It's unused now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 hw/block/vhost-user-blk.c | 1 -
 hw/scsi/vhost-scsi.c      | 1 -
 hw/scsi/vhost-user-scsi.c | 1 -
 hw/virtio/vdpa-dev.c      | 1 -
 hw/virtio/virtio-qmp.c    | 2 --
 include/hw/virtio/vhost.h | 7 -------
 6 files changed, 13 deletions(-)

diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
index 0eebbcd80d8..079a6492355 100644
--- a/hw/block/vhost-user-blk.c
+++ b/hw/block/vhost-user-blk.c
@@ -343,7 +343,6 @@ static int vhost_user_blk_connect(DeviceState *dev, Error **errp)
     s->dev.nvqs = s->num_queues;
     s->dev.vqs = s->vhost_vqs;
     s->dev.vq_index = 0;
-    s->dev.backend_features = 0;
 
     vhost_dev_set_config_notifier(&s->dev, &blk_ops);
 
diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c
index cdf405b0f86..d694a25fe2d 100644
--- a/hw/scsi/vhost-scsi.c
+++ b/hw/scsi/vhost-scsi.c
@@ -276,7 +276,6 @@ static void vhost_scsi_realize(DeviceState *dev, Error **errp)
     vqs = g_new0(struct vhost_virtqueue, vsc->dev.nvqs);
     vsc->dev.vqs = vqs;
     vsc->dev.vq_index = 0;
-    vsc->dev.backend_features = 0;
 
     ret = vhost_dev_init(&vsc->dev, (void *)(uintptr_t)vhostfd,
                          VHOST_BACKEND_TYPE_KERNEL, 0, errp);
diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
index 25f2d894e7c..0c80a271d8b 100644
--- a/hw/scsi/vhost-user-scsi.c
+++ b/hw/scsi/vhost-user-scsi.c
@@ -159,7 +159,6 @@ static int vhost_user_scsi_connect(DeviceState *dev, Error **errp)
     vsc->dev.nvqs = VIRTIO_SCSI_VQ_NUM_FIXED + vs->conf.num_queues;
     vsc->dev.vqs = s->vhost_vqs;
     vsc->dev.vq_index = 0;
-    vsc->dev.backend_features = 0;
 
     ret = vhost_dev_init(&vsc->dev, &s->vhost_user, VHOST_BACKEND_TYPE_USER, 0,
                          errp);
diff --git a/hw/virtio/vdpa-dev.c b/hw/virtio/vdpa-dev.c
index d1da40afc80..3c0eed3e8e1 100644
--- a/hw/virtio/vdpa-dev.c
+++ b/hw/virtio/vdpa-dev.c
@@ -104,7 +104,6 @@ static void vhost_vdpa_device_realize(DeviceState *dev, Error **errp)
     v->dev.vqs = vqs;
     v->dev.vq_index = 0;
     v->dev.vq_index_end = v->dev.nvqs;
-    v->dev.backend_features = 0;
     v->started = false;
 
     ret = vhost_vdpa_get_iova_range(v->vhostfd, &iova_range);
diff --git a/hw/virtio/virtio-qmp.c b/hw/virtio/virtio-qmp.c
index 3b6377cf0d2..e514a4797e3 100644
--- a/hw/virtio/virtio-qmp.c
+++ b/hw/virtio/virtio-qmp.c
@@ -788,8 +788,6 @@ VirtioStatus *qmp_x_query_virtio_status(const char *path, Error **errp)
             qmp_decode_features(vdev->device_id, hdev->features);
         status->vhost_dev->acked_features =
             qmp_decode_features(vdev->device_id, hdev->acked_features);
-        status->vhost_dev->backend_features =
-            qmp_decode_features(vdev->device_id, hdev->backend_features);
         status->vhost_dev->protocol_features =
             qmp_decode_protocols(hdev->protocol_features);
         status->vhost_dev->max_queues = hdev->max_queues;
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 38800a7156b..d6afde8b5dd 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -99,16 +99,9 @@ struct vhost_dev {
      *
      * @features: available features provided by the backend
      * @acked_features: final negotiated features with front-end driver
-     *
-     * @backend_features: this is used in a couple of places to either
-     * store VHOST_USER_F_PROTOCOL_FEATURES to apply to
-     * VHOST_USER_SET_FEATURES or VHOST_NET_F_VIRTIO_NET_HDR. Its
-     * future use should be discouraged and the variable retired as
-     * its easy to confuse with the VirtIO backend_features.
      */
     uint64_t features;
     uint64_t acked_features;
-    uint64_t backend_features;
 
     /**
      * @protocol_features: is the vhost-user only feature set by
-- 
2.48.1