virtio-blk: fail get_features when both scsi and 1.0 were set

SCSI passthrough was no longer supported in virtio 1.0, so this patch
fail the get_features() when both 1.0 and scsi is set. And also only
advertise VIRTIO_BLK_F_SCSI for legacy virtio-blk device.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>

hw/block/virtio-blk.c

@@ -731,8 +731,16 @@ static uint64_t virtio_blk_get_features(VirtIODevice *vdev, uint64_t features,
     virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY);
     virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY);
     virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE);
-    virtio_add_feature(&features, VIRTIO_BLK_F_SCSI);
     virtio_clear_feature(&features, VIRTIO_F_ANY_LAYOUT);
+    if (__virtio_has_feature(features, VIRTIO_F_VERSION_1)) {
+        if (s->conf.scsi) {
+            error_setg(errp, "Please set scsi=off for virtio-blk devices in order to use virtio 1.0");
+            return 0;
+        }
+        virtio_add_feature(&features, VIRTIO_F_ANY_LAYOUT);
+    } else {
+        virtio_add_feature(&features, VIRTIO_BLK_F_SCSI);
+    }
 
     if (s->conf.config_wce) {
         virtio_add_feature(&features, VIRTIO_BLK_F_CONFIG_WCE);