Re: [PATCHv7 net-next 00/15] BPF hardware offload (cls_bpf for now)

[David Miller]

From: Jakub Kicinski 
Date: Wed, 21 Sep 2016 11:43:52 +0100

> In the last year a lot of progress have been made on offloading
> simpler TC classifiers.  There is also growing interest in using
> BPF for generic high-speed packet processing in the kernel.
> It seems beneficial to tie those two trends together and think
> about hardware offloads of BPF programs.  This patch set presents
> such offload to Netronome smart NICs.  cls_bpf is extended with
> hardware offload capabilities and NFP driver gets a JIT translator
> which in presence of capable firmware can be used to offload
> the BPF program onto the card.
> 
> BPF JIT implementation is not 100% complete (e.g. missing instructions)
> but it is functional.  Encouragingly it should be possible to
> offload most (if not all) advanced BPF features onto the NIC - 
> including packet modification, maps, tunnel encap/decap etc.
 ...

Series applied, thanks.

Re: [PATCHv7 net-next 00/15] BPF hardware offload (cls_bpf for now)

[Daniel Borkmann]

On 09/21/2016 12:43 PM, Jakub Kicinski wrote:
[...]

Rebased and improved.


Did a couple of tests with regards to the core bits with this set
applied on top of net-next and looks good to me now.

Thanks a lot, Jakub!

[PATCHv7 net-next 00/15] BPF hardware offload (cls_bpf for now)

[Jakub Kicinski]

Hi!

Rebased and improved.

v7:
 - fix patch 6.
v6 (patch 8 only):
 - explicitly check for registers >= MAX_BPF_REG;
 - fix leaky error path.
v5:
 - fix names of guard defines in bpf_verfier.h.
v4:
 - rename parser -> analyzer;
 - reorganize the analyzer patches a bit;
 - use bitfield.h directly.

--- merge blurb:
In the last year a lot of progress have been made on offloading
simpler TC classifiers.  There is also growing interest in using
BPF for generic high-speed packet processing in the kernel.
It seems beneficial to tie those two trends together and think
about hardware offloads of BPF programs.  This patch set presents
such offload to Netronome smart NICs.  cls_bpf is extended with
hardware offload capabilities and NFP driver gets a JIT translator
which in presence of capable firmware can be used to offload
the BPF program onto the card.

BPF JIT implementation is not 100% complete (e.g. missing instructions)
but it is functional.  Encouragingly it should be possible to
offload most (if not all) advanced BPF features onto the NIC - 
including packet modification, maps, tunnel encap/decap etc.

Example of basic tests I used:
  __section_cls_entry
  int cls_entry(struct __sk_buff *skb)
  {
if (load_byte(skb, 0) != 0x0)
return 0;

if (load_byte(skb, 4) != 0x1)
return 0;

skb->mark = 0xcafe;

if (load_byte(skb, 50) != 0xff)
return 0;

return ~0U;
  }

Above code can be compiled with Clang and loaded like this:
# ethtool -K p1p1 hw-tc-offload on
# tc qdisc add dev p1p1 ingress
# tc filter add dev p1p1 parent :  bpf obj prog.o action drop

This set implements the basic transparent offload, the skip_{sw,hw}
flags and reporting statistics for cls_bpf.

Jakub Kicinski (15):
  net: cls_bpf: add hardware offload
  net: cls_bpf: limit hardware offload by software-only flag
  net: cls_bpf: add support for marking filters as hardware-only
  bpf: don't (ab)use instructions to store state
  bpf: expose internal verfier structures
  bpf: enable non-core use of the verfier
  bpf: recognize 64bit immediate loads as consts
  nfp: add BPF to NFP code translator
  nfp: bpf: add hardware bpf offload
  net: cls_bpf: allow offloaded filters to update stats
  nfp: bpf: allow offloaded filters to update stats
  nfp: bpf: add packet marking support
  net: act_mirred: allow statistic updates from offloaded actions
  nfp: bpf: add support for legacy redirect action
  nfp: bpf: add offload of TC direct action mode

 drivers/net/ethernet/netronome/nfp/Makefile|7 +
 drivers/net/ethernet/netronome/nfp/nfp_asm.h   |  233 +++
 drivers/net/ethernet/netronome/nfp/nfp_bpf.h   |  212 +++
 drivers/net/ethernet/netronome/nfp/nfp_bpf_jit.c   | 1811 
 .../net/ethernet/netronome/nfp/nfp_bpf_verifier.c  |  171 ++
 drivers/net/ethernet/netronome/nfp/nfp_net.h   |   47 +-
 .../net/ethernet/netronome/nfp/nfp_net_common.c|  134 +-
 drivers/net/ethernet/netronome/nfp/nfp_net_ctrl.h  |   51 +-
 .../net/ethernet/netronome/nfp/nfp_net_ethtool.c   |   12 +
 .../net/ethernet/netronome/nfp/nfp_net_offload.c   |  291 
 .../net/ethernet/netronome/nfp/nfp_netvf_main.c|2 +-
 include/linux/bpf_verifier.h   |   90 +
 include/linux/netdevice.h  |2 +
 include/net/pkt_cls.h  |   16 +
 include/uapi/linux/pkt_cls.h   |1 +
 kernel/bpf/verifier.c  |  406 +++--
 net/sched/act_mirred.c |8 +
 net/sched/cls_bpf.c|  117 +-
 18 files changed, 3392 insertions(+), 219 deletions(-)
 create mode 100644 drivers/net/ethernet/netronome/nfp/nfp_asm.h
 create mode 100644 drivers/net/ethernet/netronome/nfp/nfp_bpf.h
 create mode 100644 drivers/net/ethernet/netronome/nfp/nfp_bpf_jit.c
 create mode 100644 drivers/net/ethernet/netronome/nfp/nfp_bpf_verifier.c
 create mode 100644 drivers/net/ethernet/netronome/nfp/nfp_net_offload.c
 create mode 100644 include/linux/bpf_verifier.h

-- 
1.9.1