spapr/irq: Drop spapr_irq_msi_reset()

PHBs already take care of clearing the MSIs from the bitmap during reset
or unplug. No need to do this globally from the machine code. Rather add
an assert to ensure that PHBs have acted as expected.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <156415228966.1064338.190189424190233355.stgit@bahia.lan>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
[dwg: Fix crash in qtest case where spapr->irq_map can be NULL at the
 new assert()]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

hw/ppc/spapr.c

@@ -1755,10 +1755,6 @@ static void spapr_machine_reset(MachineState *machine)
         ppc_set_compat(first_ppc_cpu, spapr->max_compat_pvr, &error_fatal);
     }
 
-    if (!SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) {
-        spapr_irq_msi_reset(spapr);
-    }
-
     /*
      * This is fixing some of the default configuration of the XIVE
      * devices. To be called after the reset of the machine devices.

hw/ppc/spapr_irq.c

@@ -59,11 +59,6 @@ void spapr_irq_msi_free(SpaprMachineState *spapr, int irq, uint32_t num)
     bitmap_clear(spapr->irq_map, irq - SPAPR_IRQ_MSI, num);
 }
 
-void spapr_irq_msi_reset(SpaprMachineState *spapr)
-{
-    bitmap_clear(spapr->irq_map, 0, spapr->irq_map_nr);
-}
-
 static void spapr_irq_init_kvm(SpaprMachineState *spapr,
                                   SpaprIrq *irq, Error **errp)
 {
@@ -731,6 +726,8 @@ int spapr_irq_post_load(SpaprMachineState *spapr, int version_id)
 
 void spapr_irq_reset(SpaprMachineState *spapr, Error **errp)
 {
+    assert(!spapr->irq_map || bitmap_empty(spapr->irq_map, spapr->irq_map_nr));
+
     if (spapr->irq->reset) {
         spapr->irq->reset(spapr, errp);
     }

include/hw/ppc/spapr_irq.h

@@ -30,7 +30,6 @@ void spapr_irq_msi_init(SpaprMachineState *spapr, uint32_t nr_msis);
 int spapr_irq_msi_alloc(SpaprMachineState *spapr, uint32_t num, bool align,
                         Error **errp);
 void spapr_irq_msi_free(SpaprMachineState *spapr, int irq, uint32_t num);
-void spapr_irq_msi_reset(SpaprMachineState *spapr);
 
 typedef struct SpaprIrq {
     uint32_t    nr_irqs;