Change default PCI class of virtio-blk to PCI_CLASS_STORAGE_SCSI

Windows virtio driver cannot pass DTM (certification) tests while the
storage class is PCI_CLASS_STORAGE_UNKNOWN.

A new qdev type is introduced to allow devices using the old class
to be created for compatibility with qemu-0.10.x.
Reported-by: NDor Laor <dlaor@redhat.com>
Signed-off-by: NMark McLoughlin <markmc@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

hw/virtio-pci.c

@@ -426,7 +426,8 @@ static void virtio_init_pci(VirtIOPCIProxy *proxy, VirtIODevice *vdev,
     virtio_bind_device(vdev, &virtio_pci_bindings, proxy);
 }
 
-static void virtio_blk_init_pci(PCIDevice *pci_dev)
+static void virtio_blk_init_pci_with_class(PCIDevice *pci_dev,
+                                           uint16_t class_code)
 {
     VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
     VirtIODevice *vdev;
@@ -435,8 +436,17 @@ static void virtio_blk_init_pci(PCIDevice *pci_dev)
     virtio_init_pci(proxy, vdev,
                     PCI_VENDOR_ID_REDHAT_QUMRANET,
                     PCI_DEVICE_ID_VIRTIO_BLOCK,
-                    PCI_CLASS_STORAGE_OTHER,
-                    0x00);
+                    class_code, 0x00);
+}
+
+static void virtio_blk_init_pci(PCIDevice *pci_dev)
+{
+    virtio_blk_init_pci_with_class(pci_dev, PCI_CLASS_STORAGE_SCSI);
+}
+
+static void virtio_blk_init_pci_0_10(PCIDevice *pci_dev)
+{
+    virtio_blk_init_pci_with_class(pci_dev, PCI_CLASS_STORAGE_OTHER);
 }
 
 static void virtio_console_init_pci(PCIDevice *pci_dev)
@@ -495,6 +505,11 @@ static PCIDeviceInfo virtio_info[] = {
         .qdev.name = "virtio-balloon-pci",
         .qdev.size = sizeof(VirtIOPCIProxy),
         .init      = virtio_balloon_init_pci,
+    },{
+        /* For compatibility with 0.10 */
+        .qdev.name = "virtio-blk-pci-0-10",
+        .qdev.size = sizeof(VirtIOPCIProxy),
+        .init      = virtio_blk_init_pci_0_10,
     },{
         /* end of list */
     }