xen-pvdevice: make device-id property compulsory

The intention of the Xen PV device is that it is used as a parent
device for PV drivers in Xen HVM guests and the set of PV drivers that
bind to the device is determined by its device ID (and possibly
vendor ID and revision). As such, the device should not have a default
device ID, it should always be supplied by the Xen toolstack.
Signed-off-by: NPaul Durrant <paul.durrant@citrix.com>
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>

hw/xen/xen_pvdevice.c

@@ -74,6 +74,10 @@ static int xen_pv_init(PCIDevice *pci_dev)
     XenPVDevice *d = XEN_PV_DEVICE(pci_dev);
     uint8_t *pci_conf;
 
+    /* device-id property must always be supplied */
+    if (d->device_id == 0xffff)
+	    return -1;
+
     pci_conf = pci_dev->config;
 
     pci_set_word(pci_conf + PCI_VENDOR_ID, d->vendor_id);
@@ -99,7 +103,7 @@ static int xen_pv_init(PCIDevice *pci_dev)
 
 static Property xen_pv_props[] = {
     DEFINE_PROP_UINT16("vendor-id", XenPVDevice, vendor_id, PCI_VENDOR_ID_XEN),
-    DEFINE_PROP_UINT16("device-id", XenPVDevice, device_id, PCI_DEVICE_ID_XEN_PVDEVICE),
+    DEFINE_PROP_UINT16("device-id", XenPVDevice, device_id, 0xffff),
     DEFINE_PROP_UINT8("revision", XenPVDevice, revision, 0x01),
     DEFINE_PROP_UINT32("size", XenPVDevice, size, 0x400000),
     DEFINE_PROP_END_OF_LIST()

include/hw/pci/pci_ids.h

@@ -146,7 +146,6 @@
 
 #define PCI_VENDOR_ID_XEN                0x5853
 #define PCI_DEVICE_ID_XEN_PLATFORM       0x0001
-#define PCI_DEVICE_ID_XEN_PVDEVICE       0x0002
 
 #define PCI_VENDOR_ID_NEC                0x1033
 #define PCI_DEVICE_ID_NEC_UPD720200      0x0194