Hi,
I've checked the issue. Apparently, libbpf can't work with a skeleton on
Debian.
Version check would not help - versioning differs at different distros.
I've added a small check:
diff --git a/meson.build b/meson.build
> index ca551dd15d..4a51a25643 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -1018,6 +1018,20 @@ endif
>
> # libbpf
> libbpf = dependency('libbpf', required: get_option('bpf'))
> +if libbpf.found() and not cc.links('''
> + #include <bpf/libbpf.h>
> + int main(void)
> + {
> + bpf_object__destroy_skeleton(NULL);
> + return 0;
> + }''', dependencies: libbpf)
> + libbpf = not_found
> + if get_option('bpf').enabled()
> + error('libbpf skeleton test failed')
> + else
> + warning('libbpf skeleton test failed, disabling')
> + endif
> +endif
>
> if get_option('cfi')
> cfi_flags=[]
>
Is it possible to prepare an additional patch or should I prepare new
eBPFv7 patches?
On Sun, Apr 25, 2021 at 6:32 AM Jason Wang <jasow...@redhat.com> wrote:
>
> 在 2021/4/12 下午4:25, Andrew Melnychenko 写道:
> > 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.
>
>
> Want to merge but it fails to build on Debian 10.9:
>
> dpkg -l | grep libbpf
> ii libbpf-dev:amd64 4.19.181-1 amd64 eBPF helper
> library (development files)
> ii libbpf4.19:amd64 4.19.181-1 amd64 eBPF helper
> library (shared library)
>
> I configure use --enable-bpf --target-list=x86_64-softmmu, and I get:
>
> [3/1375] Compiling C object libcommon.fa.p/ebpf_ebpf_rss.c.o
> FAILED: libcommon.fa.p/ebpf_ebpf_rss.c.o
> cc -Ilibcommon.fa.p -I. -I.. -I../slirp -I../slirp/src -I../dtc/libfdt
> -I../capstone/include/capstone -Iqapi -Itrace -Iui -Iui/shader
> -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/uuid
> -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 -pipe -Wall -Winvalid-pch -Werror -std=gnu99
> -O2 -g -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/disas/libvixl
> -iquote /home/devel/git/qemu/tcg/i386 -iquote
> /home/devel/git/qemu/accel/tcg -pthread -U_FORTIFY_SOURCE
> -D_FORTIFY_SOURCE=2 -m64 -mcx16 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64
> -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wundef
> -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common
> -fwrapv -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 -Wno-missing-include-dirs
> -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -fPIC -MD
> -MQ libcommon.fa.p/ebpf_ebpf_rss.c.o -MF
> libcommon.fa.p/ebpf_ebpf_rss.c.o.d -o libcommon.fa.p/ebpf_ebpf_rss.c.o
> -c ../ebpf/ebpf_rss.c
> In file included from ../ebpf/ebpf_rss.c:23:
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h: In function
> ‘rss_bpf__destroy’:
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h:32:3: error: implicit
> declaration of function ‘bpf_object__destroy_skeleton’; did you mean
> ‘bpf_object__kversion’? [-Werror=implicit-function-declaration]
> bpf_object__destroy_skeleton(obj->skeleton);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
> bpf_object__kversion
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h:32:3: error: nested extern
> declaration of ‘bpf_object__destroy_skeleton’ [-Werror=nested-externs]
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h: At top level:
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h:40:33: error: ‘struct
> bpf_object_open_opts’ declared inside parameter list will not be visible
> outside of this definition or declaration [-Werror]
> rss_bpf__open_opts(const struct bpf_object_open_opts *opts)
> ^~~~~~~~~~~~~~~~~~~~
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h: In function
> ‘rss_bpf__open_opts’:
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h:49:6: error: implicit
> declaration of function ‘bpf_object__open_skeleton’; did you mean
> ‘bpf_object__open_buffer’? [-Werror=implicit-function-declaration]
> if (bpf_object__open_skeleton(obj->skeleton, opts))
> ^~~~~~~~~~~~~~~~~~~~~~~~~
> bpf_object__open_buffer
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h:49:6: error: nested extern
> declaration of ‘bpf_object__open_skeleton’ [-Werror=nested-externs]
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h: In function ‘rss_bpf__load’:
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h:67:9: error: implicit
> declaration of function ‘bpf_object__load_skeleton’; did you mean
> ‘bpf_object__load’? [-Werror=implicit-function-declaration]
> return bpf_object__load_skeleton(obj->skeleton);
> ^~~~~~~~~~~~~~~~~~~~~~~~~
> bpf_object__load
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h:67:9: error: nested extern
> declaration of ‘bpf_object__load_skeleton’ [-Werror=nested-externs]
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h: In function
> ‘rss_bpf__attach’:
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h:88:9: error: implicit
> declaration of function ‘bpf_object__attach_skeleton’; did you mean
> ‘bpf_object__for_each_safe’? [-Werror=implicit-function-declaration]
> return bpf_object__attach_skeleton(obj->skeleton);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~
> bpf_object__for_each_safe
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h:88:9: error: nested extern
> declaration of ‘bpf_object__attach_skeleton’ [-Werror=nested-externs]
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h: In function
> ‘rss_bpf__detach’:
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h:94:9: error: implicit
> declaration of function ‘bpf_object__detach_skeleton’; did you mean
> ‘bpf_object__for_each_safe’? [-Werror=implicit-function-declaration]
> return bpf_object__detach_skeleton(obj->skeleton);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~
> bpf_object__for_each_safe
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h:94:9: error: nested extern
> declaration of ‘bpf_object__detach_skeleton’ [-Werror=nested-externs]
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h:94:9: error: ‘return’ with
> a value, in function returning void [-Werror]
> return bpf_object__detach_skeleton(obj->skeleton);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h:92:1: note: declared here
> rss_bpf__detach(struct rss_bpf *obj)
> ^~~~~~~~~~~~~~~
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h: In function
> ‘rss_bpf__create_skeleton’:
> /home/devel/git/qemu/ebpf/rss.bpf.skeleton.h:102:53: error:
> dereferencing pointer to incomplete type ‘struct bpf_object_skeleton’
> s = (struct bpf_object_skeleton *)calloc(1, sizeof(*s));
> ^~
> cc1: all warnings being treated as errors
>
> Thanks
>
>
> >
> > 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.
> >
> > 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 | 9 +
> > 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, 1592 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
> >
>
>
