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charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/4/25 08:19, Borislav Petkov wrote: > +static inline void __invlpgb_all(unsigned long asid, unsigned long pcid, > + unsigned long addr, u16 nr_pages, u8 flags) > +{ > + __invlpgb(asid, pcid, addr, nr_pages, 0, flags); > +} Why would __invlpg_all() need an 'addr' or 'nr_pages'? Shouldn't those be 0? It's _better_ of course when it happens at a single site and it's close to a prototype for __invlpgb(). But it's still a magic '0' that it's impossible to make sense of without looking at the prototype. Looking at the APM again... there really are three possible values for ECX[31]: 0: increment by 4k 1: increment by 2M X: Don't care, no increment is going to happen What you wrote above could actually be written: __invlpgb(asid, pcid, addr, nr_pages, 1, flags); so the 0/1 is _actually_ completely random and arbitrary as far as the spec goes. Why does it matter? It enables you to do sanity checking. For example, we could actually enforce a rule that "no stride" can't be paired with any of the per-address invalidation characteristics: if (stride == NO_STRIDE) { WARN_ON(flags & INVLPGB_FLAG_VA); WARN_ON(addr); WARN_ON(nr_pages); } That's impossible if you pass a 'bool' in. But, honestly, I'm deep into nitpick mode here. I think differentiating the three cases is worth it, but it's also not the hill I'm going to die on. ;)