On Wed, Dec 10, 2025 at 08:36:37AM +0100, Jan Beulich wrote: > On 10.12.2025 02:04, Stefano Stabellini wrote: > > On Tue, 23 Sep 2025, [email protected] wrote: > >> From: Denis Mukhin <[email protected]> > >> > >> Add a new symbol DOMID_ANY aliasing DOMID_INVALID to improve the > >> readability > >> of the code. > >> > >> Update all relevant domid_alloc() call sites. > >> > >> Amends: 2d5065060710 ("xen/domain: unify domain ID allocation") > >> Signed-off-by: Denis Mukhin <[email protected]> > > > > Reviewed-by: Stefano Stabellini <[email protected]> > > The other day concern was voiced over aliasing DOMID_ANY with DOMID_INVALID. > I don't recall though who it was or where.
I'm afraid it was me (at least) that voiced such concern. But then I completely forgot to reply to the patch. I don't think this is a good idea, aliasing DOMID_ANY with DOMID_INVALID is likely to be dangerous in the long run. In the example here it's fine, because the function itself doesn't use DOMID_INVALID (iow: all usages of DOMID_INVALID are replaced with DOMID_ANY). However I could see a function wanting to use both DOMID_INVALID and DOMID_ANY for different purposes. Having both aliased to the same value is not going to work as expected. If we have to introduce DOMID_ANY it must use a different value than DOMID_INVALID. And given the context here I would be fine leaving domid_alloc() to handle getting passed DOMID_INVALID as a signal to search for an empty domid to use, I don't see a compelling reason to introduce DOMID_ANY. Thanks, Roger.
