[PATCH v2] vhost-blk: set features before setting inflight feature

[Jin Yu]

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

Signed-off-by: Jin Yu <jin...@intel.com>
Acked-by: Raphael Norwitz <raphael.norw...@nutanix.com>
---
v2:
* Fixed the segfault.
---
 hw/block/vhost-user-blk.c |  6 ++++++
 hw/virtio/vhost.c         | 20 ++++++++++++++++++++
 include/hw/virtio/vhost.h |  1 +
 3 files changed, 27 insertions(+)

diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
index 39aec42dae..db079a89c0 100644
--- a/hw/block/vhost-user-blk.c
+++ b/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) {
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 1a1384e7a6..6ffbfbfb9e 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1616,6 +1616,26 @@ 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)
 {
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 767a95ec0b..d25f0947f7 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -140,6 +140,7 @@ 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,
-- 
2.17.2