qemu/ebpf, branch master

ebpf: Added traces back. Changed source set for eBPF to 'system'.

2024-06-04T07:14:26Z

There was an issue with Qemu build with "--disable-system". The traces could be generated and the build fails. The traces were 'cut out' for previous patches, and overall, the 'system' source set should be used like in pre-'eBPF blob' patches. Signed-off-by: Andrew Melnychenko Signed-off-by: Jason Wang

ebpf: Return 0 when configuration fails

2024-06-04T07:14:26Z

The kernel interprets the returned value as an unsigned 32-bit so -1 will mean queue 4294967295, which is awkward. Return 0 instead. Signed-off-by: Akihiko Odaki Signed-off-by: Jason Wang

ebpf: Fix RSS error handling

2024-06-04T07:14:26Z

calculate_rss_hash() was using hash value 0 to tell if it calculated a hash, but the hash value may be 0 on a rare occasion. Have a distinct bool value for correctness. Fixes: f3fa412de2 ("ebpf: Added eBPF RSS program.") Signed-off-by: Akihiko Odaki Signed-off-by: Jason Wang

ebpf: Restrict to system emulation

2024-04-18T09:17:27Z

eBPF is not used in user emulation. Signed-off-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-ID: <20240404194757.9343-2-philmd@linaro.org> Signed-off-by: Paolo Bonzini Message-ID: <20240408155330.522792-4-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini

ebpf: Fix indirections table setting

2024-03-29T06:59:00Z

The kernel documentation says: > The value stored can be of any size, however, all array elements are > aligned to 8 bytes. https://www.kernel.org/doc/html/v6.8/bpf/map_array.html Fixes: 333b3e5fab75 ("ebpf: Added eBPF map update through mmap.") Signed-off-by: Akihiko Odaki Acked-by: Andrew Melnychenko Signed-off-by: Jason Wang

ebpf: Updated eBPF program and skeleton.

2024-03-12T11:31:47Z

Updated section name, so libbpf should init/gues proper program type without specifications during open/load. Also, added map_flags with explicitly declared BPF_F_MMAPABLE. Added check for BPF_F_MMAPABLE flag to meson script and requirements to libbpf version. Also changed fragmentation flag check - some TCP/UDP packets may be considered fragmented if DF flag is set. Signed-off-by: Andrew Melnychenko Signed-off-by: Jason Wang

qmp: Added new command to retrieve eBPF blob.

2024-03-12T11:31:47Z

Now, the binary objects may be retrieved by id. It would require for future qmp commands that may require specific eBPF blob. Added command "request-ebpf". This command returns eBPF program encoded base64. The program taken from the skeleton and essentially is an ELF object that can be loaded in the future with libbpf. The reason to use the command to provide the eBPF object instead of a separate artifact was to avoid issues related to finding the eBPF itself. eBPF object is an ELF binary that contains the eBPF program and eBPF map description(BTF). Overall, eBPF object should contain the program and enough metadata to create/load eBPF with libbpf. As the eBPF maps/program should correspond to QEMU, the eBPF can't be used from different QEMU build. The first solution was a helper that comes with QEMU and loads appropriate eBPF objects. And the issue is to find a proper helper if the system has several different QEMUs installed and/or built from the source, which helpers may not be compatible. Another issue is QEMU updating while there is a running QEMU instance. With an updated helper, it may not be possible to hotplug virtio-net device to the already running QEMU. Overall, requesting the eBPF object from QEMU itself solves possible failures with acceptable effort. Links: [PATCH 3/5] qmp: Added the helper stamp check. https://lore.kernel.org/all/20230219162100.174318-4-andrew@daynix.com/ Signed-off-by: Andrew Melnychenko Signed-off-by: Jason Wang

ebpf: Added eBPF initialization by fds.

2024-03-12T11:31:46Z

It allows using file descriptors of eBPF provided outside of QEMU. QEMU may be run without capabilities for eBPF and run RSS program provided by management tool(g.e. libvirt). Signed-off-by: Andrew Melnychenko Signed-off-by: Jason Wang

ebpf: Added eBPF map update through mmap.

2024-03-12T11:31:46Z

Changed eBPF map updates through mmaped array. Mmaped arrays provide direct access to map data. It should omit using bpf_map_update_elem() call, which may require capabilities that are not present. Signed-off-by: Andrew Melnychenko Signed-off-by: Jason Wang

trace-events: Fix the name of the tracing.rst file

2023-09-08T10:08:51Z

The file has been converted to .rst a while ago - make sure that the references in the trace-events files are pointing to the right location now. Signed-off-by: Thomas Huth Signed-off-by: Michael Tokarev