ivshmem: use symbolic constant for PCI ID, add to pci-ids.txt

Due to disagreement on a name that is generic enough for hw/pci/pci.h,
the symbolic constants are placed in the .c files.

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 2d5329a..e76b196 100644
--- a/docs/specs/pci-ids.txt
+++ b/docs/specs/pci-ids.txt
@@ -30,4 +30,6 @@
 1af4:1100  Used as PCI Subsystem ID for existing hardware devices emulated
            by qemu.
 
+1af4:1110  ivshmem device (shared memory, docs/specs/ivshmem_device_spec.txt)
+
 All other device IDs are reserved.

hw/ivshmem.c

diff --git a/hw/ivshmem.c b/hw/ivshmem.c
index fcf5d05..c86fddd 100644
--- a/hw/ivshmem.c
+++ b/hw/ivshmem.c
@@ -29,6 +29,9 @@
 #include <sys/mman.h>
 #include <sys/types.h>
 
+#define PCI_VENDOR_ID_IVSHMEM   PCI_VENDOR_ID_REDHAT_QUMRANET
+#define PCI_DEVICE_ID_IVSHMEM   0x1110
+
 #define IVSHMEM_IOEVENTFD   0
 #define IVSHMEM_MSI     1
 
@@ -800,8 +803,8 @@
 
     k->init = pci_ivshmem_init;
     k->exit = pci_ivshmem_uninit;
-    k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
-    k->device_id = 0x1110;
+    k->vendor_id = PCI_VENDOR_ID_IVSHMEM;
+    k->device_id = PCI_DEVICE_ID_IVSHMEM;
     k->class_id = PCI_CLASS_MEMORY_RAM;
     dc->reset = ivshmem_reset;
     dc->props = ivshmem_properties;