Re: [PATCH v2 1/3] x86/apic: remove delivery and destination mode fields from drivers

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

On Thu, Mar 06, 2025 at 04:33:37PM +0100, Jan Beulich wrote:
> On 06.03.2025 15:57, Roger Pau Monne wrote:
> > --- a/xen/arch/x86/genapic/bigsmp.c
> > +++ b/xen/arch/x86/genapic/bigsmp.c
> > @@ -46,8 +46,6 @@ static int __init cf_check probe_bigsmp(void)
> >  
> >  const struct genapic __initconst_cf_clobber apic_bigsmp = {
> >  	APIC_INIT("bigsmp", probe_bigsmp),
> > -	.int_delivery_mode = dest_Fixed,
> > -	.int_dest_mode = 0, /* physical delivery */
> >  	.init_apic_ldr = init_apic_ldr_phys,
> >  	.vector_allocation_cpumask = vector_allocation_cpumask_phys,
> >  	.cpu_mask_to_apicid = cpu_mask_to_apicid_phys,
> > --- a/xen/arch/x86/genapic/default.c
> > +++ b/xen/arch/x86/genapic/default.c
> > @@ -16,8 +16,6 @@
> >  /* should be called last. */
> >  const struct genapic __initconst_cf_clobber apic_default = {
> >  	APIC_INIT("default", NULL),
> > -	.int_delivery_mode = dest_Fixed,
> > -	.int_dest_mode = 0, /* physical delivery */
> >  	.init_apic_ldr = init_apic_ldr_flat,
> >  	.vector_allocation_cpumask = vector_allocation_cpumask_phys,
> >  	.cpu_mask_to_apicid = cpu_mask_to_apicid_phys,
> > --- a/xen/arch/x86/genapic/x2apic.c
> > +++ b/xen/arch/x86/genapic/x2apic.c
> > @@ -140,8 +140,6 @@ static void cf_check send_IPI_mask_x2apic_cluster(
> >  
> >  static const struct genapic __initconst_cf_clobber apic_x2apic_phys = {
> >      APIC_INIT("x2apic_phys", NULL),
> > -    .int_delivery_mode = dest_Fixed,
> > -    .int_dest_mode = 0 /* physical delivery */,
> >      .init_apic_ldr = init_apic_ldr_phys,
> >      .vector_allocation_cpumask = vector_allocation_cpumask_phys,
> >      .cpu_mask_to_apicid = cpu_mask_to_apicid_phys,
> > @@ -163,8 +161,6 @@ static const struct genapic __initconst_cf_clobber apic_x2apic_mixed = {
> >       * The following fields are exclusively used by external interrupts and
> >       * hence are set to use Physical destination mode handlers.
> >       */
> > -    .int_delivery_mode = dest_Fixed,
> > -    .int_dest_mode = 0 /* physical delivery */,
> >      .vector_allocation_cpumask = vector_allocation_cpumask_phys,
> >      .cpu_mask_to_apicid = cpu_mask_to_apicid_phys,
> 
> Like we had it everywhere above, ...
> 
> > --- a/xen/arch/x86/io_apic.c
> > +++ b/xen/arch/x86/io_apic.c
> > @@ -1080,8 +1080,8 @@ static void __init setup_IO_APIC_irqs(void)
> >               */
> >              memset(&entry,0,sizeof(entry));
> >  
> > -            entry.delivery_mode = INT_DELIVERY_MODE;
> > -            entry.dest_mode = INT_DEST_MODE;
> > +            entry.delivery_mode = dest_Fixed;
> > +            entry.dest_mode = 0;
> 
> ... here and below these zeros would better gain a comment, or be expressed
> as e.g. (untested) MASK_EXTR(APIC_DEST_PHYSICAL, APIC_DEST_MASK).

I've started adding those comments, but then I got the impression they
where a bit redundant, many of the setting of the fields didn't have a
matching comment.  I was even tempted to just not setting the field at
all, seeing as the structure is zeroed.

Also this is the IO-APIC RTE, so it feels a bit out of place to use
the local APIC defines?

I will add a comment if you are fine with it.

Thanks, Roger.