Re: [PATCH] tools/libxc: use uint32_t for pirq in xc_domain_irq_permission

[Julien Grall <julien@xxxxxxx>]

On 07/07/2021 13:54, Jan Beulich wrote:
> On 07.07.2021 14:51, Julien Grall wrote:
> > On 07/07/2021 02:02, Igor Druzhinin wrote:
> > > Current unit8_t for pirq argument in this interface is too restrictive
> > > causing failures on modern hardware with lots of GSIs. That extends down to
> > > XEN_DOMCTL_irq_permission ABI structure where it needs to be fixed up
> > > as well. Internal Xen structures appear to be fine. Existing users of
> > > the interface in tree (libxl, ocaml and python bindings) are already using
> > > int for pirq representation that should be wide enough.
> > By "int", I am assuming you imply "signed int", is that correct?
> >
> > If so, should the function xc_domain_irq_permission() interface take an
> > int in parameter and check it is not negative?
> Please let's not make things worse than they are, the more that
Well, what I am trying to prevent is surprise where the caller 
mistakenly pass a negative value that will be interpreted as a positive 
value...
Such issues are beyong annoying to debug...

> ./CODING_STYLE is unambiguous in cases like this one.

Hmmm... The coding style mention the fixed size but nothing about the 
signedness of the type...
The alternative suggestion is to keep a unsigned type but check the bit 
31 is not set.
Cheers,

--
Julien Grall