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  1. 17 Aug, 2019 4 commits
    • Magnus Karlsson's avatar
      ixgbe: add support for AF_XDP need_wakeup feature · 5c129241
      Magnus Karlsson authored 
      This patch adds support for the need_wakeup feature of AF_XDP. If the
application has told the kernel that it might sleep using the new bind
flag XDP_USE_NEED_WAKEUP, the driver will then set this flag if it has
no more buffers on the NIC Rx ring and yield to the application. For
Tx, it will set the flag if it has no outstanding Tx completion
interrupts and return to the application.
Signed-off-by: default avatarMagnus Karlsson <magnus.karlsson@intel.com>
Acked-by: default avatarJonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      5c129241
    • Magnus Karlsson's avatar
      i40e: add support for AF_XDP need_wakeup feature · 3d0c5f1c
      Magnus Karlsson authored 
      This patch adds support for the need_wakeup feature of AF_XDP. If the
application has told the kernel that it might sleep using the new bind
flag XDP_USE_NEED_WAKEUP, the driver will then set this flag if it has
no more buffers on the NIC Rx ring and yield to the application. For
Tx, it will set the flag if it has no outstanding Tx completion
interrupts and return to the application.
Signed-off-by: default avatarMagnus Karlsson <magnus.karlsson@intel.com>
Acked-by: default avatarJonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      3d0c5f1c
    • Magnus Karlsson's avatar
      xsk: add support for need_wakeup flag in AF_XDP rings · 77cd0d7b
      Magnus Karlsson authored 
      This commit adds support for a new flag called need_wakeup in the
AF_XDP Tx and fill rings. When this flag is set, it means that the
application has to explicitly wake up the kernel Rx (for the bit in
the fill ring) or kernel Tx (for bit in the Tx ring) processing by
issuing a syscall. Poll() can wake up both depending on the flags
submitted and sendto() will wake up tx processing only.

The main reason for introducing this new flag is to be able to
efficiently support the case when application and driver is executing
on the same core. Previously, the driver was just busy-spinning on the
fill ring if it ran out of buffers in the HW and there were none on
the fill ring. This approach works when the application is running on
another core as it can replenish the fill ring while the driver is
busy-spinning. Though, this is a lousy approach if both of them are
running on the same core as the probability of the fill ring getting
more entries when the driver is busy-spinning is zero. With this new
feature the driver now sets the need_wakeup flag and returns to the
application. The application can then replenish the fill queue and
then explicitly wake up the Rx processing in the kernel using the
syscall poll(). For Tx, the flag is only set to one if the driver has
no outstanding Tx completion interrupts. If it has some, the flag is
zero as it will be woken up by a completion interrupt anyway.

As a nice side effect, this new flag also improves the performance of
the case where application and driver are running on two different
cores as it reduces the number of syscalls to the kernel. The kernel
tells user space if it needs to be woken up by a syscall, and this
eliminates many of the syscalls.

This flag needs some simple driver support. If the driver does not
support this, the Rx flag is always zero and the Tx flag is always
one. This makes any application relying on this feature default to the
old behaviour of not requiring any syscalls in the Rx path and always
having to call sendto() in the Tx path.

For backwards compatibility reasons, this feature has to be explicitly
turned on using a new bind flag (XDP_USE_NEED_WAKEUP). I recommend
that you always turn it on as it so far always have had a positive
performance impact.

The name and inspiration of the flag has been taken from io_uring by
Jens Axboe. Details about this feature in io_uring can be found in
http://kernel.dk/io_uring.pdf, section 8.3.
Signed-off-by: default avatarMagnus Karlsson <magnus.karlsson@intel.com>
Acked-by: default avatarJonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      77cd0d7b
    • Magnus Karlsson's avatar
      xsk: replace ndo_xsk_async_xmit with ndo_xsk_wakeup · 9116e5e2
      Magnus Karlsson authored 
      This commit replaces ndo_xsk_async_xmit with ndo_xsk_wakeup. This new
ndo provides the same functionality as before but with the addition of
a new flags field that is used to specifiy if Rx, Tx or both should be
woken up. The previous ndo only woke up Tx, as implied by the
name. The i40e and ixgbe drivers (which are all the supported ones)
are updated with this new interface.

This new ndo will be used by the new need_wakeup functionality of XDP
sockets that need to be able to wake up both Rx and Tx driver
processing.
Signed-off-by: default avatarMagnus Karlsson <magnus.karlsson@intel.com>
Acked-by: default avatarJonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      9116e5e2
  3. 16 Aug, 2019 14 commits
  5. 14 Aug, 2019 12 commits
  7. 13 Aug, 2019 10 commits
    • Vlad Buslov's avatar
      net: devlink: remove redundant rtnl lock assert · 043b8413
      Vlad Buslov authored 
      It is enough for caller of devlink_compat_switch_id_get() to hold the net
device to guarantee that devlink port is not destroyed concurrently. Remove
rtnl lock assertion and modify comment to warn user that they must hold
either rtnl lock or reference to net device. This is necessary to
accommodate future implementation of rtnl-unlocked TC offloads driver
callbacks.
Signed-off-by: default avatarVlad Buslov <vladbu@mellanox.com>
Acked-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
      043b8413
    • Jakub Kicinski's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next · 708852dc
      Jakub Kicinski authored 
      Daniel Borkmann says:

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

There is a small merge conflict in libbpf (Cc Andrii so he's in the loop
as well):

        for (i = 1; i <= btf__get_nr_types(btf); i++) {
                t = (struct btf_type *)btf__type_by_id(btf, i);

                if (!has_datasec && btf_is_var(t)) {
                        /* replace VAR with INT */
                        t->info = BTF_INFO_ENC(BTF_KIND_INT, 0, 0);
  <<<<<<< HEAD
                        /*
                         * using size = 1 is the safest choice, 4 will be too
                         * big and cause kernel BTF validation failure if
                         * original variable took less than 4 bytes
                         */
                        t->size = 1;
                        *(int *)(t+1) = BTF_INT_ENC(0, 0, 8);
                } else if (!has_datasec && kind == BTF_KIND_DATASEC) {
  =======
                        t->size = sizeof(int);
                        *(int *)(t + 1) = BTF_INT_ENC(0, 0, 32);
                } else if (!has_datasec && btf_is_datasec(t)) {
  >>>>>>> 72ef80b5
                        /* replace DATASEC with STRUCT */

Conflict is between the two commits 1d4126c4 ("libbpf: sanitize VAR to
conservative 1-byte INT") and b03bc685 ("libbpf: convert libbpf code to
use new btf helpers"), so we need to pick the sanitation fixup as well as
use the new btf_is_datasec() helper and the whitespace cleanup. Looks like
the following:

  [...]
                if (!has_datasec && btf_is_var(t)) {
                        /* replace VAR with INT */
                        t->info = BTF_INFO_ENC(BTF_KIND_INT, 0, 0);
                        /*
                         * using size = 1 is the safest choice, 4 will be too
                         * big and cause kernel BTF validation failure if
                         * original variable took less than 4 bytes
                         */
                        t->size = 1;
                        *(int *)(t + 1) = BTF_INT_ENC(0, 0, 8);
                } else if (!has_datasec && btf_is_datasec(t)) {
                        /* replace DATASEC with STRUCT */
  [...]

The main changes are:

1) Addition of core parts of compile once - run everywhere (co-re) effort,
   that is, relocation of fields offsets in libbpf as well as exposure of
   kernel's own BTF via sysfs and loading through libbpf, from Andrii.

   More info on co-re: http://vger.kernel.org/bpfconf2019.html#session-2
   and http://vger.kernel.org/lpc-bpf2018.html#session-2

2) Enable passing input flags to the BPF flow dissector to customize parsing
   and allowing it to stop early similar to the C based one, from Stanislav.

3) Add a BPF helper function that allows generating SYN cookies from XDP and
   tc BPF, from Petar.

4) Add devmap hash-based map type for more flexibility in device lookup for
   redirects, from Toke.

5) Improvements to XDP forwarding sample code now utilizing recently enabled
   devmap lookups, from Jesper.

6) Add support for reporting the effective cgroup progs in bpftool, from Jakub
   and Takshak.

7) Fix reading kernel config from bpftool via /proc/config.gz, from Peter.

8) Fix AF_XDP umem pages mapping for 32 bit architectures, from Ivan.

9) Follow-up to add two more BPF loop tests for the selftest suite, from Alexei.

10) Add perf event output helper also for other skb-based program types, from Allan.

11) Fix a co-re related compilation error in selftests, from Yonghong.
====================
Signed-off-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
      708852dc
    • YueHaibing's avatar
      net: hns3: Make hclge_func_reset_sync_vf static · a9a96760
      YueHaibing authored 
      Fix sparse warning:

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c:3190:5:
 warning: symbol 'hclge_func_reset_sync_vf' was not declared. Should it be static?
Reported-by: default avatarHulk Robot <hulkci@huawei.com>
Signed-off-by: default avatarYueHaibing <yuehaibing@huawei.com>
Signed-off-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
      a9a96760
    • Jiri Pirko's avatar
      devlink: send notifications for deleted snapshots on region destroy · 92b49822
      Jiri Pirko authored 
      Currently the notifications for deleted snapshots are sent only in case
user deletes a snapshot manually. Send the notifications in case region
is destroyed too.
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
      92b49822
    • Daniel Borkmann's avatar
      Merge branch 'bpf-libbpf-read-sysfs-btf' · 72ef80b5
      Daniel Borkmann authored 
      Andrii Nakryiko says:

====================
Now that kernel's BTF is exposed through sysfs at well-known location, attempt
to load it first as a target BTF for the purpose of BPF CO-RE relocations.

Patch #1 is a follow-up patch to rename /sys/kernel/btf/kernel into
/sys/kernel/btf/vmlinux.

Patch #2 adds ability to load raw BTF contents from sysfs and expands the list
of locations libbpf attempts to load vmlinux BTF from.
====================
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      72ef80b5
    • Andrii Nakryiko's avatar
      libbpf: attempt to load kernel BTF from sysfs first · a1916a15
      Andrii Nakryiko authored 
      Add support for loading kernel BTF from sysfs (/sys/kernel/btf/vmlinux)
as a target BTF. Also extend the list of on disk search paths for
vmlinux ELF image with entries that perf is searching for.
Signed-off-by: default avatarAndrii Nakryiko <andriin@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      a1916a15
    • Andrii Nakryiko's avatar
      btf: rename /sys/kernel/btf/kernel into /sys/kernel/btf/vmlinux · 7fd78568
      Andrii Nakryiko authored 
      Expose kernel's BTF under the name vmlinux to be more uniform with using
kernel module names as file names in the future.

Fixes: 341dfcf8 ("btf: expose BTF info through sysfs")
Suggested-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarAndrii Nakryiko <andriin@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      7fd78568
    • Petar Penkov's avatar
      selftests/bpf: fix race in flow dissector tests · 9840a4ff
      Petar Penkov authored 
      Since the "last_dissection" map holds only the flow keys for the most
recent packet, there is a small race in the skb-less flow dissector
tests if a new packet comes between transmitting the test packet, and
reading its keys from the map. If this happens, the test packet keys
will be overwritten and the test will fail.

Changing the "last_dissection" map to a hash map, keyed on the
source/dest port pair resolves this issue. Additionally, let's clear the
last test results from the map between tests to prevent previous test
cases from interfering with the following test cases.

Fixes: 0905beec ("selftests/bpf: run flow dissector tests in skb-less mode")
Signed-off-by: default avatarPetar Penkov <ppenkov@google.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      9840a4ff
    • Peter Wu's avatar
      tools: bpftool: add feature check for zlib · d66fa3c7
      Peter Wu authored 
      bpftool requires libelf, and zlib for decompressing /proc/config.gz.
zlib is a transitive dependency via libelf, and became mandatory since
elfutils 0.165 (Jan 2016). The feature check of libelf is already done
in the elfdep target of tools/lib/bpf/Makefile, pulled in by bpftool via
a dependency on libbpf.a. Add a similar feature check for zlib.
Suggested-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: default avatarPeter Wu <peter@lekensteyn.nl>
Acked-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      d66fa3c7
    • Andrii Nakryiko's avatar
      btf: expose BTF info through sysfs · 341dfcf8
      Andrii Nakryiko authored 
      Make .BTF section allocated and expose its contents through sysfs.

/sys/kernel/btf directory is created to contain all the BTFs present
inside kernel. Currently there is only kernel's main BTF, represented as
/sys/kernel/btf/kernel file. Once kernel modules' BTFs are supported,
each module will expose its BTF as /sys/kernel/btf/<module-name> file.

Current approach relies on a few pieces coming together:
1. pahole is used to take almost final vmlinux image (modulo .BTF and
   kallsyms) and generate .BTF section by converting DWARF info into
   BTF. This section is not allocated and not mapped to any segment,
   though, so is not yet accessible from inside kernel at runtime.
2. objcopy dumps .BTF contents into binary file and subsequently
   convert binary file into linkable object file with automatically
   generated symbols _binary__btf_kernel_bin_start and
   _binary__btf_kernel_bin_end, pointing to start and end, respectively,
   of BTF raw data.
3. final vmlinux image is generated by linking this object file (and
   kallsyms, if necessary). sysfs_btf.c then creates
   /sys/kernel/btf/kernel file and exposes embedded BTF contents through
   it. This allows, e.g., libbpf and bpftool access BTF info at
   well-known location, without resorting to searching for vmlinux image
   on disk (location of which is not standardized and vmlinux image
   might not be even available in some scenarios, e.g., inside qemu
   during testing).

Alternative approach using .incbin assembler directive to embed BTF
contents directly was attempted but didn't work, because sysfs_proc.o is
not re-compiled during link-vmlinux.sh stage. This is required, though,
to update embedded BTF data (initially empty data is embedded, then
pahole generates BTF info and we need to regenerate sysfs_btf.o with
updated contents, but it's too late at that point).

If BTF couldn't be generated due to missing or too old pahole,
sysfs_btf.c handles that gracefully by detecting that
_binary__btf_kernel_bin_start (weak symbol) is 0 and not creating
/sys/kernel/btf at all.

v2->v3:
- added Documentation/ABI/testing/sysfs-kernel-btf (Greg K-H);
- created proper kobject (btf_kobj) for btf directory (Greg K-H);
- undo v2 change of reusing vmlinux, as it causes extra kallsyms pass
  due to initially missing  __binary__btf_kernel_bin_{start/end} symbols;

v1->v2:
- allow kallsyms stage to re-use vmlinux generated by gen_btf();
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarAndrii Nakryiko <andriin@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      341dfcf8
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