This set of patches introduces the usage of eBPF for packet steering
and RSS hash calculation:
* RSS(Receive Side Scaling) is used to distribute network packets to
guest virtqueues by calculating packet hash
* Additionally adding support for the usage of RSS with vhost

The eBPF works on kernels 5.8+
On earlier kerneld it fails to load and the RSS feature is reported
only without vhost and implemented in 'in-qemu' software.

Implementation notes:
Linux TAP TUNSETSTEERINGEBPF ioctl was used to set the eBPF program.
Added libbpf dependency and eBPF support.
The eBPF program is part of the qemu and presented as an array
of BPF ELF file data. The eBPF array file initially generated by bpftool.
The compilation of eBPF is not part of QEMU build and can be done
using provided Makefile.ebpf.
Added changes to virtio-net and vhost, primary eBPF RSS is used.
'in-qemu' RSS used in the case of hash population and as a fallback option.
For vhost, the hash population feature is not reported to the guest.

Please also see the documentation in PATCH 6/7.

Known issues:
* hash population not supported by eBPF RSS: 'in-qemu' RSS used
as a fallback, also, hash population feature is not reported to guests
with vhost.
* IPv6 extensions still in progress.

Changes since v1:
* using libbpf instead of direct 'bpf' system call.
* added libbpf dependency to the configure/meson scripts.
* changed python script for eBPF .h file generation.
* changed eBPF program - reading L3 proto from ethernet frame.
* added TUNSETSTEERINGEBPF define for TUN.
* changed the maintainer's info.
* added license headers.
* refactored code.

Changes since v2:
* using bpftool for eBPF skeleton generation.
* ebpf_rss is refactored to use skeleton generated by bpftool.
* added/adjasted license in comment sections and in eBPF file.
* rss.bpf.c and Makefile.ebpf moved to the tool/ebpf folder.
* virtio-net eBPF rss refactored. Now eBPF initialized during realize().

Changes since v3:
* rebased to last master.
* fixed issue with failed build without libbpf.
* fixed ebpf loading without rss option.
* refactored labels in ebpf_rss.c

Changes since v4:
* refactored configure/meson script.
* added checks for load_bytes in ebpf.
* documentation added to the index.
* refactored Makefile and rss.bpf.c.
* rebased to last master.

Changes since v5:
* fixed issue with dstopt parsing in the eBPF program.
* added fragment packet parsing to skip L4.

Changes since v6:
* Added eBPF skeleton check to the meson.build file.

Andrew (7):
  net/tap: Added TUNSETSTEERINGEBPF code.
  net: Added SetSteeringEBPF method for NetClientState.
  ebpf: Added eBPF RSS program.
  ebpf: Added eBPF RSS loader.
  virtio-net: Added eBPF RSS to virtio-net.
  docs: Added eBPF documentation.
  MAINTAINERS: Added eBPF maintainers information.

 MAINTAINERS                    |   8 +
 configure                      |   8 +-
 docs/devel/ebpf_rss.rst        | 125 ++++++++
 docs/devel/index.rst           |   1 +
 ebpf/ebpf_rss-stub.c           |  40 +++
 ebpf/ebpf_rss.c                | 165 ++++++++++
 ebpf/ebpf_rss.h                |  44 +++
 ebpf/meson.build               |   1 +
 ebpf/rss.bpf.skeleton.h        | 431 +++++++++++++++++++++++++
 ebpf/trace-events              |   4 +
 ebpf/trace.h                   |   2 +
 hw/net/vhost_net.c             |   3 +
 hw/net/virtio-net.c            | 115 ++++++-
 include/hw/virtio/virtio-net.h |   4 +
 include/net/net.h              |   2 +
 meson.build                    |  23 ++
 meson_options.txt              |   2 +
 net/tap-bsd.c                  |   5 +
 net/tap-linux.c                |  13 +
 net/tap-linux.h                |   1 +
 net/tap-solaris.c              |   5 +
 net/tap-stub.c                 |   5 +
 net/tap.c                      |   9 +
 net/tap_int.h                  |   1 +
 net/vhost-vdpa.c               |   2 +
 tools/ebpf/Makefile.ebpf       |  22 ++
 tools/ebpf/rss.bpf.c           | 569 +++++++++++++++++++++++++++++++++
 27 files changed, 1606 insertions(+), 4 deletions(-)
 create mode 100644 docs/devel/ebpf_rss.rst
 create mode 100644 ebpf/ebpf_rss-stub.c
 create mode 100644 ebpf/ebpf_rss.c
 create mode 100644 ebpf/ebpf_rss.h
 create mode 100644 ebpf/meson.build
 create mode 100644 ebpf/rss.bpf.skeleton.h
 create mode 100644 ebpf/trace-events
 create mode 100644 ebpf/trace.h
 create mode 100755 tools/ebpf/Makefile.ebpf
 create mode 100644 tools/ebpf/rss.bpf.c

-- 
2.31.1

Patchew URL: https://patchew.org/QEMU/20210428164733.56547-1-andrew@daynix.com/



Hi,

This series seems to have some coding style problems. See output below for
more information:

Type: series
Message-id: 20210428164733.56547-1-andrew@daynix.com
Subject: [PATCH v7 0/7] eBPF RSS support for virtio-net.

=== TEST SCRIPT BEGIN ===
#!/bin/bash
git rev-parse base > /dev/null || exit 0
git config --local diff.renamelimit 0
git config --local diff.renames True
git config --local diff.algorithm histogram
./scripts/checkpatch.pl --mailback base..
=== TEST SCRIPT END ===

Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
From https://github.com/patchew-project/qemu
 - [tag update]      patchew/20210426193520.4115528-1-philmd@redhat.com -> patchew/20210426193520.4115528-1-philmd@redhat.com
 - [tag update]      patchew/20210428142431.266879-1-david.edmondson@oracle.com -> patchew/20210428142431.266879-1-david.edmondson@oracle.com
 - [tag update]      patchew/20210428151804.439460-1-vsementsov@virtuozzo.com -> patchew/20210428151804.439460-1-vsementsov@virtuozzo.com
 * [new tag]         patchew/20210428164733.56547-1-andrew@daynix.com -> patchew/20210428164733.56547-1-andrew@daynix.com
Switched to a new branch 'test'
842e841 MAINTAINERS: Added eBPF maintainers information.
b931e15 docs: Added eBPF documentation.
f89d2b6 virtio-net: Added eBPF RSS to virtio-net.
15a840f3 ebpf: Added eBPF RSS loader.
44bbaca ebpf: Added eBPF RSS program.
b14810b net: Added SetSteeringEBPF method for NetClientState.
f8ae997 net/tap: Added TUNSETSTEERINGEBPF code.

=== OUTPUT BEGIN ===
1/7 Checking commit f8ae997f71c2 (net/tap: Added TUNSETSTEERINGEBPF code.)
2/7 Checking commit b14810be916e (net: Added SetSteeringEBPF method for NetClientState.)
3/7 Checking commit 44bbaca7b895 (ebpf: Added eBPF RSS program.)
Use of uninitialized value $acpi_testexpected in string eq at ./scripts/checkpatch.pl line 1529.
WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
#22: 
new file mode 100755

WARNING: line over 80 characters
#211: FILE: tools/ebpf/rss.bpf.c:157:
+ * According to https://www.iana.org/assignments/ipv6-parameters/ipv6-parameters.xhtml

WARNING: line over 80 characters
#214: FILE: tools/ebpf/rss.bpf.c:160:
+ * Need to choose reasonable amount of maximum extensions/options we may check to find

WARNING: line over 80 characters
#281: FILE: tools/ebpf/rss.bpf.c:227:
+                        *l4_offset + opt_offset + offsetof(struct ipv6_destopt_hao, addr),

total: 0 errors, 4 warnings, 591 lines checked

Patch 3/7 has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.
4/7 Checking commit 15a840f357fd (ebpf: Added eBPF RSS loader.)
Use of uninitialized value $acpi_testexpected in string eq at ./scripts/checkpatch.pl line 1529.
WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
#71: 
new file mode 100644

WARNING: architecture specific defines should be avoided
#353: FILE: ebpf/rss.bpf.skeleton.h:4:
+#ifndef __RSS_BPF_SKEL_H__

ERROR: code indent should never use tabs
#360: FILE: ebpf/rss.bpf.skeleton.h:11:
+^Istruct bpf_object_skeleton *skeleton;$

ERROR: code indent should never use tabs
#361: FILE: ebpf/rss.bpf.skeleton.h:12:
+^Istruct bpf_object *obj;$

ERROR: code indent should never use tabs
#362: FILE: ebpf/rss.bpf.skeleton.h:13:
+^Istruct {$

ERROR: code indent should never use tabs
#363: FILE: ebpf/rss.bpf.skeleton.h:14:
+^I^Istruct bpf_map *tap_rss_map_configurations;$

ERROR: code indent should never use tabs
#364: FILE: ebpf/rss.bpf.skeleton.h:15:
+^I^Istruct bpf_map *tap_rss_map_indirection_table;$

ERROR: code indent should never use tabs
#365: FILE: ebpf/rss.bpf.skeleton.h:16:
+^I^Istruct bpf_map *tap_rss_map_toeplitz_key;$

ERROR: code indent should never use tabs
#366: FILE: ebpf/rss.bpf.skeleton.h:17:
+^I} maps;$

ERROR: code indent should never use tabs
#367: FILE: ebpf/rss.bpf.skeleton.h:18:
+^Istruct {$

ERROR: code indent should never use tabs
#368: FILE: ebpf/rss.bpf.skeleton.h:19:
+^I^Istruct bpf_program *tun_rss_steering_prog;$

ERROR: code indent should never use tabs
#369: FILE: ebpf/rss.bpf.skeleton.h:20:
+^I} progs;$

ERROR: code indent should never use tabs
#370: FILE: ebpf/rss.bpf.skeleton.h:21:
+^Istruct {$

ERROR: code indent should never use tabs
#371: FILE: ebpf/rss.bpf.skeleton.h:22:
+^I^Istruct bpf_link *tun_rss_steering_prog;$

ERROR: code indent should never use tabs
#372: FILE: ebpf/rss.bpf.skeleton.h:23:
+^I} links;$

ERROR: code indent should never use tabs
#378: FILE: ebpf/rss.bpf.skeleton.h:29:
+^Iif (!obj)$

ERROR: braces {} are necessary for all arms of this statement
#378: FILE: ebpf/rss.bpf.skeleton.h:29:
+       if (!obj)
[...]

ERROR: code indent should never use tabs
#379: FILE: ebpf/rss.bpf.skeleton.h:30:
+^I^Ireturn;$

ERROR: code indent should never use tabs
#380: FILE: ebpf/rss.bpf.skeleton.h:31:
+^Iif (obj->skeleton)$

ERROR: braces {} are necessary for all arms of this statement
#380: FILE: ebpf/rss.bpf.skeleton.h:31:
+       if (obj->skeleton)
[...]

ERROR: code indent should never use tabs
#381: FILE: ebpf/rss.bpf.skeleton.h:32:
+^I^Ibpf_object__destroy_skeleton(obj->skeleton);$

ERROR: code indent should never use tabs
#382: FILE: ebpf/rss.bpf.skeleton.h:33:
+^Ifree(obj);$

ERROR: code indent should never use tabs
#391: FILE: ebpf/rss.bpf.skeleton.h:42:
+^Istruct rss_bpf *obj;$

ERROR: code indent should never use tabs
#393: FILE: ebpf/rss.bpf.skeleton.h:44:
+^Iobj = (struct rss_bpf *)calloc(1, sizeof(*obj));$

ERROR: code indent should never use tabs
#394: FILE: ebpf/rss.bpf.skeleton.h:45:
+^Iif (!obj)$

ERROR: braces {} are necessary for all arms of this statement
#394: FILE: ebpf/rss.bpf.skeleton.h:45:
+       if (!obj)
[...]

ERROR: code indent should never use tabs
#395: FILE: ebpf/rss.bpf.skeleton.h:46:
+^I^Ireturn NULL;$

ERROR: code indent should never use tabs
#396: FILE: ebpf/rss.bpf.skeleton.h:47:
+^Iif (rss_bpf__create_skeleton(obj))$

ERROR: braces {} are necessary for all arms of this statement
#396: FILE: ebpf/rss.bpf.skeleton.h:47:
+       if (rss_bpf__create_skeleton(obj))
[...]

ERROR: code indent should never use tabs
#397: FILE: ebpf/rss.bpf.skeleton.h:48:
+^I^Igoto err;$

ERROR: code indent should never use tabs
#398: FILE: ebpf/rss.bpf.skeleton.h:49:
+^Iif (bpf_object__open_skeleton(obj->skeleton, opts))$

ERROR: braces {} are necessary for all arms of this statement
#398: FILE: ebpf/rss.bpf.skeleton.h:49:
+       if (bpf_object__open_skeleton(obj->skeleton, opts))
[...]

ERROR: code indent should never use tabs
#399: FILE: ebpf/rss.bpf.skeleton.h:50:
+^I^Igoto err;$

ERROR: code indent should never use tabs
#401: FILE: ebpf/rss.bpf.skeleton.h:52:
+^Ireturn obj;$

ERROR: code indent should never use tabs
#403: FILE: ebpf/rss.bpf.skeleton.h:54:
+^Irss_bpf__destroy(obj);$

ERROR: code indent should never use tabs
#404: FILE: ebpf/rss.bpf.skeleton.h:55:
+^Ireturn NULL;$

ERROR: code indent should never use tabs
#410: FILE: ebpf/rss.bpf.skeleton.h:61:
+^Ireturn rss_bpf__open_opts(NULL);$

ERROR: code indent should never use tabs
#416: FILE: ebpf/rss.bpf.skeleton.h:67:
+^Ireturn bpf_object__load_skeleton(obj->skeleton);$

ERROR: code indent should never use tabs
#422: FILE: ebpf/rss.bpf.skeleton.h:73:
+^Istruct rss_bpf *obj;$

ERROR: code indent should never use tabs
#424: FILE: ebpf/rss.bpf.skeleton.h:75:
+^Iobj = rss_bpf__open();$

ERROR: code indent should never use tabs
#425: FILE: ebpf/rss.bpf.skeleton.h:76:
+^Iif (!obj)$

ERROR: braces {} are necessary for all arms of this statement
#425: FILE: ebpf/rss.bpf.skeleton.h:76:
+       if (!obj)
[...]

ERROR: code indent should never use tabs
#426: FILE: ebpf/rss.bpf.skeleton.h:77:
+^I^Ireturn NULL;$

ERROR: code indent should never use tabs
#427: FILE: ebpf/rss.bpf.skeleton.h:78:
+^Iif (rss_bpf__load(obj)) {$

ERROR: code indent should never use tabs
#428: FILE: ebpf/rss.bpf.skeleton.h:79:
+^I^Irss_bpf__destroy(obj);$

ERROR: code indent should never use tabs
#429: FILE: ebpf/rss.bpf.skeleton.h:80:
+^I^Ireturn NULL;$

ERROR: code indent should never use tabs
#430: FILE: ebpf/rss.bpf.skeleton.h:81:
+^I}$

ERROR: code indent should never use tabs
#431: FILE: ebpf/rss.bpf.skeleton.h:82:
+^Ireturn obj;$

ERROR: code indent should never use tabs
#437: FILE: ebpf/rss.bpf.skeleton.h:88:
+^Ireturn bpf_object__attach_skeleton(obj->skeleton);$

ERROR: code indent should never use tabs
#443: FILE: ebpf/rss.bpf.skeleton.h:94:
+^Ireturn bpf_object__detach_skeleton(obj->skeleton);$

ERROR: code indent should never use tabs
#449: FILE: ebpf/rss.bpf.skeleton.h:100:
+^Istruct bpf_object_skeleton *s;$

ERROR: code indent should never use tabs
#451: FILE: ebpf/rss.bpf.skeleton.h:102:
+^Is = (struct bpf_object_skeleton *)calloc(1, sizeof(*s));$

ERROR: code indent should never use tabs
#452: FILE: ebpf/rss.bpf.skeleton.h:103:
+^Iif (!s)$

ERROR: braces {} are necessary for all arms of this statement
#452: FILE: ebpf/rss.bpf.skeleton.h:103:
+       if (!s)
[...]

ERROR: code indent should never use tabs
#453: FILE: ebpf/rss.bpf.skeleton.h:104:
+^I^Ireturn -1;$

ERROR: code indent should never use tabs
#454: FILE: ebpf/rss.bpf.skeleton.h:105:
+^Iobj->skeleton = s;$

ERROR: code indent should never use tabs
#456: FILE: ebpf/rss.bpf.skeleton.h:107:
+^Is->sz = sizeof(*s);$

ERROR: code indent should never use tabs
#457: FILE: ebpf/rss.bpf.skeleton.h:108:
+^Is->name = "rss_bpf";$

ERROR: code indent should never use tabs
#458: FILE: ebpf/rss.bpf.skeleton.h:109:
+^Is->obj = &obj->obj;$

ERROR: code indent should never use tabs
#460: FILE: ebpf/rss.bpf.skeleton.h:111:
+^I/* maps */$

ERROR: code indent should never use tabs
#461: FILE: ebpf/rss.bpf.skeleton.h:112:
+^Is->map_cnt = 3;$

ERROR: code indent should never use tabs
#462: FILE: ebpf/rss.bpf.skeleton.h:113:
+^Is->map_skel_sz = sizeof(*s->maps);$

ERROR: code indent should never use tabs
#463: FILE: ebpf/rss.bpf.skeleton.h:114:
+^Is->maps = (struct bpf_map_skeleton *)calloc(s->map_cnt, s->map_skel_sz);$

ERROR: code indent should never use tabs
#464: FILE: ebpf/rss.bpf.skeleton.h:115:
+^Iif (!s->maps)$

ERROR: braces {} are necessary for all arms of this statement
#464: FILE: ebpf/rss.bpf.skeleton.h:115:
+       if (!s->maps)
[...]

ERROR: code indent should never use tabs
#465: FILE: ebpf/rss.bpf.skeleton.h:116:
+^I^Igoto err;$

ERROR: code indent should never use tabs
#467: FILE: ebpf/rss.bpf.skeleton.h:118:
+^Is->maps[0].name = "tap_rss_map_configurations";$

ERROR: code indent should never use tabs
#468: FILE: ebpf/rss.bpf.skeleton.h:119:
+^Is->maps[0].map = &obj->maps.tap_rss_map_configurations;$

ERROR: code indent should never use tabs
#470: FILE: ebpf/rss.bpf.skeleton.h:121:
+^Is->maps[1].name = "tap_rss_map_indirection_table";$

ERROR: code indent should never use tabs
#471: FILE: ebpf/rss.bpf.skeleton.h:122:
+^Is->maps[1].map = &obj->maps.tap_rss_map_indirection_table;$

ERROR: code indent should never use tabs
#473: FILE: ebpf/rss.bpf.skeleton.h:124:
+^Is->maps[2].name = "tap_rss_map_toeplitz_key";$

ERROR: code indent should never use tabs
#474: FILE: ebpf/rss.bpf.skeleton.h:125:
+^Is->maps[2].map = &obj->maps.tap_rss_map_toeplitz_key;$

ERROR: code indent should never use tabs
#476: FILE: ebpf/rss.bpf.skeleton.h:127:
+^I/* programs */$

ERROR: code indent should never use tabs
#477: FILE: ebpf/rss.bpf.skeleton.h:128:
+^Is->prog_cnt = 1;$

ERROR: code indent should never use tabs
#478: FILE: ebpf/rss.bpf.skeleton.h:129:
+^Is->prog_skel_sz = sizeof(*s->progs);$

WARNING: line over 80 characters
#479: FILE: ebpf/rss.bpf.skeleton.h:130:
+       s->progs = (struct bpf_prog_skeleton *)calloc(s->prog_cnt, s->prog_skel_sz);

ERROR: code indent should never use tabs
#479: FILE: ebpf/rss.bpf.skeleton.h:130:
+^Is->progs = (struct bpf_prog_skeleton *)calloc(s->prog_cnt, s->prog_skel_sz);$

ERROR: code indent should never use tabs
#480: FILE: ebpf/rss.bpf.skeleton.h:131:
+^Iif (!s->progs)$

ERROR: braces {} are necessary for all arms of this statement
#480: FILE: ebpf/rss.bpf.skeleton.h:131:
+       if (!s->progs)
[...]

ERROR: code indent should never use tabs
#481: FILE: ebpf/rss.bpf.skeleton.h:132:
+^I^Igoto err;$

ERROR: code indent should never use tabs
#483: FILE: ebpf/rss.bpf.skeleton.h:134:
+^Is->progs[0].name = "tun_rss_steering_prog";$

ERROR: code indent should never use tabs
#484: FILE: ebpf/rss.bpf.skeleton.h:135:
+^Is->progs[0].prog = &obj->progs.tun_rss_steering_prog;$

ERROR: code indent should never use tabs
#485: FILE: ebpf/rss.bpf.skeleton.h:136:
+^Is->progs[0].link = &obj->links.tun_rss_steering_prog;$

ERROR: code indent should never use tabs
#487: FILE: ebpf/rss.bpf.skeleton.h:138:
+^Is->data_sz = 8088;$

ERROR: code indent should never use tabs
#488: FILE: ebpf/rss.bpf.skeleton.h:139:
+^Is->data = (void *)"\$

ERROR: code indent should never use tabs
#774: FILE: ebpf/rss.bpf.skeleton.h:425:
+^Ireturn 0;$

ERROR: code indent should never use tabs
#776: FILE: ebpf/rss.bpf.skeleton.h:427:
+^Ibpf_object__destroy_skeleton(s);$

ERROR: code indent should never use tabs
#777: FILE: ebpf/rss.bpf.skeleton.h:428:
+^Ireturn -1;$

total: 85 errors, 3 warnings, 780 lines checked

Patch 4/7 has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.

5/7 Checking commit f89d2b6d7a13 (virtio-net: Added eBPF RSS to virtio-net.)
WARNING: line over 80 characters
#185: FILE: hw/net/virtio-net.c:2868:
+                    warn_report("Can't post-load eBPF RSS - fallback to software RSS");

total: 0 errors, 1 warnings, 214 lines checked

Patch 5/7 has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.
6/7 Checking commit b931e15ca671 (docs: Added eBPF documentation.)
Use of uninitialized value $acpi_testexpected in string eq at ./scripts/checkpatch.pl line 1529.
WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
#16: 
new file mode 100644

total: 0 errors, 1 warnings, 129 lines checked

Patch 6/7 has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.
7/7 Checking commit 842e84177ce5 (MAINTAINERS: Added eBPF maintainers information.)
=== OUTPUT END ===

Test command exited with code: 1


The full log is available at
http://patchew.org/logs/20210428164733.56547-1-andrew@daynix.com/testing.checkpatch/?type=message.
---
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