+/*
+ * Default vhost_get_features() feature bits for existing device types that do
+ * not define their own.
+ *
+ * This is a workaround for existing device types, do not use this in new vhost
+ * device types. Explicitly define a list of feature bits instead.
+ *
+ * The following feature bits are excluded because libvhost-user device
+ * backends did not advertise them for a long time. Therefore we cannot detect
+ * their presence. Instead we assume they are always supported by the device
+ * backend:
+ * VIRTIO_F_NOTIFY_ON_EMPTY
+ * VIRTIO_F_ANY_LAYOUT
+ * VIRTIO_F_VERSION_1
+ * VIRTIO_RING_F_INDIRECT_DESC
+ * VIRTIO_RING_F_EVENT_IDX
Weird. I remember that it's common for vhost-user not to set
VIRTIO_RING_F_INDIRECT_DESC - they have huge queues so
don't need it and inline descriptors give them better
performance.
So what's going on here?