diff options
Diffstat (limited to 'lib/librte_vhost/libvirt/qemu-wrap.py')
| -rwxr-xr-x | lib/librte_vhost/libvirt/qemu-wrap.py | 387 |
1 files changed, 387 insertions, 0 deletions
diff --git a/lib/librte_vhost/libvirt/qemu-wrap.py b/lib/librte_vhost/libvirt/qemu-wrap.py new file mode 100755 index 00000000..e6a2cc9d --- /dev/null +++ b/lib/librte_vhost/libvirt/qemu-wrap.py @@ -0,0 +1,387 @@ +#!/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() |