[ovs-dev] [PATCH] INSTALL.DPDK-ADVANCED: Add vhost multiqueue loopback testcase.

[Bhanuprakash Bodireddy]

Add steps for loopback test using vhost-user configured with multiqueue
doing packet forwarding in kernel.

Signed-off-by: Bhanuprakash Bodireddy <bhanuprakash.bodireddy at intel.com>
---
 INSTALL.DPDK-ADVANCED.md | 86 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)

diff --git a/INSTALL.DPDK-ADVANCED.md b/INSTALL.DPDK-ADVANCED.md
index 9ae536d..63440d0 100644
--- a/INSTALL.DPDK-ADVANCED.md
+++ b/INSTALL.DPDK-ADVANCED.md
@@ -372,6 +372,91 @@ For users wanting to do packet forwarding using kernel stack below are the steps
        where "-n 0" refers to ring '0' i.e dpdkr0
        ```
 
+### 5.3 PHY-VM-PHY [VHOST MULTIQUEUE]
+
+  The steps (1-5) in 3.3 section of [INSTALL DPDK] guide will create & initialize DB,
+  start vswitchd and add dpdk devices to bridge br0.
+
+  1. Configure PMD and RXQs. For example set no. of dpdk port rx queues to atleast 2.
+     The number of rx queues at vhost-user interface gets automatically configured after
+     virtio device connection and doesn't need manual configuration.
+
+     ```
+     ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=c
+     ovs-vsctl set Interface dpdk0 options:n_rxq=2
+     ovs-vsctl set Interface dpdk1 options:n_rxq=2
+     ```
+
+  2. Instantiate Guest VM using Qemu cmdline
+
+       Guest Configuration
+
+       ```
+       | configuration        | values | comments
+       |----------------------|--------|-----------------
+       | qemu version         | 2.5.0  |
+       | qemu thread affinity |2 cores | taskset 0x30
+       | memory               | 4GB    | -
+       | cores                | 2      | -
+       | Qcow2 image          |Fedora22| -
+       | multiqueue           |   on   | -
+       ```
+
+       Instantiate Guest
+
+       ```
+       export VM_NAME=vhost-vm
+       export GUEST_MEM=4096M
+       export QCOW2_IMAGE=/root/Fedora22_x86_64.qcow2
+       export VHOST_SOCK_DIR=/usr/local/var/run/openvswitch
+
+       taskset 0x30 qemu-system-x86_64 -cpu host -smp 2,cores=2 -drive file=$QCOW2_IMAGE -m 4096M --enable-kvm -name $VM_NAME -nographic -object memory-backend-file,id=mem,size=$GUEST_MEM,mem-path=/dev/hugepages,share=on -numa node,memdev=mem -mem-prealloc -chardev socket,id=char1,path=$VHOST_SOCK_DIR/dpdkvhostuser0 -netdev type=vhost-user,id=mynet1,chardev=char1,vhostforce,queues=2 -device virtio-net-pci,mac=00:00:00:00:00:01,netdev=mynet1,mq=on,vectors=6 -chardev socket,id=char2,path=$VHOST_SOCK_DIR/dpdkvhostuser1 -netdev type=vhost-user,id=mynet2,chardev=char2,vhostforce,queues=2 -device virtio-net-pci,mac=00:00:00:00:00:02,netdev=mynet2,mq=on,vectors=6
+       ```
+
+       Note: Queue value above should match the queues configured in OVS, The vector value
+       should be set to 'no. of queues x 2 + 2'.
+
+  3. Guest interface configuration
+
+     Assuming there are 2 interfaces in the guest named eth0, eth1 check the channel
+     configuration and set the number of combined channels to 2 for virtio devices.
+     More information can be found in [Vhost walkthrough] section.
+
+       ```
+       ethtool -l eth0
+       ethtool -L eth0 combined 2
+       ethtool -L eth1 combined 2
+       ```
+
+  4. Kernel Packet forwarding
+
+     Configure IP and enable interfaces
+
+     ```
+     ifconfig eth0 5.5.5.1/24 up
+     ifconfig eth1 90.90.90.1/24 up
+     ```
+
+     Configure IP forwarding and add route entries
+
+     ```
+     sysctl -w net.ipv4.ip_forward=1
+     sysctl -w net.ipv4.conf.all.rp_filter=0
+     sysctl -w net.ipv4.conf.eth0.rp_filter=0
+     sysctl -w net.ipv4.conf.eth1.rp_filter=0
+     ip route add 2.1.1.0/24 dev eth1
+     route add default gw 2.1.1.2 eth1
+     route add default gw 90.90.90.90 eth1
+     arp -s 90.90.90.90 DE:AD:BE:EF:CA:FE
+     arp -s 2.1.1.2 DE:AD:BE:EF:CA:FA
+     ```
+
+     Check traffic on multiple queues
+
+     ```
+     cat /proc/interrupts | grep virtio
+     ```
+
 ## <a name="vhost"></a> 6. Vhost Walkthrough
 
 DPDK 16.04 supports two types of vhost:
@@ -848,5 +933,6 @@ Please report problems to bugs at openvswitch.org.
 [DPDK Docs]: http://dpdk.org/doc
 [libvirt]: http://libvirt.org/formatdomain.html
 [Guest VM using libvirt]: INSTALL.DPDK.md#ovstc
+[Vhost walkthrough]: INSTALL.DPDK.md#vhost
 [INSTALL DPDK]: INSTALL.DPDK.md#build
 [INSTALL OVS]: INSTALL.DPDK.md#build
-- 
2.4.11