Jarno Rajahalme [Thu, 26 Mar 2015 18:18:17 +0000 (11:18 -0700)]
ofproto-dpif-xlate: Fix MPLS recirculation.
Prior to this patch MPLS recirculation was not performed on a table
lookup following an MPLS_POP action. This patch refactors MPLS
recirculation triggering so that a table action can be re-done after
recirculation if that table action follows an MPLS_POP action.
Recirculation for a patch port traversal (which also does a table
lookup) after an MPLS_POP action does not need to store the output
action, as recirculation without any post-recirculation actions causes
the table lookup to happen anyway.
Furthermore, the stack actions now have the same post-MPLS_POP
optimization as the SET_FIELD and MOVE actions had already:
recirculation is triggered only if the register in the action is L3 or
higher.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com> Acked-by: Ben Pfaff <blp@nicira.com>
Jarno Rajahalme [Thu, 26 Mar 2015 18:18:16 +0000 (11:18 -0700)]
ofproto-dpif: Restore metadata and registers on recirculation.
xlate_actions() now considers an optional recirculation context (via
'xin') and restores OpenFlow pipeline metadata (registers, 'metadata',
etc.) based on it. The recirculation context may contain an action
set and stack to be restored and further actions to be executed upon
recirculation. It also contains a table_id number to be used for rule
lookup in cases where no post-recirculation actions are used.
The translation context internal metadata is restored using a new
internal action: UNROLL_XLATE action stores the translation context
data visible to OpenFlow controllers via PACKET_IN messages. This
includes the current table number and the current rule cookie.
UNROLL_XLATE actions are inserted only when the remaining actions may
generate PACKET_IN messages.
These changes allow the post-MPLS recirculation to properly continue
with the pipeline metadata that existed at the time of recirculation.
The internal table is still consulted for bonds.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com> Acked-by: Ethan Jackson <ethan@nicira.com> Acked-by: Ben Pfaff <blp@nicira.com>
Ben Pfaff [Tue, 24 Mar 2015 17:51:56 +0000 (10:51 -0700)]
netdev-linux: Fix build with old kernel headers.
Commit 677d9158fc0a (netdev-linux: Support for SFQ, FQ_CoDel and CoDel
qdiscs.) added support for new qdiscs. The commit uses TCA_CODEL_* and
TCA_FQ_CODEL_* not in old kernel headers, causing a build failure against
such headers. This commit should fix the problem by defining these values
ourselves. (I haven't tested it against old headers, so I might have
missed something, but it's a straightforward change and at worst won't do
harm.)
It appears that sfq (also added by the same commit) was in Linux before
2.6.32, so it seems unlikely that we need any compatibility code there.
CC: Jonathan Vestin <jonavest@kau.se> Signed-off-by: Ben Pfaff <blp@nicira.com>
Jesse Gross [Tue, 24 Mar 2015 14:42:47 +0000 (07:42 -0700)]
tunnels: Enable UDP checksum computation for Geneve and VXLAN.
The kernel module can already support outer UDP checksums for
Geneve and VXLAN using the standard checksum flag in tunnel
metadata. This makes userspace aware of the capability so that
users can enable it on tunnel ports.
There is a complication in that there is no way for userspace to
probe or detect if the kernel does not support this capability
in order to warn the user. In this case, connectivity will appear
to function normally but packets will not be checksum protected.
This is mainly an issue for VXLAN which has existed in the kernel
for a some time without checksum support - while there are also
a few kernel versions that support Geneve only without checksums,
they are much less common.
There isn't a particularly good solution to the compatibility
issue without introducing a larger capabilities structure. However,
UDP checksums are likely to be used only rarely at this point in
time and the VXLAN spec (where the main problem lies) recommends
against them. Therefore, this is considered to be an advanced user
feature and we settle for just documenting the issue.
Jarno Rajahalme [Thu, 19 Mar 2015 22:39:48 +0000 (15:39 -0700)]
ofproto-dpif-xlate: More robust wildcarding for select group.
The flow key should be the same regardless of whether a live bucket is
found or not, as it would be confusing that the flow key would be
different (different mask bits) after the last group bucket goes dead.
In general, the megaflow algorithm expects the mask bits be set as
soon as we read the header bits, regardless of what happens
afterwards.
Also, use flow_mask_hash_fields() instead of individually setting mask
fields. This immediately brings in IPv6 support, and helps keeping
masks in sync with potential algorithm changes to flow hashing
functions.
Found by inspection.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com> Acked-by: Ben Pfaff <blp@nicira.com>
Jarno Rajahalme [Thu, 19 Mar 2015 22:20:21 +0000 (15:20 -0700)]
ofproto-dpif-xlate: Roll back group bucket actions after every bucket.
We used to roll back group bucket changes only for 'all' and
'indirect' group types, but the expected semantics of all group types
is that any changes by the group bucket are not visible after the
group has been executed.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com> Acked-by: Ben Pfaff <blp@nicira.com>
Jarno Rajahalme [Thu, 12 Mar 2015 20:02:07 +0000 (13:02 -0700)]
ofproto-dpif-xlate: Remove bond recirculation parameters from context.
The bond recirculation parameters in the translation context are short
lived and only carry parameters to immediate downstream functions. As
such they are better served as normal function parameters. This
simplifies the translation context, which needs to be essentially
restored after traversing patch ports.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com> Acked-by: Ben Pfaff <blp@nicira.com>
Simon Horman [Fri, 20 Mar 2015 04:50:30 +0000 (13:50 +0900)]
Support decoding of NTR selection method
This is in preparation for supporting group mod and desc reply
messages with an NTR selection method group experimenter property.
Currently decoding always fails as it only allows properties for known
selection methods and no selection methods are known yet. A subsequent
patch will propose a hash selection method.
NTR selection method Signed-off-by: Simon Horman <simon.horman@netronome.com> Signed-off-by: Ben Pfaff <blp@nicira.com>
Simon Horman [Fri, 20 Mar 2015 04:50:28 +0000 (13:50 +0900)]
Documentation: Add documentation of group selection method property
NTR selection method Signed-off-by: Simon Horman <simon.horman@netronome.com> Acked-by: Ben Pfaff <blp@nicira.com> Signed-off-by: Ben Pfaff <blp@nicira.com>
Mark D. Gray [Tue, 24 Mar 2015 10:39:11 +0000 (10:39 +0000)]
vswitch.ovsschema: Add datapath_types and port_types.
At startup enumerate datapath and port types and add this information to
the datapath_types and port_types columns in the ovsdb.
This allows an ovsdb client to query the datapath in order to determine
if certain datapath and port types exist. For example, by querying the
port_types column, an ovsdb client will be able to determine if this
instance of ovs-vswitchd was compiled with DPDK support.
Signed-off-by: Mark D. Gray <mark.d.gray@intel.com> Signed-off-by: Billy O'Mahony <billy.o.mahony@intel.com>
[blp@nicira.com made several changes] Signed-off-by: Ben Pfaff <blp@nicira.com>
Sorin Vinturis [Tue, 24 Mar 2015 14:53:11 +0000 (14:53 +0000)]
datapath-windows: Updated WFP system provider handling
If the Base Filtering Engine (BFE) is not started, the WFP system
provider failed to be added because no session to the engine could
be acquired.
The solution for this was to registered a BFE notification callback
that is called whenever the BFE's state changes. Only if the BFE's
state is running the WFP system provider is added.
Jonathan Vestin [Wed, 18 Mar 2015 16:13:01 +0000 (17:13 +0100)]
netdev-linux: Support for SFQ, FQ_CoDel and CoDel qdiscs.
This patch adds support for SFQ, CoDel and FQ_CoDel classless qdiscs to Open vSwitch. It also removes the requirement for a QoS to have at least one Queue (as this makes no sense when using classless qdiscs). I have also not implemented class_{get,set,delete,get_stats,dump_stats} because they are meant for qdiscs with classes.
Signed-off-by: Jonathan Vestin <jonavest@kau.se>
[blp@nicira.com mostly applied stylistic changes] Signed-off-by: Ben Pfaff <blp@nicira.com>
Dennis Flynn [Wed, 18 Mar 2015 18:47:14 +0000 (14:47 -0400)]
auto-attach: Support latest version of auto-attach LLDP TLVs
The following enhancements to the auto-attach feature are provided
- Support recent modifications to the AA element discovery TLV
- Support recent Avaya Organizationally Unique ID (OUI) change.
(This will change to IEEE assigned OUI once AA standard has been ratified)
- Remove some Avaya specific #defines
The primary purpose of this commit is to catch up with the latest changes made
to the auto attach TLVs as the Auto Attach feature progresses through the
802.1Q IEEE standards committee. Most notably this includes some minor rework
of the AA element discovery TLV and a recent change to the Avaya OUI value.
Signed-off-by: Dennis Flynn <drflynn@avaya.com> Signed-off-by: Ben Pfaff <blp@nicira.com>
Alex Wang [Wed, 18 Mar 2015 21:32:23 +0000 (14:32 -0700)]
bashcomp: Install and package completion scripts.
This commit makes the bash completion scripts be installed to
$(sysconfdir)/bash_completion.d/ through 'make install' and to
/etc/bash_completion.d/ through package installation. This will
make the scripts available for each bash session.
An alternative is to put scripts to /usr/share/bash_completion/
directory. However, this is not supported by earlier version of
bash completion.
Alex Wang [Fri, 13 Mar 2015 21:47:25 +0000 (14:47 -0700)]
ovs-vsctl-bashcomp: Avoid setting the COMP_WORDBREAKS.
Modifying $COMP_WORDBREAKS in completion script is not the recommended
as it is a global variable and the modification could affect the behavior
of other completion scripts. As a workaround, this commit uses the
_get_comp_words_by_ref which allows user to exclude characters out of
$COMP_WORDBREAKS and reassemble input command line. However, as a side
effect, the bash completion module cannot handle characters defined in
$COMP_WORDBREAKS (e.g. ':' and '=') correctly in the resulting completions.
Thusly, we need to trim the colon-word and equal-word prefixes from reply.
acinclude.m4: Restore --whole-archive option for DPDK.
The --whole-archive option is required to link vswitchd with DPDK,
otherwise the PMD drivers are not going to be included. Omitting the
option is not going to cause build failures, but OVS won't be able to
use most physical NICs.
Signed-off-by: Daniele Di Proietto <diproiettod@vmware.com> Acked-by: Pravin B Shelar <pshelar@nicira.com>
Ben Pfaff [Fri, 20 Mar 2015 06:22:05 +0000 (23:22 -0700)]
ovs-vsctl: Create AutoAttach records on demand, for backward compatibility.
The AutoAttach table is new in OVS 2.3.90, but ovs-vsctl was creating a
record in the table unconditionally whenever it created a new bridge.
This caused a gratuitous incompatibility with older databases, which can
be a problem during upgrade. This commit switches to creating the
AutoAttaach record for a bridge lazily, only when the first mapping is
created for the bridge.
VMware-BZ: #1413562 CC: Dennis Flynn <drflynn@avaya.com> Reported-by: Alex Wang <alexw@nicira.com> Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Justin Pettit <jpettit@nicira.com>
Kevin Traynor [Thu, 5 Mar 2015 21:42:04 +0000 (13:42 -0800)]
netdev-dpdk: add dpdk vhost-cuse ports
This patch adds support for a new port type to userspace datapath
called dpdkvhost. This allows KVM (QEMU) to offload the servicing
of virtio-net devices to its associated dpdkvhost port. Instructions
for use are in INSTALL.DPDK.
This has been tested on Intel multi-core platforms and with clients
that have virtio-net interfaces.
Signed-off-by: Ciara Loftus <ciara.loftus@intel.com> Signed-off-by: Kevin Traynor <kevin.traynor@intel.com> Signed-off-by: Maryam Tahhan <maryam.tahhan@intel.com> Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Ben Pfaff [Fri, 13 Mar 2015 21:46:23 +0000 (14:46 -0700)]
netdev-linux: Avoid RTM_GETQDISC bug workaround on new-enough kernels.
Otherwise we can't detect classless qdiscs.
This has no useful effect for the currently supported qdiscs, which all
have classes, but it makes it possible to add support for new classless
qdiscs.
This suddenly makes netdev-linux complain about qdiscs it doesn't know
about (e.g. pfifo_fast), which isn't too useful, so this commit also
demotes that INFO message to DBG level.
Reported-by: Jonathan Vestin <jonavest@kau.se> Signed-off-by: Ben Pfaff <blp@nicira.com>
Ben Pfaff [Tue, 17 Mar 2015 21:39:27 +0000 (14:39 -0700)]
include/openflow: Simplify structure checking for OpenFlow headers.
This means that anyone who adds another openflow include file automatically
gets it checked. It does mean that changing any of the OpenFlow headers
causes all of them to be checked, but that doesn't seem like a big deal
(it's quick).
Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Thomas Graf <tgraf@noironetworks.com>
Simon Horman [Mon, 9 Mar 2015 01:10:56 +0000 (10:10 +0900)]
Use NTR rather than NTR as prefix for Netronome vendor id
As pointed out by Ben Pfaff NTR (NetronoMe eXtension) is confusingly
similar to NXM (Nicira eXtended Match?) which is already used widely
in the Open vSwitch tree.
To get ease future eye strain use NTR (NeTRonome) instead of NTR,
starting with the only instance currently present in the tree,
the Netronome vendor id.
This is in preparation for actually using the Netronome vendor id.
Signed-off-by: Simon Horman <simon.horman@netronome.com> Signed-off-by: Ben Pfaff <blp@nicira.com>
Jarno Rajahalme [Thu, 12 Mar 2015 16:47:31 +0000 (09:47 -0700)]
ofproto-dpif-xlate: Do not exit if peer bridge exits.
The fact that the peer bridge exits (for any reason) does not mean
that the original bridge should exit. Specifically, if the peer
bridge recirculates (which typically modifies the packet), the
original bridge must continue processing with the original, not the
recirculated packet!
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com> Acked-by: Ben Pfaff <blp@nicira.com>
Russell Bryant [Tue, 17 Mar 2015 14:35:26 +0000 (10:35 -0400)]
command-line: add ovs_cmdl_context
I started working on a new command line utility that used this shared
code. I wanted the ability to pass some data from common
initialization code to all of the commands. You can find a similar
pattern in ovs-vsctl.
This patch updates the command handler to take a new struct,
ovs_cmdl_context, instead of argc and argv directly. It includes argc
and argv, but also includes an opaque type (void *), where the user of
this API can attach its custom data it wants passed along to command
handlers.
This patch affected the ovstest sub-programs, as well. The patch
includes a bit of an odd hack to OVSTEST_REGISTER() to avoid making
the main() function of the sub-programs take a ovs_cmdl_context.
The test main() functions still receive argc and argv directly, as
that seems more natural. The test-subprograms themselves are able to
make use of a context internally, though.
Signed-off-by: Russell Bryant <rbryant@redhat.com> Signed-off-by: Ben Pfaff <blp@nicira.com>
Jarno Rajahalme [Fri, 13 Mar 2015 19:22:51 +0000 (12:22 -0700)]
match: Do not skip formatting a zero dp_hash.
The dp_hash match should be printed whenever it is being matched. We
keep the old behavior for flow_format(), which is mostly used to
format PACKET_IN messages. This keeps those messages tidier and avoids
changing a lot of test cases.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com> Acked-by: Andy Zhou <azhou@nicira.com> Acked-by: Ben Pfaff <blp@nicira.com>
Russell Bryant [Mon, 16 Mar 2015 16:01:55 +0000 (12:01 -0400)]
command-line: add ovs_cmdl_ prefix
The coding style guidelines include the following:
- Pick a unique name prefix (ending with an underscore) for each
module, and apply that prefix to all of that module's externally
visible names. Names of macro parameters, struct and union members,
and parameters in function prototypes are not considered externally
visible for this purpose.
This patch adds the new prefix to the externally visible names. This
makes it a bit more obvious what code is coming from common command
line handling code.
Signed-off-by: Russell Bryant <rbryant@redhat.com> Signed-off-by: Ben Pfaff <blp@nicira.com>
Alex Wang [Fri, 13 Mar 2015 17:28:07 +0000 (10:28 -0700)]
ovs-vsctl-bashcomp: Fix build failure when bash version < 4.0.
The ovs-vsctl-bashcomp script does not work properly on bash (version
< 4.0). This commit adds test for the bash version and avoids running
the script/test when the bash version is not supported.
Signed-off-by: Alex Wang <alexw@nicira.com> Acked-by: Ben Pfaff <blp@nicira.com>
Alex Wang [Wed, 11 Feb 2015 19:08:57 +0000 (11:08 -0800)]
ovs-vsctl-bashcomp: Documentation and unit tests.
This commit includes the unit tests for ovs-vsctl-bashcomp
and refines the ovs-command-bashcomp.INSTALL.md to introduce
the bash completion for ovs-vsctl.
Signed-off-by: Alex Wang <alexw@nicira.com> Acked-by: Ben Pfaff <blp@nicira.com>
Peter Amidon [Wed, 4 Feb 2015 17:52:12 +0000 (09:52 -0800)]
ovs-vsctl-bashcomp: Add bash command-line completion for ovs-vsctl.
This patch adds bash command-line completion script for ovs-vsctl.
Therein, codes are added to ovs-vsctl to allow it to print the
options and command arguments. The ovs-vsctl-bashcomp.bash will
parse the vsctl command and complete on the user input.
The completion script can do the following::
- display available completions and complete on user input for
global/local options, sub-commands, and arguments.
- query database and expand keywords like 'table/record/column/key'
to available completions.
- deal with argument relations like 'one and more', 'zero or one'.
- complete multiple ovs-vsctl commands cascaded via '--'.
To use the script, either copy it inside /etc/bash_completion.d/
or manually run it via . ovs-vsctl-bashcomp.bash.
Signed-off-by: Peter Amidon <peter@picnicpark.org> Signed-off-by: Alex Wang <alexw@nicira.com> Acked-by: Ben Pfaff <blp@nicira.com>
Alex Wang [Tue, 10 Feb 2015 19:06:11 +0000 (11:06 -0800)]
ovs-appctl-bashcomp: Keep naming consistency.
Before adding the completion script ovs-vsctl-bashcomp.bash for
ovs-vsctl command, this commit renames the ovs-command-compgen.bash
to ovs-appctl-bashcomp.bash to keep the script naming consistent.
Signed-off-by: Alex Wang <alexw@nicira.com> Acked-by: Ben Pfaff <blp@nicira.com>
Commit 032c09ddd10 (XenServer: Don't reset on xe-toolstack-restart)
introduced a bug which causes the setting of 'ssl::6632' at xenserver
boot. Subsequently, at each bridge configuration, ovs will report
'|socket_util|ERR|:6632: bad IPv4 address ""' due to the empty address.
The exact calltrace is:
0 parse_sockaddr_components (ss=0xbf8dd87c, host_s=0x94c99f0 "",
port_s=0x94c99f1 "6632", default_port=6632, s=0x948b9dc ":6632")
at lib/socket-util.c:350
1 0x081163b5 in inet_parse_active (target_=0x948b9dc ":6632", default_port=
6632, ss=0xbf8dd87c) at lib/socket-util.c:412
2 0x08119dcf in stream_parse_target_with_default_port (target=0x948b9d8
"ssl::6632", default_port=6632, ss=0xbf8dd87c) at lib/stream.c:734
3 0x0804c946 in collect_in_band_managers (ovs_cfg=0x94433b0,
managersp=0xbf8dd9a8, n_managersp=0xbf8dd9a0) at vswitchd/bridge.c:516
4 0x08054b87 in bridge_reconfigure (ovs_cfg=0x94433b0) at vswitchd/bridge.c:
614
5 0x080557cf in bridge_run () at vswitchd/bridge.c:2897
6 0x080564aa in main (argc=155674720, argv=0x0) at vswitchd/ovs-vswitchd.c:
116
This commit fixes the issue.
Signed-off-by: Alex Wang <alexw@nicira.com> Acked-by: Ben Pfaff <blp@nicira.com>
Edwin Chiu [Tue, 10 Mar 2015 18:36:43 +0000 (11:36 -0700)]
xenserver: Fix build spec for XenServer 6.5.
The latest XenServer 6.5 uses a new way for kernel version naming.
Therein, the kernel flavor could not be found anymore. Also, the
directory name in 'lib/modules/' becomes a shortened version of
kernel version. e.g.:
[root@localhost ~]# ls /lib/modules/
3.10.0+2
As a workaround, this commit modifies the spec file to make
%{kernel_flavor} optional and %{xen_version} definable by users.
In the long run, I'd like to spend time refining the spec file.
Signed-off-by: Edwin Chiu <echiu@vmware.com> Signed-off-by: Alex Wang <alexw@nicira.com>
Ben Pfaff [Thu, 5 Mar 2015 19:12:21 +0000 (11:12 -0800)]
bridge: Enable RSTP if both STP and RSTP are enabled.
Until now, if both STP and RSTP were enabled, ovs-vswitchd would actually
enable only the one it first noticed to be enabled, and actually turn off
the setting for the other one in the database (!). This doesn't match
ovs-vswitchd behavior for other contradictory configurations, so this
commit changes its behavior so that, if both are enabled, RSTP takes
precedence.
Mark Kavanagh [Tue, 17 Feb 2015 21:20:04 +0000 (13:20 -0800)]
lib: upgrade to DPDK v1.8.0
DPDK v1.8.0 makes significant changes to struct rte_mbuf, including
removal of the 'pkt' and 'data' fields. The latter, formally a
pointer, is now calculated via an offset from the start of the
segment buffer. So now dp_packet data is also stored as offset
from base pointer.
Signed-off-by: Mark Kavanagh <mark.b.kavanagh@intel.com> Signed-off-by: Rory Sexton <rory.sexton@intel.com> Signed-off-by: Kevin Traynor <kevin.traynor@intel.com> Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Pravin B Shelar [Tue, 3 Mar 2015 22:08:58 +0000 (14:08 -0800)]
lldp: Fix DPDK build.
Fixes following dp-packet access. Removes netinet/if_ether.h
include due to duplicate definition of ether_addr.
------
In file included from /usr/include/netinet/if_ether.h:60:0,
from lib/lldp/lldpd.h:23,
from lib/ovs-lldp.h:26,
from lib/ovs-lldp.c:30:
/usr/include/net/ethernet.h: At top level:
/usr/include/net/ethernet.h:32:8: error: redefinition of 'struct
ether_addr'
struct ether_addr
^
In file included from
../dpdk/dpdk/x86_64-native-linuxapp-gcc/include/rte_ethdev.h:179:0,
from lib/netdev-dpdk.h:18,
from lib/dp-packet.h:25,
from lib/ovs-lldp.h:23,
from lib/ovs-lldp.c:30:
../dpdk/dpdk/x86_64-native-linuxapp-gcc/include/rte_ether.h:83:8: note:
originally defined here
struct ether_addr {
^
lib/ovs-lldp.c: In function 'lldp_process_packet':
lib/ovs-lldp.c:676:30: error: 'const struct dp_packet' has no member
named 'data_'
(char *) p->data_, p->size_);
^
lib/ovs-lldp.c:676:40: error: 'const struct dp_packet' has no member
named 'size_'
(char *) p->data_, p->size_);
------
Signed-off-by: Pravin B Shelar <pshelar@nicira.com> Acked-by: Daniele Di Proietto <diproiettod@vmware.com> Acked-by: Ben Pfaff <blp@nicira.com>
Alex Wang [Fri, 27 Feb 2015 05:16:14 +0000 (21:16 -0800)]
test-hash: Do not exit check_word_hash() when there is a failure.
This commit makes check_word_hash() run to finish even when there
is a failure during the run. The test will still fail due to the
output check in AT_CHECK. And developers can benefit from having
all failed hashes instead of only the first one.
Signed-off-by: Alex Wang <alexw@nicira.com> Acked-by: Ben Pfaff <blp@nicira.com>
Alex Wang [Thu, 26 Feb 2015 17:54:00 +0000 (09:54 -0800)]
test-hash: Test hash_bytes128() with single 128-bit word.
This commit adds a new test for hash_bytes128() using single 128-bit
word. The test shows that there is no collision in all 19 consecutive
bits checks, which indicates the hash function is good.
Signed-off-by: Alex Wang <alexw@nicira.com> Acked-by: Joe Stringer <joestringer@nicira.com>