diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index a521ca0b6e..f92c1b7d6c 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -1952,46 +1952,15 @@ qemuDomainReleaseDeviceAddress(virDomainObjPtr vm,
       (ctrl)->model == VIR_DOMAIN_CONTROLLER_MODEL_USB_ICH9_UHCI2 || \
       (ctrl)->model == VIR_DOMAIN_CONTROLLER_MODEL_USB_ICH9_UHCI3))
 
-/*
- * This assigns static PCI slots to all configured devices.
- * The ordering here is chosen to match the ordering used
- * with old QEMU < 0.12, so that if a user updates a QEMU
- * host from old QEMU to QEMU >= 0.12, their guests should
- * get PCI addresses in the same order as before.
- *
- * NB, if they previously hotplugged devices then all bets
- * are off. Hotplug for old QEMU was unfixably broken wrt
- * to stable PCI addressing.
- *
- * Order is:
- *
- *  - Host bridge (slot 0)
- *  - PIIX3 ISA bridge, IDE controller, something else unknown, USB controller (slot 1)
- *  - Video (slot 2)
- *
- * Incrementally assign slots from 3 onwards:
- *
- *  - Net
- *  - Sound
- *  - SCSI controllers
- *  - VirtIO block
- *  - VirtIO balloon
- *  - Host device passthrough
- *  - Watchdog (not IB700)
- *
- * Prior to this function being invoked, qemuCollectPCIAddress() will have
- * added all existing PCI addresses from the 'def' to 'addrs'. Thus this
- * function must only try to reserve addresses if info.type == NONE and
- * skip over info.type == PCI
- */
-int
-qemuAssignDevicePCISlots(virDomainDefPtr def,
-                         virQEMUCapsPtr qemuCaps,
-                         qemuDomainPCIAddressSetPtr addrs)
+
+static int
+qemuValidateDevicePCISlotsPIIX3(virDomainDefPtr def,
+                                virQEMUCapsPtr qemuCaps,
+                                qemuDomainPCIAddressSetPtr addrs)
 {
-    size_t i, j;
-    bool qemuDeviceVideoUsable = virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_VIDEO_PRIMARY);
+    size_t i;
     virDevicePCIAddress tmp_addr;
+    bool qemuDeviceVideoUsable = virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_VIDEO_PRIMARY);
     virDevicePCIAddressPtr addrptr;
 
     /* Verify that first IDE and USB controllers (if any) is on the PIIX3, fn 1 */
@@ -2100,6 +2069,61 @@ qemuAssignDevicePCISlots(virDomainDefPtr def,
             goto error;
         }
     }
+    return 0;
+
+error:
+    return -1;
+}
+
+
+/*
+ * This assigns static PCI slots to all configured devices.
+ * The ordering here is chosen to match the ordering used
+ * with old QEMU < 0.12, so that if a user updates a QEMU
+ * host from old QEMU to QEMU >= 0.12, their guests should
+ * get PCI addresses in the same order as before.
+ *
+ * NB, if they previously hotplugged devices then all bets
+ * are off. Hotplug for old QEMU was unfixably broken wrt
+ * to stable PCI addressing.
+ *
+ * Order is:
+ *
+ *  - Host bridge (slot 0)
+ *  - PIIX3 ISA bridge, IDE controller, something else unknown, USB controller (slot 1)
+ *  - Video (slot 2)
+ *
+ * Incrementally assign slots from 3 onwards:
+ *
+ *  - Net
+ *  - Sound
+ *  - SCSI controllers
+ *  - VirtIO block
+ *  - VirtIO balloon
+ *  - Host device passthrough
+ *  - Watchdog (not IB700)
+ *
+ * Prior to this function being invoked, qemuCollectPCIAddress() will have
+ * added all existing PCI addresses from the 'def' to 'addrs'. Thus this
+ * function must only try to reserve addresses if info.type == NONE and
+ * skip over info.type == PCI
+ */
+int
+qemuAssignDevicePCISlots(virDomainDefPtr def,
+                         virQEMUCapsPtr qemuCaps,
+                         qemuDomainPCIAddressSetPtr addrs)
+{
+    size_t i, j;
+    virDevicePCIAddress tmp_addr;
+
+    if ((STRPREFIX(def->os.machine, "pc-0.") ||
+        STRPREFIX(def->os.machine, "pc-1.") ||
+        STRPREFIX(def->os.machine, "pc-i440") ||
+        STREQ(def->os.machine, "pc") ||
+        STRPREFIX(def->os.machine, "rhel")) &&
+        qemuValidateDevicePCISlotsPIIX3(def, qemuCaps, addrs) < 0) {
+        goto error;
+    }
 
     /* PCI controllers */
     for (i = 0; i < def->ncontrollers; i++) {
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-pseries-usb-multi.args b/tests/qemuxml2argvdata/qemuxml2argv-pseries-usb-multi.args
index 3cc6cc3ab2..0d8c761451 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-pseries-usb-multi.args
+++ b/tests/qemuxml2argvdata/qemuxml2argv-pseries-usb-multi.args
@@ -3,6 +3,6 @@ LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test \
 -nographic -nodefconfig -nodefaults -chardev \
 socket,id=charmonitor,path=/tmp/test-monitor,server,nowait \
 -mon chardev=charmonitor,id=monitor,mode=readline -no-acpi \
--boot c -device piix3-usb-uhci,id=usb,bus=pci,addr=0x1.0x2 \
--device pci-ohci,id=usb1,bus=pci,addr=0x3 -chardev \
+-boot c -device piix3-usb-uhci,id=usb,bus=pci,addr=0x1 \
+-device pci-ohci,id=usb1,bus=pci,addr=0x2 -chardev \
 pty,id=charserial0 -device spapr-vty,chardev=charserial0,reg=0x30000000