RE: [patch 08/20] genirq/msi: Make MSI descriptor iterators device domain aware

[Tian, Kevin]

> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Sent: Friday, November 11, 2022 9:57 PM
> 
> +/* Invalid XA index which is outside of any searchable range */
> +#define MSI_XA_MAX_INDEX	(ULONG_MAX - 1)
> +#define MSI_XA_DOMAIN_SIZE	(MSI_MAX_INDEX + 1)
> +

Out of curiosity. Other places treat MSI_MAX_INDEX - 1 as the upper
bound of a valid range. This size definition here implies that the last ID
is wasted for every domain. Is it intended?