virtio-9p: use symbolic constant, add to pci-ids.txt

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

docs/specs/pci-ids.txt

diff --git a/docs/specs/pci-ids.txt b/docs/specs/pci-ids.txt
index df2527f..2d5329a 100644
--- a/docs/specs/pci-ids.txt
+++ b/docs/specs/pci-ids.txt
@@ -21,6 +21,7 @@
 1af4:1003  console device
 1af4:1004  SCSI host bus adapter device
 1af4:1005  entropy generator device
+1af4:1009  9p filesystem device
 
 1af4:10f0  Available for experimental usage without registration.  Must get
    to      official ID when the code leaves the test lab (i.e. when seeking

hw/9pfs/virtio-9p-device.c

diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c
index 6761bce..f16ccfb 100644
--- a/hw/9pfs/virtio-9p-device.c
+++ b/hw/9pfs/virtio-9p-device.c
@@ -170,7 +170,7 @@
 
     k->init = virtio_9p_init_pci;
     k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
-    k->device_id = 0x1009;
+    k->device_id = PCI_DEVICE_ID_VIRTIO_9P;
     k->revision = VIRTIO_PCI_ABI_VERSION;
     k->class_id = 0x2;
     dc->props = virtio_9p_properties;

hw/pci/pci.h

diff --git a/hw/pci/pci.h b/hw/pci/pci.h
index 72927e3..ed098ce 100644
--- a/hw/pci/pci.h
+++ b/hw/pci/pci.h
@@ -77,6 +77,7 @@
 #define PCI_DEVICE_ID_VIRTIO_CONSOLE     0x1003
 #define PCI_DEVICE_ID_VIRTIO_SCSI        0x1004
 #define PCI_DEVICE_ID_VIRTIO_RNG         0x1005
+#define PCI_DEVICE_ID_VIRTIO_9P          0x1009
 
 #define FMT_PCIBUS                      PRIx64