Libvirt usually launches qemu with strict permissions.
To enable eBPF RSS steering, qemu-ebpf-rss-helper was added.
Added property "ebpf_rss_fds" for "virtio-net" that allows to
initialize eBPF RSS context with passed program & maps fds.
Added qemu-ebpf-rss-helper - simple helper that loads eBPF
context and passes fds through unix socket.
Libvirt should call the helper and pass fds to qemu through
"ebpf_rss_fds" property.
Added explicit target OS check for libbpf dependency in meson.
eBPF RSS works only with Linux TAP, so there is no reason to
build eBPF loader/helper for non-Linux.
Overall, libvirt process should not be aware of the "interface"
of eBPF RSS, it will not be aware of eBPF maps/program "type" and
their quantity. That's why qemu and the helper should be from
the same build and be "synchronized". Technically each qemu may
have its own helper. That's why "query-helper-paths" qmp command
was added. Qemu should return the path to the helper that suits
and libvirt should use "that" helper for "that" emulator.
qmp sample:
C: { "execute": "query-helper-paths" }
S: { "return": [
{
"name": "qemu-ebpf-rss-helper",
"path": "/usr/local/libexec/qemu-ebpf-rss-helper"
}
]
}
Andrew Melnychenko (5):
ebpf: Added eBPF initialization by fds.
virtio-net: Added property to load eBPF RSS with fds.
ebpf_rss_helper: Added helper for eBPF RSS.
qmp: Added qemu-ebpf-rss-path command.
meson: libbpf dependency now exclusively for Linux.
ebpf/ebpf_rss-stub.c | 6 ++
ebpf/ebpf_rss.c | 31 +++++++-
ebpf/ebpf_rss.h | 5 ++
ebpf/qemu-ebpf-rss-helper.c | 130 +++++++++++++++++++++++++++++++++
hw/net/virtio-net.c | 77 ++++++++++++++++++-
include/hw/virtio/virtio-net.h | 1 +
meson.build | 37 ++++++----
monitor/qmp-cmds.c | 78 ++++++++++++++++++++
qapi/misc.json | 29 ++++++++
9 files changed, 374 insertions(+), 20 deletions(-)
create mode 100644 ebpf/qemu-ebpf-rss-helper.c
--
2.31.1
