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>

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index f9ad99c..fa6b75d 100644 (file)
--- 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 55532a4..00ec6b3 100644 (file)
--- 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 4d05671..a6d0cde 100644 (file)
--- 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? */