virtio_pci: add VIRTIO_PCI_NO_LEGACY

Add macro to disable all legacy register defines.
Helpful to make sure legacy macros don't leak
through into modern code.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

include/uapi/linux/virtio_pci.h

@@ -41,6 +41,8 @@
 
 #include <linux/virtio_config.h>
 
+#ifndef VIRTIO_PCI_NO_LEGACY
+
 /* A 32-bit r/o bitmask of the features supported by the host */
 #define VIRTIO_PCI_HOST_FEATURES	0
 
@@ -67,16 +69,11 @@
  * a read-and-acknowledge. */
 #define VIRTIO_PCI_ISR			19
 
-/* The bit of the ISR which indicates a device configuration change. */
-#define VIRTIO_PCI_ISR_CONFIG		0x2
-
 /* MSI-X registers: only enabled if MSI-X is enabled. */
 /* A 16-bit vector for configuration changes. */
 #define VIRTIO_MSI_CONFIG_VECTOR        20
 /* A 16-bit vector for selected queue notifications. */
 #define VIRTIO_MSI_QUEUE_VECTOR         22
-/* Vector value used to disable MSI for queue */
-#define VIRTIO_MSI_NO_VECTOR            0xffff
 
 /* The remaining space is defined by each driver as the per-driver
  * configuration space */
@@ -94,4 +91,12 @@
 /* The alignment to use between consumer and producer parts of vring.
  * x86 pagesize again. */
 #define VIRTIO_PCI_VRING_ALIGN		4096
+
+#endif /* VIRTIO_PCI_NO_LEGACY */
+
+/* The bit of the ISR which indicates a device configuration change. */
+#define VIRTIO_PCI_ISR_CONFIG		0x2
+/* Vector value used to disable MSI for queue */
+#define VIRTIO_MSI_NO_VECTOR            0xffff
+
 #endif