virtio: Use PCI revision field to indicate virtio PCI ABI version
As Avi pointed out, as we continue to massage the virtio PCI ABI, we can make
things a little more friendly to users by utilizing the PCI revision field to
indicate which version of the ABI we're using. This is a hard ABI version
and incrementing it will cause the guest driver to break.
This is the necessary changes to virtio_pci to support this.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/include/linux/virtio_pci.h b/include/linux/virtio_pci.h
index 860eb37..b315165 100644
--- a/include/linux/virtio_pci.h
+++ b/include/linux/virtio_pci.h
@@ -52,4 +52,6 @@
* configuration space */
#define VIRTIO_PCI_CONFIG 20
+/* Virtio ABI version, this must match exactly */
+#define VIRTIO_PCI_ABI_VERSION 0
#endif