Michael Kelley <mikelley@xxxxxxxxxxxxx> writes: > From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> Sent: Friday, January 10, 2020 4:00 AM >> >> >> I'd suggest we get rid of bool functions completely instead, something >> like (untested): > > Just curious: Why prefer returning a u16 instead of a bool? To avoid > having to test 'ret' for zero in the return statements, or is there some > broader reason? Basically to preserve hypercall failure code and not hide it under 'false'. >> - ipi_arg.cpu_mask); >> - return ((ret == 0) ? true : false); >> + return (u16)hv_do_fast_hypercall16(HVCALL_SEND_IPI, ipi_arg.vector, >> + ipi_arg.cpu_mask); > > The cast to u16 seems a bit dangerous. The hypercall status code is indeed > returned in the low 16 bits of the hypercall result value, so it works, and > maybe that is why you suggested u16 as the function return value. But it > is a non-obvious assumption. This is not obvious, I agree, and we can create a wrapper for it but we more or less must convert it to 'u16': uppper bits don't indicate a failure (e.g. 'reps complete'). -- Vitaly
