riscv_v_vstate_save
riscv_v_vstate_save(&prev->thread.vstate, regs);
riscv_v_vstate_save(¤t->thread.vstate, task_pt_regs(current));
riscv_v_vstate_save(¤t->thread.vstate, task_pt_regs(current));
riscv_v_vstate_save(¤t->thread.vstate, regs);