Simply use features instead, we have same flag here.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 hw/virtio/vhost-user.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 1b2879a90cc..cf6f53801db 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -1232,7 +1232,7 @@ static int vhost_user_set_vring_base(struct vhost_dev *dev,
 
 static bool vhost_user_set_vring_enable_supported(struct vhost_dev *dev)
 {
-    return virtio_has_feature(dev->backend_features,
+    return virtio_has_feature(dev->features,
                               VHOST_USER_F_PROTOCOL_FEATURES);
 }
 
@@ -1449,14 +1449,15 @@ static int vhost_user_set_features(struct vhost_dev *dev,
     int ret;
 
     /*
-     * We need to include any extra backend only feature bits that
-     * might be needed by our device. Currently this includes the
-     * VHOST_USER_F_PROTOCOL_FEATURES bit for enabling protocol
-     * features.
+     * Don't lose VHOST_USER_F_PROTOCOL_FEATURES, which is vhost-user
+     * specific.
      */
-    ret = vhost_user_set_u64(dev, VHOST_USER_SET_FEATURES,
-                              features | dev->backend_features,
-                              log_enabled);
+    if (virtio_has_feature(dev->features, VHOST_USER_F_PROTOCOL_FEATURES)) {
+        features |= 1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
+    }
+
+    ret = vhost_user_set_u64(dev, VHOST_USER_SET_FEATURES, features,
+                             log_enabled);
 
     if (virtio_has_feature(dev->protocol_features,
                            VHOST_USER_PROTOCOL_F_STATUS)) {
@@ -2187,8 +2188,6 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque,
             (dev->config_ops && dev->config_ops->vhost_dev_config_notifier);
         uint64_t protocol_features;
 
-        dev->backend_features |= 1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
-
         err = vhost_user_get_u64(dev, VHOST_USER_GET_PROTOCOL_FEATURES,
                                  &protocol_features);
         if (err < 0) {
-- 
2.48.1