[ovs-discuss] Behavior of netdev (dpdk) bridges with non-dpdkvhostuser ports
Chandran, Sugesh
sugesh.chandran at intel.com
Tue Oct 11 14:35:45 UTC 2016
Regards
_Sugesh
From: Geza Gemes [mailto:geza.gemes at gmail.com]
Sent: Tuesday, October 11, 2016 2:34 PM
To: Chandran, Sugesh <sugesh.chandran at intel.com>; discuss at openvswitch.org
Subject: Re: [ovs-discuss] Behavior of netdev (dpdk) bridges with non-dpdkvhostuser ports
On 10/11/2016 10:45 AM, Chandran, Sugesh wrote:
Hi Geza,
Regards
_Sugesh
From: discuss [mailto:discuss-bounces at openvswitch.org] On Behalf Of Geza Gemes
Sent: Sunday, October 9, 2016 5:30 PM
To: discuss at openvswitch.org<mailto:discuss at openvswitch.org>
Subject: [ovs-discuss] Behavior of netdev (dpdk) bridges with non-dpdkvhostuser ports
Hi,
I've created a libvirt/KVM VM with Ubuntu 16.04 for experimenting with OVS 2.6 and DPDK 16.07 (from ubuntu cloud archive, newton), it has a number of NICs, out of which I've kept one for a kernel (ens16) and one for a DPDK (dpdk0) datapath.
The bridge setup without virtual NICs:
#ovs-vsctl show
ef015869-3f47-45d4-af20-644f75208a92
Bridge "dpdk-br0"
Port "dpdk-br0"
Interface "dpdk-br0"
type: internal
Port "dpdk0"
Interface "dpdk0"
type: dpdk
Bridge "non-dpdk-br1"
Port "ens16"
Interface "ens16"
Port "non-dpdk-br1"
Interface "non-dpdk-br1"
type: internal
ovs_version: "2.6.0"
I've created an lxc container (I'm using the lxc daily ppa) with the following config:
# grep -v ^# /var/lib/lxc/ovsdpdkbr/config
lxc.include = /usr/share/lxc/config/ubuntu.common.conf
lxc.rootfs = /var/lib/lxc/ovsdpdkbr/rootfs
lxc.rootfs.backend = dir
lxc.utsname = ovsdpdkbr
lxc.arch = amd64
lxc.network.type = veth
lxc.network.link = dpdk-br0
lxc.network.flags = up
lxc.network.hwaddr = 00:16:3e:0c:c3:69
lxc.network.veth.pair = veth-dpdk
Started the lxc container and expected to have no connectivity as lxc is not aware of the bridge being netdev:
# ovs-vsctl show
ef015869-3f47-45d4-af20-644f75208a92
Bridge "dpdk-br0"
Port "dpdk-br0"
Interface "dpdk-br0"
type: internal
Port veth-dpdk
Interface veth-dpdk
Port "dpdk0"
Interface "dpdk0"
type: dpdk
Bridge "non-dpdk-br1"
Port "ens16"
Interface "ens16"
Port "non-dpdk-br1"
Interface "non-dpdk-br1"
type: internal
ovs_version: "2.6.0"
The strange thing is, that it has got an IP address over eth0:
$ ifconfig eth0
eth0 Link encap:Ethernet HWaddr 00:16:3e:0c:c3:69
inet addr:192.168.122.215 Bcast:192.168.122.255 Mask:255.255.255.0
inet6 addr: fe80::216:3eff:fe0c:c369/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:17 errors:0 dropped:0 overruns:0 frame:0
TX packets:11 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:2768 (2.7 KB) TX bytes:1374 (1.3 KB)
and is able to ping the host:
ubuntu at ovsdpdkbr:~$ ping -c 1 192.168.122.1
PING 192.168.122.1 (192.168.122.1) 56(84) bytes of data.
64 bytes from 192.168.122.1<http://192.168.122.1>: icmp_seq=1 ttl=64 time=0.290 ms
--- 192.168.122.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.290/0.290/0.290/0.000 ms
And the host is also able to ping the container:
$ ping -c 1 192.168.122.215
PING 192.168.122.215 (192.168.122.215) 56(84) bytes of data.
64 bytes from 192.168.122.215<http://192.168.122.215>: icmp_seq=1 ttl=64 time=0.265 ms
--- 192.168.122.215 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.265/0.265/0.265/0.000 ms
But while sshd listens in the container:
root at ovsdpdkbr:~# netstat -tunap
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:22<http://0.0.0.0:22> 0.0.0.0:* LISTEN 179/sshd
tcp6 0 0 :::22 :::* LISTEN 179/sshd
udp 0 0 0.0.0.0:68<http://0.0.0.0:68> 0.0.0.0:* 147/dhclient
I cannot connect to it from the host:
ssh -v -v -v ubuntu at 192.168.122.215<mailto:ubuntu at 192.168.122.215>
OpenSSH_6.6.1, OpenSSL 1.0.1f 6 Jan 2014
debug1: Reading configuration data /home/egzagme/.ssh/config
debug1: /home/egzagme/.ssh/config line 1: Applying options for 192.168.*.*
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to 192.168.122.215 [192.168.122.215] port 22.
Looks like ICMP and UDP packets go through somehow, but TCP does not.
[Sugesh] Did you configure any static rules or its just normal action in OVS?
Can you please confirm what rules are being installed in the OVS datapath?
Have you tried ssh in container with different port than 22?
Also is there any iptable rules that present in the host?
Could someone please explain the observed behavior?
Thank you in advance!
Cheers,
Geza
Hi Sugesh,
The packets shall be subject to the normal action only:
# ovs-ofctl show dpdk-br0
OFPT_FEATURES_REPLY (xid=0x2): dpid:00008e3a9f11d64e
n_tables:254, n_buffers:256
capabilities: FLOW_STATS TABLE_STATS PORT_STATS QUEUE_STATS ARP_MATCH_IP
actions: output enqueue set_vlan_vid set_vlan_pcp strip_vlan mod_dl_src mod_dl_dst mod_nw_src mod_nw_dst mod_nw_tos mod_tp_src mod_tp_dst
1(dpdk0): addr:52:54:00:03:64:b1
config: 0
state: 0
current: 10GB-FD
advertised: FIBER
supported: 1GB-HD 1GB-FD 10GB-FD COPPER FIBER AUTO_PAUSE
peer: 10MB-FD 100MB-HD 100MB-FD 10GB-FD COPPER
speed: 10000 Mbps now, 10000 Mbps max
LOCAL(dpdk-br0): addr:8e:3a:9f:11:d6:4e
config: PORT_DOWN
state: LINK_DOWN
current: 10MB-FD COPPER
speed: 10 Mbps now, 0 Mbps max
OFPT_GET_CONFIG_REPLY (xid=0x4): frags=normal miss_send_len=0
I have no iptables set up on the host:
# iptables -L
Chain INPUT (policy ACCEPT)
target prot opt source destination
ACCEPT tcp -- anywhere anywhere tcp dpt:domain
ACCEPT udp -- anywhere anywhere udp dpt:domain
ACCEPT tcp -- anywhere anywhere tcp dpt:bootps
ACCEPT udp -- anywhere anywhere udp dpt:bootps
Chain FORWARD (policy ACCEPT)
target prot opt source destination
ACCEPT all -- anywhere anywhere
ACCEPT all -- anywhere anywhere
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
On the other hand I have an other bridge, with kernel datapath and there connectivity of lxc containers works as expected. My question is how communication between an bridge with dpdk datapath and an lxc container not having a dpdkvhostuser port and not being backed by hugepages is supposed
[Sugesh] The ovs-vswitchd main thread will taken care of the kernel interfaces for the packet forwarding. The PMD threads are not involved in this packet handling, so hugepages.
I am not very familiar with lxc OVS network setup. Definitely OVS forwards packets based on the configured rules when they landed in either through kernel or DPDK managed interface.
You could verify whats happening in the ovs-dpdk data path using following commands
ovs-appctcl dpctl/show –s netdev at ovs-netdev (watch these to see the port stats)
ovs-appctl dpctl/dump-flows netdev at ovs-netdev
Please have a look at the route table and arp in host for more debugging.
In the above setup, 192.168.122.1 is the ip address assigned to the kernel interface ens16? So any packet destined for that subnet will forward to that interface than OVS? Is this assumption correct?
to work?
Thank you!
Cheers,
Geza
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