Introduce Virtio-loopback epsilon-release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes. Changes and fixes done during this development are:
- Add new memory exchange mechanism
- Update binaries command line: argument limit
- Update features exchange for vhost-user-rng backend
- Updare VQS index exchange process between driver and adapter
- Add VHOST_RAM_SLOTS constant

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/vhost_user_rng.c b/vhost_user_rng.c
index 860c33e..6d4fd5c 100644
--- a/vhost_user_rng.c
+++ b/vhost_user_rng.c
@@ -64,8 +64,9 @@ static void vu_rng_start(VirtIODevice *vdev)
     }
 
     rng->vhost_dev->acked_features = vdev->guest_features;
+    DBG("rng->vhost_dev->acked_features: 0x%lx\n", vdev->guest_features);
 
-    ret = vhost_dev_start(rng->vhost_dev, vdev);
+    ret = vhost_dev_start(rng->vhost_dev, vdev, true);
     if (ret < 0) {
         DBG("Error starting vhost-user-rng: %d\n", ret);
         return;
@@ -80,6 +81,9 @@ static void vu_rng_start(VirtIODevice *vdev)
         vhost_virtqueue_mask(rng->vhost_dev, vdev, i, false);
     }
 
+    /* Wait a bit for the vrings to be set in vhost-user-device */
+    sleep(1);
+
 }
 
 /* TODO: We need to implement this function in a future release */
@@ -190,4 +194,8 @@ void vhost_user_rng_realize(void)
 
     /* Initiale vhost-user communication */
     vhost_dev_init(dev);
+
+    /* Write the final features */
+    global_vdev->host_features = dev->features;
+    DBG("dev->host_features: 0x%lx\n", dev->features);
 }