virtio: make VIRTIO_F_VERSION_1 a transport bit

Activate VIRTIO_F_VERSION_1 automatically unless legacy_only
is set.

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

3 files changed, 9 insertions, 3 deletions

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index f9ad99c8b352..fa6b75db5f1f 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -197,7 +197,11 @@ static int virtio_dev_probe(struct device *_d)
                 driver_features_legacy = driver_features;
         }
 
-        if (driver_features & device_features & (1ULL << VIRTIO_F_VERSION_1))
+        /* Detect legacy-only drivers and disable VIRTIO_F_VERSION_1. */
+        if (drv->legacy_only)
+                device_features &= ~(1ULL << VIRTIO_F_VERSION_1);
+
+        if (device_features & (1ULL << VIRTIO_F_VERSION_1))
                 dev->features = driver_features & device_features;
         else
                 dev->features = driver_features_legacy & device_features;
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 55532a43ead3..00ec6b3f96b2 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -780,6 +780,8 @@ void vring_transport_features(struct virtio_device *vdev)
                         break;
                 case VIRTIO_RING_F_EVENT_IDX:
                         break;
+                case VIRTIO_F_VERSION_1:
+                        break;
                 default:
                         /* We don't understand this bit. */
                         __virtio_clear_bit(vdev, i);
diff --git a/include/uapi/linux/virtio_config.h b/include/uapi/linux/virtio_config.h
index 4d05671fbaec..a6d0cdeaacd4 100644
--- a/include/uapi/linux/virtio_config.h
+++ b/include/uapi/linux/virtio_config.h
@@ -43,11 +43,11 @@
 /* We've given up on this device. */
 #define VIRTIO_CONFIG_S_FAILED          0x80
 
-/* Some virtio feature bits (currently bits 28 through 31) are reserved for the
+/* Some virtio feature bits (currently bits 28 through 32) are reserved for the
  * transport being used (eg. virtio_ring), the rest are per-device feature
  * bits. */
 #define VIRTIO_TRANSPORT_F_START        28
-#define VIRTIO_TRANSPORT_F_END          32
+#define VIRTIO_TRANSPORT_F_END          33
 
 /* Do we get callbacks when the ring is completely used, even if we've
  * suppressed them? */