spapr-pci: Change the default PCI bus naming

Previously libvirt required the first/default PCI bus to have name "pci".
Since QEMU can support multiple buses now, libvirt wants "pci.0" now.

This removes custom bus name and lets QEMU make up default names.
Signed-off-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: NAndreas Färber <afaerber@suse.de>

hw/ppc/spapr_pci.c

@@ -510,7 +510,6 @@ static int spapr_phb_init(SysBusDevice *s)
     DeviceState *dev = DEVICE(s);
     sPAPRPHBState *sphb = SPAPR_PCI_HOST_BRIDGE(s);
     PCIHostState *phb = PCI_HOST_BRIDGE(s);
-    const char *busname;
     char *namebuf;
     int i;
     PCIBus *bus;
@@ -594,26 +593,8 @@ static int spapr_phb_init(SysBusDevice *s)
                              get_system_io(), 0, SPAPR_PCI_IO_WIN_SIZE);
     memory_region_add_subregion(get_system_memory(), sphb->io_win_addr,
                                 &sphb->iowindow);
-    /*
-     * Selecting a busname is more complex than you'd think, due to
-     * interacting constraints.  If the user has specified an id
-     * explicitly for the phb , then we want to use the qdev default
-     * of naming the bus based on the bridge device (so the user can
-     * then assign devices to it in the way they expect).  For the
-     * first / default PCI bus (index=0) we want to use just "pci"
-     * because libvirt expects there to be a bus called, simply,
-     * "pci".  Otherwise, we use the same name as in the device tree,
-     * since it's unique by construction, and makes the guest visible
-     * BUID clear.
-     */
-    if (dev->id) {
-        busname = NULL;
-    } else if (sphb->index == 0) {
-        busname = "pci";
-    } else {
-        busname = sphb->dtbusname;
-    }
-    bus = pci_register_bus(dev, busname,
+
+    bus = pci_register_bus(dev, NULL,
                            pci_spapr_set_irq, pci_spapr_map_irq, sphb,
                            &sphb->memspace, &sphb->iospace,
                            PCI_DEVFN(0, 0), PCI_NUM_PINS, TYPE_PCI_BUS);