Hi Ilya,

Thanks for your suggestion.
We tried pinning the PMD threads to core. But still the issue exists that only single queue is working instead of multiqueue. We tried using 'dpdkvhostuserclient' instead of 'dpdkvhostuser' but we are getting the following error and the VM is not able to find the interface.

ovs-vswitchd log

2019-03-07T07:42:40.517Z|00212|dpdk|INFO|VHOST_CONFIG: vhost-user client: socket created, fd: 1091 2019-03-07T07:42:40.517Z|00213|netdev_dpdk|INFO|vHost User device 'dpdkvhostuser0' created in 'client' mode, using client socket '/tmp/dpdkvhostclient0' 2019-03-07T07:42:40.517Z|00214|dpdk|WARN|VHOST_CONFIG: failed to connect to /tmp/dpdkvhostclient0: No such file or directory 2019-03-07T07:42:40.517Z|00215|dpdk|INFO|VHOST_CONFIG: /tmp/dpdkvhostclient0: reconnecting... 2019-03-07T07:42:40.517Z|00216|dpif_netdev|WARN|There's no available (non-isolated) pmd thread on numa node 1. Queue 0 on port 'dpdk-p0' will be assigned to the pmd on core 1 (numa node 0). Expect reduced performance.

The output of the following commands now is:


ovs-appctl dpif-netdev/pmd-rxq-show

pmd thread numa_id 0 core_id 1:
  isolated : false
  port: dpdk-p0           queue-id:  0  pmd usage:  0 %
pmd thread numa_id 0 core_id 2:
  isolated : false
  port: dpdkvhostuser0    queue-id:  0  pmd usage:  0 %


ovs-vsctl show:

356b0bfb-979c-408a-be1e-4567d52ef57f
    Bridge "br0"
        Port "dpdk-p0"
            Interface "dpdk-p0"
                type: dpdk
                options: {dpdk-devargs="0000:81:00.1,n_rxq=2"}
        Port "br0"
            Interface "br0"
                type: internal
        Port "dpdkvhostuser0"
            Interface "dpdkvhostuser0"
                type: dpdkvhostuserclient
                options: {vhost-server-path="/tmp/dpdkvhostuser0"}

ovs-vswitchd --version
     ovs-vswitchd (Open vSwitch) 2.11.90
     DPDK 18.11.0

qemu-system-x86_64 --version
QEMU emulator version 2.5.0 (Debian 1:2.5+dfsg-5ubuntu10.34), Copyright (c) 2003-2008 Fabrice Bellard

Can you please help us with what we are missing?

Thanks,
Priyanka


On 2019-03-06 18:13, Ilya Maximets wrote:
On 06.03.2019 15:18, ppnaik wrote:
Thanks for the response Ilya.
We could get this setup working now.

However, we could not get it working when we want to give two queues to the VM interface.

We added the queue option when creating the interface on OVS.

There is no 'n_rxq'/'n_txq' options for vhost interfaces. Number of queues obtained from the virtio device when QEMU connects. You could have this
in ovsdb, but it doesn't affect anything.
OTOH, physical ports has 'n_rxq' configurable.

We also enabled multiqueue in VM XML and gave the interface and set the vectors too.

ethtool inside the VM shows:

ethtool -l ens3
Channel parameters for ens3:
Pre-set maximums:
RX:        0
TX:        0
Other:        0
Combined:    2
Current hardware settings:
RX:        0
TX:        0
Other:        0
Combined:    2

However, a DPDK application inside the VM is not able to get packets from both queues. It still works with one queue.

I assume that you have only one PMD thread that polls both physical
and virtual ports. Each PMD thread uses only one Tx queue per port.
So, if you want to utilize more queues in virtual interface, you need to
create more PMD threads using pmd-cpu-mask.
For example, with pmd-cpu-mask=0x30 there will be 2 PMD threads. One on
CPU #5 and another on CPU #6. Thread on core #5 will send packets to
let's say Tx queue #0, Thread on core #6 will send packets to Tx queue #1.
These packets will appear on Rx queue #0 and Rx queue #1 accordingly
inside VM.
But you need to be sure that both threads has packets to send, i.e. they both polls some rx queues of other ports. For exmaple, you may configure 2 queues on physical port and assign them to different PMD threads (this should be done automatically). You may check the distribution of rx queues
between threads by 'ovs-appctl dpif-netdev/pmd-rxq-show'.
In this case, packets that appears on different rx queues of hw port will
go to different queues of vhost-user port.


Please help us resolve this issue.

Thanks,
Priyanka


On 2019-03-06 16:48, Ilya Maximets wrote:
Hi.

At first you need to look at ovs-vswitchd.log and the log of qemu.
There might be some errors.

Some thoughts inline.

Best regards, Ilya Maximets.

Hi All,

Our setup is as follows:

We have two servers which are connected peer to peer over 40G
interfaces.

On one server we have setup OVS and added the physical 40G interface as
a DPDK interface to the ovs bridge.

We created another dpdkvhostuser interface for the VM. We added this
interface to the VM (by editing the XML). We are able to see this
interface inside the VM and have configure IP to the interface.

We want to communicate between the other server and VM inside this
server through the OVS interface created for the VM.

The steps we followed (on the server with OVS) are:

modprobe uio

IMHO, it's better to use vfio-pci. But it's up to you.


cd /usr/src/dpdk-18.11/x86_64-native-linuxapp-gcc/kmod/

insmod igb_uio.ko

cd /usr/src/dpdk-18.11/usertools/
./dpdk-devbind.py --bind=igb_uio 0000:81:00.1

  export PATH=$PATH:/usr/local/share/openvswitch/scripts
  export DB_SOCK=/usr/local/var/run/openvswitch/db.sock

  ovsdb-server --remote=punix:/usr/local/var/run/openvswitch/db.sock
--remote=db:Open_vSwitch,Open_vSwitch,manager_options
--private-key=db:Open_vSwitch,SSL,private_key
--certificate=db:Open_vSwitch,SSL,certificate
--bootstrap-ca-cert=db:Open_vSwitch,SSL,ca_cert --pidfile --detach
--log-file

  ovs-vsctl --no-wait set Open_vSwitch . other_config:dpdk-init=true
  ovs-ctl --no-ovsdb-server --db-sock="$DB_SOCK" start

ovs-vsctl add-br br0 -- set bridge br0 datapath_type=netdev
ovs-vsctl add-port br0 dpdk-p0 -- set Interface dpdk-p0 type=dpdk
options:dpdk-devargs=0000:81:00.1
ovs-vsctl add-port br0 dpdkvhostuser0     -- set Interface
dpdkvhostuser0 type=dpdkvhostuser ofport_request=3

Consider using 'dpdkvhostuserclient' a.k.a. 'vhost-user-client' ports instead
because server mode 'dpdkvhostuser' ports are deprecated in OVS.


ovs-ofctl add-flow br0 in_port=1,action=output:3
ovs-ofctl add-flow br0 in_port=3,action=output:1

echo 'vm.nr_hugepages=2048' > /etc/sysctl.d/hugepages.conf

Here you're allocating 2048 pages of 2MB. This is not enough
for your setup. You're trying to allocate 4096 MB for qemu memory
backing + OVS will need some hugepage memory for the mempools and stuff.
It'll be at total:
    4096 + 1024 (default for OVS if you have only 1 NUMA node) MB,
i.e. you need at least 512 more pages.

Do you need to reload sysctl for changes to be applied?

grep HugePages_ /proc/meminfo

So, where is the output? If the output is empty, you have no pages allocated.


edit VM XML to add this interface:

If you're starting new VM with updated XML than I'll suggest using
better libvirt
syntax. i.e. it's better to use sections like "memoryBacking", "interface"
instead of manual attaching of cmdline arguments.
See http://docs.openvswitch.org/en/latest/topics/dpdk/vhost-user/#sample-xml


first line:
<domain type='kvm'
xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>

add before </domain> tag:

<qemu:commandline>
     <qemu:arg value='-chardev'/>
     <qemu:arg


value='socket,id=char1,path=/usr/local/var/run/openvswitch/dpdkvhostuser0'/>
     <qemu:arg value='-netdev'/>
     <qemu:arg

value='vhost-user,id=mynet1,chardev=char1,vhostforce=on,queues=1'/>
     <qemu:arg value='-device'/>
     <qemu:arg


value='virtio-net-pci,mac=00:00:00:00:00:02,netdev=mynet1,mq=on,vectors=4'/>
     <qemu:arg value='-m'/>
     <qemu:arg value='4096'/>
     <qemu:arg value='-object'/>
     <qemu:arg


value='memory-backend-file,id=mem1,size=4096M,mem-path=/dev/hugepages,share=on'/>
     <qemu:arg value='-mem-prealloc'/>
     <qemu:arg value='-numa'/>
     <qemu:arg value='node,memdev=mem1'/>
   </qemu:commandline>

Please help us resolve this issue. I assumed ping would work between the other server and the VM. But it is not working in our case. Also,
let us know if we are missing some setup step or if there is some
misconfiguration. If ping would not work can you let us know a way to
verify the connectivity?

Thanks,
Priyanka


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