hw/virtio: group virtio flags into an enum

Minimizes the possibility to assign
the same bit to different features.
Signed-off-by: NMarcel Apfelbaum <marcel@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NLaurent Vivier <lvivier@redhat.com>
Acked-by: NJason Wang <jasowang@redhat.com>
(cherry picked from commit fc1769b7)
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

hw/virtio/virtio-pci.h

@@ -59,30 +59,33 @@ typedef struct VirtioBusClass VirtioPCIBusClass;
 #define VIRTIO_PCI_BUS_CLASS(klass) \
         OBJECT_CLASS_CHECK(VirtioPCIBusClass, klass, TYPE_VIRTIO_PCI_BUS)
 
+enum {
+    VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION_BIT,
+    VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT,
+    VIRTIO_PCI_FLAG_DISABLE_LEGACY_BIT,
+    VIRTIO_PCI_FLAG_DISABLE_MODERN_BIT,
+    VIRTIO_PCI_FLAG_MIGRATE_EXTRA_BIT,
+    VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY_BIT,
+    VIRTIO_PCI_FLAG_DISABLE_PCIE_BIT,
+};
+
 /* Need to activate work-arounds for buggy guests at vmstate load. */
-#define VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION_BIT  0
 #define VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION \
     (1 << VIRTIO_PCI_FLAG_BUS_MASTER_BUG_MIGRATION_BIT)
 
 /* Performance improves when virtqueue kick processing is decoupled from the
  * vcpu thread using ioeventfd for some devices. */
-#define VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT 1
 #define VIRTIO_PCI_FLAG_USE_IOEVENTFD   (1 << VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT)
 
 /* virtio version flags */
-#define VIRTIO_PCI_FLAG_DISABLE_LEGACY_BIT 2
-#define VIRTIO_PCI_FLAG_DISABLE_MODERN_BIT 3
-#define VIRTIO_PCI_FLAG_DISABLE_PCIE_BIT 6
 #define VIRTIO_PCI_FLAG_DISABLE_LEGACY (1 << VIRTIO_PCI_FLAG_DISABLE_LEGACY_BIT)
 #define VIRTIO_PCI_FLAG_DISABLE_MODERN (1 << VIRTIO_PCI_FLAG_DISABLE_MODERN_BIT)
 #define VIRTIO_PCI_FLAG_DISABLE_PCIE (1 << VIRTIO_PCI_FLAG_DISABLE_PCIE_BIT)
 
 /* migrate extra state */
-#define VIRTIO_PCI_FLAG_MIGRATE_EXTRA_BIT 4
 #define VIRTIO_PCI_FLAG_MIGRATE_EXTRA (1 << VIRTIO_PCI_FLAG_MIGRATE_EXTRA_BIT)
 
 /* have pio notification for modern device ? */
-#define VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY_BIT 5
 #define VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY \
     (1 << VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY_BIT)