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1 | Using Open vSwitch with DPDK |
2 | ============================ | |
3 | ||
4 | Open vSwitch can use Intel(R) DPDK lib to operate entirely in | |
5 | userspace. This file explains how to install and use Open vSwitch in | |
6 | such a mode. | |
7 | ||
8 | The DPDK support of Open vSwitch is considered experimental. | |
9 | It has not been thoroughly tested. | |
10 | ||
11 | This version of Open vSwitch should be built manually with `configure` | |
12 | and `make`. | |
13 | ||
14 | OVS needs a system with 1GB hugepages support. | |
15 | ||
16 | Building and Installing: | |
17 | ------------------------ | |
18 | ||
19 | Required DPDK 1.7 | |
20 | ||
21 | 1. Configure build & install DPDK: | |
22 | 1. Set `$DPDK_DIR` | |
23 | ||
24 | ``` | |
25 | export DPDK_DIR=/usr/src/dpdk-1.7.1 | |
26 | cd $DPDK_DIR | |
27 | ``` | |
28 | ||
29 | 2. Update `config/common_linuxapp` so that DPDK generate single lib file. | |
30 | (modification also required for IVSHMEM build) | |
31 | ||
32 | `CONFIG_RTE_BUILD_COMBINE_LIBS=y` | |
33 | ||
34 | Then run `make install` to build and isntall the library. | |
35 | For default install without IVSHMEM: | |
36 | ||
37 | `make install T=x86_64-native-linuxapp-gcc` | |
38 | ||
39 | To include IVSHMEM (shared memory): | |
40 | ||
41 | `make install T=x86_64-ivshmem-linuxapp-gcc` | |
42 | ||
43 | For further details refer to http://dpdk.org/ | |
44 | ||
45 | 2. Configure & build the Linux kernel: | |
46 | ||
47 | Refer to intel-dpdk-getting-started-guide.pdf for understanding | |
48 | DPDK kernel requirement. | |
49 | ||
50 | 3. Configure & build OVS: | |
51 | ||
52 | * Non IVSHMEM: | |
53 | ||
54 | `export DPDK_BUILD=$DPDK_DIR/x86_64-native-linuxapp-gcc/` | |
55 | ||
56 | * IVSHMEM: | |
57 | ||
58 | `export DPDK_BUILD=$DPDK_DIR/x86_64-ivshmem-linuxapp-gcc/` | |
59 | ||
60 | ``` | |
61 | cd $(OVS_DIR)/openvswitch | |
62 | ./boot.sh | |
63 | ./configure --with-dpdk=$DPDK_BUILD | |
64 | make | |
65 | ``` | |
66 | ||
67 | To have better performance one can enable aggressive compiler optimizations and | |
68 | use the special instructions(popcnt, crc32) that may not be available on all | |
69 | machines. Instead of typing `make`, type: | |
70 | ||
71 | `make CFLAGS='-O3 -march=native'` | |
72 | ||
9feb1017 | 73 | Refer to [INSTALL.userspace.md] for general requirements of building userspace OVS. |
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74 | |
75 | Using the DPDK with ovs-vswitchd: | |
76 | --------------------------------- | |
77 | ||
78 | 1. Setup system boot | |
79 | Add the following options to the kernel bootline: | |
80 | ||
81 | `default_hugepagesz=1GB hugepagesz=1G hugepages=1` | |
82 | ||
83 | 2. Setup DPDK devices: | |
84 | 1. insert uio.ko: `modprobe uio` | |
85 | 2. insert igb_uio.ko: `insmod $DPDK_BUILD/kmod/igb_uio.ko` | |
86 | 3. Bind network device to igb_uio: `$DPDK_DIR/tools/dpdk_nic_bind.py --bind=igb_uio eth1` | |
87 | ||
88 | 3. Mount the hugetable filsystem | |
89 | ||
90 | `mount -t hugetlbfs -o pagesize=1G none /dev/hugepages` | |
91 | ||
92 | Ref to http://www.dpdk.org/doc/quick-start for verifying DPDK setup. | |
93 | ||
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94 | 4. Follow the instructions in [INSTALL.md] to install only the |
95 | userspace daemons and utilities (via 'make install'). | |
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96 | 1. First time only db creation (or clearing): |
97 | ||
a52b0492 GS |
98 | ``` |
99 | mkdir -p /usr/local/etc/openvswitch | |
100 | mkdir -p /usr/local/var/run/openvswitch | |
101 | rm /usr/local/etc/openvswitch/conf.db | |
102 | ovsdb-tool create /usr/local/etc/openvswitch/conf.db \ | |
103 | /usr/local/share/openvswitch/vswitch.ovsschema | |
104 | ``` | |
542cc9bb | 105 | |
a52b0492 | 106 | 2. Start ovsdb-server |
542cc9bb | 107 | |
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108 | ``` |
109 | ovsdb-server --remote=punix:/usr/local/var/run/openvswitch/db.sock \ | |
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110 | --remote=db:Open_vSwitch,Open_vSwitch,manager_options \ |
111 | --private-key=db:Open_vSwitch,SSL,private_key \ | |
112 | --certificate=Open_vSwitch,SSL,certificate \ | |
113 | --bootstrap-ca-cert=db:Open_vSwitch,SSL,ca_cert --pidfile --detach | |
a52b0492 | 114 | ``` |
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115 | |
116 | 3. First time after db creation, initialize: | |
117 | ||
a52b0492 GS |
118 | ``` |
119 | ovs-vsctl --no-wait init | |
120 | ``` | |
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121 | |
122 | 5. Start vswitchd: | |
123 | ||
124 | DPDK configuration arguments can be passed to vswitchd via `--dpdk` | |
125 | argument. This needs to be first argument passed to vswitchd process. | |
126 | dpdk arg -c is ignored by ovs-dpdk, but it is a required parameter | |
127 | for dpdk initialization. | |
128 | ||
a52b0492 GS |
129 | ``` |
130 | export DB_SOCK=/usr/local/var/run/openvswitch/db.sock | |
131 | ovs-vswitchd --dpdk -c 0x1 -n 4 -- unix:$DB_SOCK --pidfile --detach | |
132 | ``` | |
542cc9bb | 133 | |
a52b0492 GS |
134 | If allocated more than one GB hugepage (as for IVSHMEM), set amount and |
135 | use NUMA node 0 memory: | |
542cc9bb | 136 | |
a52b0492 GS |
137 | ``` |
138 | ovs-vswitchd --dpdk -c 0x1 -n 4 --socket-mem 1024,0 \ | |
139 | -- unix:$DB_SOCK --pidfile --detach | |
140 | ``` | |
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141 | |
142 | 6. Add bridge & ports | |
143 | ||
144 | To use ovs-vswitchd with DPDK, create a bridge with datapath_type | |
145 | "netdev" in the configuration database. For example: | |
146 | ||
a52b0492 | 147 | `ovs-vsctl add-br br0 -- set bridge br0 datapath_type=netdev` |
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148 | |
149 | Now you can add dpdk devices. OVS expect DPDK device name start with dpdk | |
a52b0492 GS |
150 | and end with portid. vswitchd should print (in the log file) the number |
151 | of dpdk devices found. | |
542cc9bb | 152 | |
a52b0492 GS |
153 | ``` |
154 | ovs-vsctl add-port br0 dpdk0 -- set Interface dpdk0 type=dpdk | |
155 | ovs-vsctl add-port br0 dpdk1 -- set Interface dpdk1 type=dpdk | |
156 | ``` | |
542cc9bb | 157 | |
a52b0492 GS |
158 | Once first DPDK port is added to vswitchd, it creates a Polling thread and |
159 | polls dpdk device in continuous loop. Therefore CPU utilization | |
160 | for that thread is always 100%. | |
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161 | |
162 | 7. Add test flows | |
163 | ||
164 | Test flow script across NICs (assuming ovs in /usr/src/ovs): | |
165 | Execute script: | |
166 | ||
167 | ``` | |
168 | #! /bin/sh | |
169 | # Move to command directory | |
170 | cd /usr/src/ovs/utilities/ | |
171 | ||
172 | # Clear current flows | |
173 | ./ovs-ofctl del-flows br0 | |
174 | ||
175 | # Add flows between port 1 (dpdk0) to port 2 (dpdk1) | |
176 | ./ovs-ofctl add-flow br0 in_port=1,action=output:2 | |
177 | ./ovs-ofctl add-flow br0 in_port=2,action=output:1 | |
178 | ``` | |
179 | ||
180 | 8. Performance tuning | |
181 | ||
182 | With pmd multi-threading support, OVS creates one pmd thread for each | |
183 | numa node as default. The pmd thread handles the I/O of all DPDK | |
184 | interfaces on the same numa node. The following two commands can be used | |
185 | to configure the multi-threading behavior. | |
186 | ||
a52b0492 | 187 | `ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=<hex string>` |
542cc9bb | 188 | |
a52b0492 GS |
189 | The command above asks for a CPU mask for setting the affinity of pmd |
190 | threads. A set bit in the mask means a pmd thread is created and pinned | |
191 | to the corresponding CPU core. For more information, please refer to | |
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192 | `man ovs-vswitchd.conf.db` |
193 | ||
a52b0492 | 194 | `ovs-vsctl set Open_vSwitch . other_config:n-dpdk-rxqs=<integer>` |
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195 | |
196 | The command above sets the number of rx queues of each DPDK interface. The | |
197 | rx queues are assigned to pmd threads on the same numa node in round-robin | |
198 | fashion. For more information, please refer to `man ovs-vswitchd.conf.db` | |
199 | ||
200 | Ideally for maximum throughput, the pmd thread should not be scheduled out | |
201 | which temporarily halts its execution. The following affinitization methods | |
202 | can help. | |
203 | ||
204 | Lets pick core 4,6,8,10 for pmd threads to run on. Also assume a dual 8 core | |
205 | sandy bridge system with hyperthreading enabled where CPU1 has cores 0,...,7 | |
206 | and 16,...,23 & CPU2 cores 8,...,15 & 24,...,31. (A different cpu | |
207 | configuration could have different core mask requirements). | |
208 | ||
209 | To kernel bootline add core isolation list for cores and associated hype cores | |
210 | (e.g. isolcpus=4,20,6,22,8,24,10,26,). Reboot system for isolation to take | |
211 | effect, restart everything. | |
212 | ||
213 | Configure pmd threads on core 4,6,8,10 using 'pmd-cpu-mask': | |
214 | ||
a52b0492 | 215 | `ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=00000550` |
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216 | |
217 | You should be able to check that pmd threads are pinned to the correct cores | |
218 | via: | |
219 | ||
a52b0492 GS |
220 | ``` |
221 | top -p `pidof ovs-vswitchd` -H -d1 | |
222 | ``` | |
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223 | |
224 | Note, the pmd threads on a numa node are only created if there is at least | |
225 | one DPDK interface from the numa node that has been added to OVS. | |
226 | ||
227 | Note, core 0 is always reserved from non-pmd threads and should never be set | |
228 | in the cpu mask. | |
229 | ||
230 | DPDK Rings : | |
231 | ------------ | |
232 | ||
233 | Following the steps above to create a bridge, you can now add dpdk rings | |
234 | as a port to the vswitch. OVS will expect the DPDK ring device name to | |
235 | start with dpdkr and end with a portid. | |
236 | ||
a52b0492 | 237 | `ovs-vsctl add-port br0 dpdkr0 -- set Interface dpdkr0 type=dpdkr` |
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238 | |
239 | DPDK rings client test application | |
240 | ||
241 | Included in the test directory is a sample DPDK application for testing | |
242 | the rings. This is from the base dpdk directory and modified to work | |
243 | with the ring naming used within ovs. | |
244 | ||
245 | location tests/ovs_client | |
246 | ||
247 | To run the client : | |
248 | ||
a52b0492 GS |
249 | ``` |
250 | cd /usr/src/ovs/tests/ | |
251 | ovsclient -c 1 -n 4 --proc-type=secondary -- -n "port id you gave dpdkr" | |
252 | ``` | |
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253 | |
254 | In the case of the dpdkr example above the "port id you gave dpdkr" is 0. | |
255 | ||
256 | It is essential to have --proc-type=secondary | |
257 | ||
258 | The application simply receives an mbuf on the receive queue of the | |
259 | ethernet ring and then places that same mbuf on the transmit ring of | |
260 | the ethernet ring. It is a trivial loopback application. | |
261 | ||
262 | DPDK rings in VM (IVSHMEM shared memory communications) | |
263 | ------------------------------------------------------- | |
264 | ||
265 | In addition to executing the client in the host, you can execute it within | |
266 | a guest VM. To do so you will need a patched qemu. You can download the | |
267 | patch and getting started guide at : | |
268 | ||
269 | https://01.org/packet-processing/downloads | |
270 | ||
271 | A general rule of thumb for better performance is that the client | |
272 | application should not be assigned the same dpdk core mask "-c" as | |
273 | the vswitchd. | |
274 | ||
275 | Restrictions: | |
276 | ------------- | |
277 | ||
278 | - This Support is for Physical NIC. I have tested with Intel NIC only. | |
279 | - Work with 1500 MTU, needs few changes in DPDK lib to fix this issue. | |
280 | - Currently DPDK port does not make use any offload functionality. | |
281 | ||
282 | ivshmem: | |
283 | - The shared memory is currently restricted to the use of a 1GB | |
284 | huge pages. | |
285 | - All huge pages are shared amongst the host, clients, virtual | |
286 | machines etc. | |
287 | ||
288 | Bug Reporting: | |
289 | -------------- | |
290 | ||
291 | Please report problems to bugs@openvswitch.org. | |
9feb1017 TG |
292 | |
293 | [INSTALL.userspace.md]:INSTALL.userspace.md | |
294 | [INSTALL.md]:INSTALL.md |