vhost-blk: set features before setting inflight feature

Virtqueue has split and packed, so before setting inflight,
you need to inform the back-end virtqueue format.

Signed-off-by: Jin Yu <jin.yu@intel.com>
Acked-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <20201103123617.28256-1-jin.yu@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/block/vhost-user-blk.c

@@ -131,6 +131,12 @@ static int vhost_user_blk_start(VirtIODevice *vdev)
 
     s->dev.acked_features = vdev->guest_features;
 
+    ret = vhost_dev_prepare_inflight(&s->dev, vdev);
+    if (ret < 0) {
+        error_report("Error set inflight format: %d", -ret);
+        goto err_guest_notifiers;
+    }
+
     if (!s->inflight->addr) {
         ret = vhost_dev_get_inflight(&s->dev, s->queue_size, s->inflight);
         if (ret < 0) {

hw/virtio/vhost.c

@@ -1645,6 +1645,26 @@ int vhost_dev_load_inflight(struct vhost_inflight *inflight, QEMUFile *f)
     return 0;
 }
 
+int vhost_dev_prepare_inflight(struct vhost_dev *hdev, VirtIODevice *vdev)
+{
+    int r;
+
+    if (hdev->vhost_ops->vhost_get_inflight_fd == NULL ||
+        hdev->vhost_ops->vhost_set_inflight_fd == NULL) {
+        return 0;
+    }
+
+    hdev->vdev = vdev;
+
+    r = vhost_dev_set_features(hdev, hdev->log_enabled);
+    if (r < 0) {
+        VHOST_OPS_DEBUG("vhost_dev_prepare_inflight failed");
+        return r;
+    }
+
+    return 0;
+}
+
 int vhost_dev_set_inflight(struct vhost_dev *dev,
                            struct vhost_inflight *inflight)
 {

include/hw/virtio/vhost.h

@@ -141,6 +141,7 @@ void vhost_dev_reset_inflight(struct vhost_inflight *inflight);
 void vhost_dev_free_inflight(struct vhost_inflight *inflight);
 void vhost_dev_save_inflight(struct vhost_inflight *inflight, QEMUFile *f);
 int vhost_dev_load_inflight(struct vhost_inflight *inflight, QEMUFile *f);
+int vhost_dev_prepare_inflight(struct vhost_dev *hdev, VirtIODevice *vdev);
 int vhost_dev_set_inflight(struct vhost_dev *dev,
                            struct vhost_inflight *inflight);
 int vhost_dev_get_inflight(struct vhost_dev *dev, uint16_t queue_size,