.. SPDX-License-Identifier: BSD-3-Clause Copyright 2016 Red Hat, Inc. PVP reference benchmark setup using testpmd =========================================== This guide lists the steps required to setup a PVP benchmark using testpmd as a simple forwarder between NICs and Vhost interfaces. The goal of this setup is to have a reference PVP benchmark without using external vSwitches (OVS, VPP, ...) to make it easier to obtain reproducible results and to facilitate continuous integration testing. The guide covers two ways of launching the VM, either by directly calling the QEMU command line, or by relying on libvirt. It has been tested with DPDK v16.11 using RHEL7 for both host and guest. Setup overview -------------- .. _figure_pvp_2nics: .. figure:: img/pvp_2nics.* PVP setup using 2 NICs In this diagram, each red arrow represents one logical core. This use case requires 6 dedicated logical cores. A forwarding configuration with a single NIC is also possible, requiring 3 logical cores. Host setup ---------- In this setup, we isolate 6 cores (from CPU2 to CPU7) on the same NUMA node. Two cores are assigned to the VM vCPUs running testpmd and four are assigned to testpmd on the host. Host tuning ~~~~~~~~~~~ #. On BIOS, disable turbo-boost and hyper-threads. #. Append these options to Kernel command line: .. code-block:: console intel_pstate=disable mce=ignore_ce default_hugepagesz=1G hugepagesz=1G hugepages=6 isolcpus=2-7 rcu_nocbs=2-7 nohz_full=2-7 iommu=pt intel_iommu=on #. Disable hyper-threads at runtime if necessary or if BIOS is not accessible: .. code-block:: console cat /sys/devices/system/cpu/cpu*[0-9]/topology/thread_siblings_list \ | sort | uniq \ | awk -F, '{system("echo 0 > /sys/devices/system/cpu/cpu"$2"/online")}' #. Disable NMIs: .. code-block:: console echo 0 > /proc/sys/kernel/nmi_watchdog #. Exclude isolated CPUs from the writeback cpumask: .. code-block:: console echo ffffff03 > /sys/bus/workqueue/devices/writeback/cpumask #. Isolate CPUs from IRQs: .. code-block:: console clear_mask=0xfc #Isolate CPU2 to CPU7 from IRQs for i in /proc/irq/*/smp_affinity do echo "obase=16;$(( 0x$(cat $i) & ~$clear_mask ))" | bc > $i done Qemu build ~~~~~~~~~~ Build Qemu: .. code-block:: console git clone git://git.qemu.org/qemu.git cd qemu mkdir bin cd bin ../configure --target-list=x86_64-softmmu make DPDK build ~~~~~~~~~~ Build DPDK: .. code-block:: console git clone git://dpdk.org/dpdk cd dpdk export RTE_SDK=$PWD make install T=x86_64-native-linux-gcc DESTDIR=install Testpmd launch ~~~~~~~~~~~~~~ #. Assign NICs to DPDK: .. code-block:: console modprobe vfio-pci $RTE_SDK/install/sbin/dpdk-devbind -b vfio-pci 0000:11:00.0 0000:11:00.1 .. Note:: The Sandy Bridge family seems to have some IOMMU limitations giving poor performance results. To achieve good performance on these machines consider using UIO instead. #. Launch the testpmd application: .. code-block:: console $RTE_SDK/install/bin/testpmd -l 0,2,3,4,5 --socket-mem=1024 -n 4 \ --vdev 'net_vhost0,iface=/tmp/vhost-user1' \ --vdev 'net_vhost1,iface=/tmp/vhost-user2' -- \ --portmask=f -i --rxq=1 --txq=1 \ --nb-cores=4 --forward-mode=io With this command, isolated CPUs 2 to 5 will be used as lcores for PMD threads. #. In testpmd interactive mode, set the portlist to obtain the correct port chaining: .. code-block:: console set portlist 0,2,1,3 start VM launch ~~~~~~~~~ The VM may be launched either by calling QEMU directly, or by using libvirt. Qemu way ^^^^^^^^ Launch QEMU with two Virtio-net devices paired to the vhost-user sockets created by testpmd. Below example uses default Virtio-net options, but options may be specified, for example to disable mergeable buffers or indirect descriptors. .. code-block:: console /bin/x86_64-softmmu/qemu-system-x86_64 \ -enable-kvm -cpu host -m 3072 -smp 3 \ -chardev socket,id=char0,path=/tmp/vhost-user1 \ -netdev type=vhost-user,id=mynet1,chardev=char0,vhostforce \ -device virtio-net-pci,netdev=mynet1,mac=52:54:00:02:d9:01,addr=0x10 \ -chardev socket,id=char1,path=/tmp/vhost-user2 \ -netdev type=vhost-user,id=mynet2,chardev=char1,vhostforce \ -device virtio-net-pci,netdev=mynet2,mac=52:54:00:02:d9:02,addr=0x11 \ -object memory-backend-file,id=mem,size=3072M,mem-path=/dev/hugepages,share=on \ -numa node,memdev=mem -mem-prealloc \ -net user,hostfwd=tcp::1002$1-:22 -net nic \ -qmp unix:/tmp/qmp.socket,server,nowait \ -monitor stdio .qcow2 You can use this `qmp-vcpu-pin `_ script to pin vCPUs. It can be used as follows, for example to pin 3 vCPUs to CPUs 1, 6 and 7, where isolated CPUs 6 and 7 will be used as lcores for Virtio PMDs: .. code-block:: console export PYTHONPATH=$PYTHONPATH:/scripts/qmp ./qmp-vcpu-pin -s /tmp/qmp.socket 1 6 7 Libvirt way ^^^^^^^^^^^ Some initial steps are required for libvirt to be able to connect to testpmd's sockets. First, SELinux policy needs to be set to permissive, since testpmd is generally run as root (note, as reboot is required): .. code-block:: console cat /etc/selinux/config # This file controls the state of SELinux on the system. # SELINUX= can take one of these three values: # enforcing - SELinux security policy is enforced. # permissive - SELinux prints warnings instead of enforcing. # disabled - No SELinux policy is loaded. SELINUX=permissive # SELINUXTYPE= can take one of three two values: # targeted - Targeted processes are protected, # minimum - Modification of targeted policy. # Only selected processes are protected. # mls - Multi Level Security protection. SELINUXTYPE=targeted Also, Qemu needs to be run as root, which has to be specified in ``/etc/libvirt/qemu.conf``: .. code-block:: console user = "root" Once the domain created, the following snippet is an extract of he most important information (hugepages, vCPU pinning, Virtio PCI devices): .. code-block:: xml 3145728 3145728 3 hvm
Guest setup ----------- Guest tuning ~~~~~~~~~~~~ #. Append these options to the Kernel command line: .. code-block:: console default_hugepagesz=1G hugepagesz=1G hugepages=1 intel_iommu=on iommu=pt isolcpus=1,2 rcu_nocbs=1,2 nohz_full=1,2 #. Disable NMIs: .. code-block:: console echo 0 > /proc/sys/kernel/nmi_watchdog #. Exclude isolated CPU1 and CPU2 from the writeback cpumask: .. code-block:: console echo 1 > /sys/bus/workqueue/devices/writeback/cpumask #. Isolate CPUs from IRQs: .. code-block:: console clear_mask=0x6 #Isolate CPU1 and CPU2 from IRQs for i in /proc/irq/*/smp_affinity do echo "obase=16;$(( 0x$(cat $i) & ~$clear_mask ))" | bc > $i done DPDK build ~~~~~~~~~~ Build DPDK: .. code-block:: console git clone git://dpdk.org/dpdk cd dpdk export RTE_SDK=$PWD make install T=x86_64-native-linux-gcc DESTDIR=install Testpmd launch ~~~~~~~~~~~~~~ Probe vfio module without iommu: .. code-block:: console modprobe -r vfio_iommu_type1 modprobe -r vfio modprobe vfio enable_unsafe_noiommu_mode=1 cat /sys/module/vfio/parameters/enable_unsafe_noiommu_mode modprobe vfio-pci Bind the virtio-net devices to DPDK: .. code-block:: console $RTE_SDK/usertools/dpdk-devbind.py -b vfio-pci 0000:00:10.0 0000:00:11.0 Start testpmd: .. code-block:: console $RTE_SDK/install/bin/testpmd -l 0,1,2 --socket-mem 1024 -n 4 \ --proc-type auto --file-prefix pg -- \ --portmask=3 --forward-mode=macswap --port-topology=chained \ --disable-rss -i --rxq=1 --txq=1 \ --rxd=256 --txd=256 --nb-cores=2 --auto-start Results template ---------------- Below template should be used when sharing results: .. code-block:: none Traffic Generator: Acceptable Loss: % Validation run time: min Host DPDK version/commit: Guest DPDK version/commit: Patches applied: QEMU version/commit: Virtio features: CPU: , NIC: Result: Mpps