<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/net/openvswitch/datapath.h, branch v4.11</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>netns: make struct pernet_operations::id unsigned int</title>
<updated>2016-11-18T15:59:15+00:00</updated>
<author>
<name>Alexey Dobriyan</name>
<email>adobriyan@gmail.com</email>
</author>
<published>2016-11-17T01:58:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c7d03a00b56fc23c3a01a8353789ad257363e281'/>
<id>c7d03a00b56fc23c3a01a8353789ad257363e281</id>
<content type='text'>
Make struct pernet_operations::id unsigned.

There are 2 reasons to do so:

1)
This field is really an index into an zero based array and
thus is unsigned entity. Using negative value is out-of-bound
access by definition.

2)
On x86_64 unsigned 32-bit data which are mixed with pointers
via array indexing or offsets added or subtracted to pointers
are preffered to signed 32-bit data.

"int" being used as an array index needs to be sign-extended
to 64-bit before being used.

	void f(long *p, int i)
	{
		g(p[i]);
	}

  roughly translates to

	movsx	rsi, esi
	mov	rdi, [rsi+...]
	call 	g

MOVSX is 3 byte instruction which isn't necessary if the variable is
unsigned because x86_64 is zero extending by default.

Now, there is net_generic() function which, you guessed it right, uses
"int" as an array index:

	static inline void *net_generic(const struct net *net, int id)
	{
		...
		ptr = ng-&gt;ptr[id - 1];
		...
	}

And this function is used a lot, so those sign extensions add up.

Patch snipes ~1730 bytes on allyesconfig kernel (without all junk
messing with code generation):

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)

Unfortunately some functions actually grow bigger.
This is a semmingly random artefact of code generation with register
allocator being used differently. gcc decides that some variable
needs to live in new r8+ registers and every access now requires REX
prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be
used which is longer than [r8]

However, overall balance is in negative direction:

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
	function                                     old     new   delta
	nfsd4_lock                                  3886    3959     +73
	tipc_link_build_proto_msg                   1096    1140     +44
	mac80211_hwsim_new_radio                    2776    2808     +32
	tipc_mon_rcv                                1032    1058     +26
	svcauth_gss_legacy_init                     1413    1429     +16
	tipc_bcbase_select_primary                   379     392     +13
	nfsd4_exchange_id                           1247    1260     +13
	nfsd4_setclientid_confirm                    782     793     +11
		...
	put_client_renew_locked                      494     480     -14
	ip_set_sockfn_get                            730     716     -14
	geneve_sock_add                              829     813     -16
	nfsd4_sequence_done                          721     703     -18
	nlmclnt_lookup_host                          708     686     -22
	nfsd4_lockt                                 1085    1063     -22
	nfs_get_client                              1077    1050     -27
	tcf_bpf_init                                1106    1076     -30
	nfsd4_encode_fattr                          5997    5930     -67
	Total: Before=154856051, After=154854321, chg -0.00%

Signed-off-by: Alexey Dobriyan &lt;adobriyan@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Make struct pernet_operations::id unsigned.

There are 2 reasons to do so:

1)
This field is really an index into an zero based array and
thus is unsigned entity. Using negative value is out-of-bound
access by definition.

2)
On x86_64 unsigned 32-bit data which are mixed with pointers
via array indexing or offsets added or subtracted to pointers
are preffered to signed 32-bit data.

"int" being used as an array index needs to be sign-extended
to 64-bit before being used.

	void f(long *p, int i)
	{
		g(p[i]);
	}

  roughly translates to

	movsx	rsi, esi
	mov	rdi, [rsi+...]
	call 	g

MOVSX is 3 byte instruction which isn't necessary if the variable is
unsigned because x86_64 is zero extending by default.

Now, there is net_generic() function which, you guessed it right, uses
"int" as an array index:

	static inline void *net_generic(const struct net *net, int id)
	{
		...
		ptr = ng-&gt;ptr[id - 1];
		...
	}

And this function is used a lot, so those sign extensions add up.

Patch snipes ~1730 bytes on allyesconfig kernel (without all junk
messing with code generation):

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)

Unfortunately some functions actually grow bigger.
This is a semmingly random artefact of code generation with register
allocator being used differently. gcc decides that some variable
needs to live in new r8+ registers and every access now requires REX
prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be
used which is longer than [r8]

However, overall balance is in negative direction:

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
	function                                     old     new   delta
	nfsd4_lock                                  3886    3959     +73
	tipc_link_build_proto_msg                   1096    1140     +44
	mac80211_hwsim_new_radio                    2776    2808     +32
	tipc_mon_rcv                                1032    1058     +26
	svcauth_gss_legacy_init                     1413    1429     +16
	tipc_bcbase_select_primary                   379     392     +13
	nfsd4_exchange_id                           1247    1260     +13
	nfsd4_setclientid_confirm                    782     793     +11
		...
	put_client_renew_locked                      494     480     -14
	ip_set_sockfn_get                            730     716     -14
	geneve_sock_add                              829     813     -16
	nfsd4_sequence_done                          721     703     -18
	nlmclnt_lookup_host                          708     686     -22
	nfsd4_lockt                                 1085    1063     -22
	nfs_get_client                              1077    1050     -27
	tcf_bpf_init                                1106    1076     -30
	nfsd4_encode_fattr                          5997    5930     -67
	Total: Before=154856051, After=154854321, chg -0.00%

Signed-off-by: Alexey Dobriyan &lt;adobriyan@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>openvswitch: Add packet truncation support.</title>
<updated>2016-06-11T00:58:03+00:00</updated>
<author>
<name>William Tu</name>
<email>u9012063@gmail.com</email>
</author>
<published>2016-06-10T18:49:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1'/>
<id>f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1</id>
<content type='text'>
The patch adds a new OVS action, OVS_ACTION_ATTR_TRUNC, in order to
truncate packets. A 'max_len' is added for setting up the maximum
packet size, and a 'cutlen' field is to record the number of bytes
to trim the packet when the packet is outputting to a port, or when
the packet is sent to userspace.

Signed-off-by: William Tu &lt;u9012063@gmail.com&gt;
Cc: Pravin Shelar &lt;pshelar@nicira.com&gt;
Acked-by: Pravin B Shelar &lt;pshelar@ovn.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The patch adds a new OVS action, OVS_ACTION_ATTR_TRUNC, in order to
truncate packets. A 'max_len' is added for setting up the maximum
packet size, and a 'cutlen' field is to record the number of bytes
to trim the packet when the packet is outputting to a port, or when
the packet is sent to userspace.

Signed-off-by: William Tu &lt;u9012063@gmail.com&gt;
Cc: Pravin Shelar &lt;pshelar@nicira.com&gt;
Acked-by: Pravin B Shelar &lt;pshelar@ovn.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ovs: propagate per dp max headroom to all vports</title>
<updated>2016-03-01T20:54:30+00:00</updated>
<author>
<name>Paolo Abeni</name>
<email>pabeni@redhat.com</email>
</author>
<published>2016-02-26T09:45:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3a927bc7cf9d0fbe8f4a8189dd5f8440228f64e7'/>
<id>3a927bc7cf9d0fbe8f4a8189dd5f8440228f64e7</id>
<content type='text'>
This patch implements bookkeeping support to compute the maximum
headroom for all the devices in each datapath. When said value
changes, the underlying devs are notified via the
ndo_set_rx_headroom method.

This also increases the internal vports xmit performance.

Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch implements bookkeeping support to compute the maximum
headroom for all the devices in each datapath. When said value
changes, the underlying devs are notified via the
ndo_set_rx_headroom method.

This also increases the internal vports xmit performance.

Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>openvswitch: Fix egress tunnel info.</title>
<updated>2015-10-23T02:39:25+00:00</updated>
<author>
<name>Pravin B Shelar</name>
<email>pshelar@nicira.com</email>
</author>
<published>2015-10-23T01:17:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=fc4099f17240767554ff3a73977acb78ef615404'/>
<id>fc4099f17240767554ff3a73977acb78ef615404</id>
<content type='text'>
While transitioning to netdev based vport we broke OVS
feature which allows user to retrieve tunnel packet egress
information for lwtunnel devices.  Following patch fixes it
by introducing ndo operation to get the tunnel egress info.
Same ndo operation can be used for lwtunnel devices and compat
ovs-tnl-vport devices. So after adding such device operation
we can remove similar operation from ovs-vport.

Fixes: 614732eaa12d ("openvswitch: Use regular VXLAN net_device device").
Signed-off-by: Pravin B Shelar &lt;pshelar@nicira.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
While transitioning to netdev based vport we broke OVS
feature which allows user to retrieve tunnel packet egress
information for lwtunnel devices.  Following patch fixes it
by introducing ndo operation to get the tunnel egress info.
Same ndo operation can be used for lwtunnel devices and compat
ovs-tnl-vport devices. So after adding such device operation
we can remove similar operation from ovs-vport.

Fixes: 614732eaa12d ("openvswitch: Use regular VXLAN net_device device").
Signed-off-by: Pravin B Shelar &lt;pshelar@nicira.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ip-tunnel: Use API to access tunnel metadata options.</title>
<updated>2015-08-31T19:28:56+00:00</updated>
<author>
<name>Pravin B Shelar</name>
<email>pshelar@nicira.com</email>
</author>
<published>2015-08-31T01:09:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4c22279848c531fc7f555d463daf3d0df963bd41'/>
<id>4c22279848c531fc7f555d463daf3d0df963bd41</id>
<content type='text'>
Currently tun-info options pointer is used in few cases to
pass options around. But tunnel options can be accessed using
ip_tunnel_info_opts() API without using the pointer. Following
patch removes the redundant pointer and consistently make use
of API.

Signed-off-by: Pravin B Shelar &lt;pshelar@nicira.com&gt;
Acked-by: Thomas Graf &lt;tgraf@suug.ch&gt;
Reviewed-by: Jesse Gross &lt;jesse@nicira.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently tun-info options pointer is used in few cases to
pass options around. But tunnel options can be accessed using
ip_tunnel_info_opts() API without using the pointer. Following
patch removes the redundant pointer and consistently make use
of API.

Signed-off-by: Pravin B Shelar &lt;pshelar@nicira.com&gt;
Acked-by: Thomas Graf &lt;tgraf@suug.ch&gt;
Reviewed-by: Jesse Gross &lt;jesse@nicira.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>openvswitch: Remove vport-net</title>
<updated>2015-08-30T02:07:15+00:00</updated>
<author>
<name>Pravin B Shelar</name>
<email>pshelar@nicira.com</email>
</author>
<published>2015-08-30T00:44:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a581b96dbfc52b6b498552525ec929aa635680ed'/>
<id>a581b96dbfc52b6b498552525ec929aa635680ed</id>
<content type='text'>
This structure is not used anymore.

Signed-off-by: Pravin B Shelar &lt;pshelar@nicira.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This structure is not used anymore.

Signed-off-by: Pravin B Shelar &lt;pshelar@nicira.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>openvswitch: Remove egress_tun_info.</title>
<updated>2015-08-30T02:07:15+00:00</updated>
<author>
<name>Pravin B Shelar</name>
<email>pshelar@nicira.com</email>
</author>
<published>2015-08-30T00:44:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3eedb41fb43461b5fde3f72fd00a7706f0b90103'/>
<id>3eedb41fb43461b5fde3f72fd00a7706f0b90103</id>
<content type='text'>
tun info is passed using skb-dst pointer. Now we have
converted all vports to netdev based implementation so
Now we can remove redundant pointer to tun-info from OVS_CB.

Signed-off-by: Pravin B Shelar &lt;pshelar@nicira.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
tun info is passed using skb-dst pointer. Now we have
converted all vports to netdev based implementation so
Now we can remove redundant pointer to tun-info from OVS_CB.

Signed-off-by: Pravin B Shelar &lt;pshelar@nicira.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>openvswitch: Allow matching on conntrack label</title>
<updated>2015-08-27T18:40:43+00:00</updated>
<author>
<name>Joe Stringer</name>
<email>joestringer@nicira.com</email>
</author>
<published>2015-08-26T18:31:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c2ac667358708d7cce64c78f58af6adf4c1e848b'/>
<id>c2ac667358708d7cce64c78f58af6adf4c1e848b</id>
<content type='text'>
Allow matching and setting the ct_label field. As with ct_mark, this is
populated by executing the CT action. The label field may be modified by
specifying a label and mask nested under the CT action. It is stored as
metadata attached to the connection. Label modification occurs after
lookup, and will only persist when the conntrack entry is committed by
providing the COMMIT flag to the CT action. Labels are currently fixed
to 128 bits in size.

Signed-off-by: Joe Stringer &lt;joestringer@nicira.com&gt;
Acked-by: Thomas Graf &lt;tgraf@suug.ch&gt;
Acked-by: Pravin B Shelar &lt;pshelar@nicira.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Allow matching and setting the ct_label field. As with ct_mark, this is
populated by executing the CT action. The label field may be modified by
specifying a label and mask nested under the CT action. It is stored as
metadata attached to the connection. Label modification occurs after
lookup, and will only persist when the conntrack entry is committed by
providing the COMMIT flag to the CT action. Labels are currently fixed
to 128 bits in size.

Signed-off-by: Joe Stringer &lt;joestringer@nicira.com&gt;
Acked-by: Thomas Graf &lt;tgraf@suug.ch&gt;
Acked-by: Pravin B Shelar &lt;pshelar@nicira.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>openvswitch: Add conntrack action</title>
<updated>2015-08-27T18:40:43+00:00</updated>
<author>
<name>Joe Stringer</name>
<email>joestringer@nicira.com</email>
</author>
<published>2015-08-26T18:31:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7f8a436eaa2c3ddd8e1ff2fbca267e6275085536'/>
<id>7f8a436eaa2c3ddd8e1ff2fbca267e6275085536</id>
<content type='text'>
Expose the kernel connection tracker via OVS. Userspace components can
make use of the CT action to populate the connection state (ct_state)
field for a flow. This state can be subsequently matched.

Exposed connection states are OVS_CS_F_*:
- NEW (0x01) - Beginning of a new connection.
- ESTABLISHED (0x02) - Part of an existing connection.
- RELATED (0x04) - Related to an established connection.
- INVALID (0x20) - Could not track the connection for this packet.
- REPLY_DIR (0x40) - This packet is in the reply direction for the flow.
- TRACKED (0x80) - This packet has been sent through conntrack.

When the CT action is executed by itself, it will send the packet
through the connection tracker and populate the ct_state field with one
or more of the connection state flags above. The CT action will always
set the TRACKED bit.

When the COMMIT flag is passed to the conntrack action, this specifies
that information about the connection should be stored. This allows
subsequent packets for the same (or related) connections to be
correlated with this connection. Sending subsequent packets for the
connection through conntrack allows the connection tracker to consider
the packets as ESTABLISHED, RELATED, and/or REPLY_DIR.

The CT action may optionally take a zone to track the flow within. This
allows connections with the same 5-tuple to be kept logically separate
from connections in other zones. If the zone is specified, then the
"ct_zone" match field will be subsequently populated with the zone id.

IP fragments are handled by transparently assembling them as part of the
CT action. The maximum received unit (MRU) size is tracked so that
refragmentation can occur during output.

IP frag handling contributed by Andy Zhou.

Based on original design by Justin Pettit.

Signed-off-by: Joe Stringer &lt;joestringer@nicira.com&gt;
Signed-off-by: Justin Pettit &lt;jpettit@nicira.com&gt;
Signed-off-by: Andy Zhou &lt;azhou@nicira.com&gt;
Acked-by: Thomas Graf &lt;tgraf@suug.ch&gt;
Acked-by: Pravin B Shelar &lt;pshelar@nicira.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Expose the kernel connection tracker via OVS. Userspace components can
make use of the CT action to populate the connection state (ct_state)
field for a flow. This state can be subsequently matched.

Exposed connection states are OVS_CS_F_*:
- NEW (0x01) - Beginning of a new connection.
- ESTABLISHED (0x02) - Part of an existing connection.
- RELATED (0x04) - Related to an established connection.
- INVALID (0x20) - Could not track the connection for this packet.
- REPLY_DIR (0x40) - This packet is in the reply direction for the flow.
- TRACKED (0x80) - This packet has been sent through conntrack.

When the CT action is executed by itself, it will send the packet
through the connection tracker and populate the ct_state field with one
or more of the connection state flags above. The CT action will always
set the TRACKED bit.

When the COMMIT flag is passed to the conntrack action, this specifies
that information about the connection should be stored. This allows
subsequent packets for the same (or related) connections to be
correlated with this connection. Sending subsequent packets for the
connection through conntrack allows the connection tracker to consider
the packets as ESTABLISHED, RELATED, and/or REPLY_DIR.

The CT action may optionally take a zone to track the flow within. This
allows connections with the same 5-tuple to be kept logically separate
from connections in other zones. If the zone is specified, then the
"ct_zone" match field will be subsequently populated with the zone id.

IP fragments are handled by transparently assembling them as part of the
CT action. The maximum received unit (MRU) size is tracked so that
refragmentation can occur during output.

IP frag handling contributed by Andy Zhou.

Based on original design by Justin Pettit.

Signed-off-by: Joe Stringer &lt;joestringer@nicira.com&gt;
Signed-off-by: Justin Pettit &lt;jpettit@nicira.com&gt;
Signed-off-by: Andy Zhou &lt;azhou@nicira.com&gt;
Acked-by: Thomas Graf &lt;tgraf@suug.ch&gt;
Acked-by: Pravin B Shelar &lt;pshelar@nicira.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>openvswitch: Move MASKED* macros to datapath.h</title>
<updated>2015-08-27T18:40:42+00:00</updated>
<author>
<name>Joe Stringer</name>
<email>joestringer@nicira.com</email>
</author>
<published>2015-08-26T18:31:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=be26b9a88fcee570796c67701f50800039e25aec'/>
<id>be26b9a88fcee570796c67701f50800039e25aec</id>
<content type='text'>
This will allow the ovs-conntrack code to reuse these macros.

Signed-off-by: Joe Stringer &lt;joestringer@nicira.com&gt;
Acked-by: Thomas Graf &lt;tgraf@suug.ch&gt;
Acked-by: Pravin B Shelar &lt;pshelar@nicira.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This will allow the ovs-conntrack code to reuse these macros.

Signed-off-by: Joe Stringer &lt;joestringer@nicira.com&gt;
Acked-by: Thomas Graf &lt;tgraf@suug.ch&gt;
Acked-by: Pravin B Shelar &lt;pshelar@nicira.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
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