Re: [PATCH v3 0/6] eBPF RSS through QMP support.

[Jason Wang]

On Thu, Jun 15, 2023 at 6:29 AM Andrew Melnychenko <andrew@daynix.com> wrote:
>
> This series of patches provides the ability to retrieve eBPF program
> through qmp, so management application may load bpf blob with proper 
> capabilities.
> Now, virtio-net devices can accept eBPF programs and maps through properties
> as external file descriptors. Access to the eBPF map is direct through mmap()
> call, so it should not require additional capabilities to bpf* calls.
> eBPF file descriptors can be passed to QEMU from parent process or by unix
> socket with sendfd() qmp command.
>
> Possible solution for libvirt may look like this: 
> https://github.com/daynix/libvirt/tree/RSS_eBPF (WIP)

I got a build failure:

[18/2192] Compiling C object
libqemuutil.a.p/meson-generated_.._qapi_qapi-commands-ebpf.c.o
FAILED: libqemuutil.a.p/meson-generated_.._qapi_qapi-commands-ebpf.c.o
cc -m64 -mcx16 -Ilibqemuutil.a.p -I. -I.. -Isubprojects/libvhost-user
-I../subprojects/libvhost-user -Iqapi -Itrace -Iui -Iui/shader
-I/usr/include/libmount -I/usr/include/blkid -I/usr/include/glib-2.0
-I/usr/lib/x86_64-linux-gnu/glib-2.0/include
-I/usr/include/gio-unix-2.0 -I/usr/include/pixman-1
-fdiagnostics-color=auto -Wall -Winvalid-pch -Werror -std=gnu11 -O2 -g
-fstack-protector-strong -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -Wundef
-Wwrite-strings -Wmissing-prototypes -Wstrict-prototypes
-Wredundant-decls -Wold-style-declaration -Wold-style-definition
-Wtype-limits -Wformat-security -Wformat-y2k -Winit-self
-Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels
-Wexpansion-to-defined -Wimplicit-fallthrough=2
-Wmissing-format-attribute -Wno-missing-include-dirs
-Wno-shift-negative-value -Wno-psabi -isystem
/home/devel/git/qemu/linux-headers -isystem linux-headers -iquote .
-iquote /home/devel/git/qemu -iquote /home/devel/git/qemu/include
-iquote /home/devel/git/qemu/host/include/x86_64 -iquote
/home/devel/git/qemu/host/include/generic -iquote
/home/devel/git/qemu/tcg/i386 -pthread -D_GNU_SOURCE
-D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -fno-strict-aliasing
-fno-common -fwrapv -fPIE -MD -MQ
libqemuutil.a.p/meson-generated_.._qapi_qapi-commands-ebpf.c.o -MF
libqemuutil.a.p/meson-generated_.._qapi_qapi-commands-ebpf.c.o.d -o
libqemuutil.a.p/meson-generated_.._qapi_qapi-commands-ebpf.c.o -c
qapi/qapi-commands-ebpf.c
qapi/qapi-commands-ebpf.c:24:13: error:
‘qmp_marshal_output_EbpfObject’ defined but not used
[-Werror=unused-function]
   24 | static void qmp_marshal_output_EbpfObject(EbpfObject *ret_in,
      |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors

Please fix this.

Thanks

>
> Changes since v2:
>  * moved/refactored QMP command
>  * refactored virtio-net
>
> Changes since v1:
>  * refactored virtio-net
>  * moved hunks for ebpf mmap()
>  * added qmp enum for eBPF id.
>
> Andrew Melnychenko (6):
>   ebpf: Added eBPF map update through mmap.
>   ebpf: Added eBPF initialization by fds.
>   virtio-net: Added property to load eBPF RSS with fds.
>   ebpf: Added declaration/initialization routines.
>   qmp: Added new command to retrieve eBPF blob.
>   ebpf: Updated eBPF program and skeleton.
>
>  ebpf/ebpf.c                    |   70 ++
>  ebpf/ebpf.h                    |   31 +
>  ebpf/ebpf_rss-stub.c           |    6 +
>  ebpf/ebpf_rss.c                |  150 +++-
>  ebpf/ebpf_rss.h                |   10 +
>  ebpf/meson.build               |    2 +-
>  ebpf/rss.bpf.skeleton.h        | 1469 ++++++++++++++++----------------
>  hw/net/virtio-net.c            |   55 +-
>  include/hw/virtio/virtio-net.h |    1 +
>  qapi/ebpf.json                 |   55 ++
>  qapi/meson.build               |    1 +
>  qapi/qapi-schema.json          |    1 +
>  tools/ebpf/rss.bpf.c           |    2 +-
>  13 files changed, 1093 insertions(+), 760 deletions(-)
>  create mode 100644 ebpf/ebpf.c
>  create mode 100644 ebpf/ebpf.h
>  create mode 100644 qapi/ebpf.json
>
> --
> 2.39.1
>