<feed xmlns='http://www.w3.org/2005/Atom'>
<title>wireguard-linux/net/xdp, branch jd/orphan-parallel</title>
<subtitle>WireGuard for the Linux kernel</subtitle>
<id>https://git.zx2c4.com/wireguard-linux/atom/net/xdp?h=jd%2Forphan-parallel</id>
<link rel='self' href='https://git.zx2c4.com/wireguard-linux/atom/net/xdp?h=jd%2Forphan-parallel'/>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/'/>
<updated>2020-10-12T23:16:50Z</updated>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next</title>
<updated>2020-10-12T23:16:50Z</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2020-10-12T23:16:50Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=ccdf7fae3afaeaf0e5dd03311b86ffa56adf85ae'/>
<id>urn:sha1:ccdf7fae3afaeaf0e5dd03311b86ffa56adf85ae</id>
<content type='text'>
Alexei Starovoitov says:

====================
pull-request: bpf-next 2020-10-12

The main changes are:

1) The BPF verifier improvements to track register allocation pattern, from Alexei and Yonghong.

2) libbpf relocation support for different size load/store, from Andrii.

3) bpf_redirect_peer() helper and support for inner map array with different max_entries, from Daniel.

4) BPF support for per-cpu variables, form Hao.

5) sockmap improvements, from John.
====================

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
</entry>
<entry>
<title>bpf: Allow for map-in-map with dynamic inner array map entries</title>
<updated>2020-10-11T17:21:04Z</updated>
<author>
<name>Daniel Borkmann</name>
<email>daniel@iogearbox.net</email>
</author>
<published>2020-10-10T23:40:03Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=4a8f87e60f6db40e640f1db555d063b2c4dea5f1'/>
<id>urn:sha1:4a8f87e60f6db40e640f1db555d063b2c4dea5f1</id>
<content type='text'>
Recent work in f4d05259213f ("bpf: Add map_meta_equal map ops") and 134fede4eecf
("bpf: Relax max_entries check for most of the inner map types") added support
for dynamic inner max elements for most map-in-map types. Exceptions were maps
like array or prog array where the map_gen_lookup() callback uses the maps'
max_entries field as a constant when emitting instructions.

We recently implemented Maglev consistent hashing into Cilium's load balancer
which uses map-in-map with an outer map being hash and inner being array holding
the Maglev backend table for each service. This has been designed this way in
order to reduce overall memory consumption given the outer hash map allows to
avoid preallocating a large, flat memory area for all services. Also, the
number of service mappings is not always known a-priori.

The use case for dynamic inner array map entries is to further reduce memory
overhead, for example, some services might just have a small number of back
ends while others could have a large number. Right now the Maglev backend table
for small and large number of backends would need to have the same inner array
map entries which adds a lot of unneeded overhead.

Dynamic inner array map entries can be realized by avoiding the inlined code
generation for their lookup. The lookup will still be efficient since it will
be calling into array_map_lookup_elem() directly and thus avoiding retpoline.
The patch adds a BPF_F_INNER_MAP flag to map creation which therefore skips
inline code generation and relaxes array_map_meta_equal() check to ignore both
maps' max_entries. This also still allows to have faster lookups for map-in-map
when BPF_F_INNER_MAP is not specified and hence dynamic max_entries not needed.

Example code generation where inner map is dynamic sized array:

  # bpftool p d x i 125
  int handle__sys_enter(void * ctx):
  ; int handle__sys_enter(void *ctx)
     0: (b4) w1 = 0
  ; int key = 0;
     1: (63) *(u32 *)(r10 -4) = r1
     2: (bf) r2 = r10
  ;
     3: (07) r2 += -4
  ; inner_map = bpf_map_lookup_elem(&amp;outer_arr_dyn, &amp;key);
     4: (18) r1 = map[id:468]
     6: (07) r1 += 272
     7: (61) r0 = *(u32 *)(r2 +0)
     8: (35) if r0 &gt;= 0x3 goto pc+5
     9: (67) r0 &lt;&lt;= 3
    10: (0f) r0 += r1
    11: (79) r0 = *(u64 *)(r0 +0)
    12: (15) if r0 == 0x0 goto pc+1
    13: (05) goto pc+1
    14: (b7) r0 = 0
    15: (b4) w6 = -1
  ; if (!inner_map)
    16: (15) if r0 == 0x0 goto pc+6
    17: (bf) r2 = r10
  ;
    18: (07) r2 += -4
  ; val = bpf_map_lookup_elem(inner_map, &amp;key);
    19: (bf) r1 = r0                               | No inlining but instead
    20: (85) call array_map_lookup_elem#149280     | call to array_map_lookup_elem()
  ; return val ? *val : -1;                        | for inner array lookup.
    21: (15) if r0 == 0x0 goto pc+1
  ; return val ? *val : -1;
    22: (61) r6 = *(u32 *)(r0 +0)
  ; }
    23: (bc) w0 = w6
    24: (95) exit

Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20201010234006.7075-4-daniel@iogearbox.net
</content>
</entry>
<entry>
<title>xsk: Introduce padding between ring pointers</title>
<updated>2020-10-09T14:35:01Z</updated>
<author>
<name>Magnus Karlsson</name>
<email>magnus.karlsson@intel.com</email>
</author>
<published>2020-10-08T14:12:18Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=c3f01fdcedf9459b2a27b22287414ab3a0d5d818'/>
<id>urn:sha1:c3f01fdcedf9459b2a27b22287414ab3a0d5d818</id>
<content type='text'>
Introduce one cache line worth of padding between the producer and
consumer pointers in all the lockless rings. This so that the HW
adjacency prefetcher will not prefetch the consumer pointer when the
producer pointer is used and vice versa. This improves throughput
performance for the l2fwd sample app with 2% on my machine with HW
prefetching turned on.

Signed-off-by: Magnus Karlsson &lt;magnus.karlsson@intel.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/1602166338-21378-1-git-send-email-magnus.karlsson@gmail.com
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2020-10-06T01:40:01Z</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2020-10-06T00:33:26Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=8b0308fe319b8002753ea66f8f940fb393792ddd'/>
<id>urn:sha1:8b0308fe319b8002753ea66f8f940fb393792ddd</id>
<content type='text'>
Rejecting non-native endian BTF overlapped with the addition
of support for it.

The rest were more simple overlapping changes, except the
renesas ravb binding update, which had to follow a file
move as well as a YAML conversion.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>xsk: Remove internal DMA headers</title>
<updated>2020-10-05T13:48:00Z</updated>
<author>
<name>Björn Töpel</name>
<email>bjorn.topel@intel.com</email>
</author>
<published>2020-10-05T09:05:25Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=b75597d8947f842fa525000cf9569c21e7596da9'/>
<id>urn:sha1:b75597d8947f842fa525000cf9569c21e7596da9</id>
<content type='text'>
Christoph Hellwig correctly pointed out [1] that the AF_XDP core was
pointlessly including internal headers. Let us remove those includes.

  [1] https://lore.kernel.org/bpf/20201005084341.GA3224@infradead.org/

Fixes: 1c1efc2af158 ("xsk: Create and free buffer pool independently from umem")
Reported-by: Christoph Hellwig &lt;hch@infradead.org&gt;
Signed-off-by: Björn Töpel &lt;bjorn.topel@intel.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: https://lore.kernel.org/bpf/20201005090525.116689-1-bjorn.topel@gmail.com
</content>
</entry>
<entry>
<title>xsk: Fix a documentation mistake in xsk_queue.h</title>
<updated>2020-09-29T18:25:56Z</updated>
<author>
<name>Ciara Loftus</name>
<email>ciara.loftus@intel.com</email>
</author>
<published>2020-09-28T08:23:44Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=f1fc8ece6c077bd6d460d99f4f83b9d20992b68b'/>
<id>urn:sha1:f1fc8ece6c077bd6d460d99f4f83b9d20992b68b</id>
<content type='text'>
After 'peeking' the ring, the consumer, not the producer, reads the data.
Fix this mistake in the comments.

Fixes: 15d8c9162ced ("xsk: Add function naming comments and reorder functions")
Signed-off-by: Ciara Loftus &lt;ciara.loftus@intel.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: Magnus Karlsson &lt;magnus.karlsson@intel.com&gt;
Link: https://lore.kernel.org/bpf/20200928082344.17110-1-ciara.loftus@intel.com
</content>
</entry>
<entry>
<title>xsk: Fix possible crash in socket_release when out-of-memory</title>
<updated>2020-09-28T19:18:01Z</updated>
<author>
<name>Magnus Karlsson</name>
<email>magnus.karlsson@intel.com</email>
</author>
<published>2020-09-26T09:26:13Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=1fd17c8cd0aa636afcf441ee23023b5a7cba4efa'/>
<id>urn:sha1:1fd17c8cd0aa636afcf441ee23023b5a7cba4efa</id>
<content type='text'>
Fix possible crash in socket_release when an out-of-memory error has
occurred in the bind call. If a socket using the XDP_SHARED_UMEM flag
encountered an error in xp_create_and_assign_umem, the bind code
jumped to the exit routine but erroneously forgot to set the err value
before jumping. This meant that the exit routine thought the setup
went well and set the state of the socket to XSK_BOUND. The xsk socket
release code will then, at application exit, think that this is a
properly setup socket, when it is not, leading to a crash when all
fields in the socket have in fact not been initialized properly. Fix
this by setting the err variable in xsk_bind so that the socket is not
set to XSK_BOUND which leads to the clean-up in xsk_release not being
triggered.

Fixes: 1c1efc2af158 ("xsk: Create and free buffer pool independently from umem")
Reported-by: syzbot+ddc7b4944bc61da19b81@syzkaller.appspotmail.com
Signed-off-by: Magnus Karlsson &lt;magnus.karlsson@intel.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/1601112373-10595-1-git-send-email-magnus.karlsson@gmail.com
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next</title>
<updated>2020-09-23T20:11:11Z</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2020-09-23T20:11:11Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=6d772f328d6ad3e4fb64385784571be4be25e63d'/>
<id>urn:sha1:6d772f328d6ad3e4fb64385784571be4be25e63d</id>
<content type='text'>
Alexei Starovoitov says:

====================
pull-request: bpf-next 2020-09-23

The following pull-request contains BPF updates for your *net-next* tree.

We've added 95 non-merge commits during the last 22 day(s) which contain
a total of 124 files changed, 4211 insertions(+), 2040 deletions(-).

The main changes are:

1) Full multi function support in libbpf, from Andrii.

2) Refactoring of function argument checks, from Lorenz.

3) Make bpf_tail_call compatible with functions (subprograms), from Maciej.

4) Program metadata support, from YiFei.

5) bpf iterator optimizations, from Yonghong.
====================

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2020-09-22T23:45:34Z</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2020-09-22T23:45:34Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=3ab0a7a0c349a1d7beb2bb371a62669d1528269d'/>
<id>urn:sha1:3ab0a7a0c349a1d7beb2bb371a62669d1528269d</id>
<content type='text'>
Two minor conflicts:

1) net/ipv4/route.c, adding a new local variable while
   moving another local variable and removing it's
   initial assignment.

2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes.
   One pretty prints the port mode differently, whilst another
   changes the driver to try and obtain the port mode from
   the port node rather than the switch node.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>xsk: Do not discard packet when NETDEV_TX_BUSY</title>
<updated>2020-09-16T21:36:58Z</updated>
<author>
<name>Magnus Karlsson</name>
<email>magnus.karlsson@intel.com</email>
</author>
<published>2020-09-16T12:00:25Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=642e450b6b5955f2059d0ae372183f7c6323f951'/>
<id>urn:sha1:642e450b6b5955f2059d0ae372183f7c6323f951</id>
<content type='text'>
In the skb Tx path, transmission of a packet is performed with
dev_direct_xmit(). When NETDEV_TX_BUSY is set in the drivers, it
signifies that it was not possible to send the packet right now,
please try later. Unfortunately, the xsk transmit code discarded the
packet and returned EBUSY to the application. Fix this unnecessary
packet loss, by not discarding the packet in the Tx ring and return
EAGAIN. As EAGAIN is returned to the application, it can then retry
the send operation later and the packet will then likely be sent as
the driver will then likely have space/resources to send the packet.

In summary, EAGAIN tells the application that the packet was not
discarded from the Tx ring and that it needs to call send()
again. EBUSY, on the other hand, signifies that the packet was not
sent and discarded from the Tx ring. The application needs to put
the packet on the Tx ring again if it wants it to be sent.

Fixes: 35fcde7f8deb ("xsk: support for Tx")
Reported-by: Arkadiusz Zema &lt;A.Zema@falconvsystems.com&gt;
Suggested-by: Arkadiusz Zema &lt;A.Zema@falconvsystems.com&gt;
Suggested-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Signed-off-by: Magnus Karlsson &lt;magnus.karlsson@intel.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Reviewed-by: Jesse Brandeburg &lt;jesse.brandeburg@intel.com&gt;
Link: https://lore.kernel.org/bpf/1600257625-2353-1-git-send-email-magnus.karlsson@gmail.com
</content>
</entry>
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