diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index f55d227cd3..34b693beba 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1345,7 +1345,7 @@ static void *spapr_build_fdt(SpaprMachineState *spapr)
     }
 
     QLIST_FOREACH(phb, &spapr->phbs, list) {
-        ret = spapr_dt_phb(phb, PHANDLE_INTC, fdt, spapr->irq->nr_msis, NULL);
+        ret = spapr_dt_phb(spapr, phb, PHANDLE_INTC, fdt, NULL);
         if (ret < 0) {
             error_report("couldn't setup PCI devices in fdt");
             exit(1);
@@ -3980,8 +3980,7 @@ int spapr_phb_dt_populate(SpaprDrc *drc, SpaprMachineState *spapr,
         return -1;
     }
 
-    if (spapr_dt_phb(sphb, intc_phandle, fdt, spapr->irq->nr_msis,
-                     fdt_start_offset)) {
+    if (spapr_dt_phb(spapr, sphb, intc_phandle, fdt, fdt_start_offset)) {
         error_setg(errp, "unable to create FDT node for PHB %d", sphb->index);
         return -1;
     }
diff --git a/hw/ppc/spapr_irq.c b/hw/ppc/spapr_irq.c
index 040384b0fe..799755c811 100644
--- a/hw/ppc/spapr_irq.c
+++ b/hw/ppc/spapr_irq.c
@@ -29,9 +29,14 @@ static const TypeInfo spapr_intc_info = {
     .class_size = sizeof(SpaprInterruptControllerClass),
 };
 
-void spapr_irq_msi_init(SpaprMachineState *spapr, uint32_t nr_msis)
+static void spapr_irq_msi_init(SpaprMachineState *spapr)
 {
-    spapr->irq_map_nr = nr_msis;
+    if (SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) {
+        /* Legacy mode doesn't use this allocater */
+        return;
+    }
+
+    spapr->irq_map_nr = spapr_irq_nr_msis(spapr);
     spapr->irq_map = bitmap_new(spapr->irq_map_nr);
 }
 
@@ -102,7 +107,6 @@ int spapr_irq_init_kvm(int (*fn)(SpaprInterruptController *, Error **),
 
 SpaprIrq spapr_irq_xics = {
     .nr_xirqs    = SPAPR_NR_XIRQS,
-    .nr_msis     = SPAPR_NR_MSIS,
     .xics        = true,
     .xive        = false,
 };
@@ -113,7 +117,6 @@ SpaprIrq spapr_irq_xics = {
 
 SpaprIrq spapr_irq_xive = {
     .nr_xirqs    = SPAPR_NR_XIRQS,
-    .nr_msis     = SPAPR_NR_MSIS,
     .xics        = false,
     .xive        = true,
 };
@@ -132,7 +135,6 @@ SpaprIrq spapr_irq_xive = {
  */
 SpaprIrq spapr_irq_dual = {
     .nr_xirqs    = SPAPR_NR_XIRQS,
-    .nr_msis     = SPAPR_NR_MSIS,
     .xics        = true,
     .xive        = true,
 };
@@ -245,6 +247,15 @@ void spapr_irq_dt(SpaprMachineState *spapr, uint32_t nr_servers,
     sicc->dt(spapr->active_intc, nr_servers, fdt, phandle);
 }
 
+uint32_t spapr_irq_nr_msis(SpaprMachineState *spapr)
+{
+    if (SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) {
+        return spapr->irq->nr_xirqs;
+    } else {
+        return SPAPR_XIRQ_BASE + spapr->irq->nr_xirqs - SPAPR_IRQ_MSI;
+    }
+}
+
 void spapr_irq_init(SpaprMachineState *spapr, Error **errp)
 {
     MachineState *machine = MACHINE(spapr);
@@ -267,9 +278,7 @@ void spapr_irq_init(SpaprMachineState *spapr, Error **errp)
     }
 
     /* Initialize the MSI IRQ allocator. */
-    if (!SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) {
-        spapr_irq_msi_init(spapr, spapr->irq->nr_msis);
-    }
+    spapr_irq_msi_init(spapr);
 
     if (spapr->irq->xics) {
         Object *obj;
@@ -558,7 +567,6 @@ int spapr_irq_find(SpaprMachineState *spapr, int num, bool align, Error **errp)
 
 SpaprIrq spapr_irq_xics_legacy = {
     .nr_xirqs    = SPAPR_IRQ_XICS_LEGACY_NR_XIRQS,
-    .nr_msis     = SPAPR_IRQ_XICS_LEGACY_NR_XIRQS,
     .xics        = true,
     .xive        = false,
 };
diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
index 6934d506a7..8ed06e5964 100644
--- a/hw/ppc/spapr_pci.c
+++ b/hw/ppc/spapr_pci.c
@@ -2305,8 +2305,8 @@ static void spapr_phb_pci_enumerate(SpaprPhbState *phb)
 
 }
 
-int spapr_dt_phb(SpaprPhbState *phb, uint32_t intc_phandle, void *fdt,
-                 uint32_t nr_msis, int *node_offset)
+int spapr_dt_phb(SpaprMachineState *spapr, SpaprPhbState *phb,
+                 uint32_t intc_phandle, void *fdt, int *node_offset)
 {
     int bus_off, i, j, ret;
     uint32_t bus_range[] = { cpu_to_be32(0), cpu_to_be32(0xff) };
@@ -2371,7 +2371,8 @@ int spapr_dt_phb(SpaprPhbState *phb, uint32_t intc_phandle, void *fdt,
     _FDT(fdt_setprop(fdt, bus_off, "ranges", &ranges, sizeof_ranges));
     _FDT(fdt_setprop(fdt, bus_off, "reg", &bus_reg, sizeof(bus_reg)));
     _FDT(fdt_setprop_cell(fdt, bus_off, "ibm,pci-config-space-type", 0x1));
-    _FDT(fdt_setprop_cell(fdt, bus_off, "ibm,pe-total-#msi", nr_msis));
+    _FDT(fdt_setprop_cell(fdt, bus_off, "ibm,pe-total-#msi",
+                          spapr_irq_nr_msis(spapr)));
 
     /* Dynamic DMA window */
     if (phb->ddw_enabled) {
diff --git a/include/hw/pci-host/spapr.h b/include/hw/pci-host/spapr.h
index 23506f05d9..8877ff51fb 100644
--- a/include/hw/pci-host/spapr.h
+++ b/include/hw/pci-host/spapr.h
@@ -128,8 +128,8 @@ struct SpaprPhbState {
 #define SPAPR_PCI_NV2ATSD_WIN_SIZE   (NVGPU_MAX_NUM * NVGPU_MAX_LINKS * \
                                       64 * KiB)
 
-int spapr_dt_phb(SpaprPhbState *phb, uint32_t intc_phandle, void *fdt,
-                 uint32_t nr_msis, int *node_offset);
+int spapr_dt_phb(SpaprMachineState *spapr, SpaprPhbState *phb,
+                 uint32_t intc_phandle, void *fdt, int *node_offset);
 
 void spapr_pci_rtas_init(void);
 
diff --git a/include/hw/ppc/spapr_irq.h b/include/hw/ppc/spapr_irq.h
index bc379b0761..308bfcefd1 100644
--- a/include/hw/ppc/spapr_irq.h
+++ b/include/hw/ppc/spapr_irq.h
@@ -27,7 +27,6 @@
 #define SPAPR_IRQ_MSI        (SPAPR_XIRQ_BASE + 0x0300)
 
 #define SPAPR_NR_XIRQS       0x1000
-#define SPAPR_NR_MSIS        (SPAPR_XIRQ_BASE + SPAPR_NR_XIRQS - SPAPR_IRQ_MSI)
 
 typedef struct SpaprMachineState SpaprMachineState;
 
@@ -72,15 +71,13 @@ void spapr_irq_dt(SpaprMachineState *spapr, uint32_t nr_servers,
                   void *fdt, uint32_t phandle);
 int spapr_irq_cpu_intc_create(SpaprMachineState *spapr,
                               PowerPCCPU *cpu, Error **errp);
-
-void spapr_irq_msi_init(SpaprMachineState *spapr, uint32_t nr_msis);
+uint32_t spapr_irq_nr_msis(SpaprMachineState *spapr);
 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);
 
 typedef struct SpaprIrq {
     uint32_t    nr_xirqs;
-    uint32_t    nr_msis;
     bool        xics;
     bool        xive;
 } SpaprIrq;
