Re: [PATCH bpf-next v4 0/5] selftests/bpf: xsk selftests

[Yonghong Song <yhs@fb.com>]

On 12/7/20 1:53 PM, Weqaar Janjua wrote:
> This patch set adds AF_XDP selftests based on veth to selftests/bpf.
> 
> # Topology:
> # ---------
> #                 -----------
> #               _ | Process | _
> #              /  -----------  \
> #             /        |        \
> #            /         |         \
> #      -----------     |     -----------
> #      | Thread1 |     |     | Thread2 |
> #      -----------     |     -----------
> #           |          |          |
> #      -----------     |     -----------
> #      |  xskX   |     |     |  xskY   |
> #      -----------     |     -----------
> #           |          |          |
> #      -----------     |     ----------
> #      |  vethX  | --------- |  vethY |
> #      -----------   peer    ----------
> #           |          |          |
> #      namespaceX      |     namespaceY
> 
> These selftests test AF_XDP SKB and Native/DRV modes using veth Virtual
> Ethernet interfaces.
> 
> The test program contains two threads, each thread is single socket with
> a unique UMEM. It validates in-order packet delivery and packet content
> by sending packets to each other.
> 
> Prerequisites setup by script test_xsk.sh:
> 
>     Set up veth interfaces as per the topology shown ^^:
>     * setup two veth interfaces and one namespace
>     ** veth<xxxx> in root namespace
>     ** veth<yyyy> in af_xdp<xxxx> namespace
>     ** namespace af_xdp<xxxx>
>     * create a spec file veth.spec that includes this run-time configuration
>     *** xxxx and yyyy are randomly generated 4 digit numbers used to avoid
>         conflict with any existing interface
>     
>     Adds xsk framework test to validate veth xdp DRV and SKB modes.
> 
> The following tests are provided:
> 
> 1. AF_XDP SKB mode
>     Generic mode XDP is driver independent, used when the driver does
>     not have support for XDP. Works on any netdevice using sockets and
>     generic XDP path. XDP hook from netif_receive_skb().
>     a. nopoll - soft-irq processing
>     b. poll - using poll() syscall
>     c. Socket Teardown
>        Create a Tx and a Rx socket, Tx from one socket, Rx on another.
>        Destroy both sockets, then repeat multiple times. Only nopoll mode
> 	  is used
>     d. Bi-directional Sockets
>        Configure sockets as bi-directional tx/rx sockets, sets up fill
> 	  and completion rings on each socket, tx/rx in both directions.
> 	  Only nopoll mode is used
> 
> 2. AF_XDP DRV/Native mode
>     Works on any netdevice with XDP_REDIRECT support, driver dependent.
>     Processes packets before SKB allocation. Provides better performance
>     than SKB. Driver hook available just after DMA of buffer descriptor.
>     a. nopoll
>     b. poll
>     c. Socket Teardown
>     d. Bi-directional Sockets
>     * Only copy mode is supported because veth does not currently support
>       zero-copy mode
> 
> Total tests: 8
> 
> Flow:
> * Single process spawns two threads: Tx and Rx
> * Each of these two threads attach to a veth interface within their
>    assigned namespaces
> * Each thread creates one AF_XDP socket connected to a unique umem
>    for each veth interface
> * Tx thread transmits 10k packets from veth<xxxx> to veth<yyyy>
> * Rx thread verifies if all 10k packets were received and delivered
>    in-order, and have the right content
> 
> v2 changes:
> * Move selftests/xsk to selftests/bpf
> * Remove Makefiles under selftests/xsk, and utilize selftests/bpf/Makefile
> 
> v3 changes:
> * merge all test scripts test_xsk_*.sh into test_xsk.sh
> 
> v4 changes:
> * merge xsk_env.sh into xsk_prereqs.sh
> * test_xsk.sh add cliarg -c for color-coded output
> * test_xsk.sh PREREQUISITES disables IPv6 on veth interfaces
> * test_xsk.sh PREREQUISITES adds xsk framework test
> * test_xsk.sh is independently executable
> * xdpxceiver.c Tx/Rx validates only IPv4 packets with TOS 0x9, ignores
>    others
> 
> Structure of the patch set:
> 
> Patch 1: Adds XSK selftests framework and test under selftests/bpf
> Patch 2: Adds tests: SKB poll and nopoll mode, and mac-ip-udp debug
> Patch 3: Adds tests: DRV poll and nopoll mode
> Patch 4: Adds tests: SKB and DRV Socket Teardown
> Patch 5: Adds tests: SKB and DRV Bi-directional Sockets
> 
> Thanks: Weqaar
> 
> Weqaar Janjua (5):
>    selftests/bpf: xsk selftests framework
>    selftests/bpf: xsk selftests - SKB POLL, NOPOLL
>    selftests/bpf: xsk selftests - DRV POLL, NOPOLL
>    selftests/bpf: xsk selftests - Socket Teardown - SKB, DRV
>    selftests/bpf: xsk selftests - Bi-directional Sockets - SKB, DRV
> 
>   tools/testing/selftests/bpf/Makefile       |    7 +-
>   tools/testing/selftests/bpf/test_xsk.sh    |  259 +++++
>   tools/testing/selftests/bpf/xdpxceiver.c   | 1074 ++++++++++++++++++++
>   tools/testing/selftests/bpf/xdpxceiver.h   |  160 +++
>   tools/testing/selftests/bpf/xsk_prereqs.sh |  135 +++
>   5 files changed, 1633 insertions(+), 2 deletions(-)
>   create mode 100755 tools/testing/selftests/bpf/test_xsk.sh
>   create mode 100644 tools/testing/selftests/bpf/xdpxceiver.c
>   create mode 100644 tools/testing/selftests/bpf/xdpxceiver.h
>   create mode 100755 tools/testing/selftests/bpf/xsk_prereqs.sh

All tests passed in my environment.
Tested-by: Yonghong Song <yhs@fb.com>