Re: [PATCH v2] x86/i8259: do not assume interrupts always target CPU0

["Roger Pau Monné" <roger.pau@citrix.com>]

On Tue, Oct 24, 2023 at 02:08:42PM +0200, Jan Beulich wrote:
> On 24.10.2023 14:06, Jan Beulich wrote:
> > On 24.10.2023 13:36, Roger Pau Monné wrote:
> >> What is your reasoning for wanting the smp_processor_id() check in
> >> the caller rather than bogus_8259A_irq()?  It does seem fine to me to
> >> do such check in bogus_8259A_irq(), as whether the IRQ is bogus also
> >> depends on whether it fired on the BSP or any of the APs.
> > 
> > bogus_8259A_irq() shouldn't be concerned about the CPU it runs on; it
> > should solely deal with 8259A aspects.
> 
> Or to put it differently: The function is supposed to tell whether an
> IRQ is bogus from the pov of the PIC. The caller decides under what
> conditions to actually invoke this checking.

I understand that the PIC itself is agnostic as to which the CPU the
irq (vector) has been injected, but the added CPU vendor checks are
there to deal with possibly a bogus PIC implementation, and hence
doesn't feel that off place IMO.

Anyway, will adjust as requested, albeit I think it hampers
readability and that's more valuable than whether the check is
contextually better fit in do_IRQ() or bogus_8259A_irq().

Thanks, Roger.