t target,
+				 struct vmci_transport_recv_notify_data *data);
+	int (*recv_post_dequeue) (struct sock *sk, size_t target,
+				  ssize_t copied, bool data_read,
+				  struct vmci_transport_recv_notify_data *data);
+	int (*send_init) (struct sock *sk,
+			  struct vmci_transport_send_notify_data *data);
+	int (*send_pre_block) (struct sock *sk,
+			       struct vmci_transport_send_notify_data *data);
+	int (*send_pre_enqueue) (struct sock *sk,
+				 struct vmci_transport_send_notify_data *data);
+	int (*send_post_enqueue) (struct sock *sk, ssize_t written,
+				  struct vmci_transport_send_notify_data *data);
+	void (*process_request) (struct sock *sk);
+	void (*process_negotiate) (struct sock *sk);
+};
+
+extern struct vmci_transport_notify_ops vmci_transport_notify_pkt_ops;
+extern struct vmci_transport_notify_ops vmci_transport_notify_pkt_q_state_ops;
+
+#endif /* __VMCI_TRANSPORT_NOTIFY_H__ */
diff --git a/kernel/net/vmw_vsock/vmci_transport_notify_qstate.c b/kernel/net/vmw_vsock/vmci_transport_notify_qstate.c
new file mode 100644
index 000000000..dc9c7929a
--- /dev/null
+++ b/kernel/net/vmw_vsock/vmci_transport_notify_qstate.c
@@ -0,0 +1,438 @@
+/*
+ * VMware vSockets Driver
+ *
+ * Copyright (C) 2009-2013 VMware, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation version 2 and no later version.
+ *
+ * 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.
+ */
+
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/stddef.h>
+#include <net/sock.h>
+
+#include "vmci_transport_notify.h"
+
+#define PKT_FIELD(vsk, field_name) \
+	(vmci_trans(vsk)->notify.pkt_q_state.field_name)
+
+static bool vmci_transport_notify_waiting_write(struct vsock_sock *vsk)
+{
+	bool retval;
+	u64 notify_limit;
+
+	if (!PKT_FIELD(vsk, peer_waiting_write))
+		return false;
+
+	/* When the sender blocks, we take that as a sign that the sender is
+	 * faster than the receiver. To reduce the transmit rate of the sender,
+	 * we delay the sending of the read notification by decreasing the
+	 * write_notify_window. The notification is delayed until the number of
+	 * bytes used in the queue drops below the write_notify_window.
+	 */
+
+	if (!PKT_FIELD(vsk, peer_waiting_write_detected)) {
+		PKT_FIELD(vsk, peer_waiting_write_detected) = true;
+		if (PKT_FIELD(vsk, write_notify_window) < PAGE_SIZE) {
+			PKT_FIELD(vsk, write_notify_window) =
+			    PKT_FIELD(vsk, write_notify_min_window);
+		} else {
+			PKT_FIELD(vsk, write_notify_window) -= PAGE_SIZE;
+			if (PKT_FIELD(vsk, write_notify_window) <
+			    PKT_FIELD(vsk, write_notify_min_window))
+				PKT_FIELD(vsk, write_notify_window) =
+				    PKT_FIELD(vsk, write_notify_min_window);
+
+		}
+	}
+	notify_limit = vmci_trans(vsk)->consume_size -
+		PKT_FIELD(vsk, write_notify_window);
+
+	/* The notify_limit is used to delay notifications in the case where
+	 * flow control is enabled. Below the test is expressed in terms of
+	 * free space in the queue: if free_space > ConsumeSize -
+	 * write_notify_window then notify An alternate way of expressing this
+	 * is to rewrite the expression to use the data ready in the receive
+	 * queue: if write_notify_window > bufferReady then notify as
+	 * free_space == ConsumeSize - bufferReady.
+	 */
+
+	retval = vmci_qpair_consume_free_space(vmci_trans(vsk)->qpair) >
+		notify_limit;
+
+	if (retval) {
+		/* Once we notify the peer, we reset the detected flag so the
+		 * next wait will again cause a decrease in the window size.
+		 */
+
+		PKT_FIELD(vsk, peer_waiting_write_detected) = false;
+	}
+	return retval;
+}
+
+static void
+vmci_transport_handle_read(struct sock *sk,
+			   struct vmci_transport_packet *pkt,
+			   bool bottom_half,
+			   struct sockaddr_vm *dst, struct sockaddr_vm *src)
+{
+	sk->sk_write_space(sk);
+}
+
+static void
+vmci_transport_handle_wrote(struct sock *sk,
+			    struct vmci_transport_packet *pkt,
+			    bool bottom_half,
+			    struct sockaddr_vm *dst, struct sockaddr_vm *src)
+{
+	sk->sk_data_ready(sk);
+}
+
+static void vsock_block_update_write_window(struct sock *sk)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+	if (PKT_FIELD(vsk, write_notify_window) < vmci_trans(vsk)->consume_size)
+		PKT_FIELD(vsk, write_notify_window) =
+		    min(PKT_FIELD(vsk, write_notify_window) + PAGE_SIZE,
+			vmci_trans(vsk)->consume_size);
+}
+
+static int vmci_transport_send_read_notification(struct sock *sk)
+{
+	struct vsock_sock *vsk;
+	bool sent_read;
+	unsigned int retries;
+	int err;
+
+	vsk = vsock_sk(sk);
+	sent_read = false;
+	retries = 0;
+	err = 0;
+
+	if (vmci_transport_notify_waiting_write(vsk)) {
+		/* Notify the peer that we have read, retrying the send on
+		 * failure up to our maximum value.  XXX For now we just log
+		 * the failure, but later we should schedule a work item to
+		 * handle the resend until it succeeds.  That would require
+		 * keeping track of work items in the vsk and cleaning them up
+		 * upon socket close.
+		 */
+		while (!(vsk->peer_shutdown & RCV_SHUTDOWN) &&
+		       !sent_read &&
+		       retries < VMCI_TRANSPORT_MAX_DGRAM_RESENDS) {
+			err = vmci_transport_send_read(sk);
+			if (err >= 0)
+				sent_read = true;
+
+			retries++;
+		}
+
+		if (retries >= VMCI_TRANSPORT_MAX_DGRAM_RESENDS && !sent_read)
+			pr_err("%p unable to send read notification to peer\n",
+			       sk);
+		else
+			PKT_FIELD(vsk, peer_waiting_write) = false;
+
+	}
+	return err;
+}
+
+static void vmci_transport_notify_pkt_socket_init(struct sock *sk)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+	PKT_FIELD(vsk, write_notify_window) = PAGE_SIZE;
+	PKT_FIELD(vsk, write_notify_min_window) = PAGE_SIZE;
+	PKT_FIELD(vsk, peer_waiting_write) = false;
+	PKT_FIELD(vsk, peer_waiting_write_detected) = false;
+}
+
+static void vmci_transport_notify_pkt_socket_destruct(struct vsock_sock *vsk)
+{
+	PKT_FIELD(vsk, write_notify_window) = PAGE_SIZE;
+	PKT_FIELD(vsk, write_notify_min_window) = PAGE_SIZE;
+	PKT_FIELD(vsk, peer_waiting_write) = false;
+	PKT_FIELD(vsk, peer_waiting_write_detected) = false;
+}
+
+static int
+vmci_transport_notify_pkt_poll_in(struct sock *sk,
+				  size_t target, bool *data_ready_now)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+	if (vsock_stream_has_data(vsk)) {
+		*data_ready_now = true;
+	} else {
+		/* We can't read right now because there is nothing in the
+		 * queue. Ask for notifications when there is something to
+		 * read.
+		 */
+		if (sk->sk_state == SS_CONNECTED)
+			vsock_block_update_write_window(sk);
+		*data_ready_now = false;
+	}
+
+	return 0;
+}
+
+static int
+vmci_transport_notify_pkt_poll_out(struct sock *sk,
+				   size_t target, bool *space_avail_now)
+{
+	s64 produce_q_free_space;
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+	produce_q_free_space = vsock_stream_has_space(vsk);
+	if (produce_q_free_space > 0) {
+		*space_avail_now = true;
+		return 0;
+	} else if (produce_q_free_space == 0) {
+		/* This is a connected socket but we can't currently send data.
+		 * Nothing else to do.
+		 */
+		*space_avail_now = false;
+	}
+
+	return 0;
+}
+
+static int
+vmci_transport_notify_pkt_recv_init(
+				struct sock *sk,
+				size_t target,
+				struct vmci_transport_recv_notify_data *data)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+	data->consume_head = 0;
+	data->produce_tail = 0;
+	data->notify_on_block = false;
+
+	if (PKT_FIELD(vsk, write_notify_min_window) < target + 1) {
+		PKT_FIELD(vsk, write_notify_min_window) = target + 1;
+		if (PKT_FIELD(vsk, write_notify_window) <
+		    PKT_FIELD(vsk, write_notify_min_window)) {
+			/* If the current window is smaller than the new
+			 * minimal window size, we need to reevaluate whether
+			 * we need to notify the sender. If the number of ready
+			 * bytes are smaller than the new window, we need to
+			 * send a notification to the sender before we block.
+			 */
+
+			PKT_FIELD(vsk, write_notify_window) =
+			    PKT_FIELD(vsk, write_notify_min_window);
+			data->notify_on_block = true;
+		}
+	}
+
+	return 0;
+}
+
+static int
+vmci_transport_notify_pkt_recv_pre_block(
+				struct sock *sk,
+				size_t target,
+				struct vmci_transport_recv_notify_data *data)
+{
+	int err = 0;
+
+	vsock_block_update_write_window(sk);
+
+	if (data->notify_on_block) {
+		err = vmci_transport_send_read_notification(sk);
+		if (err < 0)
+			return err;
+		data->notify_on_block = false;
+	}
+
+	return err;
+}
+
+static int
+vmci_transport_notify_pkt_recv_post_dequeue(
+				struct sock *sk,
+				size_t target,
+				ssize_t copied,
+				bool data_read,
+				struct vmci_transport_recv_notify_data *data)
+{
+	struct vsock_sock *vsk;
+	int err;
+	bool was_full = false;
+	u64 free_space;
+
+	vsk = vsock_sk(sk);
+	err = 0;
+
+	if (data_read) {
+		smp_mb();
+
+		free_space =
+			vmci_qpair_consume_free_space(vmci_trans(vsk)->qpair);
+		was_full = free_space == copied;
+
+		if (was_full)
+			PKT_FIELD(vsk, peer_waiting_write) = true;
+
+		err = vmci_transport_send_read_notification(sk);
+		if (err < 0)
+			return err;
+
+		/* See the comment in
+		 * vmci_transport_notify_pkt_send_post_enqueue().
+		 */
+		sk->sk_data_ready(sk);
+	}
+
+	return err;
+}
+
+static int
+vmci_transport_notify_pkt_send_init(
+				struct sock *sk,
+				struct vmci_transport_send_notify_data *data)
+{
+	data->consume_head = 0;
+	data->produce_tail = 0;
+
+	return 0;
+}
+
+static int
+vmci_transport_notify_pkt_send_post_enqueue(
+				struct sock *sk,
+				ssize_t written,
+				struct vmci_transport_send_notify_data *data)
+{
+	int err = 0;
+	struct vsock_sock *vsk;
+	bool sent_wrote = false;
+	bool was_empty;
+	int retries = 0;
+
+	vsk = vsock_sk(sk);
+
+	smp_mb();
+
+	was_empty =
+		vmci_qpair_produce_buf_ready(vmci_trans(vsk)->qpair) == written;
+	if (was_empty) {
+		while (!(vsk->peer_shutdown & RCV_SHUTDOWN) &&
+		       !sent_wrote &&
+		       retries < VMCI_TRANSPORT_MAX_DGRAM_RESENDS) {
+			err = vmci_transport_send_wrote(sk);
+			if (err >= 0)
+				sent_wrote = true;
+
+			retries++;
+		}
+	}
+
+	if (retries >= VMCI_TRANSPORT_MAX_DGRAM_RESENDS && !sent_wrote) {
+		pr_err("%p unable to send wrote notification to peer\n",
+		       sk);
+		return err;
+	}
+
+	return err;
+}
+
+static void
+vmci_transport_notify_pkt_handle_pkt(
+				struct sock *sk,
+				struct vmci_transport_packet *pkt,
+				bool bottom_half,
+				struct sockaddr_vm *dst,
+				struct sockaddr_vm *src, bool *pkt_processed)
+{
+	bool processed = false;
+
+	switch (pkt->type) {
+	case VMCI_TRANSPORT_PACKET_TYPE_WROTE:
+		vmci_transport_handle_wrote(sk, pkt, bottom_half, dst, src);
+		processed = true;
+		break;
+	case VMCI_TRANSPORT_PACKET_TYPE_READ:
+		vmci_transport_handle_read(sk, pkt, bottom_half, dst, src);
+		processed = true;
+		break;
+	}
+
+	if (pkt_processed)
+		*pkt_processed = processed;
+}
+
+static void vmci_transport_notify_pkt_process_request(struct sock *sk)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+	PKT_FIELD(vsk, write_notify_window) = vmci_trans(vsk)->consume_size;
+	if (vmci_trans(vsk)->consume_size <
+		PKT_FIELD(vsk, write_notify_min_window))
+		PKT_FIELD(vsk, write_notify_min_window) =
+			vmci_trans(vsk)->consume_size;
+}
+
+static void vmci_transport_notify_pkt_process_negotiate(struct sock *sk)
+{
+	struct vsock_sock *vsk = vsock_sk(sk);
+
+	PKT_FIELD(vsk, write_notify_window) = vmci_trans(vsk)->consume_size;
+	if (vmci_trans(vsk)->consume_size <
+		PKT_FIELD(vsk, write_notify_min_window))
+		PKT_FIELD(vsk, write_notify_min_window) =
+			vmci_trans(vsk)->consume_size;
+}
+
+static int
+vmci_transport_notify_pkt_recv_pre_dequeue(
+				struct sock *sk,
+				size_t target,
+				struct vmci_transport_recv_notify_data *data)
+{
+	return 0; /* NOP for QState. */
+}
+
+static int
+vmci_transport_notify_pkt_send_pre_block(
+				struct sock *sk,
+				struct vmci_transport_send_notify_data *data)
+{
+	return 0; /* NOP for QState. */
+}
+
+static int
+vmci_transport_notify_pkt_send_pre_enqueue(
+				struct sock *sk,
+				struct vmci_transport_send_notify_data *data)
+{
+	return 0; /* NOP for QState. */
+}
+
+/* Socket always on control packet based operations. */
+struct vmci_transport_notify_ops vmci_transport_notify_pkt_q_state_ops = {
+	vmci_transport_notify_pkt_socket_init,
+	vmci_transport_notify_pkt_socket_destruct,
+	vmci_transport_notify_pkt_poll_in,
+	vmci_transport_notify_pkt_poll_out,
+	vmci_transport_notify_pkt_handle_pkt,
+	vmci_transport_notify_pkt_recv_init,
+	vmci_transport_notify_pkt_recv_pre_block,
+	vmci_transport_notify_pkt_recv_pre_dequeue,
+	vmci_transport_notify_pkt_recv_post_dequeue,
+	vmci_transport_notify_pkt_send_init,
+	vmci_transport_notify_pkt_send_pre_block,
+	vmci_transport_notify_pkt_send_pre_enqueue,
+	vmci_transport_notify_pkt_send_post_enqueue,
+	vmci_transport_notify_pkt_process_request,
+	vmci_transport_notify_pkt_process_negotiate,
+};
diff --git a/kernel/net/vmw_vsock/vsock_addr.c b/kernel/net/vmw_vsock/vsock_addr.c
new file mode 100644
index 000000000..82486ee55
--- /dev/null
+++ b/kernel/net/vmw_vsock/vsock_addr.c
@@ -0,0 +1,75 @@
+/*
+ * VMware vSockets Driver
+ *
+ * Copyright (C) 2007-2012 VMware, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation version 2 and no later version.
+ *
+ * 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.
+ */
+
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/stddef.h>
+#include <net/sock.h>
+#include <net/vsock_addr.h>
+
+void vsock_addr_init(struct sockaddr_vm *addr, u32 cid, u32 port)
+{
+	memset(addr, 0, sizeof(*addr));
+	addr->svm_family = AF_VSOCK;
+	addr->svm_cid = cid;
+	addr->svm_port = port;
+}
+EXPORT_SYMBOL_GPL(vsock_addr_init);
+
+int vsock_addr_validate(const struct sockaddr_vm *addr)
+{
+	if (!addr)
+		return -EFAULT;
+
+	if (addr->svm_family != AF_VSOCK)
+		return -EAFNOSUPPORT;
+
+	if (addr->svm_zero[0] != 0)
+		return -EINVAL;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vsock_addr_validate);
+
+bool vsock_addr_bound(const struct sockaddr_vm *addr)
+{
+	return addr->svm_port != VMADDR_PORT_ANY;
+}
+EXPORT_SYMBOL_GPL(vsock_addr_bound);
+
+void vsock_addr_unbind(struct sockaddr_vm *addr)
+{
+	vsock_addr_init(addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
+}
+EXPORT_SYMBOL_GPL(vsock_addr_unbind);
+
+bool vsock_addr_equals_addr(const struct sockaddr_vm *addr,
+			    const struct sockaddr_vm *other)
+{
+	return addr->svm_cid == other->svm_cid &&
+		addr->svm_port == other->svm_port;
+}
+EXPORT_SYMBOL_GPL(vsock_addr_equals_addr);
+
+int vsock_addr_cast(const struct sockaddr *addr,
+		    size_t len, struct sockaddr_vm **out_addr)
+{
+	if (len < sizeof(**out_addr))
+		return -EFAULT;
+
+	*out_addr = (struct sockaddr_vm *)addr;
+	return vsock_addr_validate(*out_addr);
+}
+EXPORT_SYMBOL_GPL(vsock_addr_cast);