kvm, pci: Return "no device" by default

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>

include/kvm/pci.h

@@ -9,6 +9,8 @@
 #define PCI_CONFIG_ADDRESS	0xcf8
 #define PCI_CONFIG_DATA		0xcfc
 
+#define PCI_NO_DEVICE		0xffffffff
+
 struct pci_config_address {
 	unsigned		zeros		: 2;		/* 1  .. 0  */
 	unsigned		register_number	: 6;		/* 7  .. 2  */

pci.c

@@ -36,6 +36,10 @@ static bool pci_config_data_out(struct kvm *self, uint16_t port, void *data, int
 
 static bool pci_config_data_in(struct kvm *self, uint16_t port, void *data, int size, uint32_t count)
 {
+	uint32_t *value = data;
+
+	*value = PCI_NO_DEVICE;
+
 	return true;
 }