Let's say you're debugging tdg_vm_rd(). You suspect someone read the spec wrong. You pull up the spec: https://sr71.net/~dave/intel/tdg.vm.rd.png On 5/17/24 07:19, Kirill A. Shutemov wrote: > static inline u64 tdg_vm_rd(u64 field, u64 *value) > { > - struct tdx_module_args args = { > - .rdx = field, > - }; RDX is assigned 'field'. Makes sense based on the input operands. > - u64 ret; > - > - ret = __tdcall_ret(TDG_VM_RD, &args)> - *value = args.r8; 'value' is set to r8. Also matches the spec. It's obvious that this is a 'two return values' pattern. > - return ret; This is also obviously correct. Compare that to: > + return TDCALL_1(TDG_VM_RD, 0, field, 0, 0, value); > } Where it's 100% opaque which registers thing to into or that 'value' is an output, not an input. So, yeah, this is fewer lines of C code. But it's *WAY* less self-documenting. It's harder to audit. It's harder to understand and it's more opaque. While the goals here are laudable, I'm not a big fan of the end result.
