Try and explicitly document the various state of feature bits as
related to the vhost_dev structure. Importantly the backend_features
can advertise things like VHOST_USER_F_PROTOCOL_FEATURES which is
never exposed to the driver and is only present in the vhost-user
feature negotiation.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 include/hw/virtio/vhost.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index a346f23d13..586c5457e2 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -86,8 +86,11 @@ struct vhost_dev {
     /* if non-zero, minimum required value for max_queues */
     int num_queues;
     uint64_t features;
+    /** @acked_features: final set of negotiated features */
     uint64_t acked_features;
+    /** @backend_features: backend specific feature bits */
     uint64_t backend_features;
+    /** @protocol_features: final negotiated protocol features */
     uint64_t protocol_features;
     uint64_t max_queues;
     uint64_t backend_cap;
-- 
2.30.2

On 2/8/22 11:49, Alex Bennée wrote:
> Try and explicitly document the various state of feature bits as
> related to the vhost_dev structure. Importantly the backend_features
> can advertise things like VHOST_USER_F_PROTOCOL_FEATURES which is
> never exposed to the driver and is only present in the vhost-user
> feature negotiation.
> 
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> Acked-by: Jason Wang <jasowang@redhat.com>
> ---
>   include/hw/virtio/vhost.h | 3 +++
>   1 file changed, 3 insertions(+)

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>