On Thu, May 12, 2022 at 12:43:19AM -0700, Dave Marchevsky wrote: > + err = bpf_get_reg_val(&val, sizeof(val), > + ((u64)arg_spec->reg_off + BPF_GETREG_X86_XMM0) << 32, > + btf_regs, btf_task); That illustrated the point from patch 2. The above is probably the typical usage. Just BPF_GETREG_X86_XMM in uapi enum would have been enough.