Re: [PATCH v0] kvm: unsigned datatype in ioctl wrapper

[Ed Maste]

On Mon, 30 Aug 2021 at 13:34, Peter Maydell <peter.maydell@linaro.org> wrote:
>
> # As noted, this does not actually cause problems on Linux, because
> # unlike FreeBSD, Linux knows what the f*ck it is doing, and just
> # ignores the upper bits exactly because of possible sign confusion.
>
> Whether that's still true a decade later I have no idea :-)

It wasn't even true a decade ago -- FreeBSD has ignored the upper bits
since 2005[1]. That change included a warning if upper bits were set,
but the warning is now hidden behind a diagnostic option.

[1] URL: 
https://cgit.FreeBSD.org/src/commit/?id=9fc6aa0618a174f436fb1a26867c99cff4125b40