spapr: increase the size of the IRQ number space

The new layout using static IRQ number does not leave much space to
the dynamic MSI range, only 0x100 IRQ numbers. Increase the total
number of IRQS for newer machines and introduce a legacy XICS backend
for pre-3.1 machines to maintain compatibility.

For the old backend, provide a 'nr_msis' value covering the full IRQ
number space as it does not use the bitmap allocator to allocate MSI
interrupt numbers.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

hw/ppc/spapr.c

@@ -3971,6 +3971,7 @@ static void spapr_machine_3_0_class_options(MachineClass *mc)
     SET_MACHINE_COMPAT(mc, SPAPR_COMPAT_3_0);
 
     smc->legacy_irq_allocation = true;
+    smc->irq = &spapr_irq_xics_legacy;
 }
 
 DEFINE_SPAPR_MACHINE(3_0, "3.0", false);

hw/ppc/spapr_irq.c

@@ -195,7 +195,7 @@ static void spapr_irq_print_info_xics(sPAPRMachineState *spapr, Monitor *mon)
     ics_pic_print_info(spapr->ics, mon);
 }
 
-#define SPAPR_IRQ_XICS_NR_IRQS     0x400
+#define SPAPR_IRQ_XICS_NR_IRQS     0x1000
 #define SPAPR_IRQ_XICS_NR_MSIS     \
     (XICS_IRQ_BASE + SPAPR_IRQ_XICS_NR_IRQS - SPAPR_IRQ_MSI)
 
@@ -289,3 +289,16 @@ int spapr_irq_find(sPAPRMachineState *spapr, int num, bool align, Error **errp)
 
     return first + ics->offset;
 }
+
+#define SPAPR_IRQ_XICS_LEGACY_NR_IRQS     0x400
+
+sPAPRIrq spapr_irq_xics_legacy = {
+    .nr_irqs     = SPAPR_IRQ_XICS_LEGACY_NR_IRQS,
+    .nr_msis     = SPAPR_IRQ_XICS_LEGACY_NR_IRQS,
+
+    .init        = spapr_irq_init_xics,
+    .claim       = spapr_irq_claim_xics,
+    .free        = spapr_irq_free_xics,
+    .qirq        = spapr_qirq_xics,
+    .print_info  = spapr_irq_print_info_xics,
+};

include/hw/ppc/spapr_irq.h

@@ -41,6 +41,7 @@ typedef struct sPAPRIrq {
 } sPAPRIrq;
 
 extern sPAPRIrq spapr_irq_xics;
+extern sPAPRIrq spapr_irq_xics_legacy;
 
 int spapr_irq_claim(sPAPRMachineState *spapr, int irq, bool lsi, Error **errp);
 void spapr_irq_free(sPAPRMachineState *spapr, int irq, int num);