--- /dev/null
+#!/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>",
+# "/dev/hugepages",
+# ]
+#
+# 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 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
+# then this variable should be set to:
+# us_vhost_path = "/dev/usvhost"
+us_vhost_path = "/dev/usvhost"
+
+#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
+import time
+import signal
+
+
+#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"
+ ]
+
+#String of the path to the Qemu process pid
+qemu_pid = "/tmp/%d-qemu.pid" % os.getpid()
+
+#############################################
+# Signal haldler to kill Qemu subprocess
+#############################################
+def kill_qemu_process(signum, stack):
+ pidfile = open(qemu_pid, 'r')
+ pid = int(pidfile.read())
+ os.killpg(pid, signal.SIGTERM)
+ pidfile.close()
+
+
+#############################################
+# 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+= " "
+
+ emul_call += "-pidfile %s " % qemu_pid
+ #Call QEMU
+ process = subprocess.Popen(emul_call, shell=True, preexec_fn=os.setsid)
+
+ for sig in [signal.SIGTERM, signal.SIGINT, signal.SIGHUP, signal.SIGQUIT]:
+ signal.signal(sig, kill_qemu_process)
+
+ process.wait()
+
+ #Close usvhost files
+ for fd in fd_list:
+ os.close(fd)
+ #Cleanup temporary files
+ if os.access(qemu_pid, os.F_OK):
+ os.remove(qemu_pid)
+
+if __name__ == "__main__":
+ main()
Code Review / deb_dpdk.git / blobdiff