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* [RFC PATCH v2 0/5] eBPF RSS support for virtio-net
@ 2020-11-19 11:13 Andrew Melnychenko
  2020-11-19 11:13 ` [RFC PATCH v2 1/5] net: Added SetSteeringEBPF method for NetClientState Andrew Melnychenko
                   ` (6 more replies)
  0 siblings, 7 replies; 29+ messages in thread
From: Andrew Melnychenko @ 2020-11-19 11:13 UTC (permalink / raw)
  To: jasowang, mst; +Cc: yan, yuri.benditovich, qemu-devel

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 compilation of eBPF is not part of QEMU build and can be done 
using provided Makefile.ebpf(need to adjust 'linuxhdrs').
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 5/5.

I am sending those patches as RFC to initiate the discussions and get
feedback on the following points:
* Fallback when eBPF is not supported by the kernel
* Live migration to the kernel that doesn't have eBPF support
* Integration with current QEMU build
* Additional usage for eBPF for packet filtering

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.
* big-endian BPF support: for now, eBPF isn't supported on
big-endian systems. Can be added in future if required.
* huge .h file with eBPF binary. The size of .h file containing
eBPF binary is currently ~5K lines, because the binary is built with debug information.
The binary without debug/BTF info can't be loaded by libbpf.
We're looking for possibilities to reduce the size of the .h files.

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.

Andrew (5):
  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 RSS documentation.

 MAINTAINERS                    |    7 +
 configure                      |   33 +
 docs/ebpf_rss.rst              |  133 +
 ebpf/EbpfElf_to_C.py           |   36 +
 ebpf/Makefile.ebpf             |   33 +
 ebpf/ebpf_rss-stub.c           |   40 +
 ebpf/ebpf_rss.c                |  186 ++
 ebpf/ebpf_rss.h                |   44 +
 ebpf/meson.build               |    1 +
 ebpf/rss.bpf.c                 |  505 +++
 ebpf/tun_rss_steering.h        | 5439 ++++++++++++++++++++++++++++++++
 hw/net/vhost_net.c             |    2 +
 hw/net/virtio-net.c            |  120 +-
 include/hw/virtio/virtio-net.h |    4 +
 include/net/net.h              |    2 +
 meson.build                    |   11 +
 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 +
 24 files changed, 6633 insertions(+), 4 deletions(-)
 create mode 100644 docs/ebpf_rss.rst
 create mode 100644 ebpf/EbpfElf_to_C.py
 create mode 100755 ebpf/Makefile.ebpf
 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.c
 create mode 100644 ebpf/tun_rss_steering.h

-- 
2.29.2



^ permalink raw reply	[flat|nested] 29+ messages in thread

end of thread, other threads:[~2020-12-06 18:46 UTC | newest]

Thread overview: 29+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-11-19 11:13 [RFC PATCH v2 0/5] eBPF RSS support for virtio-net Andrew Melnychenko
2020-11-19 11:13 ` [RFC PATCH v2 1/5] net: Added SetSteeringEBPF method for NetClientState Andrew Melnychenko
2020-11-23  6:10   ` Jason Wang
2020-11-19 11:13 ` [RFC PATCH v2 2/5] ebpf: Added eBPF RSS program Andrew Melnychenko
2020-11-24  8:14   ` Jason Wang
2020-11-19 11:13 ` [RFC PATCH v2 3/5] ebpf: Added eBPF RSS loader Andrew Melnychenko
2020-11-24  8:33   ` Jason Wang
2020-11-19 11:13 ` [RFC PATCH v2 4/5] virtio-net: Added eBPF RSS to virtio-net Andrew Melnychenko
2020-11-24  8:48   ` Jason Wang
2020-12-01  7:40     ` Yuri Benditovich
2020-12-02  4:05       ` Jason Wang
2020-12-02  7:16         ` Yuri Benditovich
2020-12-02  8:06           ` Jason Wang
2020-11-19 11:13 ` [RFC PATCH v2 5/5] docs: Added eBPF documentation Andrew Melnychenko
2020-11-24  8:54   ` Jason Wang
2020-11-26 13:00     ` Yuri Benditovich
2020-11-27  4:36       ` Jason Wang
2020-11-23  6:08 ` [RFC PATCH v2 0/5] eBPF RSS support for virtio-net Jason Wang
2020-11-26 12:52   ` Yuri Benditovich
2020-11-27  4:35     ` Jason Wang
2020-11-27  6:06       ` Yuri Benditovich
2020-11-30  2:54         ` Jason Wang
2020-12-02 13:55 ` Jason Wang
2020-12-02 14:18   ` Toke Høiland-Jørgensen
2020-12-04  7:42     ` Yuri Benditovich
2020-12-04 10:09       ` Toke Høiland-Jørgensen
2020-12-04 12:31         ` Yuri Benditovich
2020-12-04 13:57           ` Toke Høiland-Jørgensen
2020-12-06 18:44             ` Yuri Benditovich

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