[dpdk-dev,1/2] lib/librte_vhost: vhost library support to facilitate integration with vswitch.
diff mbox

Message ID 1405661946-12534-2-git-send-email-huawei.xie@intel.com
State Superseded, archived
Headers show

Commit Message

Huawei Xie July 18, 2014, 5:39 a.m. UTC
Signed-off-by: Huawei Xie <huawei.xie@intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Acked-by: Thomos Long <thomas.long@intel.com>
---
 config/common_linuxapp                       |    6 +
 lib/Makefile                                 |    1 +
 lib/librte_vhost/Makefile                    |   48 ++
 lib/librte_vhost/eventfd_link/Makefile       |   39 +
 lib/librte_vhost/eventfd_link/eventfd_link.c |  205 ++++++
 lib/librte_vhost/eventfd_link/eventfd_link.h |   79 ++
 lib/librte_vhost/rte_virtio_net.h            |  192 +++++
 lib/librte_vhost/vhost-net-cdev.c            |  363 ++++++++++
 lib/librte_vhost/vhost-net-cdev.h            |  112 +++
 lib/librte_vhost/vhost_rxtx.c                |  292 ++++++++
 lib/librte_vhost/virtio-net.c                | 1002 ++++++++++++++++++++++++++
 11 files changed, 2339 insertions(+)
 create mode 100644 lib/librte_vhost/Makefile
 create mode 100644 lib/librte_vhost/eventfd_link/Makefile
 create mode 100644 lib/librte_vhost/eventfd_link/eventfd_link.c
 create mode 100644 lib/librte_vhost/eventfd_link/eventfd_link.h
 create mode 100644 lib/librte_vhost/rte_virtio_net.h
 create mode 100644 lib/librte_vhost/vhost-net-cdev.c
 create mode 100644 lib/librte_vhost/vhost-net-cdev.h
 create mode 100644 lib/librte_vhost/vhost_rxtx.c
 create mode 100644 lib/librte_vhost/virtio-net.c

Comments

Stephen Hemminger Aug. 7, 2014, 5:58 p.m. UTC | #1
On Fri, 18 Jul 2014 13:39:05 +0800
Huawei Xie <huawei.xie@intel.com> wrote:

> Signed-off-by: Huawei Xie <huawei.xie@intel.com>
> Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> Acked-by: Thomos Long <thomas.long@intel.com>

This looks good, but there are some style convention issues:

1. Please don't use really long lines. About 100 or 120 characters is maximum
   reasonable length in an editor

2. Don't put space here in function decl.

ERROR: space prohibited after that '*' (ctx:BxW)
#1183: FILE: lib/librte_vhost/vhost-net-cdev.h:102:
+	int (* set_vring_kick)(struct vhost_device_ctx, struct vhost_vring_file *);
 	     ^

3. Use BSD and kernel style brace
Not:

+void
+put_files_struct (struct files_struct *files)
+{
+	if (atomic_dec_and_test (&files->count))
+	{
+		BUG ();
+	}
+}

Instead:
+void
+put_files_struct (struct files_struct *files)
+{
+	if (atomic_dec_and_test (&files->count)) {
+		BUG ();
+	}
+}

4. All functions that are not used in other files should be marked static.
   For example put_files_struct

5. Switch should be indented at same level as case:
Not:
+	switch (ioctl)
+	{
+		case EVENTFD_COPY:
+			if (copy_from_user (&eventfd_copy, argp, sizeof (struct eventfd_copy)))
+				return -EFAULT;
+

Instead:
+	switch (ioctl) {
+	case EVENTFD_COPY:
+		if (copy_from_user (&eventfd_copy, argp, sizeof (struct eventfd_copy)))
+			return -EFAULT
Huawei Xie Aug. 8, 2014, 5:51 a.m. UTC | #2
> -----Original Message-----
> From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> Sent: Friday, August 08, 2014 1:59 AM
> To: Xie, Huawei
> Cc: dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH 1/2] lib/librte_vhost: vhost library support to
> facilitate integration with vswitch.
> 
> On Fri, 18 Jul 2014 13:39:05 +0800
> Huawei Xie <huawei.xie@intel.com> wrote:
> 
> > Signed-off-by: Huawei Xie <huawei.xie@intel.com>
> > Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> > Acked-by: Thomos Long <thomas.long@intel.com>
> 
> This looks good, but there are some style convention issues:
> 
> 1. Please don't use really long lines. About 100 or 120 characters is maximum
>    reasonable length in an editor
> 
I plan to fix the length issues in subsequent patch. There are plenty of them, which are inherited from old vhost code. 
> 2. Don't put space here in function decl.
> 
> ERROR: space prohibited after that '*' (ctx:BxW)
> #1183: FILE: lib/librte_vhost/vhost-net-cdev.h:102:
> +	int (* set_vring_kick)(struct vhost_device_ctx, struct vhost_vring_file *);
>  	     ^
> 
In this patch, I only run checkpatch.pl against the source file I modified rather than the patch itself, so missed these checking.  I had sent the V3 patch in which those kind of issues are fixed. Please refer to the latest V3 patch.
> 3. Use BSD and kernel style brace
> Not:
> 
> +void
> +put_files_struct (struct files_struct *files)
> +{
> +	if (atomic_dec_and_test (&files->count))
> +	{
> +		BUG ();
> +	}
> +}
> 
> Instead:
> +void
> +put_files_struct (struct files_struct *files)
> +{
> +	if (atomic_dec_and_test (&files->count)) {
> +		BUG ();
> +	}
> +}
> 
> 4. All functions that are not used in other files should be marked static.
>    For example put_files_struct
> 
> 5. Switch should be indented at same level as case:
> Not:
> +	switch (ioctl)
> +	{
> +		case EVENTFD_COPY:
> +			if (copy_from_user (&eventfd_copy, argp, sizeof (struct
> eventfd_copy)))
> +				return -EFAULT;
> +
> 
> Instead:
> +	switch (ioctl) {
> +	case EVENTFD_COPY:
> +		if (copy_from_user (&eventfd_copy, argp, sizeof (struct
> eventfd_copy)))
> +			return -EFAULT

Thanks. As stated above, have fixed all the style issues except 80 length warning in v3 patch.

Patch
diff mbox

diff --git a/config/common_linuxapp b/config/common_linuxapp
index 7bf5d80..002ed84 100644
--- a/config/common_linuxapp
+++ b/config/common_linuxapp
@@ -390,6 +390,12 @@  CONFIG_RTE_KNI_VHOST_DEBUG_RX=n
 CONFIG_RTE_KNI_VHOST_DEBUG_TX=n
 
 #
+# Compile vhost library
+#
+CONFIG_RTE_LIBRTE_VHOST=y
+CONFIG_RTE_LIBRTE_VHOST_DEBUG=n
+
+#
 #Compile Xen domain0 support
 #
 CONFIG_RTE_LIBRTE_XEN_DOM0=n
diff --git a/lib/Makefile b/lib/Makefile
index 10c5bb3..007c174 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -60,6 +60,7 @@  DIRS-$(CONFIG_RTE_LIBRTE_METER) += librte_meter
 DIRS-$(CONFIG_RTE_LIBRTE_SCHED) += librte_sched
 DIRS-$(CONFIG_RTE_LIBRTE_KVARGS) += librte_kvargs
 DIRS-$(CONFIG_RTE_LIBRTE_DISTRIBUTOR) += librte_distributor
+DIRS-$(CONFIG_RTE_LIBRTE_VHOST) += librte_vhost
 DIRS-$(CONFIG_RTE_LIBRTE_PORT) += librte_port
 DIRS-$(CONFIG_RTE_LIBRTE_TABLE) += librte_table
 DIRS-$(CONFIG_RTE_LIBRTE_PIPELINE) += librte_pipeline
diff --git a/lib/librte_vhost/Makefile b/lib/librte_vhost/Makefile
new file mode 100644
index 0000000..f79778b
--- /dev/null
+++ b/lib/librte_vhost/Makefile
@@ -0,0 +1,48 @@ 
+#   BSD LICENSE
+# 
+#   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+#   All rights reserved.
+# 
+#   Redistribution and use in source and binary forms, with or without
+#   modification, are permitted provided that the following conditions
+#   are met:
+# 
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above copyright
+#       notice, this list of conditions and the following disclaimer in
+#       the documentation and/or other materials provided with the
+#       distribution.
+#     * Neither the name of Intel Corporation nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+# 
+#   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+#   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+#   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+#   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+#   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+#   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+#   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+#   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+#   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+#   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+#   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+include $(RTE_SDK)/mk/rte.vars.mk
+
+# library name
+LIB = librte_vhost.a
+
+CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR) -O3 -D_FILE_OFFSET_BITS=64 -lfuse
+LDFLAGS += -lfuse
+# all source are stored in SRCS-y
+SRCS-$(CONFIG_RTE_LIBRTE_VHOST) := vhost-net-cdev.c virtio-net.c vhost_rxtx.c
+
+# install includes
+SYMLINK-$(CONFIG_RTE_LIBRTE_VHOST)-include += rte_virtio_net.h
+
+# this lib needs eal
+DEPDIRS-$(CONFIG_RTE_LIBRTE_VHOST) += lib/librte_eal lib/librte_mbuf
+
+include $(RTE_SDK)/mk/rte.lib.mk
diff --git a/lib/librte_vhost/eventfd_link/Makefile b/lib/librte_vhost/eventfd_link/Makefile
new file mode 100644
index 0000000..5fe7297
--- /dev/null
+++ b/lib/librte_vhost/eventfd_link/Makefile
@@ -0,0 +1,39 @@ 
+#   BSD LICENSE
+# 
+#   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+#   All rights reserved.
+# 
+#   Redistribution and use in source and binary forms, with or without
+#   modification, are permitted provided that the following conditions
+#   are met:
+# 
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above copyright
+#       notice, this list of conditions and the following disclaimer in
+#       the documentation and/or other materials provided with the
+#       distribution.
+#     * Neither the name of Intel Corporation nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+# 
+#   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+#   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+#   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+#   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+#   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+#   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+#   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+#   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+#   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+#   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+#   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ 
+obj-m += eventfd_link.o
+
+
+all:
+	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
+
+clean:
+	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean
diff --git a/lib/librte_vhost/eventfd_link/eventfd_link.c b/lib/librte_vhost/eventfd_link/eventfd_link.c
new file mode 100644
index 0000000..f7975fa
--- /dev/null
+++ b/lib/librte_vhost/eventfd_link/eventfd_link.c
@@ -0,0 +1,205 @@ 
+/*-
+ *  * GPL LICENSE SUMMARY
+ *  * 
+ *  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *  * 
+ *  *   This program is free software; you can redistribute it and/or modify
+ *  *   it under the terms of version 2 of the GNU General Public License as
+ *  *   published by the Free Software Foundation.
+ *  * 
+ *  *   This program is distributed in the hope that it will be useful, but
+ *  *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  *   General Public License for more details.
+ *  * 
+ *  *   You should have received a copy of the GNU General Public License
+ *  *   along with this program; if not, write to the Free Software
+ *  *   Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *  *   The full GNU General Public License is included in this distribution
+ *  *   in the file called LICENSE.GPL.
+ *  * 
+ *  *   Contact Information:
+ *  *   Intel Corporation
+ *   */
+
+#include <linux/eventfd.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/rcupdate.h>
+#include <linux/file.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/mmu_context.h>
+#include <linux/sched.h>
+#include <asm/mmu_context.h>
+#include <linux/fdtable.h>
+
+#include "eventfd_link.h"
+
+
+/*
+ * get_files_struct is copied from fs/file.c
+ */
+struct files_struct *
+get_files_struct (struct task_struct *task)
+{
+	struct files_struct *files;
+
+	task_lock (task);
+	files = task->files;
+	if (files)
+		atomic_inc (&files->count);
+	task_unlock (task);
+
+	return files;
+}
+
+/*
+ * put_files_struct is extracted from fs/file.c
+ */
+void
+put_files_struct (struct files_struct *files)
+{
+	if (atomic_dec_and_test (&files->count))
+	{
+		BUG ();
+	}
+}
+
+
+static long
+eventfd_link_ioctl (struct file *f, unsigned int ioctl, unsigned long arg)
+{
+	void __user *argp = (void __user *) arg;
+	struct task_struct *task_target = NULL;
+	struct file *file;
+	struct files_struct *files;
+	struct fdtable *fdt;
+	struct eventfd_copy eventfd_copy;
+
+	switch (ioctl)
+	{
+		case EVENTFD_COPY:
+			if (copy_from_user (&eventfd_copy, argp, sizeof (struct eventfd_copy)))
+				return -EFAULT;
+
+			/*
+			 * Find the task struct for the target pid
+			 */
+			task_target =
+				pid_task (find_vpid (eventfd_copy.target_pid), PIDTYPE_PID);
+			if (task_target == NULL)
+			{
+				printk (KERN_DEBUG "Failed to get mem ctx for target pid\n");
+				return -EFAULT;
+			}
+
+			files = get_files_struct (current);
+			if (files == NULL)
+			{
+				printk (KERN_DEBUG "Failed to get files struct\n");
+				return -EFAULT;
+			}
+
+			rcu_read_lock ();
+			file = fcheck_files (files, eventfd_copy.source_fd);
+			if (file)
+			{
+				if (file->f_mode & FMODE_PATH
+						|| !atomic_long_inc_not_zero (&file->f_count))
+					file = NULL;
+			}
+			rcu_read_unlock ();
+			put_files_struct (files);
+
+			if (file == NULL)
+			{
+				printk (KERN_DEBUG "Failed to get file from source pid\n");
+				return 0;
+			}
+
+			/*
+			 * Release the existing eventfd in the source process
+			 */
+			spin_lock (&files->file_lock);
+			filp_close (file, files);
+			fdt = files_fdtable (files);
+			fdt->fd[eventfd_copy.source_fd] = NULL;
+			spin_unlock (&files->file_lock);
+
+			/*
+			 * Find the file struct associated with the target fd.
+			 */
+
+			files = get_files_struct (task_target);
+			if (files == NULL)
+			{
+				printk (KERN_DEBUG "Failed to get files struct\n");
+				return -EFAULT;
+			}
+
+			rcu_read_lock ();
+			file = fcheck_files (files, eventfd_copy.target_fd);
+			if (file)
+			{
+				if (file->f_mode & FMODE_PATH
+						|| !atomic_long_inc_not_zero (&file->f_count))
+					file = NULL;
+			}
+			rcu_read_unlock ();
+			put_files_struct (files);
+
+			if (file == NULL)
+			{
+				printk (KERN_DEBUG "Failed to get file from target pid\n");
+				return 0;
+			}
+
+
+			/*
+			 * Install the file struct from the target process into the
+			 * file desciptor of the source process,
+			 */
+
+			fd_install (eventfd_copy.source_fd, file);
+
+			return 0;
+
+		default:
+			return -ENOIOCTLCMD;
+	}
+}
+
+static const struct file_operations eventfd_link_fops = {
+	.owner = THIS_MODULE,
+	.unlocked_ioctl = eventfd_link_ioctl,
+};
+
+
+static struct miscdevice eventfd_link_misc = {
+	.name = "eventfd-link",
+	.fops = &eventfd_link_fops,
+};
+
+static int __init
+eventfd_link_init (void)
+{
+	return misc_register (&eventfd_link_misc);
+}
+
+module_init (eventfd_link_init);
+
+static void __exit
+eventfd_link_exit (void)
+{
+	misc_deregister (&eventfd_link_misc);
+}
+
+module_exit (eventfd_link_exit);
+
+MODULE_VERSION ("0.0.1");
+MODULE_LICENSE ("GPL v2");
+MODULE_AUTHOR ("Anthony Fee");
+MODULE_DESCRIPTION ("Link eventfd");
+MODULE_ALIAS ("devname:eventfd-link");
diff --git a/lib/librte_vhost/eventfd_link/eventfd_link.h b/lib/librte_vhost/eventfd_link/eventfd_link.h
new file mode 100644
index 0000000..f33c2f8
--- /dev/null
+++ b/lib/librte_vhost/eventfd_link/eventfd_link.h
@@ -0,0 +1,79 @@ 
+/*-
+ *  * This file is provided under a dual BSD/GPLv2 license.  When using or
+ *  *   redistributing this file, you may do so under either license.
+ *  * 
+ *  *   GPL LICENSE SUMMARY
+ *  * 
+ *  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *  * 
+ *  *   This program is free software; you can redistribute it and/or modify
+ *  *   it under the terms of version 2 of the GNU General Public License as
+ *  *   published by the Free Software Foundation.
+ *  * 
+ *  *   This program is distributed in the hope that it will be useful, but
+ *  *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  *   General Public License for more details.
+ *  * 
+ *  *   You should have received a copy of the GNU General Public License
+ *  *   along with this program; if not, write to the Free Software
+ *  *   Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *  *   The full GNU General Public License is included in this distribution
+ *  *   in the file called LICENSE.GPL.
+ *  * 
+ *  *   Contact Information:
+ *  *   Intel Corporation
+ *  * 
+ *  *   BSD LICENSE
+ *  * 
+ *  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *  *   All rights reserved.
+ *  * 
+ *  *   Redistribution and use in source and binary forms, with or without
+ *  *   modification, are permitted provided that the following conditions
+ *  *   are met:
+ *  * 
+ *  *     * Redistributions of source code must retain the above copyright
+ *  *       notice, this list of conditions and the following disclaimer.
+ *  *     * Redistributions in binary form must reproduce the above copyright
+ *  *       notice, this list of conditions and the following disclaimer in
+ *  *       the documentation and/or other materials provided with the
+ *  *       distribution.
+ *  *     * Neither the name of Intel Corporation nor the names of its
+ *  *       contributors may be used to endorse or promote products derived
+ *  *       from this software without specific prior written permission.
+ *  * 
+ *  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *  * 
+ *   */
+
+#ifndef _EVENTFD_LINK_H_
+#define _EVENTFD_LINK_H_
+
+/*
+ *	ioctl to copy an fd entry in calling process to an fd in a target process
+ */
+#define EVENTFD_COPY 1
+
+/*
+ *	arguements for the EVENTFD_COPY ioctl
+ */
+struct eventfd_copy {
+	// fd in the target pid
+    unsigned target_fd;
+	// fd in the calling pid
+    unsigned source_fd;
+	// pid of the target pid
+    pid_t target_pid;
+};
+#endif /* _EVENTFD_LINK_H_ */
diff --git a/lib/librte_vhost/rte_virtio_net.h b/lib/librte_vhost/rte_virtio_net.h
new file mode 100644
index 0000000..7a05dab
--- /dev/null
+++ b/lib/librte_vhost/rte_virtio_net.h
@@ -0,0 +1,192 @@ 
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _VIRTIO_NET_H_
+#define _VIRTIO_NET_H_
+
+#include <stdint.h>
+#include <linux/virtio_ring.h>
+#include <linux/virtio_net.h>
+#include <sys/eventfd.h>
+
+#include <rte_memory.h>
+#include <rte_mempool.h>
+#include <rte_mbuf.h>
+
+#define VIRTIO_DEV_RUNNING 1  /**< Used to indicate that the device is running on a data core. */
+#define VIRTIO_DEV_STOPPED -1 /**< Backend value set by guest. */
+
+/* Enum for virtqueue management. */
+enum {VIRTIO_RXQ, VIRTIO_TXQ, VIRTIO_QNUM};
+
+/**
+ * Structure contains variables relevant to RX/TX virtqueues.
+ */
+struct vhost_virtqueue {
+	struct vring_desc    *desc;             /**< descriptor ring. */
+	struct vring_avail   *avail;            /**< available ring. */
+	struct vring_used    *used;             /**< used ring. */
+	uint32_t             size;              /**< Size of descriptor ring. */
+	uint32_t             backend;           /**< Backend value to determine if device should be started/stopped. */
+	uint16_t             vhost_hlen;        /**< Vhost header length (varies depending on RX merge buffers. */
+	volatile uint16_t    last_used_idx;     /**< Last index used on the available ring. */
+	volatile uint16_t    last_used_idx_res; /**< Used for multiple devices reserving buffers. */
+	eventfd_t            callfd;            /**< Currently unused as polling mode is enabled. */
+	eventfd_t            kickfd;            /**< Used to notify the guest (trigger interrupt). */
+} __rte_cache_aligned;
+
+/**
+ * Information relating to memory regions including offsets to
+ * addresses in QEMUs memory file.
+ */
+struct virtio_memory_regions {
+	uint64_t    guest_phys_address;     /**< Base guest physical address of region. */
+	uint64_t    guest_phys_address_end; /**< End guest physical address of region. */
+	uint64_t    memory_size;            /**< Size of region. */
+	uint64_t    userspace_address;      /**< Base userspace address of region. */
+	uint64_t    address_offset;         /**< Offset of region for address translation. */
+};
+
+
+/**
+ * Memory structure includes region and mapping information.
+ */
+struct virtio_memory {
+	uint64_t    base_address;    /**< Base QEMU userspace address of the memory file. */
+	uint64_t    mapped_address;  /**< Mapped address of memory file base in our applications memory space. */
+	uint64_t    mapped_size;     /**< Total size of memory file. */
+	uint32_t    nregions;        /**< Number of memory regions. */
+	struct virtio_memory_regions      regions[0]; /**< Memory region information. */
+};
+
+/**
+ * Device structure contains all configuration information relating to the device.
+ */
+struct virtio_net {
+	struct vhost_virtqueue  *virtqueue[VIRTIO_QNUM]; /**< Contains all virtqueue information. */
+	struct virtio_memory    *mem;                    /**< QEMU memory and memory region information. */
+	uint64_t features;    /**< Negotiated feature set. */
+	uint64_t device_fh;   /**< Device identifier. */
+	uint32_t flags;       /**< Device flags. Only used to check if device is running on data core. */
+	void     *priv;
+} __rte_cache_aligned;
+
+/**
+ * Device operations to add/remove device.
+ */
+struct virtio_net_device_ops {
+	int (*new_device)(struct virtio_net *); /**< Add device. */
+	void (*destroy_device)(struct virtio_net *); /**< Remove device. */
+};
+
+
+static inline uint16_t __attribute__((always_inline))
+rte_vring_available_entries(struct virtio_net *dev, uint16_t queue_id)
+{
+	struct vhost_virtqueue *vq = dev->virtqueue[queue_id];
+	return *(volatile uint16_t *)&vq->avail->idx - vq->last_used_idx_res;
+}
+
+/**
+ * Function to convert guest physical addresses to vhost virtual addresses.
+ * This is used to convert guest virtio buffer addresses.
+ */
+static inline uint64_t __attribute__((always_inline))
+gpa_to_vva(struct virtio_net *dev, uint64_t guest_pa)
+{
+	struct virtio_memory_regions *region;
+	uint32_t regionidx;
+	uint64_t vhost_va = 0;
+
+	for (regionidx = 0; regionidx < dev->mem->nregions; regionidx++) {
+		region = &dev->mem->regions[regionidx];
+		if ((guest_pa >= region->guest_phys_address) &&
+			(guest_pa <= region->guest_phys_address_end)) {
+			vhost_va = region->address_offset + guest_pa;
+			break;
+		}
+	}
+	return vhost_va;
+}
+
+/**
+ *  Disable features in feature_mask. Returns 0 on success.
+ */
+int rte_vhost_feature_disable(uint64_t feature_mask);
+
+/**
+ *  Enable features in feature_mask. Returns 0 on success.
+ */
+int rte_vhost_feature_enable(uint64_t feature_mask);
+
+/* Returns currently supported vhost features */
+uint64_t rte_vhost_feature_get(void);
+
+int rte_vhost_enable_guest_notification(struct virtio_net *dev, uint16_t queue_id, int enable);
+
+/* Register vhost driver. dev_name could be different for multiple instance support. */
+int rte_vhost_driver_register(const char *dev_name);
+
+/* Register callbacks. */
+int rte_vhost_driver_callback_register(struct virtio_net_device_ops const * const);
+
+int rte_vhost_driver_session_start(void);
+
+/**
+ * This function adds buffers to the virtio devices RX virtqueue. Buffers can
+ * be received from the physical port or from another virtual device. A packet
+ * count is returned to indicate the number of packets that were succesfully
+ * added to the RX queue.
+ * @param queue_id
+ *  virtio queue index in mq case
+ * @return
+ *  num of packets enqueued
+ */
+uint32_t rte_vhost_enqueue_burst(struct virtio_net *dev, uint16_t queue_id,
+	struct rte_mbuf **pkts, uint32_t count);
+
+/**
+ * This function gets guest buffers from the virtio device TX virtqueue,
+ * construct host mbufs, copies guest buffer content to host mbufs and
+ * store them in pkts to be processed.
+ * @param mbuf_pool
+ *  mbuf_pool where host mbuf is allocated.
+ * @param queue_id
+ *  virtio queue index in mq case.
+ * @return
+ *  num of packets dequeued
+ */
+uint32_t rte_vhost_dequeue_burst(struct virtio_net *dev, uint16_t queue_id,
+	struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint32_t count);
+
+#endif /* _VIRTIO_NET_H_ */
diff --git a/lib/librte_vhost/vhost-net-cdev.c b/lib/librte_vhost/vhost-net-cdev.c
new file mode 100644
index 0000000..1dfe918
--- /dev/null
+++ b/lib/librte_vhost/vhost-net-cdev.c
@@ -0,0 +1,363 @@ 
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <errno.h>
+#include <fuse/cuse_lowlevel.h>
+#include <linux/limits.h>
+#include <linux/vhost.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <rte_ethdev.h>
+#include <rte_log.h>
+#include <rte_string_fns.h>
+#include <rte_virtio_net.h>
+
+#include "vhost-net-cdev.h"
+
+#define FUSE_OPT_DUMMY    "\0\0"
+#define FUSE_OPT_FORE     "-f\0\0"
+#define FUSE_OPT_NOMULTI  "-s\0\0"
+
+static const uint32_t	default_major = 231;
+static const uint32_t	default_minor = 1;
+static const char	cuse_device_name[]	= "/dev/cuse";
+static const char	default_cdev[] = "vhost-net";
+
+static struct fuse_session		*session;
+static struct vhost_net_device_ops	const *ops;
+
+/**
+ * Returns vhost_device_ctx from given fuse_req_t. The index is populated later when
+ * the device is added to the device linked list.
+ */
+static struct vhost_device_ctx
+fuse_req_to_vhost_ctx(fuse_req_t req, struct fuse_file_info *fi)
+{
+	struct vhost_device_ctx ctx;
+	struct fuse_ctx const *const req_ctx = fuse_req_ctx(req);
+
+	ctx.pid = req_ctx->pid;
+	ctx.fh = fi->fh;
+
+	return ctx;
+}
+
+/**
+ * When the device is created in QEMU it gets initialised here and added to the device linked list.
+ */
+static void
+vhost_net_open(fuse_req_t req, struct fuse_file_info *fi)
+{
+	struct vhost_device_ctx ctx = fuse_req_to_vhost_ctx(req, fi);
+	int err = 0;
+
+	err = ops->new_device(ctx);
+	if (err == -1) {
+		fuse_reply_err(req, EPERM);
+		return;
+	}
+
+	fi->fh = err;
+
+	RTE_LOG(INFO, VHOST_CONFIG, "(%"PRIu64") Device configuration started\n", fi->fh);
+	fuse_reply_open(req, fi);
+}
+
+/*
+ * When QEMU is shutdown or killed the device gets released.
+ */
+static void
+vhost_net_release(fuse_req_t req, struct fuse_file_info *fi)
+{
+	int err = 0;
+	struct vhost_device_ctx ctx = fuse_req_to_vhost_ctx(req, fi);
+
+	ops->destroy_device(ctx);
+	RTE_LOG(INFO, VHOST_CONFIG, "(%"PRIu64") Device released\n", ctx.fh);
+	fuse_reply_err(req, err);
+}
+
+/*
+ * Boilerplate code for CUSE IOCTL
+ * Implicit arguments: ctx, req, result.
+ */
+#define VHOST_IOCTL(func) do { \
+	result = (func)(ctx);  \
+	fuse_reply_ioctl(req, result, NULL, 0);	 \
+} while (0)
+
+/*
+ * Boilerplate IOCTL RETRY
+ * Implicit arguments: req.
+ */
+#define VHOST_IOCTL_RETRY(size_r, size_w) do { \
+	struct iovec iov_r = { arg, (size_r) }; \
+	struct iovec iov_w = { arg, (size_w) }; \
+	fuse_reply_ioctl_retry(req, &iov_r, (size_r) ? 1 : 0, &iov_w, (size_w) ? 1 : 0); \
+} while (0)																		\
+
+/*
+ * Boilerplate code for CUSE Read IOCTL
+ * Implicit arguments: ctx, req, result, in_bufsz, in_buf.
+ */
+#define VHOST_IOCTL_R(type, var, func) do {             \
+	if (!in_bufsz) {                                \
+		VHOST_IOCTL_RETRY(sizeof(type), 0);     \
+	} else {                                        \
+		(var) = *(const type *)in_buf;          \
+		result = func(ctx, &(var));             \
+		fuse_reply_ioctl(req, result, NULL, 0); \
+	}                                               \
+} while (0)
+
+/*
+ * Boilerplate code for CUSE Write IOCTL
+ * Implicit arguments: ctx, req, result, out_bufsz.
+ */
+#define	VHOST_IOCTL_W(type, var, func) do {              \
+	if (!out_bufsz) {                                \
+		VHOST_IOCTL_RETRY(0, sizeof(type));      \
+	} else {                                         \
+		result = (func)(ctx, &(var));            \
+		fuse_reply_ioctl(req, result, &(var), sizeof(type)); \
+	} \
+} while (0)
+
+/*
+ * Boilerplate code for CUSE Read/Write IOCTL
+ * Implicit arguments: ctx, req, result, in_bufsz, in_buf.
+ */
+#define VHOST_IOCTL_RW(type1, var1, type2, var2, func) do {      \
+	if (!in_bufsz) {                                         \
+		VHOST_IOCTL_RETRY(sizeof(type1), sizeof(type2)); \
+	} else {                                                 \
+		(var1) = *(const type1 *) (in_buf);              \
+		result = (func)(ctx, (var1), &(var2));           \
+		fuse_reply_ioctl(req, result, &(var2), sizeof(type2));  \
+	} \
+} while (0)
+
+/**
+ * The IOCTLs are handled using CUSE/FUSE in userspace. Depending on
+ * the type of IOCTL a buffer is requested to read or to write. This
+ * request is handled by FUSE and the buffer is then given to CUSE.
+ */
+static void
+vhost_net_ioctl(fuse_req_t req, int cmd, void *arg,
+		struct fuse_file_info *fi, __rte_unused unsigned flags,
+		const void *in_buf, size_t in_bufsz, size_t out_bufsz)
+{
+	struct vhost_device_ctx ctx = fuse_req_to_vhost_ctx(req, fi);
+	struct vhost_vring_file file;
+	struct vhost_vring_state state;
+	struct vhost_vring_addr addr;
+	uint64_t features;
+	uint32_t index;
+	int result = 0;
+
+	switch (cmd) {
+
+	case VHOST_NET_SET_BACKEND:
+		LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") IOCTL: VHOST_NET_SET_BACKEND\n", ctx.fh);
+		VHOST_IOCTL_R(struct vhost_vring_file, file, ops->set_backend);
+		break;
+
+	case VHOST_GET_FEATURES:
+		LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") IOCTL: VHOST_GET_FEATURES\n", ctx.fh);
+		VHOST_IOCTL_W(uint64_t, features, ops->get_features);
+		break;
+
+	case VHOST_SET_FEATURES:
+		LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") IOCTL: VHOST_SET_FEATURES\n", ctx.fh);
+		VHOST_IOCTL_R(uint64_t, features, ops->set_features);
+		break;
+
+	case VHOST_RESET_OWNER:
+		LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") IOCTL: VHOST_RESET_OWNER\n", ctx.fh);
+		VHOST_IOCTL(ops->reset_owner);
+		break;
+
+	case VHOST_SET_OWNER:
+		LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") IOCTL: VHOST_SET_OWNER\n", ctx.fh);
+		VHOST_IOCTL(ops->set_owner);
+		break;
+
+	case VHOST_SET_MEM_TABLE:
+		/*TODO fix race condition.*/
+		LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") IOCTL: VHOST_SET_MEM_TABLE\n", ctx.fh);
+		static struct vhost_memory mem_temp;
+
+		switch (in_bufsz) {
+		case 0:
+			VHOST_IOCTL_RETRY(sizeof(struct vhost_memory), 0);
+			break;
+
+		case sizeof(struct vhost_memory):
+			mem_temp = *(const struct vhost_memory *) in_buf;
+
+			if (mem_temp.nregions > 0) {
+				VHOST_IOCTL_RETRY(sizeof(struct vhost_memory) + (sizeof(struct vhost_memory_region) * mem_temp.nregions), 0);
+			} else {
+				result = -1;
+				fuse_reply_ioctl(req, result, NULL, 0);
+			}
+			break;
+
+		default:
+			result = ops->set_mem_table(ctx, in_buf, mem_temp.nregions);
+			if (result)
+				fuse_reply_err(req, EINVAL);
+			else
+				fuse_reply_ioctl(req, result, NULL, 0);
+
+		}
+
+		break;
+
+	case VHOST_SET_VRING_NUM:
+		LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") IOCTL: VHOST_SET_VRING_NUM\n", ctx.fh);
+		VHOST_IOCTL_R(struct vhost_vring_state, state, ops->set_vring_num);
+		break;
+
+	case VHOST_SET_VRING_BASE:
+		LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") IOCTL: VHOST_SET_VRING_BASE\n", ctx.fh);
+		VHOST_IOCTL_R(struct vhost_vring_state, state, ops->set_vring_base);
+		break;
+
+	case VHOST_GET_VRING_BASE:
+		LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") IOCTL: VHOST_GET_VRING_BASE\n", ctx.fh);
+		VHOST_IOCTL_RW(uint32_t, index, struct vhost_vring_state, state, ops->get_vring_base);
+		break;
+
+	case VHOST_SET_VRING_ADDR:
+		LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") IOCTL: VHOST_SET_VRING_ADDR\n", ctx.fh);
+		VHOST_IOCTL_R(struct vhost_vring_addr, addr, ops->set_vring_addr);
+		break;
+
+	case VHOST_SET_VRING_KICK:
+		LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") IOCTL: VHOST_SET_VRING_KICK\n", ctx.fh);
+		VHOST_IOCTL_R(struct vhost_vring_file, file, ops->set_vring_kick);
+		break;
+
+	case VHOST_SET_VRING_CALL:
+		LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") IOCTL: VHOST_SET_VRING_CALL\n", ctx.fh);
+		VHOST_IOCTL_R(struct vhost_vring_file, file, ops->set_vring_call);
+		break;
+
+	default:
+		RTE_LOG(ERR, VHOST_CONFIG, "(%"PRIu64") IOCTL: DOESN NOT EXIST\n", ctx.fh);
+		result = -1;
+		fuse_reply_ioctl(req, result, NULL, 0);
+	}
+
+	if (result < 0)
+		LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") IOCTL: FAIL\n", ctx.fh);
+	else
+		LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") IOCTL: SUCCESS\n", ctx.fh);
+}
+
+/**
+ * Structure handling open, release and ioctl function pointers is populated.
+ */
+static const struct cuse_lowlevel_ops vhost_net_ops = {
+	.open		= vhost_net_open,
+	.release	= vhost_net_release,
+	.ioctl		= vhost_net_ioctl,
+};
+
+/**
+ * cuse_info is populated and used to register the cuse device. vhost_net_device_ops are
+ * also passed when the device is registered in main.c.
+ */
+int
+rte_vhost_driver_register(const char *dev_name)
+{
+	struct cuse_info cuse_info;
+	char device_name[PATH_MAX] = "";
+	char char_device_name[PATH_MAX] = "";
+	const char *device_argv[] = { device_name };
+
+	char fuse_opt_dummy[] = FUSE_OPT_DUMMY;
+	char fuse_opt_fore[] = FUSE_OPT_FORE;
+	char fuse_opt_nomulti[] = FUSE_OPT_NOMULTI;
+	char *fuse_argv[] = {fuse_opt_dummy, fuse_opt_fore, fuse_opt_nomulti};
+
+	if (access(cuse_device_name, R_OK | W_OK) < 0) {
+		RTE_LOG(ERR, VHOST_CONFIG, "Character device %s can't be accessed, maybe not exist\n", cuse_device_name);
+		return -1;
+	}
+
+	/*
+	 * The device name is created. This is passed to QEMU so that it can register
+	 * the device with our application. The dev_name allows us to have multiple instances
+	 * of userspace vhost which we can then add devices to separately.
+	 */
+	snprintf(device_name, PATH_MAX, "DEVNAME=%s", dev_name);
+	snprintf(char_device_name, PATH_MAX, "/dev/%s", dev_name);
+
+	/* Check if device already exists. */
+	if (access(char_device_name, F_OK) != -1) {
+		RTE_LOG(ERR, VHOST_CONFIG, "Character device %s already exists\n", char_device_name);
+		return -1;
+	}
+
+	memset(&cuse_info, 0, sizeof(cuse_info));
+	cuse_info.dev_major = default_major;
+	cuse_info.dev_minor = default_minor;
+	cuse_info.dev_info_argc = 1;
+	cuse_info.dev_info_argv = device_argv;
+	cuse_info.flags = CUSE_UNRESTRICTED_IOCTL;
+
+	ops = get_virtio_net_callbacks();
+
+	session = cuse_lowlevel_setup(3, fuse_argv,
+				&cuse_info, &vhost_net_ops, 0, NULL);
+	if (session == NULL)
+		return -1;
+
+	return 0;
+}
+
+
+/**
+ * The CUSE session is launched allowing the application to receive open, release and ioctl calls.
+ */
+int
+rte_vhost_driver_session_start(void)
+{
+	fuse_session_loop(session);
+
+	return 0;
+}
diff --git a/lib/librte_vhost/vhost-net-cdev.h b/lib/librte_vhost/vhost-net-cdev.h
new file mode 100644
index 0000000..ecf35fd
--- /dev/null
+++ b/lib/librte_vhost/vhost-net-cdev.h
@@ -0,0 +1,112 @@ 
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <linux/vhost.h>
+
+#include <rte_log.h>
+
+/* Macros for printing using RTE_LOG */
+#define RTE_LOGTYPE_VHOST_CONFIG RTE_LOGTYPE_USER1
+#define RTE_LOGTYPE_VHOST_DATA   RTE_LOGTYPE_USER1
+
+#ifdef RTE_LIBRTE_VHOST_DEBUG
+#define VHOST_MAX_PRINT_BUFF 6072
+#define LOG_LEVEL RTE_LOG_DEBUG
+#define LOG_DEBUG(log_type, fmt, args...) do {	\
+	RTE_LOG(DEBUG, log_type, fmt, ##args);	\
+} while (0)
+#define VHOST_PRINT_PACKET(device, addr, size, header) do {																\
+	char *pkt_addr = (char*)(addr);																					\
+	unsigned int index;																								\
+	char packet[VHOST_MAX_PRINT_BUFF];																					\
+																													\
+	if ((header))																									\
+		snprintf(packet, VHOST_MAX_PRINT_BUFF, "(%"PRIu64") Header size %d: ", (device->device_fh), (size));				\
+	else																											\
+		snprintf(packet, VHOST_MAX_PRINT_BUFF, "(%"PRIu64") Packet size %d: ", (device->device_fh), (size));				\
+	for (index = 0; index < (size); index++) {																		\
+		snprintf(packet + strnlen(packet, VHOST_MAX_PRINT_BUFF), VHOST_MAX_PRINT_BUFF - strnlen(packet, VHOST_MAX_PRINT_BUFF),	\
+			"%02hhx ", pkt_addr[index]);																			\
+	}																												\
+	snprintf(packet + strnlen(packet, VHOST_MAX_PRINT_BUFF), VHOST_MAX_PRINT_BUFF - strnlen(packet, VHOST_MAX_PRINT_BUFF), "\n");	\
+																													\
+	LOG_DEBUG(VHOST_DATA, "%s", packet);																					\
+} while(0)
+#else
+#define LOG_LEVEL RTE_LOG_INFO
+#define LOG_DEBUG(log_type, fmt, args...) do{} while(0)
+#define VHOST_PRINT_PACKET(device, addr, size, header) do{} while(0)
+#endif
+
+/**
+ * Structure used to identify device context.
+ */
+struct vhost_device_ctx
+{
+	pid_t		pid;	/* PID of process calling the IOCTL. */
+	uint64_t 	fh;	/* Populated with fi->fh to track the device index. */
+};
+
+/**
+ * Structure contains function pointers to be defined in virtio-net.c. These
+ * functions are called in CUSE context and are used to configure devices.
+ */
+struct vhost_net_device_ops {
+	int (* new_device)(struct vhost_device_ctx);
+	void (* destroy_device)(struct vhost_device_ctx);
+
+	int (* get_features)(struct vhost_device_ctx, uint64_t *);
+	int (* set_features)(struct vhost_device_ctx, uint64_t *);
+
+	int (* set_mem_table)(struct vhost_device_ctx, const void *, uint32_t);
+
+	int (* set_vring_num)(struct vhost_device_ctx, struct vhost_vring_state *);
+	int (* set_vring_addr)(struct vhost_device_ctx, struct vhost_vring_addr *);
+	int (* set_vring_base)(struct vhost_device_ctx, struct vhost_vring_state *);
+	int (* get_vring_base)(struct vhost_device_ctx, uint32_t, struct vhost_vring_state *);
+
+	int (* set_vring_kick)(struct vhost_device_ctx, struct vhost_vring_file *);
+	int (* set_vring_call)(struct vhost_device_ctx, struct vhost_vring_file *);
+
+	int (* set_backend)(struct vhost_device_ctx, struct vhost_vring_file *);
+
+	int (* set_owner)(struct vhost_device_ctx);
+	int (* reset_owner)(struct vhost_device_ctx);
+};
+
+
+struct vhost_net_device_ops const * get_virtio_net_callbacks(void);
diff --git a/lib/librte_vhost/vhost_rxtx.c b/lib/librte_vhost/vhost_rxtx.c
new file mode 100644
index 0000000..d25457b
--- /dev/null
+++ b/lib/librte_vhost/vhost_rxtx.c
@@ -0,0 +1,292 @@ 
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdint.h>
+#include <linux/virtio_net.h>
+
+#include <rte_mbuf.h>
+#include <rte_memcpy.h>
+#include <rte_virtio_net.h>
+
+#include "vhost-net-cdev.h"
+
+#define VHOST_MAX_PKT_BURST 64
+#define VHOST_MAX_MRG_PKT_BURST 64
+
+
+uint32_t
+rte_vhost_enqueue_burst(struct virtio_net *dev, uint16_t queue_id, struct rte_mbuf **pkts, uint32_t count)
+{
+	struct vhost_virtqueue *vq;
+	struct vring_desc *desc;
+	struct rte_mbuf *buff;
+	/* The virtio_hdr is initialised to 0. */
+	struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, 0, 0, 0, 0, 0}, 0};
+	uint64_t buff_addr = 0;
+	uint64_t buff_hdr_addr = 0;
+	uint32_t head[VHOST_MAX_PKT_BURST], packet_len = 0;
+	uint32_t head_idx, packet_success = 0;
+	uint32_t mergeable, mrg_count = 0;
+	uint16_t avail_idx, res_cur_idx;
+	uint16_t res_base_idx, res_end_idx;
+	uint16_t free_entries;
+	uint8_t success = 0;
+
+	LOG_DEBUG(VHOST_DATA, "(%"PRIu64") %s()\n", dev->device_fh, __func__);
+	if (unlikely(queue_id != VIRTIO_RXQ)) {
+		LOG_DEBUG(VHOST_DATA, "mq isn't supported in this version.\n");
+		return 0;
+	}
+
+	vq = dev->virtqueue[VIRTIO_RXQ];
+	count = (count > VHOST_MAX_PKT_BURST) ? VHOST_MAX_PKT_BURST : count;
+	/* As many data cores may want access to available buffers, they need to be reserved. */
+	do {
+		res_base_idx = vq->last_used_idx_res;
+		avail_idx = *((volatile uint16_t *)&vq->avail->idx);
+
+		free_entries = (avail_idx - res_base_idx);
+		/*check that we have enough buffers*/
+		if (unlikely(count > free_entries))
+			count = free_entries;
+
+		if (count == 0)
+			return 0;
+
+		res_end_idx = res_base_idx + count;
+		/* vq->last_used_idx_res is atomically updated. */
+		/* TODO: Allow to disable cmpset if no concurrency in application */
+		success = rte_atomic16_cmpset(&vq->last_used_idx_res,
+				res_base_idx, res_end_idx);
+		/* If there is contention here and failed, try again. */
+	} while (unlikely(success == 0));
+	res_cur_idx = res_base_idx;
+	LOG_DEBUG(VHOST_DATA, "(%"PRIu64") Current Index %d| End Index %d\n",
+			dev->device_fh,
+			res_cur_idx, res_end_idx);
+
+	/* Prefetch available ring to retrieve indexes. */
+	rte_prefetch0(&vq->avail->ring[res_cur_idx & (vq->size - 1)]);
+
+	/* Check if the VIRTIO_NET_F_MRG_RXBUF feature is enabled. */
+	mergeable = dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF);
+
+	/* Retrieve all of the head indexes first to avoid caching issues. */
+	for (head_idx = 0; head_idx < count; head_idx++)
+		head[head_idx] = vq->avail->ring[(res_cur_idx + head_idx) & (vq->size - 1)];
+
+	/*Prefetch descriptor index. */
+	rte_prefetch0(&vq->desc[head[packet_success]]);
+
+	while (res_cur_idx != res_end_idx) {
+		/* Get descriptor from available ring */
+		desc = &vq->desc[head[packet_success]];
+
+		buff = pkts[packet_success];
+
+		/* Convert from gpa to vva (guest physical addr -> vhost virtual addr) */
+		buff_addr = gpa_to_vva(dev, desc->addr);
+		/* Prefetch buffer address. */
+		rte_prefetch0((void *)(uintptr_t)buff_addr);
+
+		if (mergeable && (mrg_count != 0)) {
+			desc->len = packet_len = rte_pktmbuf_data_len(buff);
+		} else {
+			/* Copy virtio_hdr to packet and increment buffer address */
+			buff_hdr_addr = buff_addr;
+			packet_len = rte_pktmbuf_data_len(buff) + vq->vhost_hlen;
+
+			/*
+			 * If the descriptors are chained the header and data are placed in
+			 * separate buffers.
+			 */
+			if (desc->flags & VRING_DESC_F_NEXT) {
+				desc->len = vq->vhost_hlen;
+				desc = &vq->desc[desc->next];
+				/* Buffer address translation. */
+				buff_addr = gpa_to_vva(dev, desc->addr);
+				desc->len = rte_pktmbuf_data_len(buff);
+			} else {
+				buff_addr += vq->vhost_hlen;
+				desc->len = packet_len;
+			}
+		}
+
+		VHOST_PRINT_PACKET(dev, (uintptr_t)buff_addr, rte_pktmbuf_data_len(buff), 0);
+
+		/* Update used ring with desc information */
+		vq->used->ring[res_cur_idx & (vq->size - 1)].id = head[packet_success];
+		vq->used->ring[res_cur_idx & (vq->size - 1)].len = packet_len;
+
+		/* Copy mbuf data to buffer */
+		/* TODO fixme for sg mbuf and the case that desc couldn't hold the mbuf data */
+		rte_memcpy((void *)(uintptr_t)buff_addr, (const void *)buff->pkt.data, rte_pktmbuf_data_len(buff));
+
+		res_cur_idx++;
+		packet_success++;
+
+		/* If mergeable is disabled then a header is required per buffer. */
+		if (!mergeable) {
+			rte_memcpy((void *)(uintptr_t)buff_hdr_addr, (const void *)&virtio_hdr, vq->vhost_hlen);
+			VHOST_PRINT_PACKET(dev, (uintptr_t)buff_hdr_addr, vq->vhost_hlen, 1);
+		} else {
+			mrg_count++;
+			/* Merge buffer can only handle so many buffers at a time. Tell the guest if this limit is reached. */
+			if ((mrg_count == VHOST_MAX_MRG_PKT_BURST) || (res_cur_idx == res_end_idx)) {
+				virtio_hdr.num_buffers = mrg_count;
+				LOG_DEBUG(VHOST_DATA, "(%"PRIu64") RX: Num merge buffers %d\n", dev->device_fh, virtio_hdr.num_buffers);
+				rte_memcpy((void *)(uintptr_t)buff_hdr_addr, (const void *)&virtio_hdr, vq->vhost_hlen);
+				VHOST_PRINT_PACKET(dev, (uintptr_t)buff_hdr_addr, vq->vhost_hlen, 1);
+				mrg_count = 0;
+			}
+		}
+		if (res_cur_idx < res_end_idx) {
+			/* Prefetch descriptor index. */
+			rte_prefetch0(&vq->desc[head[packet_success]]);
+		}
+	}
+
+	rte_compiler_barrier();
+
+	/* Wait until it's our turn to add our buffer to the used ring. */
+	while (unlikely(vq->last_used_idx != res_base_idx))
+		rte_pause();
+
+	*(volatile uint16_t *)&vq->used->idx += count;
+	vq->last_used_idx = res_end_idx;
+
+	/* Kick the guest if necessary. */
+	if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
+		eventfd_write((int)vq->kickfd, 1);
+	return count;
+}
+
+
+uint32_t
+rte_vhost_dequeue_burst(struct virtio_net *dev, uint16_t queue_id, struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint32_t count)
+{
+	struct rte_mbuf *mbuf;
+	struct vhost_virtqueue *vq;
+	struct vring_desc *desc;
+	uint64_t buff_addr = 0;
+	uint32_t head[VHOST_MAX_PKT_BURST];
+	uint32_t used_idx;
+	uint32_t i;
+	uint16_t free_entries, packet_success = 0;
+	uint16_t avail_idx;
+
+	if (unlikely(queue_id != VIRTIO_TXQ)) {
+		LOG_DEBUG(VHOST_DATA, "mq isn't supported in this version.\n");
+		return 0;
+	}
+
+	vq = dev->virtqueue[VIRTIO_TXQ];
+	avail_idx =  *((volatile uint16_t *)&vq->avail->idx);
+
+	/* If there are no available buffers then return. */
+	if (vq->last_used_idx == avail_idx)
+		return 0;
+
+	LOG_DEBUG(VHOST_DATA, "(%"PRIu64") virtio_dev_tx()\n", dev->device_fh);
+
+	/* Prefetch available ring to retrieve head indexes. */
+	rte_prefetch0(&vq->avail->ring[vq->last_used_idx & (vq->size - 1)]);
+
+	/*get the number of free entries in the ring*/
+	free_entries = (avail_idx - vq->last_used_idx);
+
+	if (free_entries > count)
+		free_entries = count;
+	/* Limit to MAX_PKT_BURST. */
+	if (free_entries > VHOST_MAX_PKT_BURST)
+		free_entries = VHOST_MAX_PKT_BURST;
+
+	LOG_DEBUG(VHOST_DATA, "(%"PRIu64") Buffers available %d\n", dev->device_fh, free_entries);
+	/* Retrieve all of the head indexes first to avoid caching issues. */
+	for (i = 0; i < free_entries; i++)
+		head[i] = vq->avail->ring[(vq->last_used_idx + i) & (vq->size - 1)];
+
+	/* Prefetch descriptor index. */
+	rte_prefetch0(&vq->desc[head[packet_success]]);
+	rte_prefetch0(&vq->used->ring[vq->last_used_idx & (vq->size - 1)]);
+
+	while (packet_success < free_entries) {
+		desc = &vq->desc[head[packet_success]];
+
+		/* Discard first buffer as it is the virtio header */
+		desc = &vq->desc[desc->next];
+
+		/* Buffer address translation. */
+		buff_addr = gpa_to_vva(dev, desc->addr);
+		/* Prefetch buffer address. */
+		rte_prefetch0((void *)(uintptr_t)buff_addr);
+
+		used_idx = vq->last_used_idx & (vq->size - 1);
+
+		if (packet_success < (free_entries - 1)) {
+			/* Prefetch descriptor index. */
+			rte_prefetch0(&vq->desc[head[packet_success+1]]);
+			rte_prefetch0(&vq->used->ring[(used_idx + 1) & (vq->size - 1)]);
+		}
+
+		/* Update used index buffer information. */
+		vq->used->ring[used_idx].id = head[packet_success];
+		vq->used->ring[used_idx].len = 0;
+
+		mbuf = rte_pktmbuf_alloc(mbuf_pool);
+		if (unlikely(mbuf == NULL)) {
+			RTE_LOG(ERR, VHOST_DATA, "Failed to allocate memory for mbuf.\n");
+			return packet_success;
+		}
+		mbuf->pkt.data_len = desc->len;
+		mbuf->pkt.pkt_len  = mbuf->pkt.data_len;
+
+		rte_memcpy((void *) mbuf->pkt.data,
+			(const void *) buff_addr, mbuf->pkt.data_len);
+
+		pkts[packet_success] = mbuf;
+
+		VHOST_PRINT_PACKET(dev, (uintptr_t)buff_addr, desc->len, 0);
+
+		vq->last_used_idx++;
+		packet_success++;
+	}
+
+	rte_compiler_barrier();
+	vq->used->idx += packet_success;
+	/* Kick guest if required. */
+	if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
+		eventfd_write((int)vq->kickfd, 1);
+
+	return packet_success;
+}
diff --git a/lib/librte_vhost/virtio-net.c b/lib/librte_vhost/virtio-net.c
new file mode 100644
index 0000000..ccda8e9
--- /dev/null
+++ b/lib/librte_vhost/virtio-net.c
@@ -0,0 +1,1002 @@ 
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <dirent.h>
+#include <fuse/cuse_lowlevel.h>
+#include <linux/vhost.h>
+#include <linux/virtio_net.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <sys/eventfd.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include <rte_ethdev.h>
+#include <rte_log.h>
+#include <rte_string_fns.h>
+#include <rte_memory.h>
+#include <rte_virtio_net.h>
+
+#include "vhost-net-cdev.h"
+#include "eventfd_link/eventfd_link.h"
+
+/**
+ * Device linked list structure for configuration.
+ */
+struct virtio_net_config_ll {
+	struct virtio_net             dev;    /* Virtio device. */
+	struct virtio_net_config_ll   *next;  /* Next entry on linked list. */
+};
+
+static const char eventfd_cdev[] = "/dev/eventfd-link";
+
+/* device ops to add/remove device to data core. */
+static struct virtio_net_device_ops const *notify_ops;
+/* Root address of the linked list in the configuration core. */
+static struct virtio_net_config_ll *ll_root;
+
+/* Features supported by this library. */
+#define VHOST_SUPPORTED_FEATURES (1ULL << VIRTIO_NET_F_MRG_RXBUF)
+static uint64_t VHOST_FEATURES = VHOST_SUPPORTED_FEATURES;
+
+/* Line size for reading maps file. */
+static const uint32_t BUFSIZE = PATH_MAX;
+
+/* Size of prot char array in procmap. */
+#define PROT_SZ 5
+
+/* Number of elements in procmap struct. */
+#define PROCMAP_SZ 8
+
+/* Structure containing information gathered from maps file. */
+struct procmap {
+	uint64_t    va_start;         /* Start virtual address in file. */
+	uint64_t    len;              /* Size of file. */
+	uint64_t    pgoff;            /* Not used. */
+	uint32_t    maj;              /* Not used. */
+	uint32_t    min;              /* Not used. */
+	uint32_t    ino;              /* Not used. */
+	char        prot[PROT_SZ];    /* Not used. */
+	char        fname[PATH_MAX];  /* File name. */
+};
+
+/**
+ * Converts QEMU virtual address to Vhost virtual address. This function is used
+ * to convert the ring addresses to our address space.
+ */
+static uint64_t
+qva_to_vva(struct virtio_net *dev, uint64_t qemu_va)
+{
+	struct virtio_memory_regions *region;
+	uint64_t vhost_va = 0;
+	uint32_t regionidx = 0;
+
+	/* Find the region where the address lives. */
+	for (regionidx = 0; regionidx < dev->mem->nregions; regionidx++) {
+		region = &dev->mem->regions[regionidx];
+		if ((qemu_va >= region->userspace_address) &&
+			(qemu_va <= region->userspace_address +
+			region->memory_size)) {
+			vhost_va = dev->mem->mapped_address + qemu_va - dev->mem->base_address;
+			break;
+		}
+	}
+	return vhost_va;
+}
+
+/**
+ * Locate the file containing QEMU's memory space and map it to our address space.
+ */
+static int
+host_memory_map(struct virtio_net *dev, struct virtio_memory *mem, pid_t pid, uint64_t addr)
+{
+	struct dirent *dptr = NULL;
+	struct procmap procmap;
+	DIR *dp = NULL;
+	int fd;
+	int i;
+	char memfile[PATH_MAX];
+	char mapfile[PATH_MAX];
+	char procdir[PATH_MAX];
+	char resolved_path[PATH_MAX];
+	FILE *fmap;
+	void *map;
+	uint8_t	found = 0;
+	char line[BUFSIZE];
+	char dlm[] = "-   :   ";
+	char *str, *sp, *in[PROCMAP_SZ];
+	char *end = NULL;
+
+	/* Path where mem files are located. */
+	snprintf(procdir, PATH_MAX, "/proc/%u/fd/", pid);
+	/* Maps file used to locate mem file. */
+	snprintf(mapfile, PATH_MAX, "/proc/%u/maps", pid);
+
+	fmap = fopen(mapfile, "r");
+	if (fmap == NULL) {
+		RTE_LOG(ERR, VHOST_CONFIG, "(%"PRIu64") Failed to open maps file for pid %d\n", dev->device_fh, pid);
+		return -1;
+	}
+
+	/* Read through maps file until we find out base_address. */
+	while (fgets(line, BUFSIZE, fmap) != 0) {
+		str = line;
+		errno = 0;
+		/* Split line in to fields. */
+		for (i = 0; i < PROCMAP_SZ; i++) {
+			in[i] = strtok_r(str, &dlm[i], &sp);
+			if ((in[i] == NULL) || (errno != 0)) {
+				fclose(fmap);
+				return -1;
+			}
+			str = NULL;
+		}
+
+		/* Convert/Copy each field as needed. */
+		procmap.va_start = strtoull(in[0], &end, 16);
+		if ((in[0] == '\0') || (end == NULL) || (*end != '\0') || (errno != 0)) {
+			fclose(fmap);
+			return -1;
+		}
+
+		procmap.len = strtoull(in[1], &end, 16);
+		if ((in[1] == '\0') || (end == NULL) || (*end != '\0') || (errno != 0)) {
+			fclose(fmap);
+			return -1;
+		}
+
+		procmap.pgoff = strtoull(in[3], &end, 16);
+		if ((in[3] == '\0') || (end == NULL) || (*end != '\0') || (errno != 0)) {
+			fclose(fmap);
+			return -1;
+		}
+
+		procmap.maj = strtoul(in[4], &end, 16);
+		if ((in[4] == '\0') || (end == NULL) || (*end != '\0') || (errno != 0)) {
+			fclose(fmap);
+			return -1;
+		}
+
+		procmap.min = strtoul(in[5], &end, 16);
+		if ((in[5] == '\0') || (end == NULL) || (*end != '\0') || (errno != 0)) {
+			fclose(fmap);
+			return -1;
+		}
+
+		procmap.ino = strtoul(in[6], &end, 16);
+		if ((in[6] == '\0') || (end == NULL) || (*end != '\0') || (errno != 0)) {
+			fclose(fmap);
+			return -1;
+		}
+
+		memcpy(&procmap.prot, in[2], PROT_SZ);
+		memcpy(&procmap.fname, in[7], PATH_MAX);
+
+		if (procmap.va_start == addr) {
+			procmap.len = procmap.len - procmap.va_start;
+			found = 1;
+			break;
+		}
+	}
+	fclose(fmap);
+
+	if (!found) {
+		RTE_LOG(ERR, VHOST_CONFIG, "(%"PRIu64") Failed to find memory file in pid %d maps file\n", dev->device_fh, pid);
+		return -1;
+	}
+
+	/* Find the guest memory file among the process fds. */
+	dp = opendir(procdir);
+	if (dp == NULL) {
+		RTE_LOG(ERR, VHOST_CONFIG, "(%"PRIu64") Cannot open pid %d process directory \n", dev->device_fh, pid);
+		return -1;
+
+	}
+
+	found = 0;
+
+	/* Read the fd directory contents. */
+	while (NULL != (dptr = readdir(dp))) {
+		snprintf(memfile, PATH_MAX, "/proc/%u/fd/%s", pid, dptr->d_name);
+		realpath(memfile, resolved_path);
+		if (resolved_path == NULL) {
+			RTE_LOG(ERR, VHOST_CONFIG, "(%"PRIu64") Failed to resolve fd directory\n", dev->device_fh);
+			closedir(dp);
+			return -1;
+		}
+		if (strncmp(resolved_path, procmap.fname,
+			strnlen(procmap.fname, PATH_MAX)) == 0) {
+			found = 1;
+			break;
+		}
+	}
+
+	closedir(dp);
+
+	if (found == 0) {
+		RTE_LOG(ERR, VHOST_CONFIG, "(%"PRIu64") Failed to find memory file for pid %d\n", dev->device_fh, pid);
+		return -1;
+	}
+	/* Open the shared memory file and map the memory into this process. */
+	fd = open(memfile, O_RDWR);
+
+	if (fd == -1) {
+		RTE_LOG(ERR, VHOST_CONFIG, "(%"PRIu64") Failed to open %s for pid %d\n", dev->device_fh, memfile, pid);
+		return -1;
+	}
+
+	map = mmap(0, (size_t)procmap.len, PROT_READ|PROT_WRITE , MAP_POPULATE|MAP_SHARED, fd, 0);
+	close(fd);
+
+	if (map == MAP_FAILED) {
+		RTE_LOG(ERR, VHOST_CONFIG, "(%"PRIu64") Error mapping the file %s for pid %d\n",  dev->device_fh, memfile, pid);
+		return -1;
+	}
+
+	/* Store the memory address and size in the device data structure */
+	mem->mapped_address = (uint64_t)(uintptr_t)map;
+	mem->mapped_size = procmap.len;
+
+	LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") Mem File: %s->%s - Size: %llu - VA: %p\n", dev->device_fh,
+		memfile, resolved_path, (long long unsigned)mem->mapped_size, map);
+
+	return 0;
+}
+
+/**
+ *  Initialise all variables in device structure.
+ */
+static void
+init_device(struct virtio_net *dev)
+{
+	uint64_t vq_offset;
+
+	/* Virtqueues have already been malloced so we don't want to set them to NULL. */
+	vq_offset = offsetof(struct virtio_net, mem);
+
+	/* Set everything to 0. */
+	memset((void *)(uintptr_t)((uint64_t)(uintptr_t)dev + vq_offset), 0,
+		(sizeof(struct virtio_net) - (size_t)vq_offset));
+	memset(dev->virtqueue[VIRTIO_RXQ], 0, sizeof(struct vhost_virtqueue));
+	memset(dev->virtqueue[VIRTIO_TXQ], 0, sizeof(struct vhost_virtqueue));
+
+	/* Backends are set to -1 indicating an inactive device. */
+	dev->virtqueue[VIRTIO_RXQ]->backend = VIRTIO_DEV_STOPPED;
+	dev->virtqueue[VIRTIO_TXQ]->backend = VIRTIO_DEV_STOPPED;
+}
+
+/**
+ * Unmap any memory, close any file descriptors and free any memory owned by a device.
+ */
+static void
+cleanup_device(struct virtio_net *dev)
+{
+	/* Unmap QEMU memory file if mapped. */
+	if (dev->mem) {
+		munmap((void *)(uintptr_t)dev->mem->mapped_address, (size_t)dev->mem->mapped_size);
+		free(dev->mem);
+	}
+
+	/* Close any event notifiers opened by device. */
+	if (dev->virtqueue[VIRTIO_RXQ]->callfd)
+		close((int)dev->virtqueue[VIRTIO_RXQ]->callfd);
+	if (dev->virtqueue[VIRTIO_RXQ]->kickfd)
+		close((int)dev->virtqueue[VIRTIO_RXQ]->kickfd);
+	if (dev->virtqueue[VIRTIO_TXQ]->callfd)
+		close((int)dev->virtqueue[VIRTIO_TXQ]->callfd);
+	if (dev->virtqueue[VIRTIO_TXQ]->kickfd)
+		close((int)dev->virtqueue[VIRTIO_TXQ]->kickfd);
+}
+
+/**
+ * Release virtqueues and device memory.
+ */
+static void
+free_device(struct virtio_net_config_ll *ll_dev)
+{
+	/* Free any malloc'd memory */
+	free(ll_dev->dev.virtqueue[VIRTIO_RXQ]);
+	free(ll_dev->dev.virtqueue[VIRTIO_TXQ]);
+	free(ll_dev);
+}
+
+/**
+ * Retrieves an entry from the devices configuration linked list.
+ */
+static struct virtio_net_config_ll *
+get_config_ll_entry(struct vhost_device_ctx ctx)
+{
+	struct virtio_net_config_ll *ll_dev = ll_root;
+
+	/* Loop through linked list until the device_fh is found. */
+	while (ll_dev != NULL) {
+		if (ll_dev->dev.device_fh == ctx.fh)
+			return ll_dev;
+		ll_dev = ll_dev->next;
+	}
+
+	return NULL;
+}
+
+/**
+ * Searches the configuration core linked list and retrieves the device if it exists.
+ */
+static struct virtio_net *
+get_device(struct vhost_device_ctx ctx)
+{
+	struct virtio_net_config_ll *ll_dev;
+
+	ll_dev = get_config_ll_entry(ctx);
+
+	/* If a matching entry is found in the linked list, return the device in that entry. */
+	if (ll_dev)
+		return &ll_dev->dev;
+
+	RTE_LOG(ERR, VHOST_CONFIG, "(%"PRIu64") Device not found in linked list.\n", ctx.fh);
+	return NULL;
+}
+
+/**
+ * Add entry containing a device to the device configuration linked list.
+ */
+static void
+add_config_ll_entry(struct virtio_net_config_ll *new_ll_dev)
+{
+	struct virtio_net_config_ll *ll_dev = ll_root;
+
+	/* If ll_dev == NULL then this is the first device so go to else */
+	if (ll_dev) {
+		/* If the 1st device_fh != 0 then we insert our device here. */
+		if (ll_dev->dev.device_fh != 0)	{
+			new_ll_dev->dev.device_fh = 0;
+			new_ll_dev->next = ll_dev;
+			ll_root = new_ll_dev;
+		} else {
+			/* Increment through the ll until we find un unused device_fh. Insert the device at that entry*/
+			while ((ll_dev->next != NULL) && (ll_dev->dev.device_fh == (ll_dev->next->dev.device_fh - 1)))
+				ll_dev = ll_dev->next;
+
+			new_ll_dev->dev.device_fh = ll_dev->dev.device_fh + 1;
+			new_ll_dev->next = ll_dev->next;
+			ll_dev->next = new_ll_dev;
+		}
+	} else {
+		ll_root = new_ll_dev;
+		ll_root->dev.device_fh = 0;
+	}
+
+}
+
+/**
+ * Remove an entry from the device configuration linked list.
+ */
+static struct virtio_net_config_ll *
+rm_config_ll_entry(struct virtio_net_config_ll *ll_dev, struct virtio_net_config_ll *ll_dev_last)
+{
+	/* First remove the device and then clean it up. */
+	if (ll_dev == ll_root) {
+		ll_root = ll_dev->next;
+		cleanup_device(&ll_dev->dev);
+		free_device(ll_dev);
+		return ll_root;
+	} else {
+		if (likely(ll_dev_last != NULL)) {
+			ll_dev_last->next = ll_dev->next;
+			cleanup_device(&ll_dev->dev);
+			free_device(ll_dev);
+			return ll_dev_last->next;
+		} else {
+			cleanup_device(&ll_dev->dev);
+			free_device(ll_dev);
+			RTE_LOG(ERR, VHOST_CONFIG, "Remove entry from config_ll failed\n");
+			return NULL;
+		}
+	}
+}
+
+
+/**
+ * Function is called from the CUSE open function. The device structure is
+ * initialised and a new entry is added to the device configuration linked
+ * list.
+ */
+static int
+new_device(struct vhost_device_ctx ctx)
+{
+	struct virtio_net_config_ll *new_ll_dev;
+	struct vhost_virtqueue *virtqueue_rx, *virtqueue_tx;
+
+	/* Setup device and virtqueues. */
+	new_ll_dev = malloc(sizeof(struct virtio_net_config_ll));
+	if (new_ll_dev == NULL) {
+		RTE_LOG(ERR, VHOST_CONFIG, "(%"PRIu64") Failed to allocate memory for dev.\n", ctx.fh);
+		return -1;
+	}
+
+	virtqueue_rx = malloc(sizeof(struct vhost_virtqueue));
+	if (virtqueue_rx == NULL) {
+		free(new_ll_dev);
+		RTE_LOG(ERR, VHOST_CONFIG, "(%"PRIu64") Failed to allocate memory for virtqueue_rx.\n", ctx.fh);
+		return -1;
+	}
+
+	virtqueue_tx = malloc(sizeof(struct vhost_virtqueue));
+	if (virtqueue_tx == NULL) {
+		free(virtqueue_rx);
+		free(new_ll_dev);
+		RTE_LOG(ERR, VHOST_CONFIG, "(%"PRIu64") Failed to allocate memory for virtqueue_tx.\n", ctx.fh);
+		return -1;
+	}
+
+	new_ll_dev->dev.virtqueue[VIRTIO_RXQ] = virtqueue_rx;
+	new_ll_dev->dev.virtqueue[VIRTIO_TXQ] = virtqueue_tx;
+
+	/* Initialise device and virtqueues. */
+	init_device(&new_ll_dev->dev);
+
+	new_ll_dev->next = NULL;
+
+	/* Add entry to device configuration linked list. */
+	add_config_ll_entry(new_ll_dev);
+
+	return new_ll_dev->dev.device_fh;
+}
+
+/**
+ * Function is called from the CUSE release function. This function will cleanup
+ * the device and remove it from device configuration linked list.
+ */
+static void
+destroy_device(struct vhost_device_ctx ctx)
+{
+	struct virtio_net_config_ll *ll_dev_cur_ctx, *ll_dev_last = NULL;
+	struct virtio_net_config_ll *ll_dev_cur = ll_root;
+
+	/* Find the linked list entry for the device to be removed. */
+	ll_dev_cur_ctx = get_config_ll_entry(ctx);
+	while (ll_dev_cur != NULL) {
+		/* If the device is found or a device that doesn't exist is found then it is removed. */
+		if (ll_dev_cur == ll_dev_cur_ctx) {
+			/*
+			 * If the device is running on a data core then call the function to remove it from
+			 * the data core.
+			 */
+			if ((ll_dev_cur->dev.flags & VIRTIO_DEV_RUNNING))
+				notify_ops->destroy_device(&(ll_dev_cur->dev));
+			ll_dev_cur = rm_config_ll_entry(ll_dev_cur, ll_dev_last);
+			/*TODO return here? */
+		} else {
+			ll_dev_last = ll_dev_cur;
+			ll_dev_cur = ll_dev_cur->next;
+		}
+	}
+}
+
+/**
+ * Called from CUSE IOCTL: VHOST_SET_OWNER
+ * This function just returns success at the moment unless the device hasn't been initialised.
+ */
+static int
+set_owner(struct vhost_device_ctx ctx)
+{
+	struct virtio_net *dev;
+
+	dev = get_device(ctx);
+	if (dev == NULL)
+		return -1;
+
+	return 0;
+}
+
+/**
+ * Called from CUSE IOCTL: VHOST_RESET_OWNER
+ */
+static int
+reset_owner(struct vhost_device_ctx ctx)
+{
+	struct virtio_net_config_ll *ll_dev;
+
+	ll_dev = get_config_ll_entry(ctx);
+
+	cleanup_device(&ll_dev->dev);
+	init_device(&ll_dev->dev);
+
+	return 0;
+}
+
+/**
+ * Called from CUSE IOCTL: VHOST_GET_FEATURES
+ * The features that we support are requested.
+ */
+static int
+get_features(struct vhost_device_ctx ctx, uint64_t *pu)
+{
+	struct virtio_net *dev;
+
+	dev = get_device(ctx);
+	if (dev == NULL)
+		return -1;
+
+	/* Send our supported features. */
+	*pu = VHOST_FEATURES;
+	return 0;
+}
+
+/**
+ * Called from CUSE IOCTL: VHOST_SET_FEATURES
+ * We receive the negotiated set of features supported by us and the virtio device.
+ */
+static int
+set_features(struct vhost_device_ctx ctx, uint64_t *pu)
+{
+	struct virtio_net *dev;
+
+	dev = get_device(ctx);
+	if (dev == NULL)
+		return -1;
+	if (*pu & ~VHOST_FEATURES)
+		return -1;
+
+	/* Store the negotiated feature list for the device. */
+	dev->features = *pu;
+
+	/* Set the vhost_hlen depending on if VIRTIO_NET_F_MRG_RXBUF is set. */
+	if (dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF)) {
+		LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") Mergeable RX buffers enabled\n", dev->device_fh);
+		dev->virtqueue[VIRTIO_RXQ]->vhost_hlen = sizeof(struct virtio_net_hdr_mrg_rxbuf);
+		dev->virtqueue[VIRTIO_TXQ]->vhost_hlen = sizeof(struct virtio_net_hdr_mrg_rxbuf);
+	} else {
+		LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") Mergeable RX buffers disabled\n", dev->device_fh);
+		dev->virtqueue[VIRTIO_RXQ]->vhost_hlen = sizeof(struct virtio_net_hdr);
+		dev->virtqueue[VIRTIO_TXQ]->vhost_hlen = sizeof(struct virtio_net_hdr);
+	}
+	return 0;
+}
+
+
+/**
+ * Called from CUSE IOCTL: VHOST_SET_MEM_TABLE
+ * This function creates and populates the memory structure for the device. This includes
+ * storing offsets used to translate buffer addresses.
+ */
+static int
+set_mem_table(struct vhost_device_ctx ctx, const void *mem_regions_addr, uint32_t nregions)
+{
+	struct virtio_net *dev;
+	struct vhost_memory_region *mem_regions;
+	struct virtio_memory *mem;
+	uint64_t size = offsetof(struct vhost_memory, regions);
+	uint32_t regionidx, valid_regions;
+
+	dev = get_device(ctx);
+	if (dev == NULL)
+		return -1;
+
+	if (dev->mem) {
+		munmap((void *)(uintptr_t)dev->mem->mapped_address, (size_t)dev->mem->mapped_size);
+		free(dev->mem);
+	}
+
+	/* Malloc the memory structure depending on the number of regions. */
+	mem = calloc(1, sizeof(struct virtio_memory) + (sizeof(struct virtio_memory_regions) * nregions));
+	if (mem == NULL) {
+		RTE_LOG(ERR, VHOST_CONFIG, "(%"PRIu64") Failed to allocate memory for dev->mem.\n", dev->device_fh);
+		return -1;
+	}
+
+	mem->nregions = nregions;
+
+	mem_regions = (void *)(uintptr_t)((uint64_t)(uintptr_t)mem_regions_addr + size);
+
+	for (regionidx = 0; regionidx < mem->nregions; regionidx++) {
+		/* Populate the region structure for each region. */
+		mem->regions[regionidx].guest_phys_address = mem_regions[regionidx].guest_phys_addr;
+		mem->regions[regionidx].guest_phys_address_end = mem->regions[regionidx].guest_phys_address +
+			mem_regions[regionidx].memory_size;
+		mem->regions[regionidx].memory_size = mem_regions[regionidx].memory_size;
+		mem->regions[regionidx].userspace_address = mem_regions[regionidx].userspace_addr;
+
+		LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") REGION: %u - GPA: %p - QEMU VA: %p - SIZE (%"PRIu64")\n", dev->device_fh,
+				regionidx, (void *)(uintptr_t)mem->regions[regionidx].guest_phys_address,
+				(void *)(uintptr_t)mem->regions[regionidx].userspace_address,
+				mem->regions[regionidx].memory_size);
+
+		/*set the base address mapping*/
+		if (mem->regions[regionidx].guest_phys_address == 0x0) {
+			mem->base_address = mem->regions[regionidx].userspace_address;
+			/* Map VM memory file */
+			if (host_memory_map(dev, mem, ctx.pid, mem->base_address) != 0) {
+				free(mem);
+				return -1;
+			}
+		}
+	}
+
+	/* Check that we have a valid base address. */
+	if (mem->base_address == 0) {
+		RTE_LOG(ERR, VHOST_CONFIG, "(%"PRIu64") Failed to find base address of qemu memory file.\n", dev->device_fh);
+		free(mem);
+		return -1;
+	}
+
+	/* Check if all of our regions have valid mappings. Usually one does not exist in the QEMU memory file. */
+	valid_regions = mem->nregions;
+	for (regionidx = 0; regionidx < mem->nregions; regionidx++) {
+		if ((mem->regions[regionidx].userspace_address < mem->base_address) ||
+			(mem->regions[regionidx].userspace_address > (mem->base_address + mem->mapped_size)))
+				valid_regions--;
+	}
+
+	/* If a region does not have a valid mapping we rebuild our memory struct to contain only valid entries. */
+	if (valid_regions != mem->nregions) {
+		LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") Not all memory regions exist in the QEMU mem file. Re-populating mem structure\n",
+			dev->device_fh);
+
+		/* Re-populate the memory structure with only valid regions. Invalid regions are over-written with memmove. */
+		valid_regions = 0;
+
+		for (regionidx = mem->nregions; 0 != regionidx--;) {
+			if ((mem->regions[regionidx].userspace_address < mem->base_address) ||
+					(mem->regions[regionidx].userspace_address > (mem->base_address + mem->mapped_size))) {
+				memmove(&mem->regions[regionidx], &mem->regions[regionidx + 1],
+					sizeof(struct virtio_memory_regions) * valid_regions);
+			} else {
+				valid_regions++;
+			}
+		}
+	}
+	mem->nregions = valid_regions;
+	dev->mem = mem;
+
+	/*
+	 * Calculate the address offset for each region. This offset is used to identify the vhost virtual address
+	 * corresponding to a QEMU guest physical address.
+	 */
+	for (regionidx = 0; regionidx < dev->mem->nregions; regionidx++)
+		dev->mem->regions[regionidx].address_offset = dev->mem->regions[regionidx].userspace_address - dev->mem->base_address
+			+ dev->mem->mapped_address - dev->mem->regions[regionidx].guest_phys_address;
+
+	return 0;
+}
+
+/**
+ * Called from CUSE IOCTL: VHOST_SET_VRING_NUM
+ * The virtio device sends us the size of the descriptor ring.
+ */
+static int
+set_vring_num(struct vhost_device_ctx ctx, struct vhost_vring_state *state)
+{
+	struct virtio_net *dev;
+
+	dev = get_device(ctx);
+	if (dev == NULL)
+		return -1;
+
+	/* State->index refers to the queue index. The TX queue is 1, RX queue is 0. */
+	dev->virtqueue[state->index]->size = state->num;
+
+	return 0;
+}
+
+/**
+ * Called from CUSE IOCTL: VHOST_SET_VRING_ADDR
+ * The virtio device sends us the desc, used and avail ring addresses. This function
+ * then converts these to our address space.
+ */
+static int
+set_vring_addr(struct vhost_device_ctx ctx, struct vhost_vring_addr *addr)
+{
+	struct virtio_net *dev;
+	struct vhost_virtqueue *vq;
+
+	dev = get_device(ctx);
+	if (dev == NULL)
+		return -1;
+
+	/* addr->index refers to the queue index. The TX queue is 1, RX queue is 0. */
+	vq = dev->virtqueue[addr->index];
+
+	/* The addresses are converted from QEMU virtual to Vhost virtual. */
+	vq->desc = (struct vring_desc *)(uintptr_t)qva_to_vva(dev, addr->desc_user_addr);
+	if (vq->desc == 0) {
+		RTE_LOG(ERR, VHOST_CONFIG, "(%"PRIu64") Failed to find descriptor ring address.\n", dev->device_fh);
+		return -1;
+	}
+
+	vq->avail = (struct vring_avail *)(uintptr_t)qva_to_vva(dev, addr->avail_user_addr);
+	if (vq->avail == 0) {
+		RTE_LOG(ERR, VHOST_CONFIG, "(%"PRIu64") Failed to find available ring address.\n", dev->device_fh);
+		return -1;
+	}
+
+	vq->used = (struct vring_used *)(uintptr_t)qva_to_vva(dev, addr->used_user_addr);
+	if (vq->used == 0) {
+		RTE_LOG(ERR, VHOST_CONFIG, "(%"PRIu64") Failed to find used ring address.\n", dev->device_fh);
+		return -1;
+	}
+
+	LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") mapped address desc: %p\n", dev->device_fh, vq->desc);
+	LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") mapped address avail: %p\n", dev->device_fh, vq->avail);
+	LOG_DEBUG(VHOST_CONFIG, "(%"PRIu64") mapped address used: %p\n", dev->device_fh, vq->used);
+
+	return 0;
+}
+
+/**
+ * Called from CUSE IOCTL: VHOST_SET_VRING_BASE
+ * The virtio device sends us the available ring last used index.
+ */
+static int
+set_vring_base(struct vhost_device_ctx ctx, struct vhost_vring_state *state)
+{
+	struct virtio_net *dev;
+
+	dev = get_device(ctx);
+	if (dev == NULL)
+		return -1;
+
+	/* State->index refers to the queue index. The TX queue is 1, RX queue is 0. */
+	dev->virtqueue[state->index]->last_used_idx = state->num;
+	dev->virtqueue[state->index]->last_used_idx_res = state->num;
+
+	return 0;
+}
+
+/**
+ * Called from CUSE IOCTL: VHOST_GET_VRING_BASE
+ * We send the virtio device our available ring last used index.
+ */
+static int
+get_vring_base(struct vhost_device_ctx ctx, uint32_t index, struct vhost_vring_state *state)
+{
+	struct virtio_net *dev;
+
+	dev = get_device(ctx);
+	if (dev == NULL)
+		return -1;
+
+	state->index = index;
+	/* State->index refers to the queue index. The TX queue is 1, RX queue is 0. */
+	state->num = dev->virtqueue[state->index]->last_used_idx;
+
+	return 0;
+}
+
+/**
+ * This function uses the eventfd_link kernel module to copy an eventfd file descriptor
+ * provided by QEMU in to our process space.
+ */
+static int
+eventfd_copy(struct virtio_net *dev, struct eventfd_copy *eventfd_copy)
+{
+	int eventfd_link, ret;
+
+	/* Open the character device to the kernel module. */
+	eventfd_link = open(eventfd_cdev, O_RDWR);
+	if (eventfd_link < 0) {
+		RTE_LOG(ERR, VHOST_CONFIG, "(%"PRIu64") eventfd_link module is not loaded\n",  dev->device_fh);
+		return -1;
+	}
+
+	/* Call the IOCTL to copy the eventfd. */
+	ret = ioctl(eventfd_link, EVENTFD_COPY, eventfd_copy);
+	close(eventfd_link);
+
+	if (ret < 0) {
+		RTE_LOG(ERR, VHOST_CONFIG, "(%"PRIu64") EVENTFD_COPY ioctl failed\n",  dev->device_fh);
+		return -1;
+	}
+
+
+	return 0;
+}
+
+/**
+ * Called from CUSE IOCTL: VHOST_SET_VRING_CALL
+ * The virtio device sends an eventfd to interrupt the guest. This fd gets copied in
+ * to our process space.
+ */
+static int
+set_vring_call(struct vhost_device_ctx ctx, struct vhost_vring_file *file)
+{
+	struct virtio_net *dev;
+	struct eventfd_copy	eventfd_kick;
+	struct vhost_virtqueue *vq;
+
+	dev = get_device(ctx);
+	if (dev == NULL)
+		return -1;
+
+	/* file->index refers to the queue index. The TX queue is 1, RX queue is 0. */
+	vq = dev->virtqueue[file->index];
+
+	if (vq->kickfd)
+		close((int)vq->kickfd);
+
+	/* Populate the eventfd_copy structure and call eventfd_copy. */
+	vq->kickfd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
+	eventfd_kick.source_fd = vq->kickfd;
+	eventfd_kick.target_fd = file->fd;
+	eventfd_kick.target_pid = ctx.pid;
+
+	if (eventfd_copy(dev, &eventfd_kick))
+		return -1;
+
+	return 0;
+}
+
+/**
+ * Called from CUSE IOCTL: VHOST_SET_VRING_KICK
+ * The virtio device sends an eventfd that it can use to notify us. This fd gets copied in
+ * to our process space.
+ */
+static int
+set_vring_kick(struct vhost_device_ctx ctx, struct vhost_vring_file *file)
+{
+	struct virtio_net *dev;
+	struct eventfd_copy eventfd_call;
+	struct vhost_virtqueue *vq;
+
+	dev = get_device(ctx);
+	if (dev == NULL)
+		return -1;
+
+	/* file->index refers to the queue index. The TX queue is 1, RX queue is 0. */
+	vq = dev->virtqueue[file->index];
+
+	if (vq->callfd)
+		close((int)vq->callfd);
+
+	/* Populate the eventfd_copy structure and call eventfd_copy. */
+	vq->callfd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
+	eventfd_call.source_fd = vq->callfd;
+	eventfd_call.target_fd = file->fd;
+	eventfd_call.target_pid = ctx.pid;
+
+	if (eventfd_copy(dev, &eventfd_call))
+		return -1;
+
+	return 0;
+}
+
+/**
+ * Called from CUSE IOCTL: VHOST_NET_SET_BACKEND
+ * To complete device initialisation when the virtio driver is loaded we are provided with a
+ * valid fd for a tap device (not used by us). If this happens then we can add the device to a
+ * data core. When the virtio driver is removed we get fd=-1. At that point we remove the device
+ * from the data core. The device will still exist in the device configuration linked list.
+ */
+static int
+set_backend(struct vhost_device_ctx ctx, struct vhost_vring_file *file)
+{
+	struct virtio_net *dev;
+
+	dev = get_device(ctx);
+	if (dev == NULL)
+		return -1;
+
+	/* file->index refers to the queue index. The TX queue is 1, RX queue is 0. */
+	dev->virtqueue[file->index]->backend = file->fd;
+
+	/* If the device isn't already running and both backend fds are set we add the device. */
+	if (!(dev->flags & VIRTIO_DEV_RUNNING)) {
+		if (((int)dev->virtqueue[VIRTIO_TXQ]->backend != VIRTIO_DEV_STOPPED) &&
+			((int)dev->virtqueue[VIRTIO_RXQ]->backend != VIRTIO_DEV_STOPPED))
+			return notify_ops->new_device(dev);
+	/* Otherwise we remove it. */
+	} else
+		if (file->fd == VIRTIO_DEV_STOPPED)
+			notify_ops->destroy_device(dev);
+	return 0;
+}
+
+/**
+ * Function pointers are set for the device operations to allow CUSE to call functions
+ * when an IOCTL, device_add or device_release is received.
+ */
+static const struct vhost_net_device_ops vhost_device_ops = {
+	.new_device = new_device,
+	.destroy_device = destroy_device,
+
+	.get_features = get_features,
+	.set_features = set_features,
+
+	.set_mem_table = set_mem_table,
+
+	.set_vring_num = set_vring_num,
+	.set_vring_addr = set_vring_addr,
+	.set_vring_base = set_vring_base,
+	.get_vring_base = get_vring_base,
+
+	.set_vring_kick = set_vring_kick,
+	.set_vring_call = set_vring_call,
+
+	.set_backend = set_backend,
+
+	.set_owner = set_owner,
+	.reset_owner = reset_owner,
+};
+
+/**
+ * Called by main to setup callbacks when registering CUSE device.
+ */
+struct vhost_net_device_ops const *
+get_virtio_net_callbacks(void)
+{
+	return &vhost_device_ops;
+}
+
+int rte_vhost_enable_guest_notification(struct virtio_net *dev, uint16_t queue_id, int enable)
+{
+	if (enable) {
+		RTE_LOG(ERR, VHOST_CONFIG, "guest notification isn't supported.\n");
+		return -1;
+	}
+
+	dev->virtqueue[queue_id]->used->flags = enable ? 0 : VRING_USED_F_NO_NOTIFY;
+	return 0;
+}
+
+uint64_t rte_vhost_feature_get(void)
+{
+	return VHOST_FEATURES;
+}
+
+int rte_vhost_feature_disable(uint64_t feature_mask)
+{
+	VHOST_FEATURES = VHOST_FEATURES & ~feature_mask;
+	return 0;
+}
+
+int rte_vhost_feature_enable(uint64_t feature_mask)
+{
+	if ((feature_mask & VHOST_SUPPORTED_FEATURES) == feature_mask) {
+		VHOST_FEATURES = VHOST_FEATURES | feature_mask;
+		return 0;
+	}
+	return -1;
+}
+
+
+/*
+ * Register ops so that we can add/remove device to data core.
+ */
+int
+rte_vhost_driver_callback_register(struct virtio_net_device_ops const * const ops)
+{
+	notify_ops = ops;
+
+	return 0;
+}