Re: [Xen-devel] [PATCH v2 3/4] x86/smp: check APIC ID on AP bringup

[Jan Beulich <jbeulich@xxxxxxxx>]

On 29.11.2019 12:28, Roger Pau Monne wrote:
> --- a/xen/arch/x86/smpboot.c
> +++ b/xen/arch/x86/smpboot.c
> @@ -1317,6 +1317,13 @@ int __cpu_up(unsigned int cpu)
>      if ( (apicid = x86_cpu_to_apicid[cpu]) == BAD_APICID )
>          return -ENODEV;
>  
> +    if ( (!x2apic_enabled || !iommu_intremap) && (apicid >> 8) )
> +    {
> +        printk("Processor with APIC ID %u cannot be onlined in xAPIC mode "
> +               "or without interrupt remapping\n", apicid);

Please log the APIC ID in hex, to match how it gets logged e.g.
by the ACPI table parsing code. I'd also prefer if the message
could be shortened a little: I don't think the "or" is needed,
"Processor" could become "CPU", and slight re-wording could
save even a little more: "Cannot online CPU with APIC ID %#x in
xAPIC mode w/o interrupt remapping".

Then again this isn't fully correct: We could bring such a
CPU online in x2APIC mode but without interrupt remapping.
There would be a restriction on which CPUs physical interrupts
could be delivered to. So perhaps "Unsupported: APIC ID %#x in
xAPIC mode w/o interrupt remapping" or some such?

Jan

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel