examples/vhost: import userspace vhost application
authorBruce Richardson <bruce.richardson@intel.com>
Mon, 10 Feb 2014 13:57:48 +0000 (13:57 +0000)
committerDavid Marchand <david.marchand@6wind.com>
Wed, 26 Feb 2014 09:47:59 +0000 (10:47 +0100)
The vhost sample application demonstrates integration of the Intel(R) Data Plane
Development Kit (Intel(R) DPDK) with the Linux KVM hypervisor by implementing the
vhost-net offload API. The sample application performs simple packet switching
between virtual machines based on Media Access Control (MAC) address or Virtual
Local Area Network (VLAN) tag. The splitting of ethernet traffic from an external switch
is performed in hardware by the Virtual Machine Device Queues (VMDQ) and Data
Center Bridging (DCB) features of the Intel(R) 82599 10 Gigabit Ethernet Controller.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
examples/vhost/Makefile [new file with mode: 0644]
examples/vhost/eventfd_link/Makefile [new file with mode: 0644]
examples/vhost/eventfd_link/eventfd_link.c [new file with mode: 0644]
examples/vhost/eventfd_link/eventfd_link.h [new file with mode: 0644]
examples/vhost/libvirt/qemu-wrap.py [new file with mode: 0755]
examples/vhost/main.c [new file with mode: 0644]
examples/vhost/main.h [new file with mode: 0644]
examples/vhost/vhost-net-cdev.c [new file with mode: 0644]
examples/vhost/vhost-net-cdev.h [new file with mode: 0644]
examples/vhost/virtio-net.c [new file with mode: 0644]
examples/vhost/virtio-net.h [new file with mode: 0644]

diff --git a/examples/vhost/Makefile b/examples/vhost/Makefile
new file mode 100644 (file)
index 0000000..e56b184
--- /dev/null
@@ -0,0 +1,52 @@
+#   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.
+
+ifeq ($(RTE_SDK),)
+$(error "Please define RTE_SDK environment variable")
+endif
+
+# Default target, can be overriden by command line or environment
+RTE_TARGET ?= x86_64-default-linuxapp-gcc
+
+include $(RTE_SDK)/mk/rte.vars.mk
+
+# binary name
+APP = vhost-switch
+
+# all source are stored in SRCS-y
+#SRCS-y := cusedrv.c loopback-userspace.c
+SRCS-y := main.c virtio-net.c vhost-net-cdev.c
+
+CFLAGS += -O2 -I/usr/local/include -D_FILE_OFFSET_BITS=64 -Wno-unused-parameter
+CFLAGS += $(WERROR_FLAGS)
+LDFLAGS += -lfuse
+
+include $(RTE_SDK)/mk/rte.extapp.mk
diff --git a/examples/vhost/eventfd_link/Makefile b/examples/vhost/eventfd_link/Makefile
new file mode 100644 (file)
index 0000000..5fe7297
--- /dev/null
@@ -0,0 +1,39 @@
+#   BSD LICENSE
+# 
+#   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+#   All rights reserved.
+# 
+#   Redistribution and use in source and binary forms, with or without
+#   modification, are permitted provided that the following conditions
+#   are met:
+# 
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above copyright
+#       notice, this list of conditions and the following disclaimer in
+#       the documentation and/or other materials provided with the
+#       distribution.
+#     * Neither the name of Intel Corporation nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+# 
+#   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+#   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+#   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+#   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+#   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+#   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+#   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+#   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+#   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+#   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+#   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+obj-m += eventfd_link.o
+
+
+all:
+       make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
+
+clean:
+       make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean
diff --git a/examples/vhost/eventfd_link/eventfd_link.c b/examples/vhost/eventfd_link/eventfd_link.c
new file mode 100644 (file)
index 0000000..f7975fa
--- /dev/null
@@ -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/examples/vhost/eventfd_link/eventfd_link.h b/examples/vhost/eventfd_link/eventfd_link.h
new file mode 100644 (file)
index 0000000..f33c2f8
--- /dev/null
@@ -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/examples/vhost/libvirt/qemu-wrap.py b/examples/vhost/libvirt/qemu-wrap.py
new file mode 100755 (executable)
index 0000000..e073b7c
--- /dev/null
@@ -0,0 +1,367 @@
+#!/usr/bin/python
+#/*
+# *   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.
+# */
+
+#####################################################################
+# This script is designed to modify the call to the QEMU emulator 
+# to support userspace vhost when starting a guest machine through 
+# libvirt with vhost enabled. The steps to enable this are as follows 
+# and should be run as root:
+#
+# 1. Place this script in a libvirtd's binary search PATH ($PATH)
+#    A good location would be in the same directory that the QEMU 
+#    binary is located
+#   
+# 2. Ensure that the script has the same owner/group and file 
+#    permissions as the QEMU binary
+#
+# 3. Update the VM xml file using "virsh edit VM.xml"
+#
+#    3.a) Set the VM to use the launch script
+#
+#      Set the emulator path contained in the 
+#              <emulator><emulator/> tags
+#
+#      e.g replace <emulator>/usr/bin/qemu-kvm<emulator/>
+#        with    <emulator>/usr/bin/qemu-wrap.py<emulator/>
+#
+#       3.b) Set the VM's device's to use vhost-net offload
+#
+#              <interface type="network">
+#              <model type="virtio"/>
+#              <driver name="vhost"/>
+#              <interface/>
+#
+# 4. Enable libvirt to access our userpace device file by adding it to 
+#    controllers cgroup for libvirtd using the following steps
+#    
+#   4.a) In /etc/libvirt/qemu.conf add/edit the following lines:
+#         1) cgroup_controllers = [ ... "devices", ... ]
+#                2) clear_emulator_capabilities = 0
+#         3) user = "root"
+#         4) group = "root"
+#         5) cgroup_device_acl = [
+#                "/dev/null", "/dev/full", "/dev/zero",
+#                "/dev/random", "/dev/urandom",
+#                "/dev/ptmx", "/dev/kvm", "/dev/kqemu",
+#                "/dev/rtc", "/dev/hpet", "/dev/net/tun",
+#                "/dev/<devbase-name>-<index>",
+#            ]
+#
+#   4.b) Disable SELinux or set to permissive mode
+#
+#   4.c) Mount cgroup device controller 
+#        "mkdir /dev/cgroup"
+#        "mount -t cgroup none /dev/cgroup -o devices"
+#
+#   4.d) Set hugetlbfs_mount variable - ( Optional ) 
+#        VMs using userspace vhost must use hugepage backed 
+#        memory. This can be enabled in the libvirt XML
+#        config by adding a memory backing section to the 
+#        XML config e.g.
+#             <memoryBacking>
+#             <hugepages/>
+#             </memoryBacking>
+#        This memory backing section should be added after the
+#        <memory> and <currentMemory> sections. This will add
+#        flags "-mem-prealloc -mem-path <path>" to the QEMU 
+#        command line. The hugetlbfs_mount variable can be used 
+#        to override the default <path> passed through by libvirt.
+# 
+#        if "-mem-prealloc" or "-mem-path <path>" are not passed 
+#        through and a vhost device is detected then these options will
+#        be automatically added by this script. This script will detect
+#        the system hugetlbfs mount point to be used for <path>. The 
+#        default <path> for this script can be overidden by the 
+#        hugetlbfs_dir variable in the configuration section of this script.
+#        
+#
+#   4.e) Restart the libvirtd system process
+#        e.g. on Fedora "systemctl restart libvirtd.service"
+#
+#
+#   4.f) Edit the Configuration Parameters section of this script
+#        to point to the correct emulator location and set any 
+#        addition options
+#
+# The script modifies the libvirtd Qemu call by modifying/adding 
+# options based on the configuration parameters below.
+# NOTE:
+#     emul_path and us_vhost_path must be set
+#     All other parameters are optional
+#####################################################################
+
+
+#############################################
+# Configuration Parameters
+#############################################
+#Path to QEMU binary 
+emul_path = "/usr/local/bin/qemu-system-x86_64"
+
+#Path to userspace vhost device file
+# This filename should match the --dev-basename --dev-index parameters of 
+# the command used to launch the userspace vhost sample application e.g.
+# if the sample app lauch command is:
+#    ./build/vhost-switch ..... --dev-basename usvhost --dev-index 1
+# then this variable should be set to:
+#   us_vhost_path = "/dev/usvhost-1" 
+us_vhost_path = "/dev/usvhost-1" 
+
+#List of additional user defined emulation options. These options will
+#be added to all Qemu calls 
+emul_opts_user = []
+
+#List of additional user defined emulation options for vhost only.
+#These options will only be added to vhost enabled guests 
+emul_opts_user_vhost = []
+
+#For all VHOST enabled VMs, the VM memory is preallocated from hugetlbfs
+# Set this variable to one to enable this option for all VMs
+use_huge_all = 0
+
+#Instead of autodetecting, override the hugetlbfs directory by setting
+#this variable
+hugetlbfs_dir = ""
+
+#############################################
+
+
+#############################################
+# ****** Do Not Modify Below this Line ******
+#############################################
+
+import sys, os, subprocess 
+
+
+#List of open userspace vhost file descriptors
+fd_list = []
+
+#additional virtio device flags when using userspace vhost            
+vhost_flags = [ "csum=off",
+                "gso=off",
+                "guest_tso4=off",
+                "guest_tso6=off",
+                "guest_ecn=off"
+              ]
+
+
+#############################################
+# Find the system hugefile mount point.
+# Note:
+# if multiple hugetlbfs mount points exist
+# then the first one found will be used
+############################################# 
+def find_huge_mount():
+
+    if (len(hugetlbfs_dir)):
+        return hugetlbfs_dir
+
+    huge_mount = ""
+
+    if (os.access("/proc/mounts", os.F_OK)):
+        f = open("/proc/mounts", "r")
+        line = f.readline()
+        while line:
+            line_split = line.split(" ")
+            if line_split[2] == 'hugetlbfs':
+                huge_mount = line_split[1]                
+                break
+            line = f.readline()
+    else:
+        print "/proc/mounts not found"
+        exit (1)
+
+    f.close
+    if len(huge_mount) == 0:
+        print "Failed to find hugetlbfs mount point"
+        exit (1)    
+
+    return huge_mount
+
+
+#############################################
+# Get a userspace Vhost file descriptor
+############################################# 
+def get_vhost_fd():
+
+    if (os.access(us_vhost_path, os.F_OK)):
+        fd = os.open( us_vhost_path, os.O_RDWR)
+    else:
+        print ("US-Vhost file %s not found" %us_vhost_path)
+        exit (1)
+    
+    return fd
+
+
+#############################################
+# Check for vhostfd. if found then replace
+# with our own vhost fd and append any vhost
+# flags onto the end
+############################################# 
+def modify_netdev_arg(arg):
+       
+    global fd_list
+    vhost_in_use = 0 
+    s = ''
+    new_opts = []
+    netdev_opts = arg.split(",")
+    
+    for opt in netdev_opts:
+        #check if vhost is used
+        if "vhost" == opt[:5]:
+            vhost_in_use = 1        
+        else:
+            new_opts.append(opt)
+
+    #if using vhost append vhost options 
+    if vhost_in_use == 1:
+        #append vhost on option
+        new_opts.append('vhost=on')
+        #append vhostfd ption
+        new_fd = get_vhost_fd()
+        new_opts.append('vhostfd=' + str(new_fd))
+        fd_list.append(new_fd)
+
+    #concatenate all options 
+    for opt in new_opts:
+        if len(s) > 0:
+                       s+=','
+        
+        s+=opt
+
+    return s   
+
+
+#############################################
+# Main
+#############################################
+def main():
+
+    global fd_list
+    global vhost_in_use    
+    new_args = []
+    num_cmd_args = len(sys.argv)
+    emul_call = ''
+    mem_prealloc_set = 0
+    mem_path_set = 0 
+    num = 0;
+
+    #parse the parameters
+    while (num < num_cmd_args):
+        arg = sys.argv[num]
+        
+               #Check netdev +1 parameter for vhostfd
+        if arg == '-netdev':
+            num_vhost_devs = len(fd_list)
+            new_args.append(arg)
+            
+            num+=1
+            arg = sys.argv[num]
+            mod_arg = modify_netdev_arg(arg)
+            new_args.append(mod_arg)
+
+            #append vhost flags if this is a vhost device
+            # and -device is the next arg
+            # i.e -device -opt1,-opt2,...,-opt3,%vhost
+            if (num_vhost_devs < len(fd_list)):
+                num+=1
+                arg = sys.argv[num]
+                if arg == '-device':
+                    new_args.append(arg)
+                    num+=1
+                    new_arg = sys.argv[num]
+                    for flag in vhost_flags:
+                        new_arg = ''.join([new_arg,',',flag])
+                    new_args.append(new_arg)
+                else:
+                    new_args.append(arg)
+        elif arg == '-mem-prealloc':
+            mem_prealloc_set = 1
+            new_args.append(arg)
+        elif arg == '-mem-path':
+            mem_path_set = 1
+            new_args.append(arg)
+    
+        else:
+            new_args.append(arg)
+
+        num+=1
+
+    #Set Qemu binary location 
+    emul_call+=emul_path
+    emul_call+=" "
+
+    #Add prealloc mem options if using vhost and not already added
+    if ((len(fd_list) > 0) and (mem_prealloc_set == 0)):
+        emul_call += "-mem-prealloc "
+
+    #Add mempath mem options if using vhost and not already added
+    if ((len(fd_list) > 0) and (mem_path_set == 0)):
+        #Detect and add hugetlbfs mount point 
+        mp = find_huge_mount()
+        mp = "".join(["-mem-path ", mp])
+        emul_call += mp
+        emul_call += " "   
+    
+
+    #add user options        
+    for opt in emul_opts_user:
+        emul_call += opt
+        emul_call += " "
+
+    #Add add user vhost only options
+    if len(fd_list) > 0:
+        for opt in emul_opts_user_vhost:
+            emul_call += opt
+            emul_call += " "
+
+    #Add updated libvirt options
+    iter_args = iter(new_args)
+    #skip 1st arg i.e. call to this script
+    next(iter_args)
+    for arg in iter_args:
+        emul_call+=str(arg)
+        emul_call+= " "
+
+    #Call QEMU 
+    subprocess.call(emul_call, shell=True)
+
+
+    #Close usvhost files
+    for fd in fd_list:
+        os.close(fd)
+
+
+if __name__ == "__main__":
+    main()
+
diff --git a/examples/vhost/main.c b/examples/vhost/main.c
new file mode 100644 (file)
index 0000000..816a71a
--- /dev/null
@@ -0,0 +1,1742 @@
+/*-
+ *   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 <arpa/inet.h>
+#include <getopt.h>
+#include <linux/if_ether.h>
+#include <linux/if_vlan.h>
+#include <linux/virtio_net.h>
+#include <linux/virtio_ring.h>
+#include <signal.h>
+#include <stdint.h>
+#include <sys/eventfd.h>
+#include <sys/param.h>
+#include <unistd.h>
+
+#include <rte_atomic.h>
+#include <rte_cycles.h>
+#include <rte_ethdev.h>
+#include <rte_log.h>
+#include <rte_string_fns.h>
+
+#include "main.h"
+#include "virtio-net.h"
+#include "vhost-net-cdev.h"
+
+#define MAX_QUEUES 128
+
+/* the maximum number of external ports supported */
+#define MAX_SUP_PORTS 1
+
+/*
+ * Calculate the number of buffers needed per port
+ */
+#define NUM_MBUFS_PER_PORT ((MAX_QUEUES*RTE_TEST_RX_DESC_DEFAULT) +            \
+                                                       (num_switching_cores*MAX_PKT_BURST) +                   \
+                                                       (num_switching_cores*RTE_TEST_TX_DESC_DEFAULT) +\
+                                                       (num_switching_cores*MBUF_CACHE_SIZE))
+
+#define MBUF_CACHE_SIZE 128 
+#define MBUF_SIZE (2048 + sizeof(struct rte_mbuf) + RTE_PKTMBUF_HEADROOM)
+
+/*
+ * RX and TX Prefetch, Host, and Write-back threshold values should be
+ * carefully set for optimal performance. Consult the network
+ * controller's datasheet and supporting DPDK documentation for guidance
+ * on how these parameters should be set.
+ */
+#define RX_PTHRESH 8 /* Default values of RX prefetch threshold reg. */
+#define RX_HTHRESH 8 /* Default values of RX host threshold reg. */
+#define RX_WTHRESH 4 /* Default values of RX write-back threshold reg. */
+
+/*
+ * These default values are optimized for use with the Intel(R) 82599 10 GbE
+ * Controller and the DPDK ixgbe PMD. Consider using other values for other
+ * network controllers and/or network drivers.
+ */
+#define TX_PTHRESH 36 /* Default values of TX prefetch threshold reg. */
+#define TX_HTHRESH 0  /* Default values of TX host threshold reg. */
+#define TX_WTHRESH 0  /* Default values of TX write-back threshold reg. */
+
+#define MAX_PKT_BURST 32               /* Max burst size for RX/TX */
+#define MAX_MRG_PKT_BURST 16   /* Max burst for merge buffers. Set to 1 due to performance issue. */
+#define BURST_TX_DRAIN_US 100  /* TX drain every ~100us */
+
+#define BURST_RX_WAIT_US 15    /* Defines how long we wait between retries on RX */
+#define BURST_RX_RETRIES 4             /* Number of retries on RX. */
+
+/* State of virtio device. */
+#define DEVICE_MAC_LEARNING 0
+#define DEVICE_RX                      1
+#define DEVICE_SAFE_REMOVE     2
+
+/* Config_core_flag status definitions. */
+#define REQUEST_DEV_REMOVAL 1
+#define ACK_DEV_REMOVAL 0
+
+/* Configurable number of RX/TX ring descriptors */
+#define RTE_TEST_RX_DESC_DEFAULT 1024 
+#define RTE_TEST_TX_DESC_DEFAULT 512
+
+#define INVALID_PORT_ID 0xFF
+
+/* Max number of devices. Limited by vmdq. */
+#define MAX_DEVICES 64
+
+/* Size of buffers used for rte_snprintfs. */
+#define MAX_PRINT_BUFF 6072
+
+/* Maximum character device basename size. */
+#define MAX_BASENAME_SZ 10
+
+/* Maximum long option length for option parsing. */
+#define MAX_LONG_OPT_SZ 64
+
+/* Used to compare MAC addresses. */
+#define MAC_ADDR_CMP 0xFFFFFFFFFFFFULL
+
+/* Number of descriptors per cacheline. */
+#define DESC_PER_CACHELINE (CACHE_LINE_SIZE / sizeof(struct vring_desc))
+
+/* mask of enabled ports */
+static uint32_t enabled_port_mask = 0;
+
+/*Number of switching cores enabled*/
+static uint32_t num_switching_cores = 0;
+
+/* number of devices/queues to support*/
+static uint32_t num_queues = 0;
+uint32_t num_devices = 0;
+
+/* Enable VM2VM communications. If this is disabled then the MAC address compare is skipped. */
+static uint32_t enable_vm2vm = 1;
+/* Enable stats. */
+static uint32_t enable_stats = 0;
+/* Enable retries on RX. */
+static uint32_t enable_retry = 1;
+/* Specify timeout (in useconds) between retries on RX. */
+static uint32_t burst_rx_delay_time = BURST_RX_WAIT_US;
+/* Specify the number of retries on RX. */
+static uint32_t burst_rx_retry_num = BURST_RX_RETRIES;
+
+/* Character device basename. Can be set by user. */
+static char dev_basename[MAX_BASENAME_SZ] = "vhost-net";
+
+/* Charater device index. Can be set by user. */
+static uint32_t dev_index = 0;
+
+/* This can be set by the user so it is made available here. */
+extern uint64_t VHOST_FEATURES;
+
+/* Default configuration for rx and tx thresholds etc. */
+static const struct rte_eth_rxconf rx_conf_default = {
+       .rx_thresh = {
+               .pthresh = RX_PTHRESH,
+               .hthresh = RX_HTHRESH,
+               .wthresh = RX_WTHRESH,
+       },
+       .rx_drop_en = 1,
+};
+
+/*
+ * These default values are optimized for use with the Intel(R) 82599 10 GbE
+ * Controller and the DPDK ixgbe/igb PMD. Consider using other values for other
+ * network controllers and/or network drivers.
+ */
+static const struct rte_eth_txconf tx_conf_default = {
+       .tx_thresh = {
+               .pthresh = TX_PTHRESH,
+               .hthresh = TX_HTHRESH,
+               .wthresh = TX_WTHRESH,
+       },
+       .tx_free_thresh = 0, /* Use PMD default values */
+       .tx_rs_thresh = 0, /* Use PMD default values */
+};
+
+/* empty vmdq configuration structure. Filled in programatically */
+static const struct rte_eth_conf vmdq_conf_default = {
+       .rxmode = {
+               .mq_mode        = ETH_MQ_RX_VMDQ_ONLY,
+               .split_hdr_size = 0,
+               .header_split   = 0, /**< Header Split disabled */
+               .hw_ip_checksum = 0, /**< IP checksum offload disabled */
+               .hw_vlan_filter = 0, /**< VLAN filtering disabled */
+               /*
+                * It is necessary for 1G NIC such as I350,
+                * this fixes bug of ipv4 forwarding in guest can't
+                * forward pakets from one virtio dev to another virtio dev.
+                */
+               .hw_vlan_strip  = 1, /**< VLAN strip enabled. */
+               .jumbo_frame    = 0, /**< Jumbo Frame Support disabled */
+               .hw_strip_crc   = 0, /**< CRC stripped by hardware */
+       },
+
+       .txmode = {
+               .mq_mode = ETH_MQ_TX_NONE,
+       },
+       .rx_adv_conf = {
+               /*
+                * should be overridden separately in code with
+                * appropriate values
+                */
+               .vmdq_rx_conf = {
+                       .nb_queue_pools = ETH_8_POOLS,
+                       .enable_default_pool = 0,
+                       .default_pool = 0,
+                       .nb_pool_maps = 0,
+                       .pool_map = {{0, 0},},
+               },
+       },
+};
+
+static unsigned lcore_ids[RTE_MAX_LCORE];
+static uint8_t ports[RTE_MAX_ETHPORTS];
+static unsigned num_ports = 0; /**< The number of ports specified in command line */
+
+const uint16_t vlan_tags[] = {
+       1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007,
+       1008, 1009, 1010, 1011, 1012, 1013, 1014, 1015,
+       1016, 1017, 1018, 1019, 1020, 1021, 1022, 1023,
+       1024, 1025, 1026, 1027, 1028, 1029, 1030, 1031,
+       1032, 1033, 1034, 1035, 1036, 1037, 1038, 1039,
+       1040, 1041, 1042, 1043, 1044, 1045, 1046, 1047,
+       1048, 1049, 1050, 1051, 1052, 1053, 1054, 1055,
+       1056, 1057, 1058, 1059, 1060, 1061, 1062, 1063,
+};
+
+/* ethernet addresses of ports */
+static struct ether_addr vmdq_ports_eth_addr[RTE_MAX_ETHPORTS];
+
+/* heads for the main used and free linked lists for the data path. */
+static struct virtio_net_data_ll *ll_root_used = NULL;
+static struct virtio_net_data_ll *ll_root_free = NULL;
+
+/* Array of data core structures containing information on individual core linked lists. */
+static struct lcore_info lcore_info[RTE_MAX_LCORE];
+
+/* Used for queueing bursts of TX packets. */
+struct mbuf_table {
+       unsigned len;
+       unsigned txq_id;
+       struct rte_mbuf *m_table[MAX_PKT_BURST];
+};
+
+/* TX queue for each data core. */
+struct mbuf_table lcore_tx_queue[RTE_MAX_LCORE];
+
+/* Vlan header struct used to insert vlan tags on TX. */
+struct vlan_ethhdr {
+       unsigned char   h_dest[ETH_ALEN];
+       unsigned char   h_source[ETH_ALEN];
+       __be16          h_vlan_proto;
+       __be16          h_vlan_TCI;
+       __be16          h_vlan_encapsulated_proto;
+};
+
+/* Header lengths. */
+#define VLAN_HLEN       4
+#define VLAN_ETH_HLEN   18
+
+/* Per-device statistics struct */
+struct device_statistics {
+       uint64_t tx_total;
+       rte_atomic64_t rx_total;
+       uint64_t tx;
+       rte_atomic64_t rx;
+} __rte_cache_aligned;
+struct device_statistics dev_statistics[MAX_DEVICES];
+
+/*
+ * Builds up the correct configuration for VMDQ VLAN pool map
+ * according to the pool & queue limits.
+ */
+static inline int
+get_eth_conf(struct rte_eth_conf *eth_conf, uint32_t num_devices)
+{
+       struct rte_eth_vmdq_rx_conf conf;
+       unsigned i;
+
+       memset(&conf, 0, sizeof(conf));
+       conf.nb_queue_pools = (enum rte_eth_nb_pools)num_devices;
+       conf.nb_pool_maps = num_devices;
+
+       for (i = 0; i < conf.nb_pool_maps; i++) {
+               conf.pool_map[i].vlan_id = vlan_tags[ i ];
+               conf.pool_map[i].pools = (1UL << i);
+       }
+
+       (void)(rte_memcpy(eth_conf, &vmdq_conf_default, sizeof(*eth_conf)));
+       (void)(rte_memcpy(&eth_conf->rx_adv_conf.vmdq_rx_conf, &conf,
+                  sizeof(eth_conf->rx_adv_conf.vmdq_rx_conf)));
+       return 0;
+}
+
+/*
+ * Validate the device number according to the max pool number gotten form dev_info
+ * If the device number is invalid, give the error message and return -1.
+ * Each device must have its own pool.
+ */
+static inline int
+validate_num_devices(uint32_t max_nb_devices)
+{
+       if (num_devices > max_nb_devices) {
+               RTE_LOG(ERR, PORT, "invalid number of devices\n");
+               return -1;
+       }
+       return 0;
+}
+
+/*
+ * Initialises a given port using global settings and with the rx buffers
+ * coming from the mbuf_pool passed as parameter
+ */
+static inline int
+port_init(uint8_t port, struct rte_mempool *mbuf_pool)
+{
+       struct rte_eth_dev_info dev_info;
+       struct rte_eth_conf port_conf;
+       uint16_t rx_rings, tx_rings = (uint16_t)rte_lcore_count();
+       const uint16_t rx_ring_size = RTE_TEST_RX_DESC_DEFAULT, tx_ring_size = RTE_TEST_TX_DESC_DEFAULT;
+       int retval;
+       uint16_t q;
+
+       /* The max pool number from dev_info will be used to validate the pool number specified in cmd line */
+       rte_eth_dev_info_get (port, &dev_info);
+
+       /*configure the number of supported virtio devices based on VMDQ limits */
+       num_devices = dev_info.max_vmdq_pools;
+       num_queues = dev_info.max_rx_queues;
+
+       retval = validate_num_devices(MAX_DEVICES);
+       if (retval < 0)
+               return retval;
+
+       /* Get port configuration. */
+       retval = get_eth_conf(&port_conf, num_devices);
+       if (retval < 0)
+               return retval;
+
+       if (port >= rte_eth_dev_count()) return -1;
+
+       rx_rings = (uint16_t)num_queues,
+       /* Configure ethernet device. */
+       retval = rte_eth_dev_configure(port, rx_rings, tx_rings, &port_conf);
+       if (retval != 0)
+               return retval;
+
+       /* Setup the queues. */
+       for (q = 0; q < rx_rings; q ++) {
+               retval = rte_eth_rx_queue_setup(port, q, rx_ring_size,
+                                               rte_eth_dev_socket_id(port), &rx_conf_default,
+                                               mbuf_pool);
+               if (retval < 0)
+                       return retval;
+       }
+       for (q = 0; q < tx_rings; q ++) {
+               retval = rte_eth_tx_queue_setup(port, q, tx_ring_size,
+                                               rte_eth_dev_socket_id(port), &tx_conf_default);
+               if (retval < 0)
+                       return retval;
+       }
+
+       /* Start the device. */
+       retval  = rte_eth_dev_start(port);
+       if (retval < 0)
+               return retval;
+
+       rte_eth_macaddr_get(port, &vmdq_ports_eth_addr[port]);
+       RTE_LOG(INFO, PORT, "Max virtio devices supported: %u\n", num_devices);
+       RTE_LOG(INFO, PORT, "Port %u MAC: %02"PRIx8" %02"PRIx8" %02"PRIx8
+                       " %02"PRIx8" %02"PRIx8" %02"PRIx8"\n",
+                       (unsigned)port,
+                       vmdq_ports_eth_addr[port].addr_bytes[0],
+                       vmdq_ports_eth_addr[port].addr_bytes[1],
+                       vmdq_ports_eth_addr[port].addr_bytes[2],
+                       vmdq_ports_eth_addr[port].addr_bytes[3],
+                       vmdq_ports_eth_addr[port].addr_bytes[4],
+                       vmdq_ports_eth_addr[port].addr_bytes[5]);
+
+       return 0;
+}
+
+/*
+ * Set character device basename.
+ */
+static int
+us_vhost_parse_basename(const char *q_arg)
+{
+       /* parse number string */
+
+       if (strnlen(q_arg, MAX_BASENAME_SZ) > MAX_BASENAME_SZ)
+               return -1;
+       else
+               rte_snprintf((char*)&dev_basename, MAX_BASENAME_SZ, "%s", q_arg);
+
+       return 0;
+}
+
+/*
+ * Parse the portmask provided at run time.
+ */
+static int
+parse_portmask(const char *portmask)
+{
+       char *end = NULL;
+       unsigned long pm;
+
+       errno = 0;
+
+       /* parse hexadecimal string */
+       pm = strtoul(portmask, &end, 16);
+       if ((portmask[0] == '\0') || (end == NULL) || (*end != '\0') || (errno != 0))
+               return -1;
+
+       if (pm == 0)
+               return -1;
+
+       return pm;
+
+}
+
+/*
+ * Parse num options at run time.
+ */
+static int
+parse_num_opt(const char *q_arg, uint32_t max_valid_value)
+{
+       char *end = NULL;
+       unsigned long num;
+
+       errno = 0;
+
+       /* parse unsigned int string */
+       num = strtoul(q_arg, &end, 10);
+       if ((q_arg[0] == '\0') || (end == NULL) || (*end != '\0') || (errno != 0))
+               return -1;
+
+       if (num > max_valid_value)
+               return -1;
+
+       return num;
+
+}
+
+/*
+ * Display usage
+ */
+static void
+us_vhost_usage(const char *prgname)
+{
+       RTE_LOG(INFO, CONFIG, "%s [EAL options] -- -p PORTMASK --vm2vm [0|1] --rx_retry [0|1] --mergeable [0|1] --stats [0-N] --dev-basename <name> --dev-index [0-N] --nb-devices ND\n"
+       "               -p PORTMASK: Set mask for ports to be used by application\n"
+       "               --vm2vm [0|1]: disable/enable(default) vm2vm comms\n"
+       "               --rx-retry [0|1]: disable/enable(default) retries on rx. Enable retry if destintation queue is full\n"
+       "               --rx-retry-delay [0-N]: timeout(in usecond) between retries on RX. This makes effect only if retries on rx enabled\n"
+       "               --rx-retry-num [0-N]: the number of retries on rx. This makes effect only if retries on rx enabled\n"
+       "               --mergeable [0|1]: disable(default)/enable RX mergeable buffers\n"
+       "               --stats [0-N]: 0: Disable stats, N: Time in seconds to print stats\n"
+       "               --dev-basename: The basename to be used for the character device.\n"
+       "               --dev-index [0-N]: Defaults to zero if not used. Index is appended to basename.\n",
+              prgname);
+}
+
+/*
+ * Parse the arguments given in the command line of the application.
+ */
+static int
+us_vhost_parse_args(int argc, char **argv)
+{
+       int opt, ret;
+       int option_index;
+       unsigned i;
+       const char *prgname = argv[0];
+       static struct option long_option[] = {
+               {"vm2vm", required_argument, NULL, 0},
+               {"rx-retry", required_argument, NULL, 0},
+               {"rx-retry-delay", required_argument, NULL, 0},
+               {"rx-retry-num", required_argument, NULL, 0},
+               {"mergeable", required_argument, NULL, 0},
+               {"stats", required_argument, NULL, 0},
+               {"dev-basename", required_argument, NULL, 0},
+               {"dev-index", required_argument, NULL, 0},
+               {NULL, 0, 0, 0}
+       };
+
+       /* Parse command line */
+       while ((opt = getopt_long(argc, argv, "p:",long_option, &option_index)) != EOF) {
+               switch (opt) {
+               /* Portmask */
+               case 'p':
+                       enabled_port_mask = parse_portmask(optarg);
+                       if (enabled_port_mask == 0) {
+                               RTE_LOG(INFO, CONFIG, "Invalid portmask\n");
+                               us_vhost_usage(prgname);
+                               return -1;
+                       }
+                       break;
+
+               case 0:
+                       /* Enable/disable vm2vm comms. */
+                       if (!strncmp(long_option[option_index].name, "vm2vm", MAX_LONG_OPT_SZ)) {
+                               ret = parse_num_opt(optarg, 1);
+                               if (ret == -1) {
+                                       RTE_LOG(INFO, CONFIG, "Invalid argument for vm2vm [0|1]\n");
+                                       us_vhost_usage(prgname);
+                                       return -1;
+                               } else {
+                                       enable_vm2vm = ret;
+                               }
+                       }
+
+                       /* Enable/disable retries on RX. */
+                       if (!strncmp(long_option[option_index].name, "rx-retry", MAX_LONG_OPT_SZ)) {
+                               ret = parse_num_opt(optarg, 1);
+                               if (ret == -1) {
+                                       RTE_LOG(INFO, CONFIG, "Invalid argument for rx-retry [0|1]\n");
+                                       us_vhost_usage(prgname);
+                                       return -1;
+                               } else {
+                                       enable_retry = ret;
+                               }
+                       }
+
+                       /* Specify the retries delay time (in useconds) on RX. */
+                       if (!strncmp(long_option[option_index].name, "rx-retry-delay", MAX_LONG_OPT_SZ)) {
+                               ret = parse_num_opt(optarg, INT32_MAX);
+                               if (ret == -1) {
+                                       RTE_LOG(INFO, CONFIG, "Invalid argument for rx-retry-delay [0-N]\n");
+                                       us_vhost_usage(prgname);
+                                       return -1;
+                               } else {
+                                       burst_rx_delay_time = ret;
+                               }
+                       }
+
+                       /* Specify the retries number on RX. */
+                       if (!strncmp(long_option[option_index].name, "rx-retry-num", MAX_LONG_OPT_SZ)) {
+                               ret = parse_num_opt(optarg, INT32_MAX);
+                               if (ret == -1) {
+                                       RTE_LOG(INFO, CONFIG, "Invalid argument for rx-retry-num [0-N]\n");
+                                       us_vhost_usage(prgname);
+                                       return -1;
+                               } else {
+                                       burst_rx_retry_num = ret;
+                               }
+                       }
+
+                       /* Enable/disable RX mergeable buffers. */
+                       if (!strncmp(long_option[option_index].name, "mergeable", MAX_LONG_OPT_SZ)) {
+                               ret = parse_num_opt(optarg, 1);
+                               if (ret == -1) {
+                                       RTE_LOG(INFO, CONFIG, "Invalid argument for mergeable [0|1]\n");
+                                       us_vhost_usage(prgname);
+                                       return -1;
+                               } else {
+                                       if (ret)
+                                               VHOST_FEATURES = (1ULL << VIRTIO_NET_F_MRG_RXBUF);
+                               }
+                       }
+
+                       /* Enable/disable stats. */
+                       if (!strncmp(long_option[option_index].name, "stats", MAX_LONG_OPT_SZ)) {
+                               ret = parse_num_opt(optarg, INT32_MAX);
+                               if (ret == -1) {
+                                       RTE_LOG(INFO, CONFIG, "Invalid argument for stats [0..N]\n");
+                                       us_vhost_usage(prgname);
+                                       return -1;
+                               } else {
+                                       enable_stats = ret;
+                               }
+                       }
+
+                       /* Set character device basename. */
+                       if (!strncmp(long_option[option_index].name, "dev-basename", MAX_LONG_OPT_SZ)) {
+                               if (us_vhost_parse_basename(optarg) == -1) {
+                                       RTE_LOG(INFO, CONFIG, "Invalid argument for character device basename (Max %d characters)\n", MAX_BASENAME_SZ);
+                                       us_vhost_usage(prgname);
+                                       return -1;
+                               }
+                       }
+
+                       /* Set character device index. */
+                       if (!strncmp(long_option[option_index].name, "dev-index", MAX_LONG_OPT_SZ)) {
+                               ret = parse_num_opt(optarg, INT32_MAX);
+                               if (ret == -1) {
+                                       RTE_LOG(INFO, CONFIG, "Invalid argument for character device index [0..N]\n");
+                                       us_vhost_usage(prgname);
+                                       return -1;
+                               } else {
+                                       dev_index = ret;
+                               }
+                       }
+
+                       break;
+
+                       /* Invalid option - print options. */
+               default:
+                       us_vhost_usage(prgname);
+                       return -1;
+               }
+       }
+
+       for (i = 0; i < RTE_MAX_ETHPORTS; i++) {
+               if (enabled_port_mask & (1 << i))
+                       ports[num_ports++] = (uint8_t)i;
+       }
+
+       if ((num_ports ==  0) || (num_ports > MAX_SUP_PORTS)) {
+               RTE_LOG(INFO, PORT, "Current enabled port number is %u,"
+                       "but only %u port can be enabled\n",num_ports, MAX_SUP_PORTS);
+               return -1;
+       }
+
+       return 0;
+}
+
+/*
+ * Update the global var NUM_PORTS and array PORTS according to system ports number
+ * and return valid ports number
+ */
+static unsigned check_ports_num(unsigned nb_ports)
+{
+       unsigned valid_num_ports = num_ports;
+       unsigned portid;
+
+       if (num_ports > nb_ports) {
+               RTE_LOG(INFO, PORT, "\nSpecified port number(%u) exceeds total system port number(%u)\n",
+                       num_ports, nb_ports);
+               num_ports = nb_ports;
+       }
+
+       for (portid = 0; portid < num_ports; portid ++) {
+               if (ports[portid] >= nb_ports) {
+                       RTE_LOG(INFO, PORT, "\nSpecified port ID(%u) exceeds max system port ID(%u)\n",
+                               ports[portid], (nb_ports - 1));
+                       ports[portid] = INVALID_PORT_ID;
+                       valid_num_ports--;
+               }
+       }
+       return valid_num_ports;
+}
+
+/*
+ * Macro to print out packet contents. Wrapped in debug define so that the
+ * data path is not effected when debug is disabled.
+ */
+#ifdef DEBUG
+#define PRINT_PACKET(device, addr, size, header) do {                                                                                                                          \
+       char *pkt_addr = (char*)(addr);                                                                                                                                                                 \
+       unsigned int index;                                                                                                                                                                                             \
+       char packet[MAX_PRINT_BUFF];                                                                                                                                                                    \
+                                                                                                                                                                                                                                       \
+       if ((header))                                                                                                                                                                                                   \
+               rte_snprintf(packet, MAX_PRINT_BUFF, "(%"PRIu64") Header size %d: ", (device->device_fh), (size));                              \
+       else                                                                                                                                                                                                                    \
+               rte_snprintf(packet, MAX_PRINT_BUFF, "(%"PRIu64") Packet size %d: ", (device->device_fh), (size));                              \
+       for (index = 0; index < (size); index++) {                                                                                                                                              \
+               rte_snprintf(packet + strnlen(packet, MAX_PRINT_BUFF), MAX_PRINT_BUFF - strnlen(packet, MAX_PRINT_BUFF),        \
+                       "%02hhx ", pkt_addr[index]);                                                                                                                                                    \
+       }                                                                                                                                                                                                                               \
+       rte_snprintf(packet + strnlen(packet, MAX_PRINT_BUFF), MAX_PRINT_BUFF - strnlen(packet, MAX_PRINT_BUFF), "\n"); \
+                                                                                                                                                                                                                                       \
+       LOG_DEBUG(DATA, "%s", packet);                                                                                                                                                                  \
+} while(0)
+#else
+#define PRINT_PACKET(device, addr, size, header) do{} while(0)
+#endif
+
+/*
+ * Function to convert guest physical addresses to vhost virtual addresses. This
+ * is used to convert 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;
+               }
+       }
+       LOG_DEBUG(DATA, "(%"PRIu64") GPA %p| VVA %p\n",
+               dev->device_fh, (void*)(uintptr_t)guest_pa, (void*)(uintptr_t)vhost_va);
+
+       return vhost_va;
+}
+
+/*
+ * This function adds buffers to the virtio devices RX virtqueue. Buffers can
+ * be received from the physical port or from another virtio device. A packet
+ * count is returned to indicate the number of packets that were succesfully
+ * added to the RX queue.
+ */
+static inline uint32_t __attribute__((always_inline))
+virtio_dev_rx(struct virtio_net *dev, 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[MAX_PKT_BURST], packet_len = 0;
+       uint32_t head_idx, packet_success = 0;
+       uint32_t mergeable, mrg_count = 0;
+       uint32_t retry = 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(DATA, "(%"PRIu64") virtio_dev_rx()\n", dev->device_fh);
+       vq = dev->virtqueue[VIRTIO_RXQ];
+       count = (count > MAX_PKT_BURST) ? 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);              
+               /* If retry is enabled and the queue is full then we wait and retry to avoid packet loss. */
+               if (enable_retry && unlikely(count > free_entries)) {
+                       for (retry = 0; retry < burst_rx_retry_num; retry++) {
+                               rte_delay_us(burst_rx_delay_time);
+                               avail_idx =
+                                       *((volatile uint16_t *)&vq->avail->idx);
+                               free_entries = (avail_idx - res_base_idx);
+                               if (count <= free_entries)
+                                       break;
+                       }
+               }
+
+               /*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. */
+               success = rte_atomic16_cmpset(&vq->last_used_idx_res, res_base_idx,
+                                                                       res_end_idx);
+       } while (unlikely(success == 0));
+       res_cur_idx = res_base_idx;
+       LOG_DEBUG(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;
+                       }
+               }
+
+               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 */
+               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);
+                       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 == MAX_MRG_PKT_BURST) || (res_cur_idx == res_end_idx)) {
+                               virtio_hdr.num_buffers = mrg_count;
+                               LOG_DEBUG(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);
+                               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;
+}
+
+/*
+ * Compares a packet destination MAC address to a device MAC address.
+ */
+static inline int __attribute__((always_inline))
+ether_addr_cmp(struct ether_addr *ea, struct ether_addr *eb)
+{
+       return (((*(uint64_t *)ea ^ *(uint64_t *)eb) & MAC_ADDR_CMP) == 0);
+}
+
+/*
+ * This function learns the MAC address of the device and registers this along with a
+ * vlan tag to a VMDQ.
+ */
+static int
+link_vmdq(struct virtio_net *dev, struct rte_mbuf *m)
+{
+       struct ether_hdr *pkt_hdr;
+       struct virtio_net_data_ll *dev_ll;
+       int i, ret;
+
+       /* Learn MAC address of guest device from packet */
+       pkt_hdr = (struct ether_hdr *)m->pkt.data;
+
+       dev_ll = ll_root_used;
+
+       while (dev_ll != NULL) {
+               if (ether_addr_cmp(&(pkt_hdr->s_addr), &dev_ll->dev->mac_address)) {
+                       RTE_LOG(INFO, DATA, "(%"PRIu64") WARNING: This device is using an existing MAC address and has not been registered.\n", dev->device_fh);
+                       return -1;
+               }
+               dev_ll = dev_ll->next;
+       }
+
+       for (i = 0; i < ETHER_ADDR_LEN; i++)
+               dev->mac_address.addr_bytes[i] = pkt_hdr->s_addr.addr_bytes[i];
+
+       /* vlan_tag currently uses the device_id. */
+       dev->vlan_tag = vlan_tags[dev->device_fh];
+       dev->vmdq_rx_q = dev->device_fh * (num_queues/num_devices);
+
+       /* Print out VMDQ registration info. */
+       RTE_LOG(INFO, DATA, "(%"PRIu64") MAC_ADDRESS %02x:%02x:%02x:%02x:%02x:%02x and VLAN_TAG %d registered\n",
+               dev->device_fh,
+               dev->mac_address.addr_bytes[0], dev->mac_address.addr_bytes[1],
+               dev->mac_address.addr_bytes[2], dev->mac_address.addr_bytes[3],
+               dev->mac_address.addr_bytes[4], dev->mac_address.addr_bytes[5],
+               dev->vlan_tag);
+
+       /* Register the MAC address. */
+       ret = rte_eth_dev_mac_addr_add(ports[0], &dev->mac_address, (uint32_t)dev->device_fh);
+       if (ret)
+               RTE_LOG(ERR, DATA, "(%"PRIu64") Failed to add device MAC address to VMDQ\n",
+                                       dev->device_fh);
+
+       /* Enable stripping of the vlan tag as we handle routing. */
+       rte_eth_dev_set_vlan_strip_on_queue(ports[0], (uint16_t)dev->vmdq_rx_q, 1);
+
+       /* Set device as ready for RX. */
+       dev->ready = DEVICE_RX;
+
+       return 0;
+}
+
+/*
+ * Removes MAC address and vlan tag from VMDQ. Ensures that nothing is adding buffers to the RX
+ * queue before disabling RX on the device.
+ */
+static inline void
+unlink_vmdq(struct virtio_net *dev)
+{
+       unsigned i = 0;
+       unsigned rx_count;
+       struct rte_mbuf *pkts_burst[MAX_PKT_BURST];
+
+       if (dev->ready == DEVICE_RX) {
+               /*clear MAC and VLAN settings*/
+               rte_eth_dev_mac_addr_remove(ports[0], &dev->mac_address);
+               for (i = 0; i < 6; i++)
+                       dev->mac_address.addr_bytes[i] = 0;
+
+               dev->vlan_tag = 0;
+
+               /*Clear out the receive buffers*/
+               rx_count = rte_eth_rx_burst(ports[0],
+                                       (uint16_t)dev->vmdq_rx_q, pkts_burst, MAX_PKT_BURST);
+
+               while (rx_count) {
+                       for (i = 0; i < rx_count; i++)
+                               rte_pktmbuf_free(pkts_burst[i]);
+
+                       rx_count = rte_eth_rx_burst(ports[0],
+                                       (uint16_t)dev->vmdq_rx_q, pkts_burst, MAX_PKT_BURST);
+               }
+
+               dev->ready = DEVICE_MAC_LEARNING;
+       }
+}
+
+/*
+ * Check if the packet destination MAC address is for a local device. If so then put
+ * the packet on that devices RX queue. If not then return.
+ */
+static inline unsigned __attribute__((always_inline))
+virtio_tx_local(struct virtio_net *dev, struct rte_mbuf *m)
+{
+       struct virtio_net_data_ll *dev_ll;
+       struct ether_hdr *pkt_hdr;
+       uint64_t ret = 0;
+
+       pkt_hdr = (struct ether_hdr *)m->pkt.data;
+
+       /*get the used devices list*/
+       dev_ll = ll_root_used;
+
+       while (dev_ll != NULL) {
+               if ((dev_ll->dev->ready == DEVICE_RX) && ether_addr_cmp(&(pkt_hdr->d_addr),
+                                         &dev_ll->dev->mac_address)) {
+
+                       /* Drop the packet if the TX packet is destined for the TX device. */
+                       if (dev_ll->dev->device_fh == dev->device_fh) {
+                               LOG_DEBUG(DATA, "(%"PRIu64") TX: Source and destination MAC addresses are the same. Dropping packet.\n",
+                                                       dev_ll->dev->device_fh);
+                               return 0;
+                       }
+
+
+                       LOG_DEBUG(DATA, "(%"PRIu64") TX: MAC address is local\n", dev_ll->dev->device_fh);
+
+                       if (dev_ll->dev->remove) {
+                               /*drop the packet if the device is marked for removal*/
+                               LOG_DEBUG(DATA, "(%"PRIu64") Device is marked for removal\n", dev_ll->dev->device_fh);
+                       } else {
+                               /*send the packet to the local virtio device*/
+                               ret = virtio_dev_rx(dev_ll->dev, &m, 1);
+                               if (enable_stats) {
+                                       rte_atomic64_add(&dev_statistics[dev_ll->dev->device_fh].rx_total, 1);
+                                       rte_atomic64_add(&dev_statistics[dev_ll->dev->device_fh].rx, ret);
+                                       dev_statistics[dev->device_fh].tx_total++;
+                                       dev_statistics[dev->device_fh].tx += ret;
+                               }
+                       }
+
+                       return 0;
+               }
+               dev_ll = dev_ll->next;
+       }
+
+       return -1;
+}
+
+/*
+ * This function routes the TX packet to the correct interface. This may be a local device
+ * or the physical port.
+ */
+static inline void __attribute__((always_inline))
+virtio_tx_route(struct virtio_net* dev, struct rte_mbuf *m, struct rte_mempool *mbuf_pool, uint16_t vlan_tag)
+{
+       struct mbuf_table *tx_q;
+       struct vlan_ethhdr *vlan_hdr;
+       struct rte_mbuf **m_table;
+       struct rte_mbuf *mbuf;
+       unsigned len, ret;
+       const uint16_t lcore_id = rte_lcore_id();
+
+       /*check if destination is local VM*/
+       if (enable_vm2vm && (virtio_tx_local(dev, m) == 0)) {
+               return;
+       }
+
+       LOG_DEBUG(DATA, "(%"PRIu64") TX: MAC address is external\n", dev->device_fh);
+
+       /*Add packet to the port tx queue*/
+       tx_q = &lcore_tx_queue[lcore_id];
+       len = tx_q->len;
+
+       /* Allocate an mbuf and populate the structure. */
+       mbuf = rte_pktmbuf_alloc(mbuf_pool);
+       if (unlikely(mbuf == NULL)) {
+               RTE_LOG(ERR, DATA, "Failed to allocate memory for mbuf.\n");
+               return;
+       }
+
+       mbuf->pkt.data_len = m->pkt.data_len + VLAN_HLEN;
+       mbuf->pkt.pkt_len = mbuf->pkt.data_len;
+
+       /* Copy ethernet header to mbuf. */
+       rte_memcpy((void*)mbuf->pkt.data, (const void*)m->pkt.data, ETH_HLEN);
+
+
+       /* Setup vlan header. Bytes need to be re-ordered for network with htons()*/
+       vlan_hdr = (struct vlan_ethhdr *) mbuf->pkt.data;
+       vlan_hdr->h_vlan_encapsulated_proto = vlan_hdr->h_vlan_proto;
+       vlan_hdr->h_vlan_proto = htons(ETH_P_8021Q);
+       vlan_hdr->h_vlan_TCI = htons(vlan_tag);
+
+       /* Copy the remaining packet contents to the mbuf. */
+       rte_memcpy((void*) ((uint8_t*)mbuf->pkt.data + VLAN_ETH_HLEN),
+               (const void*) ((uint8_t*)m->pkt.data + ETH_HLEN), (m->pkt.data_len - ETH_HLEN));
+       tx_q->m_table[len] = mbuf;
+       len++;
+       if (enable_stats) {
+               dev_statistics[dev->device_fh].tx_total++;
+               dev_statistics[dev->device_fh].tx++;
+       }
+
+       if (unlikely(len == MAX_PKT_BURST)) {
+               m_table = (struct rte_mbuf **)tx_q->m_table;
+               ret = rte_eth_tx_burst(ports[0], (uint16_t)tx_q->txq_id, m_table, (uint16_t) len);
+               /* Free any buffers not handled by TX and update the port stats. */
+               if (unlikely(ret < len)) {
+                       do {
+                               rte_pktmbuf_free(m_table[ret]);
+                       } while (++ret < len);
+               }
+
+               len = 0;
+       }
+
+       tx_q->len = len;
+       return;
+}
+
+static inline void __attribute__((always_inline))
+virtio_dev_tx(struct virtio_net* dev, struct rte_mempool *mbuf_pool)
+{
+       struct rte_mbuf m;
+       struct vhost_virtqueue *vq;
+       struct vring_desc *desc;
+       uint64_t buff_addr = 0;
+       uint32_t head[MAX_PKT_BURST];
+       uint32_t used_idx;
+       uint32_t i;
+       uint16_t free_entries, packet_success = 0;
+       uint16_t avail_idx;
+
+       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;
+
+       LOG_DEBUG(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);
+
+       /* Limit to MAX_PKT_BURST. */
+       if (free_entries > MAX_PKT_BURST)
+               free_entries = MAX_PKT_BURST;
+
+       LOG_DEBUG(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;
+
+               /* Setup dummy mbuf. This is copied to a real mbuf if transmitted out the physical port. */
+               m.pkt.data_len = desc->len;
+               m.pkt.data = (void*)(uintptr_t)buff_addr;
+
+               PRINT_PACKET(dev, (uintptr_t)buff_addr, desc->len, 0);
+
+               /* If this is the first received packet we need to learn the MAC and setup VMDQ */
+               if (dev->ready == DEVICE_MAC_LEARNING) {
+                       if (dev->remove || (link_vmdq(dev, &m) == -1)) {
+                               /*discard frame if device is scheduled for removal or a duplicate MAC address is found. */
+                               packet_success += free_entries;
+                               vq->last_used_idx += packet_success;
+                               break;
+                       }
+               }
+               virtio_tx_route(dev, &m, mbuf_pool, (uint16_t)dev->device_fh);
+
+               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);
+}
+
+/*
+ * This function is called by each data core. It handles all RX/TX registered with the
+ * core. For TX the specific lcore linked list is used. For RX, MAC addresses are compared
+ * with all devices in the main linked list.
+ */
+static int
+switch_worker(__attribute__((unused)) void *arg)
+{
+       struct rte_mempool *mbuf_pool = arg;
+       struct virtio_net *dev = NULL;
+       struct rte_mbuf *pkts_burst[MAX_PKT_BURST];
+       struct virtio_net_data_ll *dev_ll;
+       struct mbuf_table *tx_q;
+       volatile struct lcore_ll_info *lcore_ll;
+       const uint64_t drain_tsc = (rte_get_tsc_hz() + US_PER_S - 1) / US_PER_S * BURST_TX_DRAIN_US;
+       uint64_t prev_tsc, diff_tsc, cur_tsc, ret_count = 0;
+       unsigned ret, i;
+       const uint16_t lcore_id = rte_lcore_id();
+       const uint16_t num_cores = (uint16_t)rte_lcore_count();
+       uint16_t rx_count = 0;
+
+       RTE_LOG(INFO, DATA, "Procesing on Core %u started \n", lcore_id);
+       lcore_ll = lcore_info[lcore_id].lcore_ll;
+       prev_tsc = 0;
+
+       tx_q = &lcore_tx_queue[lcore_id];
+       for (i = 0; i < num_cores; i ++) {
+               if (lcore_ids[i] == lcore_id) {
+                       tx_q->txq_id = i;
+                       break;
+               }
+       }
+
+       while(1) {
+               cur_tsc = rte_rdtsc();
+               /*
+                * TX burst queue drain
+                */
+               diff_tsc = cur_tsc - prev_tsc;
+               if (unlikely(diff_tsc > drain_tsc)) {
+
+                       if (tx_q->len) {
+                               LOG_DEBUG(DATA, "TX queue drained after timeout with burst size %u \n", tx_q->len);
+
+                               /*Tx any packets in the queue*/
+                               ret = rte_eth_tx_burst(ports[0], (uint16_t)tx_q->txq_id,
+                                                                          (struct rte_mbuf **)tx_q->m_table,
+                                                                          (uint16_t)tx_q->len);
+                               if (unlikely(ret < tx_q->len)) {
+                                       do {
+                                               rte_pktmbuf_free(tx_q->m_table[ret]);
+                                       } while (++ret < tx_q->len);
+                               }
+
+                               tx_q->len = 0;
+                       }
+
+                       prev_tsc = cur_tsc;
+
+               }
+
+               rte_prefetch0(lcore_ll->ll_root_used);
+               /* 
+                * Inform the configuration core that we have exited the linked list and that no devices are
+                * in use if requested.
+                */
+               if (lcore_ll->dev_removal_flag == REQUEST_DEV_REMOVAL) 
+                       lcore_ll->dev_removal_flag = ACK_DEV_REMOVAL;
+
+               /*
+                * Process devices
+                */
+               dev_ll = lcore_ll->ll_root_used;
+
+               while (dev_ll != NULL) {
+                       /*get virtio device ID*/
+                       dev = dev_ll->dev;
+
+                       if (dev->remove) {
+                               dev_ll = dev_ll->next;
+                               unlink_vmdq(dev);
+                               dev->ready = DEVICE_SAFE_REMOVE;
+                               continue;
+                       }
+                       if (likely(dev->ready == DEVICE_RX)) {
+                               /*Handle guest RX*/
+                               rx_count = rte_eth_rx_burst(ports[0],
+                                       (uint16_t)dev->vmdq_rx_q, pkts_burst, MAX_PKT_BURST);
+
+                               if (rx_count) {
+                                       ret_count = virtio_dev_rx(dev, pkts_burst, rx_count);
+                                       if (enable_stats) {
+                                               rte_atomic64_add(&dev_statistics[dev_ll->dev->device_fh].rx_total, rx_count);
+                                               rte_atomic64_add(&dev_statistics[dev_ll->dev->device_fh].rx, ret_count);
+                                       }
+                                       while (likely(rx_count)) {
+                                               rx_count--;
+                                               rte_pktmbuf_free_seg(pkts_burst[rx_count]);
+                                       }
+
+                               }
+                       }
+
+                       if (!dev->remove)
+                               /*Handle guest TX*/
+                               virtio_dev_tx(dev, mbuf_pool);
+
+                       /*move to the next device in the list*/
+                       dev_ll = dev_ll->next;
+               }
+       }
+
+       return 0;
+}
+
+/*
+ * Add an entry to a used linked list. A free entry must first be found in the free linked list
+ * using get_data_ll_free_entry();
+ */
+static void
+add_data_ll_entry(struct virtio_net_data_ll **ll_root_addr, struct virtio_net_data_ll *ll_dev)
+{
+       struct virtio_net_data_ll *ll = *ll_root_addr;
+
+       /* Set next as NULL and use a compiler barrier to avoid reordering. */
+       ll_dev->next = NULL;
+       rte_compiler_barrier();
+
+       /* If ll == NULL then this is the first device. */
+       if (ll) {
+               /* Increment to the tail of the linked list. */
+               while ((ll->next != NULL) )
+                       ll = ll->next;
+
+               ll->next = ll_dev;
+       } else {
+               *ll_root_addr = ll_dev;
+       }
+}
+
+/*
+ * Remove an entry from a used linked list. The entry must then be added to the free linked list
+ * using put_data_ll_free_entry().
+ */
+static void
+rm_data_ll_entry(struct virtio_net_data_ll **ll_root_addr, struct virtio_net_data_ll *ll_dev, struct virtio_net_data_ll *ll_dev_last)
+{
+       struct virtio_net_data_ll *ll = *ll_root_addr;
+       
+       if (unlikely((ll == NULL) || (ll_dev == NULL)))
+               return;
+
+       if (ll_dev == ll)
+               *ll_root_addr = ll_dev->next;
+       else
+               if (likely(ll_dev_last != NULL))
+                       ll_dev_last->next = ll_dev->next;
+               else
+                       RTE_LOG(ERR, CONFIG, "Remove entry form ll failed.\n");
+}
+
+/*
+ * Find and return an entry from the free linked list.
+ */
+static struct virtio_net_data_ll *
+get_data_ll_free_entry(struct virtio_net_data_ll **ll_root_addr)
+{
+       struct virtio_net_data_ll *ll_free = *ll_root_addr;
+       struct virtio_net_data_ll *ll_dev;
+
+       if (ll_free == NULL)
+               return NULL;
+
+       ll_dev = ll_free;
+       *ll_root_addr = ll_free->next;
+
+       return ll_dev;
+}
+
+/*
+ * Place an entry back on to the free linked list.
+ */
+static void
+put_data_ll_free_entry(struct virtio_net_data_ll **ll_root_addr, struct virtio_net_data_ll *ll_dev)
+{
+       struct virtio_net_data_ll *ll_free = *ll_root_addr;
+
+       if (ll_dev == NULL)
+               return;
+
+       ll_dev->next = ll_free;
+       *ll_root_addr = ll_dev;
+}
+
+/*
+ * Creates a linked list of a given size.
+ */
+static struct virtio_net_data_ll *
+alloc_data_ll(uint32_t size)
+{
+       struct virtio_net_data_ll *ll_new;
+       uint32_t i;
+
+       /* Malloc and then chain the linked list. */
+       ll_new = malloc(size * sizeof(struct virtio_net_data_ll));
+       if (ll_new == NULL) {
+               RTE_LOG(ERR, CONFIG, "Failed to allocate memory for ll_new.\n");
+               return NULL;
+       }
+
+       for (i = 0; i < size - 1; i++) {
+               ll_new[i].dev = NULL;
+               ll_new[i].next = &ll_new[i+1];
+       }
+       ll_new[i].next = NULL;
+
+       return (ll_new);
+}
+
+/*
+ * Create the main linked list along with each individual cores linked list. A used and a free list
+ * are created to manage entries.
+ */
+static int
+init_data_ll (void)
+{
+       int lcore;
+
+       RTE_LCORE_FOREACH_SLAVE(lcore) {
+               lcore_info[lcore].lcore_ll = malloc(sizeof(struct lcore_ll_info));
+               if (lcore_info[lcore].lcore_ll == NULL) {
+                       RTE_LOG(ERR, CONFIG, "Failed to allocate memory for lcore_ll.\n");
+                       return -1;
+               }
+
+               lcore_info[lcore].lcore_ll->device_num = 0;
+               lcore_info[lcore].lcore_ll->dev_removal_flag = ACK_DEV_REMOVAL;
+               lcore_info[lcore].lcore_ll->ll_root_used = NULL;
+               if (num_devices % num_switching_cores)
+                       lcore_info[lcore].lcore_ll->ll_root_free = alloc_data_ll((num_devices / num_switching_cores) + 1);
+               else
+                       lcore_info[lcore].lcore_ll->ll_root_free = alloc_data_ll(num_devices / num_switching_cores);
+       }
+
+       /* Allocate devices up to a maximum of MAX_DEVICES. */
+       ll_root_free = alloc_data_ll(MIN((num_devices), MAX_DEVICES));
+
+       return 0;
+}
+
+/*
+ * Set virtqueue flags so that we do not receive interrupts.
+ */
+static void
+set_irq_status (struct virtio_net *dev)
+{
+       dev->virtqueue[VIRTIO_RXQ]->used->flags = VRING_USED_F_NO_NOTIFY;
+       dev->virtqueue[VIRTIO_TXQ]->used->flags = VRING_USED_F_NO_NOTIFY;
+}
+
+/*
+ * Remove a device from the specific data core linked list and from the main linked list. Synchonization 
+ * occurs through the use of the lcore dev_removal_flag. Device is made volatile here to avoid re-ordering 
+ * of dev->remove=1 which can cause an infinite loop in the rte_pause loop.
+ */
+static void
+destroy_device (volatile struct virtio_net *dev)
+{
+       struct virtio_net_data_ll *ll_lcore_dev_cur;
+       struct virtio_net_data_ll *ll_main_dev_cur;
+       struct virtio_net_data_ll *ll_lcore_dev_last = NULL;
+       struct virtio_net_data_ll *ll_main_dev_last = NULL;
+       int lcore;
+
+       dev->flags &= ~VIRTIO_DEV_RUNNING;
+
+       /*set the remove flag. */
+       dev->remove = 1;
+
+       while(dev->ready != DEVICE_SAFE_REMOVE) {
+               rte_pause();
+       }
+
+       /* Search for entry to be removed from lcore ll */
+       ll_lcore_dev_cur = lcore_info[dev->coreid].lcore_ll->ll_root_used;
+       while (ll_lcore_dev_cur != NULL) {
+               if (ll_lcore_dev_cur->dev == dev) {
+                       break;
+               } else {
+                       ll_lcore_dev_last = ll_lcore_dev_cur;
+                       ll_lcore_dev_cur = ll_lcore_dev_cur->next;
+               }
+       }
+
+       if (ll_lcore_dev_cur == NULL) {
+               RTE_LOG(ERR, CONFIG, "Failed to find the dev to be destroy.\n");
+               return;
+       }
+
+       /* Search for entry to be removed from main ll */
+       ll_main_dev_cur = ll_root_used;
+       ll_main_dev_last = NULL;
+       while (ll_main_dev_cur != NULL) {
+               if (ll_main_dev_cur->dev == dev) {
+                       break;
+               } else {
+                       ll_main_dev_last = ll_main_dev_cur;
+                       ll_main_dev_cur = ll_main_dev_cur->next;
+               }
+       }
+
+       /* Remove entries from the lcore and main ll. */
+       rm_data_ll_entry(&lcore_info[ll_lcore_dev_cur->dev->coreid].lcore_ll->ll_root_used, ll_lcore_dev_cur, ll_lcore_dev_last);
+       rm_data_ll_entry(&ll_root_used, ll_main_dev_cur, ll_main_dev_last);
+
+       /* Set the dev_removal_flag on each lcore. */
+       RTE_LCORE_FOREACH_SLAVE(lcore) {
+               lcore_info[lcore].lcore_ll->dev_removal_flag = REQUEST_DEV_REMOVAL;
+       }
+       
+       /* 
+        * Once each core has set the dev_removal_flag to ACK_DEV_REMOVAL we can be sure that
+        * they can no longer access the device removed from the linked lists and that the devices
+        * are no longer in use.
+        */
+       RTE_LCORE_FOREACH_SLAVE(lcore) {
+               while (lcore_info[lcore].lcore_ll->dev_removal_flag != ACK_DEV_REMOVAL) {
+                       rte_pause();
+               }
+       }
+
+       /* Add the entries back to the lcore and main free ll.*/
+       put_data_ll_free_entry(&lcore_info[ll_lcore_dev_cur->dev->coreid].lcore_ll->ll_root_free, ll_lcore_dev_cur);
+       put_data_ll_free_entry(&ll_root_free, ll_main_dev_cur);
+       
+       /* Decrement number of device on the lcore. */
+       lcore_info[ll_lcore_dev_cur->dev->coreid].lcore_ll->device_num--;
+       
+       RTE_LOG(INFO, DATA, "(%"PRIu64") Device has been removed from data core\n", dev->device_fh);
+}
+
+/*
+ * A new device is added to a data core. First the device is added to the main linked list
+ * and the allocated to a specific data core.
+ */
+static int
+new_device (struct virtio_net *dev)
+{
+       struct virtio_net_data_ll *ll_dev;
+       int lcore, core_add = 0;
+       uint32_t device_num_min = num_devices;
+
+       /* Add device to main ll */
+       ll_dev = get_data_ll_free_entry(&ll_root_free);
+       if (ll_dev == NULL) {
+               RTE_LOG(INFO, DATA, "(%"PRIu64") No free entry found in linked list. Device limit "
+                       "of %d devices per core has been reached\n",
+                       dev->device_fh, num_devices);
+               return -1;
+       }
+       ll_dev->dev = dev;
+       add_data_ll_entry(&ll_root_used, ll_dev);
+
+       /*reset ready flag*/
+       dev->ready = DEVICE_MAC_LEARNING;
+       dev->remove = 0;
+
+       /* Find a suitable lcore to add the device. */
+       RTE_LCORE_FOREACH_SLAVE(lcore) {
+               if (lcore_info[lcore].lcore_ll->device_num < device_num_min) {
+                       device_num_min = lcore_info[lcore].lcore_ll->device_num;
+                       core_add = lcore;
+               }
+       }
+       /* Add device to lcore ll */
+       ll_dev->dev->coreid = core_add;
+       ll_dev = get_data_ll_free_entry(&lcore_info[ll_dev->dev->coreid].lcore_ll->ll_root_free);
+       if (ll_dev == NULL) {
+               RTE_LOG(INFO, DATA, "(%"PRIu64") Failed to add device to data core\n", dev->device_fh);
+               destroy_device(dev);
+               return -1;
+       }
+       ll_dev->dev = dev;
+       add_data_ll_entry(&lcore_info[ll_dev->dev->coreid].lcore_ll->ll_root_used, ll_dev);
+
+       /* Initialize device stats */
+       memset(&dev_statistics[dev->device_fh], 0, sizeof(struct device_statistics));
+
+       /* Disable notifications. */
+       set_irq_status(dev);
+       lcore_info[ll_dev->dev->coreid].lcore_ll->device_num++;
+       dev->flags |= VIRTIO_DEV_RUNNING;
+
+       RTE_LOG(INFO, DATA, "(%"PRIu64") Device has been added to data core %d\n", dev->device_fh, dev->coreid);
+
+       return 0;
+}
+
+/*
+ * These callback allow devices to be added to the data core when configuration
+ * has been fully complete.
+ */
+static const struct virtio_net_device_ops virtio_net_device_ops =
+{
+       .new_device =  new_device,
+       .destroy_device = destroy_device,
+};
+
+/*
+ * This is a thread will wake up after a period to print stats if the user has
+ * enabled them.
+ */
+static void
+print_stats(void)
+{
+       struct virtio_net_data_ll *dev_ll;
+       uint64_t tx_dropped, rx_dropped;
+       uint64_t tx, tx_total, rx, rx_total;
+       uint32_t device_fh;
+       const char clr[] = { 27, '[', '2', 'J', '\0' };
+       const char top_left[] = { 27, '[', '1', ';', '1', 'H','\0' };
+
+       while(1) {
+               sleep(enable_stats);
+
+               /* Clear screen and move to top left */
+               printf("%s%s", clr, top_left);
+
+               printf("\nDevice statistics ====================================");
+
+               dev_ll = ll_root_used;
+               while (dev_ll != NULL) {
+                       device_fh = (uint32_t)dev_ll->dev->device_fh;
+                       tx_total = dev_statistics[device_fh].tx_total;
+                       tx = dev_statistics[device_fh].tx;
+                       tx_dropped = tx_total - tx;
+                       rx_total = rte_atomic64_read(&dev_statistics[device_fh].rx_total);
+                       rx = rte_atomic64_read(&dev_statistics[device_fh].rx);
+                       rx_dropped = rx_total - rx;
+
+                       printf("\nStatistics for device %"PRIu32" ------------------------------"
+                                       "\nTX total:            %"PRIu64""
+                                       "\nTX dropped:          %"PRIu64""
+                                       "\nTX successful:               %"PRIu64""
+                                       "\nRX total:            %"PRIu64""
+                                       "\nRX dropped:          %"PRIu64""
+                                       "\nRX successful:               %"PRIu64"",
+                                       device_fh,
+                                       tx_total,
+                                       tx_dropped,
+                                       tx,
+                                       rx_total,
+                                       rx_dropped,
+                                       rx);
+
+                       dev_ll = dev_ll->next;
+               }
+               printf("\n======================================================\n");
+       }
+}
+
+/*
+ * Main function, does initialisation and calls the per-lcore functions. The CUSE
+ * device is also registered here to handle the IOCTLs.
+ */
+int
+MAIN(int argc, char *argv[])
+{
+       struct rte_mempool *mbuf_pool;
+       unsigned lcore_id, core_id = 0;
+       unsigned nb_ports, valid_num_ports;
+       int ret;
+       uint8_t portid;
+       static pthread_t tid;
+
+       /* init EAL */
+       ret = rte_eal_init(argc, argv);
+       if (ret < 0)
+               rte_exit(EXIT_FAILURE, "Error with EAL initialization\n");
+       argc -= ret;
+       argv += ret;
+
+       /* parse app arguments */
+       ret = us_vhost_parse_args(argc, argv);
+       if (ret < 0)
+               rte_exit(EXIT_FAILURE, "Invalid argument\n");
+
+       if (rte_pmd_init_all() != 0 || rte_eal_pci_probe() != 0)
+               rte_exit(EXIT_FAILURE, "Error with NIC driver initialization\n");
+
+       for (lcore_id = 0; lcore_id < RTE_MAX_LCORE; lcore_id ++)
+               if (rte_lcore_is_enabled(lcore_id))
+                       lcore_ids[core_id ++] = lcore_id;
+
+       if (rte_lcore_count() > RTE_MAX_LCORE)
+               rte_exit(EXIT_FAILURE,"Not enough cores\n");
+
+       /*set the number of swithcing cores available*/
+       num_switching_cores = rte_lcore_count()-1;
+
+       /* Get the number of physical ports. */
+       nb_ports = rte_eth_dev_count();
+       if (nb_ports > RTE_MAX_ETHPORTS)
+               nb_ports = RTE_MAX_ETHPORTS;
+
+       /*
+        * Update the global var NUM_PORTS and global array PORTS
+        * and get value of var VALID_NUM_PORTS according to system ports number
+        */
+       valid_num_ports = check_ports_num(nb_ports);
+
+       if ((valid_num_ports ==  0) || (valid_num_ports > MAX_SUP_PORTS)) {
+               RTE_LOG(INFO, PORT, "Current enabled port number is %u,"
+                       "but only %u port can be enabled\n",num_ports, MAX_SUP_PORTS);
+               return -1;
+       }
+
+       /* Create the mbuf pool. */
+       mbuf_pool = rte_mempool_create("MBUF_POOL", NUM_MBUFS_PER_PORT * valid_num_ports,
+                                      MBUF_SIZE, MBUF_CACHE_SIZE,
+                                      sizeof(struct rte_pktmbuf_pool_private),
+                                      rte_pktmbuf_pool_init, NULL,
+                                      rte_pktmbuf_init, NULL,
+                                      rte_socket_id(), 0);
+       if (mbuf_pool == NULL)
+               rte_exit(EXIT_FAILURE, "Cannot create mbuf pool\n");
+
+       /* Set log level. */
+       rte_set_log_level(LOG_LEVEL);
+
+       /* initialize all ports */
+       for (portid = 0; portid < nb_ports; portid++) {
+               /* skip ports that are not enabled */
+               if ((enabled_port_mask & (1 << portid)) == 0) {
+                       RTE_LOG(INFO, PORT, "Skipping disabled port %d\n", portid);
+                       continue;
+               }
+               if (port_init(portid, mbuf_pool) != 0)
+                       rte_exit(EXIT_FAILURE, "Cannot initialize network ports\n");
+       }
+
+       /* Initialise all linked lists. */
+       if (init_data_ll() == -1)
+               rte_exit(EXIT_FAILURE, "Failed to initialize linked list\n");
+
+       /* Initialize device stats */
+       memset(&dev_statistics, 0, sizeof(dev_statistics));
+
+       /* Enable stats if the user option is set. */
+       if (enable_stats)
+               pthread_create(&tid, NULL, (void*)print_stats, NULL );
+
+       /* Launch all data cores. */
+       RTE_LCORE_FOREACH_SLAVE(lcore_id) {
+               rte_eal_remote_launch(switch_worker, mbuf_pool, lcore_id);
+       }
+
+       /* Register CUSE device to handle IOCTLs. */
+       ret = register_cuse_device((char*)&dev_basename, dev_index, get_virtio_net_callbacks());
+       if (ret != 0)
+               rte_exit(EXIT_FAILURE,"CUSE device setup failure.\n");
+
+       init_virtio_net(&virtio_net_device_ops);
+
+       /* Start CUSE session. */
+       start_cuse_session_loop();
+       return 0;
+
+}
+
diff --git a/examples/vhost/main.h b/examples/vhost/main.h
new file mode 100644 (file)
index 0000000..45db454
--- /dev/null
@@ -0,0 +1,86 @@
+/*-
+ *   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 _MAIN_H_
+#define _MAIN_H_
+
+#ifdef RTE_EXEC_ENV_BAREMETAL
+#define MAIN _main
+#else
+#define MAIN main
+#endif
+
+//#define DEBUG
+
+#ifdef DEBUG
+#define LOG_LEVEL RTE_LOG_DEBUG
+#define LOG_DEBUG(log_type, fmt, args...) do { \
+       RTE_LOG(DEBUG, log_type, fmt, ##args);          \
+} while (0)
+#else
+#define LOG_LEVEL RTE_LOG_INFO
+#define LOG_DEBUG(log_type, fmt, args...) do{} while(0)
+#endif
+
+/* Macros for printing using RTE_LOG */
+#define RTE_LOGTYPE_CONFIG RTE_LOGTYPE_USER1
+#define RTE_LOGTYPE_DATA RTE_LOGTYPE_USER2
+#define RTE_LOGTYPE_PORT RTE_LOGTYPE_USER3
+
+/*
+ * Device linked list structure for data path.
+ */
+struct virtio_net_data_ll
+{
+       struct virtio_net                       *dev;   /* Pointer to device created by configuration core. */
+       struct virtio_net_data_ll       *next;  /* Pointer to next device in linked list. */
+};
+
+/*
+ * Structure containing data core specific information.
+ */
+struct lcore_ll_info
+{
+       struct virtio_net_data_ll       *ll_root_free;          /* Pointer to head in free linked list. */
+       struct virtio_net_data_ll       *ll_root_used;          /* Pointer to head of used linked list. */
+       uint32_t                                        device_num;                     /* Number of devices on lcore. */
+       volatile uint8_t                        dev_removal_flag;       /* Flag to synchronize device removal. */
+};
+
+struct lcore_info
+{
+       struct lcore_ll_info    *lcore_ll;      /* Pointer to data core specific lcore_ll_info struct */
+};
+
+int MAIN(int argc, char **argv);
+#endif /* _MAIN_H_ */
diff --git a/examples/vhost/vhost-net-cdev.c b/examples/vhost/vhost-net-cdev.c
new file mode 100644 (file)
index 0000000..4cf3c56
--- /dev/null
@@ -0,0 +1,367 @@
+/*-
+ *   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 "main.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"
+
+const uint32_t default_major = 231;
+const uint32_t default_minor = 1;
+const char             cuse_device_name[]      = "/dev/cuse";
+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, 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, 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(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(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(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(CONFIG, "(%"PRIu64") IOCTL: VHOST_RESET_OWNER\n", ctx.fh);
+                       VHOST_IOCTL(ops->reset_owner);
+                       break;
+
+               case VHOST_SET_OWNER:
+                       LOG_DEBUG(CONFIG, "(%"PRIu64") IOCTL: VHOST_SET_OWNER\n", ctx.fh);
+                       VHOST_IOCTL(ops->set_owner);
+                       break;
+
+               case VHOST_SET_MEM_TABLE:
+                       LOG_DEBUG(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(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(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(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(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(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(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, CONFIG, "(%"PRIu64") IOCTL: DOESN NOT EXIST\n", ctx.fh);
+                       result = -1;
+                       fuse_reply_ioctl(req, result, NULL, 0);
+       }
+
+       if (result < 0) {
+               LOG_DEBUG(CONFIG, "(%"PRIu64") IOCTL: FAIL\n", ctx.fh);
+       } else {
+               LOG_DEBUG(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
+register_cuse_device(const char *base_name, int index, struct vhost_net_device_ops const * const pops)
+{
+       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, 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 index allows us to have multiple instances
+        * of userspace vhost which we can then add devices to separately.
+        */
+       if (strncmp(base_name, default_cdev, PATH_MAX)!=0) {
+               rte_snprintf(device_name, PATH_MAX, "DEVNAME=%s-%d", base_name, index);
+               rte_snprintf(char_device_name, PATH_MAX, "/dev/%s-%d", base_name, index);
+       } else {
+               rte_snprintf(device_name, PATH_MAX, "DEVNAME=%s", base_name);
+               rte_snprintf(char_device_name, PATH_MAX, "/dev/%s", base_name);
+       }
+
+       /* Check if device already exists. */
+       if (access(char_device_name, F_OK) != -1) {
+               RTE_LOG(ERR, 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 + index;
+       cuse_info.dev_info_argc = 1;
+       cuse_info.dev_info_argv = device_argv;
+       cuse_info.flags = CUSE_UNRESTRICTED_IOCTL;
+
+       ops = pops;
+
+       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
+start_cuse_session_loop(void)
+{
+       fuse_session_loop(session);
+
+       return 0;
+}
diff --git a/examples/vhost/vhost-net-cdev.h b/examples/vhost/vhost-net-cdev.h
new file mode 100644 (file)
index 0000000..7f16b6d
--- /dev/null
@@ -0,0 +1,83 @@
+/*-
+ *   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 _VHOST_NET_CDEV_H_
+#define _VHOST_NET_CDEV_H_
+
+#include <linux/vhost.h>
+
+struct vhost_memory;
+struct vhost_vring_state;
+struct vhost_vring_addr;
+struct vhost_vring_file;
+
+/*
+ * 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);
+};
+
+int register_cuse_device(const char *base_name, int index, struct vhost_net_device_ops const * const);
+int start_cuse_session_loop(void);
+
+#endif /* _VHOST_NET_CDEV_H_ */
diff --git a/examples/vhost/virtio-net.c b/examples/vhost/virtio-net.c
new file mode 100644 (file)
index 0000000..b7b39be
--- /dev/null
@@ -0,0 +1,985 @@
+/*-
+ *   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 "main.h"
+#include "virtio-net.h"
+#include "vhost-net-cdev.h"
+#include "eventfd_link/eventfd_link.h"
+
+const char eventfd_cdev[] = "/dev/eventfd-link";
+
+extern uint32_t num_devices;
+static uint32_t num_cur_devices = 0;
+
+/* 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 = NULL;
+
+/* Features supported by this application. RX merge buffers are disabled by default. */
+uint64_t VHOST_FEATURES = (0ULL << VIRTIO_NET_F_MRG_RXBUF);
+
+/* Line size for reading maps file. */
+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. */
+       rte_snprintf (procdir, PATH_MAX, "/proc/%u/fd/", pid);
+       /* Maps file used to locate mem file. */
+       rte_snprintf (mapfile, PATH_MAX, "/proc/%u/maps", pid);
+
+       fmap = fopen(mapfile, "r");
+       if (fmap == NULL) {
+               RTE_LOG(ERR, 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++) {
+                       if (((in[i] = strtok_r(str, &dlm[i], &sp)) == 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, 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, 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))) {
+               rte_snprintf (memfile, PATH_MAX, "/proc/%u/fd/%s", pid, dptr->d_name);
+           realpath(memfile, resolved_path);
+               if (resolved_path == NULL) {
+                       RTE_LOG(ERR, 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, 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, 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, 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(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;
+}
+
+/*
+ * 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, 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++;
+                       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;
+       }
+
+}
+
+/*
+ * 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);
+}
+/*
+ * 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, CONFIG, "Remove entry from config_ll failed\n");
+                       return NULL;
+               }
+       }
+}
+
+/*
+ *  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;
+}
+
+/*
+ * 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;
+
+       /*check the number of devices in the system*/
+       if (num_cur_devices == num_devices) {
+               RTE_LOG(ERR, CONFIG, "() Max num devices (%u) exceeded\n", num_devices);
+               return -1;
+       }
+
+       /* Setup device and virtqueues. */
+       new_ll_dev = malloc(sizeof(struct virtio_net_config_ll));
+       if (new_ll_dev == NULL) {
+               RTE_LOG(ERR, 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, 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, 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);
+
+       /*increment the number of devices in the system*/
+       num_cur_devices++;
+
+       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);
+               } else {
+                       ll_dev_last = ll_dev_cur;
+                       ll_dev_cur = ll_dev_cur->next;
+               }
+       }
+
+       /*decrement the number of devices in the system*/
+       num_cur_devices--;
+}
+
+/*
+ * 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(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(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, 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(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, 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(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, 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, 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, CONFIG, "(%"PRIu64") Failed to find used ring address.\n", dev->device_fh);
+               return -1;
+       }
+
+       LOG_DEBUG(CONFIG, "(%"PRIu64") mapped address desc: %p\n", dev->device_fh, vq->desc);
+       LOG_DEBUG(CONFIG, "(%"PRIu64") mapped address avail: %p\n", dev->device_fh, vq->avail);
+       LOG_DEBUG(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, 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, 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))
+                       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;
+}
+
+/*
+ * Register ops so that we can add/remove device to data core.
+ */
+int
+init_virtio_net(struct virtio_net_device_ops const * const ops)
+{
+       notify_ops = ops;
+
+       return 0;
+}
+
+/*
+ * Currently not used as we Ctrl+c to exit application.
+ */
+int
+deinit_virtio_net(void)
+{
+       return 0;
+}
diff --git a/examples/vhost/virtio-net.h b/examples/vhost/virtio-net.h
new file mode 100644 (file)
index 0000000..3e677e7
--- /dev/null
@@ -0,0 +1,126 @@
+/*-
+ *   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_
+
+/* Used to indicate that the device is running on a data core */
+#define VIRTIO_DEV_RUNNING 1
+
+/* Backend value set by guest. */
+#define VIRTIO_DEV_STOPPED -1
+
+
+/* Enum for virtqueue management. */
+enum {VIRTIO_RXQ, VIRTIO_TXQ, VIRTIO_QNUM};
+
+/*
+ * Structure contains variables relevant to TX/RX virtqueues.
+ */
+struct vhost_virtqueue
+{
+       struct vring_desc       *desc;                          /* Virtqueue descriptor ring. */
+       struct vring_avail      *avail;                         /* Virtqueue available ring. */
+       struct vring_used       *used;                          /* Virtqueue used ring. */
+       uint32_t                        size;                           /* Size of descriptor ring. */
+       uint32_t                        backend;                        /* Backend value to determine if device should 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;
+
+/*
+ * 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. */
+       struct ether_addr               mac_address;                            /* Device MAC address (Obtained on first TX packet). */
+       uint64_t                                features;                                       /* Negotiated feature set. */
+       uint64_t                                device_fh;                                      /* device identifier. */
+       uint32_t                                vmdq_rx_q;                                      /* RX VMDQ queue number. */
+       uint32_t                                flags;                                          /* Device flags. Only used to check if device is running on data core. */
+       uint32_t                                vlan_tag;                                       /* Vlan tag for device. Currently set to device_id (0-63). */
+       uint16_t                                coreid;                                         /* Data core that the device is added to. */
+       volatile uint8_t                ready;                                          /* A device is set as ready if the MAC address has been set. */
+       volatile uint8_t                remove;                                         /* Device is marked for removal from the data core. */
+} __rte_cache_aligned;
+
+/*
+ * 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. */
+};
+
+/*
+ * 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 operations to add/remove device.
+ */
+struct virtio_net_device_ops {
+       int (* new_device)              (struct virtio_net *);  /* Add device. */
+       void (* destroy_device) (volatile struct virtio_net *); /* Remove device. */
+};
+
+int init_virtio_net(struct virtio_net_device_ops const * const);
+int deinit_virtio_net(void);
+
+struct vhost_net_device_ops const * get_virtio_net_callbacks(void);
+
+#endif /* _VIRTIO_NET_H_ */