support StructOps declarative initialization in bpf2go
Author: shun159Created Feb 28, 2026Updated Mar 29, 2026
Labelsenhancement
This proposal introduces StructOps Initialization Structs in bpf2go. This allows users to define the initial state of a struct_ops map (currently, I consider scalar values such as flags) using standard Go struct literals, which are then synchronized with the MapSpec during the LoadAndAssign process.
Initialization Struct Generation: bpf2go generates Go structs that mirror the BTF definition of struct_ops members. These structs are used as templates for map creation.
Pre-load Synchronization: It patches the MapSpec.Contents with the provided values before the map is created in the kernel.
example:
generated code
// bpfStructOpsMinimalSched is a struct type for the struct_ops map.
type bpfStructOpsMinimalSched struct {
_ structs.HostLayout
Init *ebpf.Program `ebpf:"init"`
Flags uint64 `ebpf:"flags"`
TimeoutMs uint32 `ebpf:"timeout_ms"`
Name [128]int8 `ebpf:"name"`
}user code
func main() {
if err := rlimit.RemoveMemlock(); err != nil {
log.Fatal(err)
}
objs := bpfObjects{}
objs.bpfStructOps.StructOpsMinimalSched.Flags = ScxOpsSwitchPartial
objs.bpfStructOps.StructOpsMinimalSched.TimeoutMs = 1000
if err := loadBpfObjects(&objs, nil); err != nil {
log.Fatalf("loading objects: %v", err)
}
defer objs.Close()
m := objs.MinimalSched
l, err := link.AttachStructOps(link.StructOpsOptions{Map: m})
if err != nil {
log.Fatalf("failed to attach sched_ext: %s", err)
}
defer l.Close()
stopper := make(chan os.Signal, 1)
signal.Notify(stopper, os.Interrupt, syscall.SIGTERM)
<-stopper
log.Print("quit sched_ext")
}Source: cilium/ebpf