diff --git a/hw/intc/xics.c b/hw/intc/xics.c
index 634101ac23..6cd980a735 100644
--- a/hw/intc/xics.c
+++ b/hw/intc/xics.c
@@ -687,6 +687,94 @@ void xics_set_irq_type(XICSState *icp, int irq, bool lsi)
     ics_set_irq_type(ics, irq - ics->offset, lsi);
 }
 
+#define ICS_IRQ_FREE(ics, srcno)   \
+    (!((ics)->irqs[(srcno)].flags & (XICS_FLAGS_IRQ_MASK)))
+
+static int ics_find_free_block(ICSState *ics, int num, int alignnum)
+{
+    int first, i;
+
+    for (first = 0; first < ics->nr_irqs; first += alignnum) {
+        if (num > (ics->nr_irqs - first)) {
+            return -1;
+        }
+        for (i = first; i < first + num; ++i) {
+            if (!ICS_IRQ_FREE(ics, i)) {
+                break;
+            }
+        }
+        if (i == (first + num)) {
+            return first;
+        }
+    }
+
+    return -1;
+}
+
+int xics_alloc(XICSState *icp, int src, int irq_hint, bool lsi)
+{
+    ICSState *ics = &icp->ics[src];
+    int irq;
+
+    if (irq_hint) {
+        assert(src == xics_find_source(icp, irq_hint));
+        if (!ICS_IRQ_FREE(ics, irq_hint - ics->offset)) {
+            trace_xics_alloc_failed_hint(src, irq_hint);
+            return -1;
+        }
+        irq = irq_hint;
+    } else {
+        irq = ics_find_free_block(ics, 1, 1);
+        if (irq < 0) {
+            trace_xics_alloc_failed_no_left(src);
+            return -1;
+        }
+        irq += ics->offset;
+    }
+
+    ics_set_irq_type(ics, irq - ics->offset, lsi);
+    trace_xics_alloc(src, irq);
+
+    return irq;
+}
+
+/*
+ * Allocate block of consequtive IRQs, returns a number of the first.
+ * If align==true, aligns the first IRQ number to num.
+ */
+int xics_alloc_block(XICSState *icp, int src, int num, bool lsi, bool align)
+{
+    int i, first = -1;
+    ICSState *ics = &icp->ics[src];
+
+    assert(src == 0);
+    /*
+     * MSIMesage::data is used for storing VIRQ so
+     * it has to be aligned to num to support multiple
+     * MSI vectors. MSI-X is not affected by this.
+     * The hint is used for the first IRQ, the rest should
+     * be allocated continuously.
+     */
+    if (align) {
+        assert((num == 1) || (num == 2) || (num == 4) ||
+               (num == 8) || (num == 16) || (num == 32));
+        first = ics_find_free_block(ics, num, num);
+    } else {
+        first = ics_find_free_block(ics, num, 1);
+    }
+
+    if (first >= 0) {
+        for (i = first; i < first + num; ++i) {
+            ics_set_irq_type(ics, i, lsi);
+        }
+    }
+    first += ics->offset;
+
+    trace_xics_alloc_block(src, first, num, lsi, align);
+
+    return first;
+}
+
 /*
  * Guest interfaces
  */
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 8d14f6b993..ea9bda9a68 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -104,73 +104,6 @@ struct sPAPRMachineState {
 
 sPAPREnvironment *spapr;
 
-int spapr_allocate_irq(int hint, bool lsi)
-{
-    int irq;
-
-    if (hint) {
-        irq = hint;
-        if (hint >= spapr->next_irq) {
-            spapr->next_irq = hint + 1;
-        }
-        /* FIXME: we should probably check for collisions somehow */
-    } else {
-        irq = spapr->next_irq++;
-    }
-
-    /* Configure irq type */
-    if (!xics_get_qirq(spapr->icp, irq)) {
-        return 0;
-    }
-
-    xics_set_irq_type(spapr->icp, irq, lsi);
-
-    return irq;
-}
-
-/*
- * Allocate block of consequtive IRQs, returns a number of the first.
- * If msi==true, aligns the first IRQ number to num.
- */
-int spapr_allocate_irq_block(int num, bool lsi, bool msi)
-{
-    int first = -1;
-    int i, hint = 0;
-
-    /*
-     * MSIMesage::data is used for storing VIRQ so
-     * it has to be aligned to num to support multiple
-     * MSI vectors. MSI-X is not affected by this.
-     * The hint is used for the first IRQ, the rest should
-     * be allocated continuously.
-     */
-    if (msi) {
-        assert((num == 1) || (num == 2) || (num == 4) ||
-               (num == 8) || (num == 16) || (num == 32));
-        hint = (spapr->next_irq + num - 1) & ~(num - 1);
-    }
-
-    for (i = 0; i < num; ++i) {
-        int irq;
-
-        irq = spapr_allocate_irq(hint, lsi);
-        if (!irq) {
-            return -1;
-        }
-
-        if (0 == i) {
-            first = irq;
-            hint = 0;
-        }
-
-        /* If the above doesn't create a consecutive block then that's
-         * an internal bug */
-        assert(irq == (first + i));
-    }
-
-    return first;
-}
-
 static XICSState *try_create_xics(const char *type, int nr_servers,
                                   int nr_irqs)
 {
diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c
index 5ce96a7196..1b6157dec4 100644
--- a/hw/ppc/spapr_events.c
+++ b/hw/ppc/spapr_events.c
@@ -314,7 +314,7 @@ static void check_exception(PowerPCCPU *cpu, sPAPREnvironment *spapr,
 
 void spapr_events_init(sPAPREnvironment *spapr)
 {
-    spapr->epow_irq = spapr_allocate_msi(0);
+    spapr->epow_irq = xics_alloc(spapr->icp, 0, 0, false);
     spapr->epow_notifier.notify = spapr_powerdown_req;
     qemu_register_powerdown_notifier(&spapr->epow_notifier);
     spapr_rtas_register(RTAS_CHECK_EXCEPTION, "check-exception",
diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
index d1e3e0ff10..d115fca31e 100644
--- a/hw/ppc/spapr_pci.c
+++ b/hw/ppc/spapr_pci.c
@@ -360,8 +360,8 @@ static void rtas_ibm_change_msi(PowerPCCPU *cpu, sPAPREnvironment *spapr,
 
     /* There is no cached config, allocate MSIs */
     if (!phb->msi_table[ndev].nvec) {
-        irq = spapr_allocate_irq_block(req_num, false,
-                                       ret_intr_type == RTAS_TYPE_MSI);
+        irq = xics_alloc_block(spapr->icp, 0, req_num, false,
+                               ret_intr_type == RTAS_TYPE_MSI);
         if (irq < 0) {
             error_report("Cannot allocate MSIs for device#%d", ndev);
             rtas_st(rets, 0, RTAS_OUT_HW_ERROR);
@@ -634,7 +634,7 @@ static void spapr_phb_realize(DeviceState *dev, Error **errp)
     for (i = 0; i < PCI_NUM_PINS; i++) {
         uint32_t irq;
 
-        irq = spapr_allocate_lsi(0);
+        irq = xics_alloc_block(spapr->icp, 0, 1, true, false);
         if (!irq) {
             error_setg(errp, "spapr_allocate_lsi failed");
             return;
diff --git a/hw/ppc/spapr_vio.c b/hw/ppc/spapr_vio.c
index 8b765c65e8..dc9e46a7b1 100644
--- a/hw/ppc/spapr_vio.c
+++ b/hw/ppc/spapr_vio.c
@@ -449,7 +449,7 @@ static int spapr_vio_busdev_init(DeviceState *qdev)
         dev->qdev.id = id;
     }
 
-    dev->irq = spapr_allocate_msi(dev->irq);
+    dev->irq = xics_alloc(spapr->icp, 0, dev->irq, false);
     if (!dev->irq) {
         return -1;
     }
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 3b6ccd395a..6b2f21c50a 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -339,16 +339,6 @@ target_ulong spapr_hypercall(PowerPCCPU *cpu, target_ulong opcode,
 int spapr_allocate_irq(int hint, bool lsi);
 int spapr_allocate_irq_block(int num, bool lsi, bool msi);
 
-static inline int spapr_allocate_msi(int hint)
-{
-    return spapr_allocate_irq(hint, false);
-}
-
-static inline int spapr_allocate_lsi(int hint)
-{
-    return spapr_allocate_irq(hint, true);
-}
-
 /* RTAS return codes */
 #define RTAS_OUT_SUCCESS            0
 #define RTAS_OUT_NO_ERRORS_FOUND    1
diff --git a/include/hw/ppc/xics.h b/include/hw/ppc/xics.h
index 2891599e38..30b14419a4 100644
--- a/include/hw/ppc/xics.h
+++ b/include/hw/ppc/xics.h
@@ -160,6 +160,8 @@ struct ICSIRQState {
 
 qemu_irq xics_get_qirq(XICSState *icp, int irq);
 void xics_set_irq_type(XICSState *icp, int irq, bool lsi);
+int xics_alloc(XICSState *icp, int src, int irq_hint, bool lsi);
+int xics_alloc_block(XICSState *icp, int src, int num, bool lsi, bool align);
 
 void xics_cpu_setup(XICSState *icp, PowerPCCPU *cpu);
 
diff --git a/trace-events b/trace-events
index ba01ad52cf..2a46e6c737 100644
--- a/trace-events
+++ b/trace-events
@@ -1188,6 +1188,10 @@ xics_set_irq_lsi(int srcno, int nr) "set_irq_lsi: srcno %d [irq %#x]"
 xics_ics_write_xive(int nr, int srcno, int server, uint8_t priority) "ics_write_xive: irq %#x [src %d] server %#x prio %#x"
 xics_ics_reject(int nr, int srcno) "reject irq %#x [src %d]"
 xics_ics_eoi(int nr) "ics_eoi: irq %#x"
+xics_alloc(int src, int irq) "source#%d, irq %d"
+xics_alloc_failed_hint(int src, int irq) "source#%d, irq %d is already in use"
+xics_alloc_failed_no_left(int src) "source#%d, no irq left"
+xics_alloc_block(int src, int first, int num, bool lsi, int align) "source#%d, first irq %d, %d irqs, lsi=%d, alignnum %d"
 
 # hw/ppc/spapr.c
 spapr_cas_failed(unsigned long n) "DT diff buffer is too small: %ld bytes"