Re: [PATCH] x86/x2apic: remove usage of ACPI_FADT_APIC_CLUSTER

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Mon, Oct 30, 2023 at 03:13:50PM +0100, Jan Beulich wrote:
> On 24.10.2023 12:26, Roger Pau Monne wrote:
> > The ACPI FADT APIC_CLUSTER flag mandates that when the interrupt delivery is
> > Logical mode APIC must be configured for Cluster destination model.  
> > However in
> > apic_x2apic_probe() such flag is incorrectly used to gate whether Physical 
> > mode
> > can be used.
> > 
> > Since Xen when in x2APIC mode only uses Logical mode together with Cluster
> > model completely remove checking for ACPI_FADT_APIC_CLUSTER, as Xen always
> > fulfills the requirement signaled by the flag.
> 
> Actually, one remark: The text in the 6.5 spec really only mentions xAPIC
> mode, so it's not entirely clear whether the two flags actually have any
> meaning for x2APIC mode.

Hm, indeed.  That wants to be in a different fix however.

Thanks, Roger.